feat: add anime metadata editing and NFO diagnostics

- Add PUT /anime/{key} endpoint for updating anime key, tmdb_id, tvdb_id
- Add NFO diagnostics and repair endpoints (GET/POST /nfo/diagnostics)
- Add edit modal UI with context menu integration
- Add frontend JS modules for context-menu and edit-modal
- Add comprehensive tests for edit, rename, and NFO repair flows

src/server/api/anime.py

@@ -17,12 +17,14 @@ from src.server.exceptions import (
     ServerError,
     ValidationError,
 )
+from src.server.models.anime import AnimeMetadataUpdate
 from src.server.services.anime_service import AnimeService, AnimeServiceError
 from src.server.services.background_loader_service import BackgroundLoaderService
 from src.server.services.folder_rename_service import _scan_for_pre_existing_duplicates
 from src.server.utils.dependencies import (
     get_anime_service,
     get_background_loader_service,
+    get_database_session,
     get_optional_database_session,
     get_series_app,
     require_auth,
@@ -1186,3 +1188,75 @@ async def get_anime(
 # Maximum allowed input size for security
 MAX_INPUT_LENGTH = 100000  # 100KB
 
+
+@router.put("/{anime_key}")
+async def update_anime_metadata(
+    anime_key: str,
+    body: AnimeMetadataUpdate,
+    _auth: dict = Depends(require_auth),
+    db: AsyncSession = Depends(get_database_session),
+) -> dict:
+    """Update anime metadata (key, tmdb_id, tvdb_id).
+
+    Args:
+        anime_key: Current series key to update
+        body: Fields to update (all optional)
+        _auth: Authentication dependency
+        db: Database session
+
+    Returns:
+        Updated series metadata
+
+    Raises:
+        HTTPException 404: Series not found
+        HTTPException 409: Key conflict (new key already exists)
+        HTTPException 422: Validation error
+    """
+    series = await AnimeSeriesService.get_by_key(db, anime_key)
+    if not series:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"Series with key '{anime_key}' not found",
+        )
+
+    updates = {}
+
+    if body.key is not None and body.key != anime_key:
+        existing = await AnimeSeriesService.get_by_key(db, body.key)
+        if existing:
+            raise HTTPException(
+                status_code=status.HTTP_409_CONFLICT,
+                detail=f"A series with key '{body.key}' already exists",
+            )
+        updates["key"] = body.key
+
+    if body.tmdb_id is not None:
+        updates["tmdb_id"] = body.tmdb_id
+
+    if body.tvdb_id is not None:
+        updates["tvdb_id"] = body.tvdb_id
+
+    if not updates:
+        return {
+            "key": series.key,
+            "tmdb_id": series.tmdb_id,
+            "tvdb_id": series.tvdb_id,
+            "message": "No changes",
+        }
+
+    updated = await AnimeSeriesService.update(db, series.id, **updates)
+    await db.commit()
+
+    logger.info(
+        "Updated metadata for '%s': %s",
+        anime_key,
+        updates,
+    )
+
+    return {
+        "key": updated.key,
+        "tmdb_id": updated.tmdb_id,
+        "tvdb_id": updated.tvdb_id,
+        "message": "Metadata updated successfully",
+    }
+

src/server/api/nfo.py

@@ -16,6 +16,11 @@ from src.core.entities.series import Serie
 from src.core.SeriesApp import SeriesApp
 from src.core.services.nfo_factory import get_nfo_factory
 from src.core.services.nfo_service import NFOService
+from src.core.services.nfo_repair_service import (
+    REQUIRED_TAGS,
+    NfoRepairService,
+    find_missing_tags,
+)
 from src.core.services.tmdb_client import TMDBAPIError
 from src.server.models.nfo import (
     MediaDownloadRequest,
@@ -27,8 +32,10 @@ from src.server.models.nfo import (
     NFOContentResponse,
     NFOCreateRequest,
     NFOCreateResponse,
+    NfoDiagnosticsResponse,
     NFOMissingResponse,
     NFOMissingSeries,
+    NfoRepairResponse,
 )
 from src.server.utils.dependencies import get_series_app, require_auth
 from src.server.utils.media import check_media_files, get_media_file_paths
@@ -808,3 +815,142 @@ async def download_media(
             status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
             detail=f"Failed to download media: {str(e)}"
         ) from e
+
+
+@router.get("/{serie_key}/diagnostics", response_model=NfoDiagnosticsResponse)
+async def get_nfo_diagnostics(
+    serie_key: str,
+    _auth: dict = Depends(require_auth),
+    series_app: SeriesApp = Depends(get_series_app),
+) -> NfoDiagnosticsResponse:
+    """Get NFO diagnostics showing missing required tags.
+
+    Args:
+        serie_key: Series key identifier
+        _auth: Authentication dependency
+        series_app: SeriesApp instance
+
+    Returns:
+        NfoDiagnosticsResponse with has_nfo, missing_tags, required_tags
+
+    Raises:
+        HTTPException 404: Series not found
+    """
+    serie = None
+    for s in series_app.list.GetList():
+        if getattr(s, "key", None) == serie_key:
+            serie = s
+            break
+
+    if not serie:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"Series with key '{serie_key}' not found",
+        )
+
+    serie_folder = serie.ensure_folder_with_year()
+    folder_path = Path(settings.anime_directory) / serie_folder
+    nfo_path = folder_path / "tvshow.nfo"
+
+    required_tag_names = list(REQUIRED_TAGS.values())
+
+    if not nfo_path.exists():
+        return NfoDiagnosticsResponse(
+            has_nfo=False,
+            nfo_path=None,
+            missing_tags=required_tag_names,
+            required_tags=required_tag_names,
+        )
+
+    missing = find_missing_tags(nfo_path)
+
+    return NfoDiagnosticsResponse(
+        has_nfo=True,
+        nfo_path=str(nfo_path),
+        missing_tags=missing,
+        required_tags=required_tag_names,
+    )
+
+
+@router.post("/{serie_key}/repair", response_model=NfoRepairResponse)
+async def repair_nfo(
+    serie_key: str,
+    _auth: dict = Depends(require_auth),
+    series_app: SeriesApp = Depends(get_series_app),
+    nfo_service: NFOService = Depends(get_nfo_service),
+) -> NfoRepairResponse:
+    """Repair or recreate NFO file for a series.
+
+    Detects missing required tags and re-fetches metadata from TMDB.
+
+    Args:
+        serie_key: Series key identifier
+        _auth: Authentication dependency
+        series_app: SeriesApp instance
+        nfo_service: NFO service for TMDB operations
+
+    Returns:
+        NfoRepairResponse with success status and details
+
+    Raises:
+        HTTPException 404: Series not found
+        HTTPException 400: Cannot repair (e.g., no TMDB data available)
+    """
+    serie = None
+    for s in series_app.list.GetList():
+        if getattr(s, "key", None) == serie_key:
+            serie = s
+            break
+
+    if not serie:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"Series with key '{serie_key}' not found",
+        )
+
+    serie_folder = serie.ensure_folder_with_year()
+    folder_path = Path(settings.anime_directory) / serie_folder
+    nfo_path = folder_path / "tvshow.nfo"
+
+    # Get missing tags before repair for reporting
+    missing_before = find_missing_tags(nfo_path) if nfo_path.exists() else list(REQUIRED_TAGS.values())
+
+    try:
+        repair_service = NfoRepairService(nfo_service)
+
+        if nfo_path.exists():
+            repaired = await repair_service.repair_series(folder_path, serie_folder)
+            if not repaired:
+                return NfoRepairResponse(
+                    success=True,
+                    message="NFO is already complete, no repair needed",
+                    repaired_tags=[],
+                )
+        else:
+            # No NFO exists — create new one
+            await nfo_service.create_tvshow_nfo(
+                serie_name=serie.name,
+                serie_folder=serie_folder,
+                download_poster=True,
+                download_logo=True,
+                download_fanart=True,
+            )
+
+        return NfoRepairResponse(
+            success=True,
+            message=f"NFO repaired successfully. Fixed {len(missing_before)} missing tags.",
+            repaired_tags=missing_before,
+        )
+
+    except TMDBAPIError as e:
+        logger.warning("NFO repair failed for '%s': %s", serie_key, e)
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail=f"Cannot repair NFO: {str(e)}. Ensure TMDB ID is set.",
+        ) from e
+    except Exception as e:
+        logger.error("NFO repair error for '%s': %s", serie_key, e, exc_info=True)
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail=f"Failed to repair NFO: {str(e)}",
+        ) from e

src/server/models/anime.py

@@ -83,6 +83,30 @@ class AnimeSeriesResponse(BaseModel):
         return v
 
 
+class AnimeMetadataUpdate(BaseModel):
+    """Request model for updating anime metadata (key, tmdb_id, tvdb_id)."""
+
+    key: Optional[str] = Field(None, description="New series key (URL-safe, lowercase)")
+    tmdb_id: Optional[int] = Field(None, ge=1, description="TMDB ID (positive integer)")
+    tvdb_id: Optional[int] = Field(None, ge=1, description="TVDB ID (positive integer)")
+
+    @field_validator('key', mode='before')
+    @classmethod
+    def validate_key_format(cls, v: Optional[str]) -> Optional[str]:
+        """Validate key is URL-safe lowercase with hyphens only."""
+        if v is None:
+            return v
+        v = v.strip().lower()
+        if not v:
+            raise ValueError("Key cannot be empty")
+        if not KEY_PATTERN.match(v):
+            raise ValueError(
+                "Key must contain only lowercase letters, numbers, and hyphens. "
+                "Cannot start or end with a hyphen."
+            )
+        return v
+
+
 class SearchRequest(BaseModel):
     """Request payload for searching series."""
 

src/server/models/nfo.py

@@ -355,3 +355,29 @@ class NFOMissingResponse(BaseModel):
         ...,
         description="List of series missing NFO"
     )
+
+
+class NfoDiagnosticsResponse(BaseModel):
+    """Response for NFO diagnostics showing missing required tags."""
+
+    has_nfo: bool = Field(..., description="Whether tvshow.nfo exists")
+    nfo_path: Optional[str] = Field(None, description="Path to NFO file if exists")
+    missing_tags: List[str] = Field(
+        default_factory=list,
+        description="List of missing required tag names"
+    )
+    required_tags: List[str] = Field(
+        default_factory=list,
+        description="All required tag names for reference"
+    )
+
+
+class NfoRepairResponse(BaseModel):
+    """Response after NFO repair attempt."""
+
+    success: bool = Field(..., description="Whether repair succeeded")
+    message: str = Field(..., description="Human-readable result message")
+    repaired_tags: List[str] = Field(
+        default_factory=list,
+        description="Tags that were missing before repair"
+    )

src/server/web/static/css/components/modals.css

@@ -268,3 +268,205 @@
     gap: 4px;
   }
 }
+
+/* ============================================================================
+   Context Menu
+   ============================================================================ */
+
+.context-menu {
+  position: fixed;
+  z-index: 1500;
+  background: var(--color-surface);
+  border: 1px solid var(--color-border);
+  border-radius: var(--border-radius);
+  box-shadow: var(--shadow-elevated);
+  min-width: 180px;
+  padding: var(--spacing-xs) 0;
+  animation: contextMenuFadeIn 0.12s ease-out;
+}
+
+@keyframes contextMenuFadeIn {
+  from { opacity: 0; transform: scale(0.95); }
+  to { opacity: 1; transform: scale(1); }
+}
+
+.context-menu-item {
+  display: flex;
+  align-items: center;
+  gap: var(--spacing-sm);
+  padding: var(--spacing-sm) var(--spacing-md);
+  cursor: pointer;
+  color: var(--color-text-primary);
+  font-size: var(--font-size-body);
+  transition: background-color 0.1s ease;
+}
+
+.context-menu-item:hover {
+  background-color: var(--color-hover);
+}
+
+.context-menu-item i {
+  width: 16px;
+  text-align: center;
+  color: var(--color-text-secondary);
+}
+
+/* ============================================================================
+   Edit Metadata Modal
+   ============================================================================ */
+
+.edit-modal-content {
+  max-width: 520px;
+}
+
+.edit-section {
+  margin-bottom: var(--spacing-lg);
+  padding-bottom: var(--spacing-lg);
+  border-bottom: 1px solid var(--color-divider);
+}
+
+.edit-section:last-child {
+  border-bottom: none;
+  margin-bottom: 0;
+  padding-bottom: 0;
+}
+
+.edit-section h4 {
+  margin: 0 0 var(--spacing-md) 0;
+  font-size: var(--font-size-body);
+  font-weight: 600;
+  color: var(--color-text-primary);
+  display: flex;
+  align-items: center;
+  gap: var(--spacing-sm);
+}
+
+.edit-section h4 i {
+  color: var(--color-accent);
+}
+
+.form-group {
+  margin-bottom: var(--spacing-md);
+}
+
+.form-group label {
+  display: block;
+  margin-bottom: var(--spacing-xs);
+  font-size: var(--font-size-caption);
+  font-weight: 500;
+  color: var(--color-text-secondary);
+}
+
+.form-row {
+  display: grid;
+  grid-template-columns: 1fr 1fr;
+  gap: var(--spacing-md);
+}
+
+.field-error {
+  display: block;
+  margin-top: var(--spacing-xs);
+  font-size: var(--font-size-caption);
+  color: var(--color-error, #e74c3c);
+}
+
+.input-error {
+  border-color: var(--color-error, #e74c3c) !important;
+}
+
+.key-warning {
+  background: rgba(255, 193, 7, 0.1);
+  border: 1px solid rgba(255, 193, 7, 0.3);
+  border-radius: var(--border-radius);
+  padding: var(--spacing-sm) var(--spacing-md);
+  margin-top: var(--spacing-sm);
+  font-size: var(--font-size-caption);
+  color: var(--color-warning, #f39c12);
+  display: flex;
+  align-items: center;
+  gap: var(--spacing-sm);
+}
+
+/* NFO Diagnostics */
+.nfo-diagnostics {
+  display: flex;
+  flex-direction: column;
+  gap: var(--spacing-sm);
+}
+
+.nfo-status-badge {
+  display: inline-block;
+  padding: 4px 12px;
+  border-radius: 12px;
+  font-size: var(--font-size-caption);
+  font-weight: 600;
+  width: fit-content;
+}
+
+.nfo-status-badge.nfo-complete {
+  background: rgba(46, 204, 113, 0.15);
+  color: var(--color-success, #2ecc71);
+}
+
+.nfo-status-badge.nfo-incomplete {
+  background: rgba(243, 156, 18, 0.15);
+  color: var(--color-warning, #f39c12);
+}
+
+.nfo-status-badge.nfo-missing {
+  background: rgba(231, 76, 60, 0.15);
+  color: var(--color-error, #e74c3c);
+}
+
+.missing-tags-list {
+  display: flex;
+  flex-wrap: wrap;
+  gap: var(--spacing-xs);
+  margin-top: var(--spacing-xs);
+}
+
+.missing-tag-chip {
+  display: inline-block;
+  padding: 2px 8px;
+  background: var(--color-background-subtle);
+  border: 1px solid var(--color-border);
+  border-radius: 4px;
+  font-size: var(--font-size-caption);
+  color: var(--color-text-secondary);
+}
+
+.nfo-all-good {
+  color: var(--color-success, #2ecc71);
+  font-size: var(--font-size-caption);
+  margin: 0;
+}
+
+.nfo-error {
+  color: var(--color-error, #e74c3c);
+  font-size: var(--font-size-caption);
+  margin: 0;
+}
+
+.repair-hint {
+  font-size: var(--font-size-caption);
+  color: var(--color-text-secondary);
+  margin: 0;
+  display: flex;
+  align-items: center;
+  gap: var(--spacing-xs);
+}
+
+.btn-repair {
+  align-self: flex-start;
+  margin-top: var(--spacing-sm);
+}
+
+.modal-footer {
+  display: flex;
+  justify-content: flex-end;
+  padding: var(--spacing-md) var(--spacing-lg);
+  border-top: 1px solid var(--color-border);
+  flex-shrink: 0;
+}
+
+

src/server/web/static/js/index/app-init.js

@@ -45,6 +45,7 @@ AniWorld.IndexApp = (function() {
         AniWorld.Search.init();
         AniWorld.ScanManager.init();
         AniWorld.ConfigManager.init();
+        AniWorld.ContextMenu.init();
 
         // Bind global events
         bindGlobalEvents();

src/server/web/static/js/index/context-menu.js

@@ -0,0 +1,123 @@
+/**
+ * AniWorld - Context Menu Component
+ *
+ * Right-click context menu for anime series cards.
+ * Provides quick access to edit metadata.
+ *
+ * Dependencies: ui-utils.js, edit-modal.js
+ */
+
+var AniWorld = window.AniWorld || {};
+
+AniWorld.ContextMenu = (function() {
+    'use strict';
+
+    let menuElement = null;
+    let currentSeriesKey = null;
+
+    /**
+     * Initialize the context menu system.
+     * Attaches global dismissal listeners.
+     */
+    function init() {
+        // Dismiss on click outside
+        document.addEventListener('click', function(e) {
+            if (menuElement && !menuElement.contains(e.target)) {
+                hide();
+            }
+        });
+
+        // Dismiss on Escape
+        document.addEventListener('keydown', function(e) {
+            if (e.key === 'Escape') {
+                hide();
+            }
+        });
+
+        // Dismiss on scroll or resize
+        window.addEventListener('scroll', hide, true);
+        window.addEventListener('resize', hide);
+
+        // Attach context menu via event delegation on the series grid
+        const grid = document.getElementById('series-grid');
+        if (grid) {
+            grid.addEventListener('contextmenu', function(e) {
+                const card = e.target.closest('.series-card');
+                if (card) {
+                    e.preventDefault();
+                    const key = card.getAttribute('data-key');
+                    if (key) {
+                        show(e, key);
+                    }
+                }
+            });
+        }
+    }
+
+    /**
+     * Show context menu at cursor position.
+     * @param {MouseEvent} event - The contextmenu event
+     * @param {string} seriesKey - The series key to operate on
+     */
+    function show(event, seriesKey) {
+        hide(); // Remove any existing menu first
+
+        currentSeriesKey = seriesKey;
+
+        menuElement = document.createElement('div');
+        menuElement.className = 'context-menu';
+        menuElement.innerHTML = `
+            <div class="context-menu-item" data-action="edit">
+                <i class="fa-solid fa-pen-to-square"></i>
+                <span>Edit Metadata</span>
+            </div>
+        `;
+
+        document.body.appendChild(menuElement);
+
+        // Position within viewport bounds
+        const x = event.clientX;
+        const y = event.clientY;
+        const menuRect = menuElement.getBoundingClientRect();
+        const viewportWidth = window.innerWidth;
+        const viewportHeight = window.innerHeight;
+
+        let posX = x;
+        let posY = y;
+
+        if (x + menuRect.width > viewportWidth) {
+            posX = viewportWidth - menuRect.width - 8;
+        }
+        if (y + menuRect.height > viewportHeight) {
+            posY = viewportHeight - menuRect.height - 8;
+        }
+
+        menuElement.style.left = posX + 'px';
+        menuElement.style.top = posY + 'px';
+
+        // Attach action handlers
+        menuElement.querySelector('[data-action="edit"]').addEventListener('click', function() {
+            hide();
+            if (AniWorld.EditModal) {
+                AniWorld.EditModal.open(currentSeriesKey);
+            }
+        });
+    }
+
+    /**
+     * Hide and remove the context menu from DOM.
+     */
+    function hide() {
+        if (menuElement) {
+            menuElement.remove();
+            menuElement = null;
+            currentSeriesKey = null;
+        }
+    }
+
+    return {
+        init: init,
+        show: show,
+        hide: hide
+    };
+})();

src/server/web/static/js/index/edit-modal.js

@@ -0,0 +1,450 @@
+/**
+ * AniWorld - Edit Modal Component
+ *
+ * Modal dialog for viewing/editing anime metadata (key, tmdb_id, tvdb_id)
+ * and NFO diagnostics with repair functionality.
+ *
+ * Dependencies: api-client.js, ui-utils.js
+ */
+
+var AniWorld = window.AniWorld || {};
+
+AniWorld.EditModal = (function() {
+    'use strict';
+
+    let modalElement = null;
+    let originalData = null;
+    let currentKey = null;
+
+    /**
+     * Open the edit modal for a specific anime series.
+     * @param {string} seriesKey - The series key to edit
+     */
+    async function open(seriesKey) {
+        currentKey = seriesKey;
+        modalElement = document.getElementById('edit-metadata-modal');
+        if (!modalElement) return;
+
+        // Show modal
+        modalElement.classList.remove('hidden');
+
+        // Reset form state
+        setLoading(true);
+        clearErrors();
+        hideKeyWarning();
+
+        try {
+            // Find series data from the local series list
+            const seriesData = findSeriesData(seriesKey);
+
+            originalData = {
+                key: seriesKey,
+                tmdb_id: seriesData ? seriesData.tmdb_id : null,
+                tvdb_id: seriesData ? seriesData.tvdb_id : null,
+            };
+
+            // Populate form fields
+            setFieldValue('edit-key', originalData.key);
+            setFieldValue('edit-tmdb-id', originalData.tmdb_id || '');
+            setFieldValue('edit-tvdb-id', originalData.tvdb_id || '');
+
+            // Load NFO diagnostics
+            await loadDiagnostics(seriesKey);
+
+        } catch (err) {
+            AniWorld.UI.showToast('Failed to load series data', 'error');
+            console.error('Edit modal load error:', err);
+        } finally {
+            setLoading(false);
+        }
+
+        // Attach event listeners
+        attachListeners();
+    }
+
+    /**
+     * Close the edit modal and reset state.
+     */
+    function close() {
+        if (modalElement) {
+            modalElement.classList.add('hidden');
+        }
+        originalData = null;
+        currentKey = null;
+        detachListeners();
+    }
+
+    /**
+     * Save changed metadata to the backend.
+     */
+    async function save() {
+        clearErrors();
+
+        const newKey = getFieldValue('edit-key').trim().toLowerCase();
+        const tmdbIdStr = getFieldValue('edit-tmdb-id').trim();
+        const tvdbIdStr = getFieldValue('edit-tvdb-id').trim();
+
+        // Validate key
+        if (!newKey) {
+            showFieldError('edit-key', 'Key cannot be empty');
+            return;
+        }
+        if (!/^[a-z0-9][a-z0-9-]*[a-z0-9]$|^[a-z0-9]$/.test(newKey)) {
+            showFieldError('edit-key', 'Key must contain only lowercase letters, numbers, and hyphens');
+            return;
+        }
+
+        // Validate IDs
+        const tmdbId = tmdbIdStr ? parseInt(tmdbIdStr, 10) : null;
+        const tvdbId = tvdbIdStr ? parseInt(tvdbIdStr, 10) : null;
+
+        if (tmdbIdStr && (isNaN(tmdbId) || tmdbId < 1)) {
+            showFieldError('edit-tmdb-id', 'TMDB ID must be a positive number');
+            return;
+        }
+        if (tvdbIdStr && (isNaN(tvdbId) || tvdbId < 1)) {
+            showFieldError('edit-tvdb-id', 'TVDB ID must be a positive number');
+            return;
+        }
+
+        // Check if key changed — show confirmation
+        if (newKey !== originalData.key) {
+            const confirmed = await AniWorld.UI.showConfirmModal(
+                'Rename Series Key',
+                `Changing the key from "${originalData.key}" to "${newKey}" will update the primary identifier. ` +
+                'This may affect provider linkage. Are you sure?'
+            );
+            if (!confirmed) return;
+        }
+
+        // Build update payload (only changed fields)
+        const payload = {};
+        if (newKey !== originalData.key) payload.key = newKey;
+        if (tmdbId !== originalData.tmdb_id) payload.tmdb_id = tmdbId;
+        if (tvdbId !== originalData.tvdb_id) payload.tvdb_id = tvdbId;
+
+        if (Object.keys(payload).length === 0) {
+            AniWorld.UI.showToast('No changes to save', 'info');
+            return;
+        }
+
+        // Send update
+        setSaveLoading(true);
+        try {
+            const response = await AniWorld.ApiClient.put(
+                '/api/anime/' + encodeURIComponent(currentKey),
+                payload
+            );
+
+            if (!response) return;
+
+            if (response.ok) {
+                const result = await response.json();
+                AniWorld.UI.showToast('Metadata updated successfully', 'success');
+
+                // Update local state
+                const oldKey = currentKey;
+                currentKey = result.key;
+                originalData = {
+                    key: result.key,
+                    tmdb_id: result.tmdb_id,
+                    tvdb_id: result.tvdb_id,
+                };
+
+                // Update the card in the DOM
+                updateCardAfterSave(oldKey, result);
+
+                // Update repair button state
+                updateRepairButtonState();
+
+            } else if (response.status === 409) {
+                showFieldError('edit-key', 'A series with this key already exists');
+            } else if (response.status === 422) {
+                const err = await response.json();
+                AniWorld.UI.showToast('Validation error: ' + (err.detail || 'Invalid input'), 'error');
+            } else {
+                AniWorld.UI.showToast('Failed to update metadata', 'error');
+            }
+        } catch (err) {
+            AniWorld.UI.showToast('Connection error. Check your network.', 'error');
+            console.error('Save error:', err);
+        } finally {
+            setSaveLoading(false);
+        }
+    }
+
+    /**
+     * Trigger NFO repair for the current series.
+     */
+    async function repairNfo() {
+        setRepairLoading(true);
+        try {
+            const response = await AniWorld.ApiClient.post(
+                '/api/nfo/' + encodeURIComponent(currentKey) + '/repair',
+                {}
+            );
+
+            if (!response) return;
+
+            if (response.ok) {
+                const result = await response.json();
+                AniWorld.UI.showToast(result.message, 'success');
+
+                // Refresh diagnostics
+                await loadDiagnostics(currentKey);
+            } else if (response.status === 400) {
+                const err = await response.json();
+                AniWorld.UI.showToast(err.detail || 'Cannot repair NFO', 'error');
+            } else {
+                AniWorld.UI.showToast('Failed to repair NFO', 'error');
+            }
+        } catch (err) {
+            AniWorld.UI.showToast('Connection error during repair', 'error');
+            console.error('Repair error:', err);
+        } finally {
+            setRepairLoading(false);
+        }
+    }
+
+    /**
+     * Load NFO diagnostics for the current series.
+     * @param {string} key - Series key
+     */
+    async function loadDiagnostics(key) {
+        const container = document.getElementById('nfo-diagnostics-container');
+        if (!container) return;
+
+        try {
+            const response = await AniWorld.ApiClient.get(
+                '/api/nfo/' + encodeURIComponent(key) + '/diagnostics'
+            );
+
+            if (!response || !response.ok) {
+                container.innerHTML = '<p class="nfo-error">Failed to load NFO diagnostics</p>';
+                return;
+            }
+
+            const data = await response.json();
+            renderDiagnostics(data);
+            updateRepairButtonState();
+
+        } catch (err) {
+            container.innerHTML = '<p class="nfo-error">Error loading diagnostics</p>';
+            console.error('Diagnostics error:', err);
+        }
+    }
+
+    /**
+     * Render NFO diagnostics data into the modal.
+     * @param {Object} data - NfoDiagnosticsResponse
+     */
+    function renderDiagnostics(data) {
+        const badge = document.getElementById('nfo-status-badge');
+        const tagsList = document.getElementById('nfo-missing-tags');
+
+        if (badge) {
+            if (!data.has_nfo) {
+                badge.className = 'nfo-status-badge nfo-missing';
+                badge.textContent = 'No NFO File';
+            } else if (data.missing_tags.length === 0) {
+                badge.className = 'nfo-status-badge nfo-complete';
+                badge.textContent = 'Complete';
+            } else {
+                badge.className = 'nfo-status-badge nfo-incomplete';
+                badge.textContent = data.missing_tags.length + ' Missing';
+            }
+        }
+
+        if (tagsList) {
+            if (data.missing_tags.length === 0) {
+                tagsList.innerHTML = '<p class="nfo-all-good">All required tags present</p>';
+            } else {
+                tagsList.innerHTML = data.missing_tags.map(function(tag) {
+                    return '<span class="missing-tag-chip">' + escapeHtml(tag) + '</span>';
+                }).join('');
+            }
+        }
+    }
+
+    /**
+     * Update repair button disabled state based on tmdb_id field.
+     */
+    function updateRepairButtonState() {
+        const btn = document.getElementById('btn-repair-nfo');
+        const hint = document.getElementById('repair-hint');
+        const tmdbValue = getFieldValue('edit-tmdb-id').trim();
+
+        if (btn) {
+            // Enable repair even without tmdb_id — the service can search by name
+            btn.disabled = false;
+        }
+        if (hint) {
+            hint.style.display = tmdbValue ? 'none' : 'block';
+        }
+    }
+
+    // ---- Helpers ----
+
+    function findSeriesData(key) {
+        // Access the series data from the series manager if available
+        if (AniWorld.SeriesManager && AniWorld.SeriesManager.getSeriesData) {
+            const allSeries = AniWorld.SeriesManager.getSeriesData();
+            if (allSeries) {
+                return allSeries.find(function(s) { return s.key === key; });
+            }
+        }
+        return null;
+    }
+
+    function updateCardAfterSave(oldKey, result) {
+        const card = document.querySelector('[data-series-id="' + oldKey + '"]');
+        if (card) {
+            card.setAttribute('data-key', result.key);
+            card.setAttribute('data-series-id', result.key);
+            // Update checkbox data-key
+            const checkbox = card.querySelector('.series-checkbox');
+            if (checkbox) {
+                checkbox.setAttribute('data-key', result.key);
+            }
+        }
+
+        // Update local series data array
+        if (AniWorld.SeriesManager && AniWorld.SeriesManager.updateSeriesKey) {
+            AniWorld.SeriesManager.updateSeriesKey(oldKey, result.key);
+        }
+    }
+
+    function setFieldValue(id, value) {
+        const el = document.getElementById(id);
+        if (el) el.value = value !== null && value !== undefined ? value : '';
+    }
+
+    function getFieldValue(id) {
+        const el = document.getElementById(id);
+        return el ? el.value : '';
+    }
+
+    function showFieldError(fieldId, message) {
+        const el = document.getElementById(fieldId);
+        if (el) {
+            const errorEl = el.parentElement.querySelector('.field-error');
+            if (errorEl) {
+                errorEl.textContent = message;
+                errorEl.style.display = 'block';
+            }
+            el.classList.add('input-error');
+        }
+    }
+
+    function clearErrors() {
+        if (!modalElement) return;
+        modalElement.querySelectorAll('.field-error').forEach(function(el) {
+            el.style.display = 'none';
+            el.textContent = '';
+        });
+        modalElement.querySelectorAll('.input-error').forEach(function(el) {
+            el.classList.remove('input-error');
+        });
+    }
+
+    function hideKeyWarning() {
+        const warning = document.getElementById('key-change-warning');
+        if (warning) warning.style.display = 'none';
+    }
+
+    function setLoading(loading) {
+        const form = document.getElementById('edit-metadata-form');
+        if (form) {
+            form.style.opacity = loading ? '0.5' : '1';
+            form.style.pointerEvents = loading ? 'none' : 'auto';
+        }
+    }
+
+    function setSaveLoading(loading) {
+        const btn = document.getElementById('btn-save-metadata');
+        if (btn) {
+            btn.disabled = loading;
+            btn.innerHTML = loading
+                ? '<i class="fa-solid fa-spinner fa-spin"></i> Saving...'
+                : '<i class="fa-solid fa-floppy-disk"></i> Save';
+        }
+    }
+
+    function setRepairLoading(loading) {
+        const btn = document.getElementById('btn-repair-nfo');
+        if (btn) {
+            btn.disabled = loading;
+            btn.innerHTML = loading
+                ? '<i class="fa-solid fa-spinner fa-spin"></i> Repairing...'
+                : '<i class="fa-solid fa-wrench"></i> Repair NFO';
+        }
+    }
+
+    function escapeHtml(str) {
+        var div = document.createElement('div');
+        div.textContent = str;
+        return div.innerHTML;
+    }
+
+    // Event listener management
+    let listeners = [];
+
+    function attachListeners() {
+        detachListeners();
+
+        const saveBtn = document.getElementById('btn-save-metadata');
+        const cancelBtn = document.getElementById('btn-cancel-metadata');
+        const repairBtn = document.getElementById('btn-repair-nfo');
+        const overlay = modalElement ? modalElement.querySelector('.modal-overlay') : null;
+        const keyInput = document.getElementById('edit-key');
+
+        if (saveBtn) {
+            var saveFn = function() { save(); };
+            saveBtn.addEventListener('click', saveFn);
+            listeners.push({ el: saveBtn, event: 'click', fn: saveFn });
+        }
+
+        if (cancelBtn) {
+            var cancelFn = function() { close(); };
+            cancelBtn.addEventListener('click', cancelFn);
+            listeners.push({ el: cancelBtn, event: 'click', fn: cancelFn });
+        }
+
+        if (repairBtn) {
+            var repairFn = function() { repairNfo(); };
+            repairBtn.addEventListener('click', repairFn);
+            listeners.push({ el: repairBtn, event: 'click', fn: repairFn });
+        }
+
+        if (overlay) {
+            var overlayFn = function() { close(); };
+            overlay.addEventListener('click', overlayFn);
+            listeners.push({ el: overlay, event: 'click', fn: overlayFn });
+        }
+
+        if (keyInput) {
+            var keyFn = function() {
+                var warning = document.getElementById('key-change-warning');
+                if (warning) {
+                    warning.style.display = keyInput.value !== originalData.key ? 'block' : 'none';
+                }
+            };
+            keyInput.addEventListener('input', keyFn);
+            listeners.push({ el: keyInput, event: 'input', fn: keyFn });
+        }
+    }
+
+    function detachListeners() {
+        listeners.forEach(function(l) {
+            l.el.removeEventListener(l.event, l.fn);
+        });
+        listeners = [];
+    }
+
+    return {
+        open: open,
+        close: close,
+        save: save,
+        repairNfo: repairNfo
+    };
+})();

src/server/web/static/js/index/series-manager.js

@@ -392,6 +392,22 @@ AniWorld.SeriesManager = (function() {
         return seriesData;
     }
 
+    /**
+     * Update a series key in the local data arrays after rename.
+     * @param {string} oldKey - The previous key
+     * @param {string} newKey - The new key
+     */
+    function updateSeriesKey(oldKey, newKey) {
+        if (seriesData) {
+            var s = seriesData.find(function(item) { return item.key === oldKey; });
+            if (s) s.key = newKey;
+        }
+        if (filteredSeriesData) {
+            var fs = filteredSeriesData.find(function(item) { return item.key === oldKey; });
+            if (fs) fs.key = newKey;
+        }
+    }
+
     /**
      * Get filtered series data
      * @returns {Array} Filtered series data array
@@ -543,6 +559,7 @@ AniWorld.SeriesManager = (function() {
         getFilteredSeriesData: getFilteredSeriesData,
         findByKey: findByKey,
         updateSeriesLoadingStatus: updateSeriesLoadingStatus,
-        updateSingleSeries: updateSingleSeries
+        updateSingleSeries: updateSingleSeries,
+        updateSeriesKey: updateSeriesKey
     };
 })();

src/server/web/templates/index.html

@@ -640,6 +640,80 @@
             </div>
         </div>
 
+        <!-- Edit Metadata Modal -->
+        <div id="edit-metadata-modal" class="modal hidden">
+            <div class="modal-overlay"></div>
+            <div class="modal-content edit-modal-content">
+                <div class="modal-header">
+                    <h3>Edit Metadata</h3>
+                    <button id="btn-cancel-metadata" class="btn btn-icon">
+                        <i class="fas fa-times"></i>
+                    </button>
+                </div>
+                <div class="modal-body">
+                    <form id="edit-metadata-form" onsubmit="return false;">
+                        <!-- Identity Section -->
+                        <div class="edit-section">
+                            <h4><i class="fa-solid fa-key"></i> Identity</h4>
+                            <div class="form-group">
+                                <label for="edit-key">Series Key</label>
+                                <input type="text" id="edit-key" class="input-field"
+                                    placeholder="e.g. attack-on-titan"
+                                    pattern="[a-z0-9][a-z0-9-]*[a-z0-9]">
+                                <span class="field-error" style="display:none;"></span>
+                            </div>
+                            <div id="key-change-warning" class="key-warning" style="display:none;">
+                                <i class="fa-solid fa-triangle-exclamation"></i>
+                                Changing the key will update the primary identifier. This may affect provider linkage.
+                            </div>
+                        </div>
+
+                        <!-- External IDs Section -->
+                        <div class="edit-section">
+                            <h4><i class="fa-solid fa-database"></i> External IDs</h4>
+                            <div class="form-row">
+                                <div class="form-group">
+                                    <label for="edit-tmdb-id">TMDB ID</label>
+                                    <input type="number" id="edit-tmdb-id" class="input-field"
+                                        placeholder="e.g. 1429" min="1">
+                                    <span class="field-error" style="display:none;"></span>
+                                </div>
+                                <div class="form-group">
+                                    <label for="edit-tvdb-id">TVDB ID</label>
+                                    <input type="number" id="edit-tvdb-id" class="input-field"
+                                        placeholder="e.g. 267440" min="1">
+                                    <span class="field-error" style="display:none;"></span>
+                                </div>
+                            </div>
+                        </div>
+
+                        <!-- NFO Status Section -->
+                        <div class="edit-section">
+                            <h4><i class="fa-solid fa-file-lines"></i> NFO Status</h4>
+                            <div class="nfo-diagnostics">
+                                <div id="nfo-status-badge" class="nfo-status-badge">Loading...</div>
+                                <div id="nfo-diagnostics-container">
+                                    <div id="nfo-missing-tags" class="missing-tags-list"></div>
+                                </div>
+                                <p id="repair-hint" class="repair-hint" style="display:none;">
+                                    <i class="fa-solid fa-circle-info"></i>
+                                    No TMDB ID set. Repair will search TMDB by series name.
+                                </p>
+                                <button type="button" id="btn-repair-nfo" class="btn btn-secondary btn-repair">
+                                    <i class="fa-solid fa-wrench"></i> Repair NFO
+                                </button>
+                            </div>
+                        </div>
+                    </form>
+                </div>
+                <div class="modal-footer">
+                    <button type="button" id="btn-save-metadata" class="btn btn-primary">
+                        <i class="fa-solid fa-floppy-disk"></i> Save
+                    </button>
+                </div>
+            </div>
+        </div>
+
         <!-- Toast notifications -->
         <div id="toast-container" class="toast-container"></div>
     </div>
@@ -665,6 +739,8 @@
     <script src="/static/js/user_preferences.js?v={{ static_v }}"></script>
 
     <!-- Index Page Modules -->
+    <script src="/static/js/index/context-menu.js?v={{ static_v }}"></script>
+    <script src="/static/js/index/edit-modal.js?v={{ static_v }}"></script>
     <script src="/static/js/index/series-manager.js?v={{ static_v }}"></script>
     <script src="/static/js/index/selection-manager.js?v={{ static_v }}"></script>
     <script src="/static/js/index/search.js?v={{ static_v }}"></script>

tests/api/test_anime_edit_endpoints.py

@@ -0,0 +1,255 @@
+"""Tests for anime metadata edit (PUT /api/anime/{anime_key}) endpoint."""
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+from httpx import ASGITransport, AsyncClient
+
+from src.server.fastapi_app import app
+from src.server.services.auth_service import auth_service
+
+
+@pytest.fixture
+def reset_auth():
+    """Reset auth state before each test."""
+    auth_service._hash = None
+    auth_service._failed = {}
+
+
+@pytest.fixture
+async def client():
+    """Create async test client."""
+    transport = ASGITransport(app=app)
+    async with AsyncClient(transport=transport, base_url="http://test") as ac:
+        yield ac
+
+
+@pytest.fixture
+async def authenticated_client(client):
+    """Get authenticated client with Bearer token."""
+    # Setup auth
+    await client.post("/api/auth/setup", json={"master_password": "TestPass123!"})
+    response = await client.post(
+        "/api/auth/login", json={"password": "TestPass123!"}
+    )
+    token = response.json()["access_token"]
+    client.headers["Authorization"] = f"Bearer {token}"
+    return client
+
+
+@pytest.fixture
+def mock_db_session():
+    """Create a mock async database session."""
+    session = AsyncMock()
+    session.commit = AsyncMock()
+    session.flush = AsyncMock()
+    session.refresh = AsyncMock()
+    return session
+
+
+@pytest.fixture
+def mock_series_in_db():
+    """Create a mock AnimeSeries DB record."""
+    series = MagicMock()
+    series.id = 1
+    series.key = "test-anime"
+    series.name = "Test Anime"
+    series.tmdb_id = 1234
+    series.tvdb_id = 5678
+    series.folder = "Test Anime (2023)"
+    return series
+
+
+@pytest.fixture
+def override_db_dependency(mock_db_session):
+    """Override database session dependency."""
+    from src.server.utils.dependencies import get_database_session
+
+    app.dependency_overrides[get_database_session] = lambda: mock_db_session
+    yield mock_db_session
+    app.dependency_overrides.pop(get_database_session, None)
+
+
+class TestUpdateAnimeMetadata:
+    """Tests for PUT /api/anime/{anime_key}."""
+
+    @pytest.mark.asyncio
+    async def test_update_tmdb_id_success(
+        self, reset_auth, authenticated_client, override_db_dependency, mock_series_in_db
+    ):
+        """Test successful tmdb_id update."""
+        with patch(
+            "src.server.api.anime.AnimeSeriesService.get_by_key",
+            new_callable=AsyncMock,
+            return_value=mock_series_in_db,
+        ), patch(
+            "src.server.api.anime.AnimeSeriesService.update",
+            new_callable=AsyncMock,
+        ) as mock_update:
+            mock_series_in_db.tmdb_id = 9999
+            mock_update.return_value = mock_series_in_db
+
+            response = await authenticated_client.put(
+                "/api/anime/test-anime",
+                json={"tmdb_id": 9999},
+            )
+
+            assert response.status_code == 200
+            data = response.json()
+            assert data["tmdb_id"] == 9999
+            assert data["message"] == "Metadata updated successfully"
+
+    @pytest.mark.asyncio
+    async def test_update_tvdb_id_success(
+        self, reset_auth, authenticated_client, override_db_dependency, mock_series_in_db
+    ):
+        """Test successful tvdb_id update."""
+        with patch(
+            "src.server.api.anime.AnimeSeriesService.get_by_key",
+            new_callable=AsyncMock,
+            return_value=mock_series_in_db,
+        ), patch(
+            "src.server.api.anime.AnimeSeriesService.update",
+            new_callable=AsyncMock,
+        ) as mock_update:
+            mock_series_in_db.tvdb_id = 7777
+            mock_update.return_value = mock_series_in_db
+
+            response = await authenticated_client.put(
+                "/api/anime/test-anime",
+                json={"tvdb_id": 7777},
+            )
+
+            assert response.status_code == 200
+            data = response.json()
+            assert data["tvdb_id"] == 7777
+
+    @pytest.mark.asyncio
+    async def test_update_key_success(
+        self, reset_auth, authenticated_client, override_db_dependency, mock_series_in_db
+    ):
+        """Test successful key rename."""
+        with patch(
+            "src.server.api.anime.AnimeSeriesService.get_by_key",
+            new_callable=AsyncMock,
+        ) as mock_get:
+            # First call finds the series, second call checks uniqueness (returns None)
+            mock_get.side_effect = [mock_series_in_db, None]
+
+            mock_series_in_db.key = "new-anime-key"
+            with patch(
+                "src.server.api.anime.AnimeSeriesService.update",
+                new_callable=AsyncMock,
+                return_value=mock_series_in_db,
+            ):
+                response = await authenticated_client.put(
+                    "/api/anime/test-anime",
+                    json={"key": "new-anime-key"},
+                )
+
+                assert response.status_code == 200
+                data = response.json()
+                assert data["key"] == "new-anime-key"
+
+    @pytest.mark.asyncio
+    async def test_update_key_conflict_409(
+        self, reset_auth, authenticated_client, override_db_dependency, mock_series_in_db
+    ):
+        """Test key rename conflict returns 409."""
+        existing_series = MagicMock()
+        existing_series.key = "existing-key"
+
+        with patch(
+            "src.server.api.anime.AnimeSeriesService.get_by_key",
+            new_callable=AsyncMock,
+        ) as mock_get:
+            # First call finds original series, second call finds conflict
+            mock_get.side_effect = [mock_series_in_db, existing_series]
+
+            response = await authenticated_client.put(
+                "/api/anime/test-anime",
+                json={"key": "existing-key"},
+            )
+
+            assert response.status_code == 409
+            assert "already exists" in response.json()["detail"]
+
+    @pytest.mark.asyncio
+    async def test_update_key_invalid_chars_422(
+        self, reset_auth, authenticated_client, override_db_dependency
+    ):
+        """Test key with invalid characters returns 422."""
+        response = await authenticated_client.put(
+            "/api/anime/test-anime",
+            json={"key": "Invalid Key With Spaces!"},
+        )
+
+        assert response.status_code == 422
+
+    @pytest.mark.asyncio
+    async def test_update_key_empty_422(
+        self, reset_auth, authenticated_client, override_db_dependency
+    ):
+        """Test empty key returns 422."""
+        response = await authenticated_client.put(
+            "/api/anime/test-anime",
+            json={"key": ""},
+        )
+
+        assert response.status_code == 422
+
+    @pytest.mark.asyncio
+    async def test_update_unauthenticated_401(self, reset_auth, client):
+        """Test unauthenticated access returns 401."""
+        response = await client.put(
+            "/api/anime/test-anime",
+            json={"tmdb_id": 1234},
+        )
+
+        assert response.status_code == 401
+
+    @pytest.mark.asyncio
+    async def test_update_nonexistent_anime_404(
+        self, reset_auth, authenticated_client, override_db_dependency
+    ):
+        """Test update of non-existent anime returns 404."""
+        with patch(
+            "src.server.api.anime.AnimeSeriesService.get_by_key",
+            new_callable=AsyncMock,
+            return_value=None,
+        ):
+            response = await authenticated_client.put(
+                "/api/anime/nonexistent-key",
+                json={"tmdb_id": 1234},
+            )
+
+            assert response.status_code == 404
+
+    @pytest.mark.asyncio
+    async def test_update_no_changes(
+        self, reset_auth, authenticated_client, override_db_dependency, mock_series_in_db
+    ):
+        """Test sending empty body returns no-op response."""
+        with patch(
+            "src.server.api.anime.AnimeSeriesService.get_by_key",
+            new_callable=AsyncMock,
+            return_value=mock_series_in_db,
+        ):
+            response = await authenticated_client.put(
+                "/api/anime/test-anime",
+                json={},
+            )
+
+            assert response.status_code == 200
+            assert response.json()["message"] == "No changes"
+
+    @pytest.mark.asyncio
+    async def test_update_negative_tmdb_id_422(
+        self, reset_auth, authenticated_client, override_db_dependency
+    ):
+        """Test negative TMDB ID returns 422."""
+        response = await authenticated_client.put(
+            "/api/anime/test-anime",
+            json={"tmdb_id": -5},
+        )
+
+        assert response.status_code == 422

tests/api/test_nfo_diagnostics_repair.py

@@ -0,0 +1,317 @@
+"""Tests for NFO diagnostics and repair API endpoints."""
+from unittest.mock import AsyncMock, Mock, patch
+
+import pytest
+from httpx import ASGITransport, AsyncClient
+
+from src.server.fastapi_app import app
+from src.server.services.auth_service import auth_service
+
+
+@pytest.fixture(autouse=True)
+def reset_auth():
+    """Reset authentication state before each test."""
+    original_hash = auth_service._hash
+    auth_service._hash = None
+    auth_service._failed.clear()
+    yield
+    auth_service._hash = original_hash
+    auth_service._failed.clear()
+
+
+@pytest.fixture
+async def client():
+    """Create an async test client."""
+    transport = ASGITransport(app=app)
+    async with AsyncClient(transport=transport, base_url="http://test") as ac:
+        yield ac
+
+
+@pytest.fixture
+async def authenticated_client(client):
+    """Create an authenticated test client with token."""
+    await client.post(
+        "/api/auth/setup",
+        json={"master_password": "TestPassword123!"}
+    )
+    response = await client.post(
+        "/api/auth/login",
+        json={"password": "TestPassword123!"}
+    )
+    token = response.json()["access_token"]
+    client.headers.update({"Authorization": f"Bearer {token}"})
+    yield client
+
+
+@pytest.fixture
+def mock_series_app():
+    """Create mock series app with one test series."""
+    app_mock = Mock()
+    serie = Mock()
+    serie.key = "test-anime"
+    serie.folder = "Test Anime (2024)"
+    serie.name = "Test Anime"
+    serie.ensure_folder_with_year = Mock(return_value="Test Anime (2024)")
+
+    list_manager = Mock()
+    list_manager.GetList = Mock(return_value=[serie])
+    app_mock.list = list_manager
+
+    return app_mock
+
+
+@pytest.fixture
+def mock_nfo_service():
+    """Create mock NFO service."""
+    service = Mock()
+    service.check_nfo_exists = AsyncMock(return_value=False)
+    service.create_tvshow_nfo = AsyncMock(return_value="/path/to/tvshow.nfo")
+    service.update_tvshow_nfo = AsyncMock(return_value="/path/to/tvshow.nfo")
+    return service
+
+
+@pytest.fixture
+def override_dependencies(mock_series_app, mock_nfo_service):
+    """Override dependencies for NFO tests."""
+    from src.server.api.nfo import get_nfo_service
+    from src.server.utils.dependencies import get_series_app
+
+    app.dependency_overrides[get_series_app] = lambda: mock_series_app
+    app.dependency_overrides[get_nfo_service] = lambda: mock_nfo_service
+
+    yield
+
+    if get_series_app in app.dependency_overrides:
+        del app.dependency_overrides[get_series_app]
+    if get_nfo_service in app.dependency_overrides:
+        del app.dependency_overrides[get_nfo_service]
+
+
+class TestNfoDiagnostics:
+    """Tests for GET /api/nfo/{serie_key}/diagnostics."""
+
+    @pytest.mark.asyncio
+    async def test_diagnostics_complete_nfo(
+        self, authenticated_client, override_dependencies
+    ):
+        """Test diagnostics with complete NFO returns no missing tags."""
+        with patch(
+            "src.server.api.nfo.Path.exists", return_value=True
+        ), patch(
+            "src.server.api.nfo.find_missing_tags", return_value=[]
+        ):
+            response = await authenticated_client.get(
+                "/api/nfo/test-anime/diagnostics"
+            )
+
+            assert response.status_code == 200
+            data = response.json()
+            assert data["has_nfo"] is True
+            assert data["missing_tags"] == []
+            assert len(data["required_tags"]) > 0
+
+    @pytest.mark.asyncio
+    async def test_diagnostics_missing_tags(
+        self, authenticated_client, override_dependencies
+    ):
+        """Test diagnostics with missing tags returns them."""
+        with patch(
+            "src.server.api.nfo.Path.exists", return_value=True
+        ), patch(
+            "src.server.api.nfo.find_missing_tags",
+            return_value=["plot", "genre", "actor/name"],
+        ):
+            response = await authenticated_client.get(
+                "/api/nfo/test-anime/diagnostics"
+            )
+
+            assert response.status_code == 200
+            data = response.json()
+            assert data["has_nfo"] is True
+            assert "plot" in data["missing_tags"]
+            assert "genre" in data["missing_tags"]
+            assert len(data["missing_tags"]) == 3
+
+    @pytest.mark.asyncio
+    async def test_diagnostics_no_nfo_file(
+        self, authenticated_client, override_dependencies
+    ):
+        """Test diagnostics when no NFO exists returns all tags as missing."""
+        with patch("src.server.api.nfo.Path") as MockPath:
+            # Make nfo_path.exists() return False
+            mock_path_instance = Mock()
+            mock_path_instance.exists.return_value = False
+            mock_path_instance.__truediv__ = Mock(return_value=mock_path_instance)
+            MockPath.return_value = mock_path_instance
+
+            response = await authenticated_client.get(
+                "/api/nfo/test-anime/diagnostics"
+            )
+
+            assert response.status_code == 200
+            data = response.json()
+            assert data["has_nfo"] is False
+            assert len(data["missing_tags"]) > 0
+            # All required tags should be listed as missing
+            assert data["missing_tags"] == data["required_tags"]
+
+    @pytest.mark.asyncio
+    async def test_diagnostics_nonexistent_series_404(
+        self, authenticated_client, override_dependencies, mock_series_app
+    ):
+        """Test diagnostics for non-existent series returns 404."""
+        # Override to return empty list
+        mock_series_app.list.GetList.return_value = []
+
+        response = await authenticated_client.get(
+            "/api/nfo/nonexistent-key/diagnostics"
+        )
+
+        assert response.status_code == 404
+
+    @pytest.mark.asyncio
+    async def test_diagnostics_unauthenticated_401(self, client):
+        """Test diagnostics requires authentication."""
+        response = await client.get("/api/nfo/test-anime/diagnostics")
+        # May return 401 or 503 depending on NFO service availability
+        assert response.status_code in (401, 503)
+
+
+class TestNfoRepair:
+    """Tests for POST /api/nfo/{serie_key}/repair."""
+
+    @pytest.mark.asyncio
+    async def test_repair_success(
+        self, authenticated_client, override_dependencies
+    ):
+        """Test successful NFO repair."""
+        with patch("src.server.api.nfo.Path") as MockPath:
+            mock_path = Mock()
+            mock_path.exists.return_value = True
+            mock_path.__truediv__ = Mock(return_value=mock_path)
+            MockPath.return_value = mock_path
+
+            with patch(
+                "src.server.api.nfo.find_missing_tags",
+                return_value=["plot", "genre"],
+            ), patch(
+                "src.server.api.nfo.NfoRepairService"
+            ) as MockRepairService:
+                mock_instance = Mock()
+                mock_instance.repair_series = AsyncMock(return_value=True)
+                MockRepairService.return_value = mock_instance
+
+                response = await authenticated_client.post(
+                    "/api/nfo/test-anime/repair", json={}
+                )
+
+                assert response.status_code == 200
+                data = response.json()
+                assert data["success"] is True
+                assert "2" in data["message"]  # "Fixed 2 missing tags"
+                assert "plot" in data["repaired_tags"]
+                assert "genre" in data["repaired_tags"]
+
+    @pytest.mark.asyncio
+    async def test_repair_already_complete(
+        self, authenticated_client, override_dependencies
+    ):
+        """Test repair when NFO is already complete."""
+        with patch("src.server.api.nfo.Path") as MockPath:
+            mock_path = Mock()
+            mock_path.exists.return_value = True
+            mock_path.__truediv__ = Mock(return_value=mock_path)
+            MockPath.return_value = mock_path
+
+            with patch(
+                "src.server.api.nfo.find_missing_tags", return_value=[]
+            ), patch(
+                "src.server.api.nfo.NfoRepairService"
+            ) as MockRepairService:
+                mock_instance = Mock()
+                mock_instance.repair_series = AsyncMock(return_value=False)
+                MockRepairService.return_value = mock_instance
+
+                response = await authenticated_client.post(
+                    "/api/nfo/test-anime/repair", json={}
+                )
+
+                assert response.status_code == 200
+                data = response.json()
+                assert data["success"] is True
+                assert "already complete" in data["message"]
+
+    @pytest.mark.asyncio
+    async def test_repair_creates_new_nfo(
+        self, authenticated_client, override_dependencies, mock_nfo_service
+    ):
+        """Test repair when no NFO exists creates a new one."""
+        with patch("src.server.api.nfo.Path") as MockPath:
+            mock_path = Mock()
+            mock_path.exists.return_value = False
+            mock_path.__truediv__ = Mock(return_value=mock_path)
+            MockPath.return_value = mock_path
+
+            with patch(
+                "src.server.api.nfo.REQUIRED_TAGS",
+                {"./title": "title", "./plot": "plot"},
+            ):
+                response = await authenticated_client.post(
+                    "/api/nfo/test-anime/repair", json={}
+                )
+
+                assert response.status_code == 200
+                data = response.json()
+                assert data["success"] is True
+                mock_nfo_service.create_tvshow_nfo.assert_awaited_once()
+
+    @pytest.mark.asyncio
+    async def test_repair_nonexistent_series_404(
+        self, authenticated_client, override_dependencies, mock_series_app
+    ):
+        """Test repair for non-existent series returns 404."""
+        mock_series_app.list.GetList.return_value = []
+
+        response = await authenticated_client.post(
+            "/api/nfo/nonexistent-key/repair", json={}
+        )
+
+        assert response.status_code == 404
+
+    @pytest.mark.asyncio
+    async def test_repair_unauthenticated_401(self, client):
+        """Test repair requires authentication."""
+        response = await client.post("/api/nfo/test-anime/repair", json={})
+        assert response.status_code in (401, 503)
+
+    @pytest.mark.asyncio
+    async def test_repair_tmdb_api_failure(
+        self, authenticated_client, override_dependencies
+    ):
+        """Test repair handles TMDB API failure gracefully."""
+        from src.core.services.tmdb_client import TMDBAPIError
+
+        with patch("src.server.api.nfo.Path") as MockPath:
+            mock_path = Mock()
+            mock_path.exists.return_value = True
+            mock_path.__truediv__ = Mock(return_value=mock_path)
+            MockPath.return_value = mock_path
+
+            with patch(
+                "src.server.api.nfo.find_missing_tags",
+                return_value=["plot"],
+            ), patch(
+                "src.server.api.nfo.NfoRepairService"
+            ) as MockRepairService:
+                mock_instance = Mock()
+                mock_instance.repair_series = AsyncMock(
+                    side_effect=TMDBAPIError("No TMDB ID found")
+                )
+                MockRepairService.return_value = mock_instance
+
+                response = await authenticated_client.post(
+                    "/api/nfo/test-anime/repair", json={}
+                )
+
+                assert response.status_code == 400
+                assert "Cannot repair NFO" in response.json()["detail"]

tests/frontend/test_edit_modal.py

@@ -0,0 +1,115 @@
+"""Frontend tests for the edit metadata modal HTML structure."""
+from unittest.mock import AsyncMock, Mock, patch
+
+import pytest
+from httpx import ASGITransport, AsyncClient
+
+from src.server.fastapi_app import app
+from src.server.services.auth_service import auth_service
+
+
+@pytest.fixture(autouse=True)
+def reset_auth():
+    """Reset authentication state before each test."""
+    original_hash = auth_service._hash
+    auth_service._hash = None
+    auth_service._failed.clear()
+    yield
+    auth_service._hash = original_hash
+    auth_service._failed.clear()
+
+
+@pytest.fixture
+async def client():
+    """Create an async test client."""
+    transport = ASGITransport(app=app)
+    async with AsyncClient(transport=transport, base_url="http://test") as ac:
+        yield ac
+
+
+@pytest.fixture
+async def authenticated_client(client):
+    """Create authenticated client to access index page."""
+    await client.post(
+        "/api/auth/setup",
+        json={"master_password": "TestPassword123!"}
+    )
+    response = await client.post(
+        "/api/auth/login",
+        json={"password": "TestPassword123!"}
+    )
+    token = response.json()["access_token"]
+    client.headers.update({"Authorization": f"Bearer {token}"})
+    # Set cookie for page access
+    client.cookies.set("access_token", token)
+    yield client
+
+
+class TestEditModalHtmlPresence:
+    """Tests verifying edit modal HTML elements exist in index page."""
+
+    @pytest.mark.asyncio
+    async def test_index_page_contains_edit_modal(self, authenticated_client):
+        """Verify #edit-metadata-modal exists in rendered index page."""
+        response = await authenticated_client.get("/")
+
+        # Page may redirect or require different auth for HTML pages
+        if response.status_code == 200:
+            html = response.text
+            assert 'id="edit-metadata-modal"' in html
+
+    @pytest.mark.asyncio
+    async def test_index_page_loads_context_menu_script(self, authenticated_client):
+        """Verify context-menu.js script tag is present."""
+        response = await authenticated_client.get("/")
+
+        if response.status_code == 200:
+            html = response.text
+            assert "context-menu.js" in html
+
+    @pytest.mark.asyncio
+    async def test_index_page_loads_edit_modal_script(self, authenticated_client):
+        """Verify edit-modal.js script tag is present."""
+        response = await authenticated_client.get("/")
+
+        if response.status_code == 200:
+            html = response.text
+            assert "edit-modal.js" in html
+
+    @pytest.mark.asyncio
+    async def test_modal_form_fields_present(self, authenticated_client):
+        """Verify key, tmdb_id, tvdb_id input fields exist in modal."""
+        response = await authenticated_client.get("/")
+
+        if response.status_code == 200:
+            html = response.text
+            assert 'id="edit-key"' in html
+            assert 'id="edit-tmdb-id"' in html
+            assert 'id="edit-tvdb-id"' in html
+
+    @pytest.mark.asyncio
+    async def test_nfo_repair_button_present(self, authenticated_client):
+        """Verify repair NFO button exists in modal."""
+        response = await authenticated_client.get("/")
+
+        if response.status_code == 200:
+            html = response.text
+            assert 'id="btn-repair-nfo"' in html
+
+    @pytest.mark.asyncio
+    async def test_save_button_present(self, authenticated_client):
+        """Verify save button exists in modal."""
+        response = await authenticated_client.get("/")
+
+        if response.status_code == 200:
+            html = response.text
+            assert 'id="btn-save-metadata"' in html
+
+    @pytest.mark.asyncio
+    async def test_modal_starts_hidden(self, authenticated_client):
+        """Verify modal has hidden class by default."""
+        response = await authenticated_client.get("/")
+
+        if response.status_code == 200:
+            html = response.text
+            assert 'id="edit-metadata-modal" class="modal hidden"' in html

tests/unit/test_anime_key_rename.py

@@ -0,0 +1,161 @@
+"""Unit tests for anime key rename logic and validation."""
+import pytest
+from pydantic import ValidationError
+
+from src.server.models.anime import AnimeMetadataUpdate, KEY_PATTERN
+
+
+class TestKeyValidation:
+    """Tests for AnimeMetadataUpdate key validation."""
+
+    def test_valid_key_simple(self):
+        """Test simple valid key."""
+        model = AnimeMetadataUpdate(key="attack-on-titan")
+        assert model.key == "attack-on-titan"
+
+    def test_valid_key_single_char(self):
+        """Test single character key is valid."""
+        model = AnimeMetadataUpdate(key="a")
+        assert model.key == "a"
+
+    def test_valid_key_numbers(self):
+        """Test key with numbers."""
+        model = AnimeMetadataUpdate(key="86-eighty-six")
+        assert model.key == "86-eighty-six"
+
+    def test_valid_key_allows_hyphens(self):
+        """Test hyphens in key are allowed."""
+        model = AnimeMetadataUpdate(key="my-anime-key")
+        assert model.key == "my-anime-key"
+
+    def test_valid_key_normalizes_to_lowercase(self):
+        """Test key is normalized to lowercase."""
+        model = AnimeMetadataUpdate(key="Attack-On-Titan")
+        assert model.key == "attack-on-titan"
+
+    def test_valid_key_strips_whitespace(self):
+        """Test key strips leading/trailing whitespace."""
+        model = AnimeMetadataUpdate(key="  my-key  ")
+        assert model.key == "my-key"
+
+    def test_invalid_key_spaces(self):
+        """Test key with spaces is rejected."""
+        with pytest.raises(ValidationError) as exc_info:
+            AnimeMetadataUpdate(key="my anime key")
+        assert "Key must contain only" in str(exc_info.value)
+
+    def test_invalid_key_uppercase_special(self):
+        """Test key with special characters is rejected."""
+        with pytest.raises(ValidationError) as exc_info:
+            AnimeMetadataUpdate(key="anime!@#key")
+        assert "Key must contain only" in str(exc_info.value)
+
+    def test_invalid_key_empty(self):
+        """Test empty key is rejected."""
+        with pytest.raises(ValidationError) as exc_info:
+            AnimeMetadataUpdate(key="")
+        assert "cannot be empty" in str(exc_info.value)
+
+    def test_invalid_key_only_whitespace(self):
+        """Test whitespace-only key is rejected."""
+        with pytest.raises(ValidationError) as exc_info:
+            AnimeMetadataUpdate(key="   ")
+        assert "cannot be empty" in str(exc_info.value)
+
+    def test_invalid_key_starts_with_hyphen(self):
+        """Test key starting with hyphen is rejected."""
+        with pytest.raises(ValidationError):
+            AnimeMetadataUpdate(key="-my-key")
+
+    def test_invalid_key_ends_with_hyphen(self):
+        """Test key ending with hyphen is rejected."""
+        with pytest.raises(ValidationError):
+            AnimeMetadataUpdate(key="my-key-")
+
+    def test_key_none_is_allowed(self):
+        """Test None key (no change requested) is allowed."""
+        model = AnimeMetadataUpdate(key=None)
+        assert model.key is None
+
+    def test_key_omitted_is_allowed(self):
+        """Test omitting key entirely is allowed."""
+        model = AnimeMetadataUpdate(tmdb_id=1234)
+        assert model.key is None
+
+
+class TestTmdbIdValidation:
+    """Tests for tmdb_id validation."""
+
+    def test_valid_tmdb_id(self):
+        """Test valid positive TMDB ID."""
+        model = AnimeMetadataUpdate(tmdb_id=1429)
+        assert model.tmdb_id == 1429
+
+    def test_tmdb_id_none(self):
+        """Test None tmdb_id is allowed."""
+        model = AnimeMetadataUpdate(tmdb_id=None)
+        assert model.tmdb_id is None
+
+    def test_tmdb_id_negative_rejected(self):
+        """Test negative tmdb_id is rejected."""
+        with pytest.raises(ValidationError):
+            AnimeMetadataUpdate(tmdb_id=-1)
+
+    def test_tmdb_id_zero_rejected(self):
+        """Test zero tmdb_id is rejected."""
+        with pytest.raises(ValidationError):
+            AnimeMetadataUpdate(tmdb_id=0)
+
+
+class TestTvdbIdValidation:
+    """Tests for tvdb_id validation."""
+
+    def test_valid_tvdb_id(self):
+        """Test valid positive TVDB ID."""
+        model = AnimeMetadataUpdate(tvdb_id=267440)
+        assert model.tvdb_id == 267440
+
+    def test_tvdb_id_none(self):
+        """Test None tvdb_id is allowed."""
+        model = AnimeMetadataUpdate(tvdb_id=None)
+        assert model.tvdb_id is None
+
+    def test_tvdb_id_negative_rejected(self):
+        """Test negative tvdb_id is rejected."""
+        with pytest.raises(ValidationError):
+            AnimeMetadataUpdate(tvdb_id=-5)
+
+    def test_tvdb_id_zero_rejected(self):
+        """Test zero tvdb_id is rejected."""
+        with pytest.raises(ValidationError):
+            AnimeMetadataUpdate(tvdb_id=0)
+
+
+class TestKeyPattern:
+    """Tests for the KEY_PATTERN regex directly."""
+
+    @pytest.mark.parametrize("key", [
+        "a",
+        "abc",
+        "attack-on-titan",
+        "86-eighty-six",
+        "a1b2c3",
+        "x",
+        "1",
+    ])
+    def test_valid_patterns(self, key):
+        """Test keys that should match the pattern."""
+        assert KEY_PATTERN.match(key) is not None
+
+    @pytest.mark.parametrize("key", [
+        "-start",
+        "end-",
+        "has space",
+        "UPPER",
+        "special!char",
+        "under_score",
+        "",
+    ])
+    def test_invalid_patterns(self, key):
+        """Test keys that should not match the pattern."""
+        assert KEY_PATTERN.match(key) is None