"""NFO Management API endpoints.

Provides endpoints for NFO settings, repair, and validation for anime series.
"""
import logging
import os
from typing import Any, List, Optional

from fastapi import APIRouter, Depends, HTTPException, status
from pydantic import BaseModel

from src.config.settings import settings
from src.server.models.nfo import (
    NfoRepairResponse,
    NfoSeriesSettings,
    NfoSettingsResponse,
)
from src.server.services.anime_service import AnimeService
from src.server.utils.dependencies import get_anime_service, require_auth

logger = logging.getLogger(__name__)

router = APIRouter(prefix="/api/nfo", tags=["nfo"])

# Required tags for a valid Kodi tvshow.nfo
REQUIRED_TAGS = [
    "title",
    "plot",
    "tmdbid",
]
OPTIONAL_TAGS = [
    "year",
    "premiered",
    "genre",
    "studio",
    "rating",
    "mpaa",
    "outline",
    "tagline",
    "runtime",
    "status",
    "id",
    "imdb_id",
    "tvdbid",
    "imdbid",
    "uniqueid",
    "thumb",
    "fanart",
    "actor",
    "trailer",
]


class NfoValidateResponse(BaseModel):
    """Response for NFO XML validation."""

    valid: bool
    error: Optional[str] = None


class NfoNeedsRepairListResponse(BaseModel):
    """Response listing series that need NFO repair."""

    total: int
    series: List[NfoSeriesSettings]


def _get_nfo_path(folder: str) -> str:
    """Get the full path to a series' tvshow.nfo file."""
    anime_dir = getattr(settings, "anime_directory", None)
    if not anime_dir:
        raise HTTPException(
            status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
            detail="Anime directory not configured",
        )
    return os.path.join(anime_dir, folder, "tvshow.nfo")


def _parse_nfo_file(nfo_path: str) -> tuple[Optional[Any], List[str]]:
    """Parse an NFO file and return (xml_root, missing_tags).

    Returns tuple of (xml_root element or None, list of missing required tags).
    If file cannot be read/parsed, returns (None, all_required_tags).
    """
    from lxml import etree

    missing: List[str] = []

    if not os.path.isfile(nfo_path):
        return None, REQUIRED_TAGS.copy()

    try:
        tree = etree.parse(nfo_path)
        root = tree.getroot()
    except Exception as exc:
        logger.warning("Failed to parse NFO file %s: %s", nfo_path, exc)
        return None, REQUIRED_TAGS.copy()

    # Check for required tags
    for tag in REQUIRED_TAGS:
        elements = root.findall(tag)
        # Check if tag exists and has non-empty text
        found = False
        for elem in elements:
            if elem.text and elem.text.strip():
                found = True
                break
        if not found:
            missing.append(tag)

    return root, missing


async def _get_series_data(
    anime_service: AnimeService, key: str
) -> Optional[dict]:
    """Get series data by key from anime_service."""
    # Get all series and find by key
    all_series = await anime_service.list_series_with_filters()
    for series in all_series:
        if series.get("key") == key:
            return series
    return None


@router.get("/{key}/diagnostics", response_model=NfoSettingsResponse)
async def get_nfo_settings(
    key: str,
    _auth: dict = Depends(require_auth),
    anime_service: AnimeService = Depends(get_anime_service),
) -> NfoSettingsResponse:
    """Get NFO settings inspection for a specific series.

    Checks if tvshow.nfo exists in the series folder and validates
    that required tags are present.

    Args:
        key: Series unique key (provider-assigned, URL-safe identifier)
        _auth: Authentication dependency
        anime_service: AnimeService dependency

    Returns:
        NfoSettingsResponse with has_nfo, nfo_path, missing_tags, required_tags

    Raises:
        HTTPException 404: If series not found
        HTTPException 503: If anime directory not configured
    """
    # Get series data
    series_data = await _get_series_data(anime_service, key)
    if not series_data:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Series not found: {key}",
        )

    folder = series_data.get("folder", "")
    if not folder:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=f"Series has no folder configured: {key}",
        )

    nfo_path = _get_nfo_path(folder)
    nfo_exists = os.path.isfile(nfo_path)

    if not nfo_exists:
        return NfoSettingsResponse(
            has_nfo=False,
            nfo_path=None,
            missing_tags=REQUIRED_TAGS.copy(),
            required_tags=REQUIRED_TAGS.copy(),
        )

    # Parse and check for missing tags
    _, missing = _parse_nfo_file(nfo_path)

    return NfoSettingsResponse(
        has_nfo=True,
        nfo_path=nfo_path,
        missing_tags=missing,
        required_tags=REQUIRED_TAGS.copy(),
    )


@router.post("/{key}/repair", response_model=NfoRepairResponse)
async def repair_nfo_settings(
    key: str,
    _auth: dict = Depends(require_auth),
    anime_service: AnimeService = Depends(get_anime_service),
) -> NfoRepairResponse:
    """Repair NFO for a specific series.

    Creates or updates the tvshow.nfo file using TMDB metadata.

    Args:
        key: Series unique key
        _auth: Authentication dependency
        anime_service: AnimeService dependency

    Returns:
        NfoRepairResponse with success status, message, and repaired_tags

    Raises:
        HTTPException 404: If series not found
        HTTPException 400: If no TMDB ID available and cannot lookup by name
        HTTPException 503: If anime directory not configured
    """
    # Get series data
    series_data = await _get_series_data(anime_service, key)
    if not series_data:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Series not found: {key}",
        )

    folder = series_data.get("folder", "")
    if not folder:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=f"Series has no folder configured: {key}",
        )

    tmdb_id = series_data.get("tmdb_id")
    name = series_data.get("name", "")

    if not tmdb_id:
        logger.info("No TMDB ID for %s, attempting lookup by name: %s", key, name)
        # Try to lookup TMDB ID by series name
        tmdb_id = await _lookup_tmdb_id_by_name(anime_service, name)
        if not tmdb_id:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail=f"No TMDB ID available for {key} and could not find match for '{name}'",
            )

    # Fetch TMDB data and create NFO
    try:
        repaired_tags = await _create_or_update_nfo(
            key=key,
            folder=folder,
            tmdb_id=tmdb_id,
            series_data=series_data,
        )
    except Exception as exc:
        logger.error("Failed to repair NFO for %s: %s", key, exc)
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"Failed to repair NFO: {str(exc)}",
        )

    if repaired_tags:
        return NfoRepairResponse(
            success=True,
            message=f"NFO repaired successfully. {len(repaired_tags)} tags updated.",
            repaired_tags=repaired_tags,
        )
    else:
        return NfoRepairResponse(
            success=True,
            message="NFO is already complete, no changes needed.",
            repaired_tags=[],
        )


async def _lookup_tmdb_id_by_name(anime_service: AnimeService, name: str) -> Optional[int]:
    """Try to lookup a TMDB ID by series name using TMDB provider."""
    try:
        from src.server.providers.tmdb_provider import TMDBProvider

        provider = TMDBProvider()
        results = await provider.search(name)
        if results:
            return results[0].get("tmdb_id")
    except Exception as exc:
        logger.warning("TMDB lookup failed for %s: %s", name, exc)
    return None


async def _create_or_update_nfo(
    key: str,
    folder: str,
    tmdb_id: int,
    series_data: dict,
) -> List[str]:
    """Create or update NFO file for a series.

    Returns list of tags that were repaired/added.
    """
    from src.server.providers.tmdb_provider import TMDBProvider

    from src.server.nfo.nfo_generator import generate_tvshow_nfo
    from src.server.nfo.nfo_mapper import tmdb_to_nfo_model

    anime_dir = getattr(settings, "anime_directory", None)
    if not anime_dir:
        raise HTTPException(
            status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
            detail="Anime directory not configured",
        )

    series_path = os.path.join(anime_dir, folder)
    nfo_path = os.path.join(series_path, "tvshow.nfo")

    # Fetch TMDB data
    provider = TMDBProvider()
    tmdb_data = await provider.get_series_info(tmdb_id)
    if not tmdb_data:
        raise Exception(f"No TMDB data returned for TMDB ID {tmdb_id}")

    # Convert to NFO model
    nfo_model = tmdb_to_nfo_model(
        tmdb_data,
        content_ratings=None,
        get_image_url=provider.get_image_url,
        image_size="original",
    )

    # Generate XML
    xml_content = generate_tvshow_nfo(nfo_model)

    # Ensure directory exists
    os.makedirs(series_path, exist_ok=True)

    # Check existing NFO for missing tags before overwriting
    _, missing_before = _parse_nfo_file(nfo_path)

    # Write NFO file
    with open(nfo_path, "w", encoding="utf-8") as f:
        f.write(xml_content)

    logger.info("Created/updated tvshow.nfo for %s at %s", key, nfo_path)

    # Update series NFO status in DB
    await anime_service.update_nfo_status(
        key=key,
        has_nfo=True,
    )

    # Also update nfo_path in DB (not part of update_nfo_status signature)
    from src.server.database.connection import get_db_session
    from src.server.database.service import AnimeSeriesService

    async with get_db_session() as db:
        series = await AnimeSeriesService.get_by_key(db, key)
        if series is not None:
            await AnimeSeriesService.update(db, series.id, nfo_path=nfo_path)

    # Return list of repaired tags (all tags that were missing before)
    return missing_before


@router.get("/{key}/validate", response_model=NfoValidateResponse)
async def validate_nfo(
    key: str,
    _auth: dict = Depends(require_auth),
    anime_service: AnimeService = Depends(get_anime_service),
) -> NfoValidateResponse:
    """Validate NFO XML structure for a series.

    Checks if the tvshow.nfo file is valid XML.

    Args:
        key: Series unique key
        _auth: Authentication dependency
        anime_service: AnimeService dependency

    Returns:
        NfoValidateResponse with valid=True/False and optional error message
    """
    series_data = await _get_series_data(anime_service, key)
    if not series_data:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Series not found: {key}",
        )

    folder = series_data.get("folder", "")
    if not folder:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=f"Series has no folder configured: {key}",
        )

    nfo_path = _get_nfo_path(folder)

    if not os.path.isfile(nfo_path):
        return NfoValidateResponse(
            valid=False,
            error="No NFO file found",
        )

    try:
        from lxml import etree

        etree.parse(nfo_path)
        return NfoValidateResponse(valid=True)
    except Exception as exc:
        return NfoValidateResponse(
            valid=False,
            error=str(exc),
        )


@router.get("/needs-repair", response_model=NfoNeedsRepairListResponse)
async def get_series_needing_repair(
    _auth: dict = Depends(require_auth),
    anime_service: AnimeService = Depends(get_anime_service),
) -> NfoNeedsRepairListResponse:
    """Get list of all series that need NFO repair.

    Returns series that either have no NFO file or have missing required tags.

    Args:
        _auth: Authentication dependency
        anime_service: AnimeService dependency

    Returns:
        NfoNeedsRepairListResponse with total count and list of series diagnostics
    """
    all_series = await anime_service.list_series_with_filters()
    series_needing_repair: List[NfoSeriesSettings] = []

    anime_dir = getattr(settings, "anime_directory", None)
    if not anime_dir:
        raise HTTPException(
            status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
            detail="Anime directory not configured",
        )

    for series in all_series:
        key = series.get("key", "")
        folder = series.get("folder", "")
        name = series.get("name", "")

        if not folder:
            continue

        nfo_path = os.path.join(anime_dir, folder, "tvshow.nfo")
        nfo_exists = os.path.isfile(nfo_path)

        if not nfo_exists:
            series_needing_repair.append(NfoSeriesSettings(
                key=key,
                name=name,
                folder=folder,
                has_nfo=False,
                missing_tags=REQUIRED_TAGS.copy(),
            ))
            continue

        # Parse and check for missing tags
        _, missing = _parse_nfo_file(nfo_path)
        if missing:
            series_needing_repair.append(NfoSeriesSettings(
                key=key,
                name=name,
                folder=folder,
                has_nfo=True,
                missing_tags=missing,
            ))

    return NfoNeedsRepairListResponse(
        total=len(series_needing_repair),
        series=series_needing_repair,
    )


@router.post("/batch/repair")
async def batch_repair_nfo(
    keys: List[str],
    _auth: dict = Depends(require_auth),
    anime_service: AnimeService = Depends(get_anime_service),
) -> dict:
    """Repair NFO for multiple series at once.

    Args:
        keys: List of series keys to repair
        _auth: Authentication dependency
        anime_service: AnimeService dependency

    Returns:
        Summary dict with success count, failure count, and errors
    """
    results = {
        "total": len(keys),
        "success": 0,
        "failed": 0,
        "errors": [],
    }

    for key in keys:
        try:
            # Get series data
            series_data = await _get_series_data(anime_service, key)
            if not series_data:
                results["failed"] += 1
                results["errors"].append(f"{key}: Series not found")
                continue

            folder = series_data.get("folder", "")
            if not folder:
                results["failed"] += 1
                results["errors"].append(f"{key}: No folder configured")
                continue

            tmdb_id = series_data.get("tmdb_id")
            name = series_data.get("name", "")

            if not tmdb_id:
                tmdb_id = await _lookup_tmdb_id_by_name(anime_service, name)
                if not tmdb_id:
                    results["failed"] += 1
                    results["errors"].append(f"{key}: No TMDB ID and lookup failed")
                    continue

            await _create_or_update_nfo(
                key=key,
                folder=folder,
                tmdb_id=tmdb_id,
                series_data=series_data,
            )
            results["success"] += 1

        except Exception as exc:
            results["failed"] += 1
            results["errors"].append(f"{key}: {str(exc)}")

    return results