/**
 * AniWorld - Anime Settings Page Manager
 *
 * Handles the per-anime settings page reached via the right-click
 * context menu. Loads the current settings via
 * GET /api/anime/{key}/settings and saves changes via
 * PUT /api/anime/{key}/settings.
 *
 * Public API:
 *   - init()                       : bind DOM events and start initial load
 *   - loadSeries(key)              : fetch settings for a series key
 *   - saveSettings(opts)           : PUT settings, opts.applyToNfo / opts.renameDisk
 *   - regenerateNfo()              : POST regenerate-nfo endpoint
 *   - validateField(name, value)   : client-side validation, returns error string or null
 *   - populateForm(data)           : fill the form from a payload
 *   - showSaveSuccess(msg)         : success toast
 *   - showError(msg)               : error toast
 *
 * Dependencies: shared/constants.js, shared/auth.js, shared/api-client.js,
 * shared/ui-utils.js
 */
var AniWorld = window.AniWorld || {};

AniWorld.AnimeSettingsManager = (function () {
    'use strict';

    // API paths (kept in sync with constants.js)
    const API_BASE = '/api/anime';
    const API_NFO_BASE = '/api/nfo';

    // Page state
    let currentKey = null;
    let currentData = null;
    let originalData = null;
    let elements = null;

    /**
     * Initialize the page — bind events and start the initial load.
     */
    function init() {
        ensureElements();
        bindEvents();

        // Read ?key=... from the URL
        const url = new URL(window.location.href);
        currentKey = url.searchParams.get('key');

        if (currentKey) {
            loadSeries(currentKey);
        } else {
            showNoKey();
            populateSeriesSelect();
        }
    }

    /**
     * Cache the DOM elements we'll touch repeatedly.
     * Idempotent — safe to call from public functions that need elements.
     */
    function ensureElements() {
        if (elements) return;
        const ids = [
            'no-key-section', 'loading-section', 'error-section',
            'settings-section', 'series-select', 'load-series-btn',
            'retry-btn', 'error-message', 'series-display-name',
            'badge-loading-status', 'badge-has-nfo', 'badge-episode-counts',
            'overview-key', 'overview-year', 'overview-loading-status',
            'overview-episode-count', 'overview-missing-count',
            'overview-nfo-created', 'overview-nfo-updated', 'overview-nfo-path',
            'field-name', 'field-folder', 'field-tmdb-id', 'field-tvdb-id',
            'field-site', 'hint-name', 'hint-folder', 'hint-tmdb-id',
            'hint-tvdb-id', 'hint-site',
            'save-db-btn', 'save-db-nfo-btn', 'reset-btn',
            'rename-disk-toggle',
            'regenerate-nfo-btn', 'view-nfo-btn', 'nfo-content',
        ];
        const map = {};
        ids.forEach(function (id) {
            map[id] = document.getElementById(id);
        });
        elements = map;
    }

    /**
     * Cache the DOM elements we'll touch repeatedly.
     * @deprecated Use ensureElements() instead.
     */
    function cacheElements() {
        ensureElements();
    }

    /**
     * Wire up click handlers and escape-key dismissal.
     */
    function bindEvents() {
        if (elements['load-series-btn']) {
            elements['load-series-btn'].addEventListener('click', function () {
                const v = elements['series-select'].value;
                if (v) {
                    window.location.href = '/anime/settings?key=' +
                        encodeURIComponent(v);
                }
            });
        }
        if (elements['retry-btn']) {
            elements['retry-btn'].addEventListener('click', function () {
                if (currentKey) {
                    loadSeries(currentKey);
                } else {
                    showNoKey();
                }
            });
        }
        if (elements['save-db-btn']) {
            elements['save-db-btn'].addEventListener('click', function () {
                saveSettings({ applyToNfo: false });
            });
        }
        if (elements['save-db-nfo-btn']) {
            elements['save-db-nfo-btn'].addEventListener('click', function () {
                saveSettings({ applyToNfo: true });
            });
        }
        if (elements['reset-btn']) {
            elements['reset-btn'].addEventListener('click', function () {
                if (originalData) {
                    populateForm(originalData);
                    clearValidationHints();
                }
            });
        }
        if (elements['regenerate-nfo-btn']) {
            elements['regenerate-nfo-btn'].addEventListener('click',
                regenerateNfo);
        }
        if (elements['view-nfo-btn']) {
            elements['view-nfo-btn'].addEventListener('click', viewNfoContent);
        }
    }

    /**
     * Fetch the AnimeSettingsResponse for a series and populate the page.
     *
     * @param {string} key - Series unique key
     */
    async function loadSeries(key) {
        ensureElements();
        if (!key) {
            showNoKey();
            return;
        }
        currentKey = key;
        showLoading();
        try {
            const token = AniWorld.Auth && AniWorld.Auth.getToken
                ? AniWorld.Auth.getToken() : null;
            const headers = token
                ? { 'Authorization': 'Bearer ' + token }
                : {};
            const resp = await fetch(
                API_BASE + '/' + encodeURIComponent(key) + '/settings',
                { headers: headers, method: 'GET' }
            );
            if (resp.status === 401) {
                showError('Not authenticated — please log in again.');
                showErrorState('Authentication required.');
                // Redirect to login, preserving the intended destination
                setTimeout(function() {
                    window.location.href = '/login?next=' + encodeURIComponent(window.location.href);
                }, 1500);
                return;
            }
            if (resp.status === 404) {
                showErrorState('Series not found: ' + key);
                return;
            }
            if (!resp.ok) {
                const text = await resp.text();
                throw new Error('HTTP ' + resp.status + ': ' + text);
            }
            const data = await resp.json();
            currentData = data;
            // Deep clone for original-data reset
            originalData = JSON.parse(JSON.stringify(data));
            populateForm(data);
            showSettings();
        } catch (err) {
            console.error('Failed to load series settings:', err);
            showErrorState(err && err.message ? err.message : String(err));
        }
    }

    /**
     * Save the current form contents via PUT /api/anime/{key}/settings.
     *
     * @param {Object} opts
     * @param {boolean} opts.applyToNfo - Regenerate tvshow.nfo after save
     * @param {boolean} [opts.renameDisk] - Also rename folder on disk
     */
    async function saveSettings(opts) {
        ensureElements();
        if (!currentKey) {
            showError('No series selected.');
            return;
        }
        opts = opts || {};
        const renameDisk = !!(elements['rename-disk-toggle'] &&
            elements['rename-disk-toggle'].checked);

        const payload = collectFormPayload();
        const validationError = validatePayload(payload);
        if (validationError) {
            showError(validationError);
            return;
        }

        payload.apply_to_nfo = !!opts.applyToNfo;
        payload.rename_disk = renameDisk && payload.folder !== undefined &&
            payload.folder !== (currentData && currentData.folder);

        try {
            const token = AniWorld.Auth && AniWorld.Auth.getToken
                ? AniWorld.Auth.getToken() : null;
            const headers = { 'Content-Type': 'application/json' };
            if (token) {
                headers['Authorization'] = 'Bearer ' + token;
            }
            const resp = await fetch(
                API_BASE + '/' + encodeURIComponent(currentKey) + '/settings',
                {
                    headers: headers,
                    method: 'PUT',
                    body: JSON.stringify(payload),
                }
            );
            if (resp.status === 401) {
                showError('Not authenticated — please log in again.');
                return;
            }
            if (resp.status === 422) {
                const body = await resp.json().catch(function () { return {}; });
                showError('Validation failed: ' + (body.detail || resp.status));
                return;
            }
            if (!resp.ok) {
                const text = await resp.text();
                throw new Error('HTTP ' + resp.status + ': ' + text);
            }
            const data = await resp.json();
            currentData = data;
            originalData = JSON.parse(JSON.stringify(data));
            populateForm(data);
            if (opts.applyToNfo) {
                showSaveSuccess('Settings saved and tvshow.nfo regenerated.');
            } else {
                showSaveSuccess('Settings saved to database.');
            }
        } catch (err) {
            console.error('Failed to save settings:', err);
            showError('Save failed: ' + (err && err.message ? err.message : err));
        }
    }

    /**
     * Call POST /api/anime/{key}/regenerate-nfo to regenerate tvshow.nfo.
     */
    async function regenerateNfo() {
        ensureElements();
        if (!currentKey) {
            showError('No series selected.');
            return;
        }
        try {
            const token = AniWorld.Auth && AniWorld.Auth.getToken
                ? AniWorld.Auth.getToken() : null;
            const headers = {};
            if (token) {
                headers['Authorization'] = 'Bearer ' + token;
            }
            const resp = await fetch(
                API_BASE + '/' + encodeURIComponent(currentKey) +
                '/regenerate-nfo',
                { headers: headers, method: 'POST' }
            );
            if (resp.status === 400) {
                const body = await resp.json().catch(function () { return {}; });
                showError('Cannot regenerate: ' + (body.detail || resp.status));
                return;
            }
            if (resp.status === 404) {
                showError('Series not found.');
                return;
            }
            if (!resp.ok) {
                const text = await resp.text();
                throw new Error('HTTP ' + resp.status + ': ' + text);
            }
            const data = await resp.json();
            showSaveSuccess(data.message || 'NFO regenerated.');
            // Refresh data so the NFO badges update
            loadSeries(currentKey);
        } catch (err) {
            console.error('NFO regeneration failed:', err);
            showError('Regenerate failed: ' +
                (err && err.message ? err.message : err));
        }
    }

    /**
     * Fetch and display the raw tvshow.nfo XML in a <pre>.
     */
    async function viewNfoContent() {
        if (!currentKey) {
            showError('No series selected.');
            return;
        }
        try {
            const token = AniWorld.Auth && AniWorld.Auth.getToken
                ? AniWorld.Auth.getToken() : null;
            const headers = { 'Accept': 'application/json' };
            if (token) {
                headers['Authorization'] = 'Bearer ' + token;
            }
            const resp = await fetch(
                API_NFO_BASE + '/' + encodeURIComponent(currentKey) + '/content',
                { headers: headers, method: 'GET' }
            );
            if (!resp.ok) {
                const text = await resp.text();
                throw new Error('HTTP ' + resp.status + ': ' + text);
            }
            const data = await resp.json();
            const pre = elements['nfo-content'];
            if (pre) {
                pre.textContent = data.content || JSON.stringify(data, null, 2);
                pre.classList.remove('hidden');
            }
        } catch (err) {
            console.error('Failed to fetch NFO content:', err);
            showError('Could not fetch NFO content: ' +
                (err && err.message ? err.message : err));
        }
    }

    /**
     * Validate a single field. Returns null if valid, or an error message.
     *
     * @param {string} name  Field name (name, folder, tmdb_id, tvdb_id, site)
     * @param {*}      value Value from the form
     * @returns {string|null}
     */
    function validateField(name, value) {
        switch (name) {
            case 'name':
                if (value === '' || value == null) {
                    return 'Name cannot be empty.';
                }
                if (typeof value === 'string' && value.length > 500) {
                    return 'Name exceeds 500 characters.';
                }
                return null;
            case 'folder':
                if (value === '' || value == null) {
                    return 'Folder cannot be empty.';
                }
                if (typeof value === 'string' && /\.\./.test(value)) {
                    return 'Folder name cannot contain ".." (path traversal).';
                }
                if (typeof value === 'string' && /[<>:"|?*\x00]/.test(value)) {
                    return 'Folder name contains invalid characters.';
                }
                return null;
            case 'tmdb_id':
                if (value === '' || value == null || value === undefined) {
                    return null; // optional
                }
                const tmdb = Number(value);
                if (!Number.isFinite(tmdb) || !Number.isInteger(tmdb)) {
                    return 'TMDB ID must be an integer.';
                }
                if (tmdb <= 0) {
                    return 'TMDB ID must be a positive integer.';
                }
                if (tmdb > 9999999999) {
                    return 'TMDB ID exceeds 10 digits.';
                }
                return null;
            case 'tvdb_id':
                if (value === '' || value == null || value === undefined) {
                    return null;
                }
                const tvdb = Number(value);
                if (!Number.isFinite(tvdb) || !Number.isInteger(tvdb)) {
                    return 'TVDB ID must be an integer.';
                }
                if (tvdb <= 0) {
                    return 'TVDB ID must be a positive integer.';
                }
                if (tvdb > 9999999999) {
                    return 'TVDB ID exceeds 10 digits.';
                }
                return null;
            case 'site':
                if (value && typeof value === 'string' && value.length > 500) {
                    return 'Site URL exceeds 500 characters.';
                }
                return null;
            default:
                return null;
        }
    }

    /**
     * Validate the whole payload. Returns null if all fields valid, or the
     * first error message encountered.
     *
     * @param {Object} payload
     * @returns {string|null}
     */
    function validatePayload(payload) {
        const fields = ['name', 'folder', 'tmdb_id', 'tvdb_id', 'site'];
        for (let i = 0; i < fields.length; i++) {
            const name = fields[i];
            if (payload[name] === undefined) continue;
            const err = validateField(name, payload[name]);
            if (err) return name + ': ' + err;
        }
        return null;
    }

    /**
     * Populate the form from a settings payload.
     *
     * @param {Object} data AnimeSettingsResponse dict
     */
    function populateForm(data) {
        ensureElements();
        if (!data) return;

        // Overview
        setText(elements['series-display-name'], data.name || '(unnamed)');
        setText(elements['overview-key'], data.key || '—');
        setText(elements['overview-year'], data.year || '—');
        setText(elements['overview-loading-status'],
            data.loading_status || '—');
        setText(elements['overview-episode-count'],
            data.episode_count != null ? String(data.episode_count) : '—');
        setText(elements['overview-missing-count'],
            data.missing_episode_count != null
                ? String(data.missing_episode_count) : '—');
        setText(elements['overview-nfo-created'],
            data.nfo_created_at || '—');
        setText(elements['overview-nfo-updated'],
            data.nfo_updated_at || '—');
        setText(elements['overview-nfo-path'], data.nfo_path || '—');

        // Badges
        const lstatus = elements['badge-loading-status'];
        if (lstatus) {
            lstatus.textContent = 'Loading: ' + (data.loading_status || '—');
            lstatus.className = 'status-badge ' +
                (data.loading_status === 'completed'
                    ? 'status-complete'
                    : data.loading_status === 'failed'
                        ? 'status-failed'
                        : 'status-pending');
        }
        const nfoBadge = elements['badge-has-nfo'];
        if (nfoBadge) {
            nfoBadge.textContent = data.has_nfo ? 'NFO ✓' : 'NFO ✗';
            nfoBadge.className = 'status-badge ' +
                (data.has_nfo ? 'status-complete' : 'status-incomplete');
        }
        const epBadge = elements['badge-episode-counts'];
        if (epBadge) {
            epBadge.textContent =
                (data.missing_episode_count || 0) + ' / ' +
                (data.episode_count || 0) + ' missing';
            epBadge.className = 'status-badge';
        }

        // Editable inputs
        setValue(elements['field-name'], data.name || '');
        setValue(elements['field-folder'], data.folder || '');
        setValue(elements['field-tmdb-id'],
            data.tmdb_id != null ? data.tmdb_id : '');
        setValue(elements['field-tvdb-id'],
            data.tvdb_id != null ? data.tvdb_id : '');
        setValue(elements['field-site'], data.site || '');

        clearValidationHints();
    }

    /**
     * Collect current form values into a partial payload (omits empty
     * string / null fields so the server treats them as no-change).
     */
    function collectFormPayload() {
        const payload = {};
        const setIfPresent = function (key, raw) {
            if (raw === undefined || raw === null) return;
            const trimmed = typeof raw === 'string' ? raw.trim() : raw;
            if (trimmed === '' || trimmed === null) return;
            payload[key] = typeof raw === 'string' ? trimmed : raw;
        };
        setIfPresent('name', elements['field-name'].value);
        setIfPresent('folder', elements['field-folder'].value);
        setIfPresent('tmdb_id', elements['field-tmdb-id'].value);
        setIfPresent('tvdb_id', elements['field-tvdb-id'].value);
        setIfPresent('site', elements['field-site'].value);
        return payload;
    }

    /**
     * Populate the series-select dropdown with options for keys without
     * ?key=... in the URL.
     */
    async function populateSeriesSelect() {
        const select = elements['series-select'];
        if (!select) return;
        select.innerHTML = '<option value="">Loading…</option>';
        try {
            const token = AniWorld.Auth && AniWorld.Auth.getToken
                ? AniWorld.Auth.getToken() : null;
            const headers = token
                ? { 'Authorization': 'Bearer ' + token }
                : {};
            const resp = await fetch(API_BASE + '?per_page=500', {
                headers: headers, method: 'GET',
            });
            if (!resp.ok) {
                select.innerHTML = '<option value="">Failed to load series</option>';
                return;
            }
            const list = await resp.json();
            select.innerHTML = '<option value="">Select a series…</option>' +
                list.map(function (s) {
                    return '<option value="' + escapeHtml(s.key) + '">' +
                        escapeHtml(s.name || s.key) + '</option>';
                }).join('');
        } catch (err) {
            console.error('Failed to populate series select:', err);
            select.innerHTML = '<option value="">Failed to load series</option>';
        }
    }

    /**
     * Show a success toast via shared UI utilities.
     */
    function showSaveSuccess(msg) {
        if (AniWorld.UI && AniWorld.UI.showToast) {
            AniWorld.UI.showToast(msg, 'success');
        } else {
            console.info('[AnimeSettings] ' + msg);
        }
    }

    /**
     * Show an error toast via shared UI utilities.
     */
    function showError(msg) {
        if (AniWorld.UI && AniWorld.UI.showToast) {
            AniWorld.UI.showToast(msg, 'error');
        } else {
            console.error('[AnimeSettings] ' + msg);
        }
    }

    // View-state helpers --------------------------------------------------

    function showLoading() {
        showOnly('loading-section');
    }
    function showSettings() {
        showOnly('settings-section');
    }
    function showNoKey() {
        showOnly('no-key-section');
    }
    function showErrorState(msg) {
        showOnly('error-section');
        if (elements['error-message']) {
            elements['error-message'].textContent = msg || 'Unknown error.';
        }
    }
    function showOnly(id) {
        const sections = ['no-key-section', 'loading-section',
            'error-section', 'settings-section'];
        sections.forEach(function (s) {
            const el = document.getElementById(s);
            if (!el) return;
            if (s === id) {
                el.classList.remove('hidden');
            } else {
                el.classList.add('hidden');
            }
        });
    }

    function clearValidationHints() {
        ['hint-name', 'hint-folder', 'hint-tmdb-id',
         'hint-tvdb-id', 'hint-site'].forEach(function (id) {
            const el = elements[id];
            if (el) {
                el.textContent = '';
                el.classList.remove('hint-error');
            }
        });
    }

    function setText(el, text) {
        if (el) el.textContent = text;
    }
    function setValue(el, text) {
        if (el) el.value = text;
    }

    function escapeHtml(s) {
        if (s == null) return '';
        return String(s)
            .replace(/&/g, '&amp;')
            .replace(/</g, '&lt;')
            .replace(/>/g, '&gt;')
            .replace(/"/g, '&quot;')
            .replace(/'/g, '&#39;');
    }

    // Public API ----------------------------------------------------------

    return {
        init: init,
        loadSeries: loadSeries,
        saveSettings: saveSettings,
        regenerateNfo: regenerateNfo,
        validateField: validateField,
        populateForm: populateForm,
        showSaveSuccess: showSaveSuccess,
        showError: showError,
    };
})();

// Bootstrap on DOMContentLoaded — only register the listener.
// Tests call AnimeSettingsManager.init() explicitly after seeding the DOM.
if (typeof document !== 'undefined') {
    document.addEventListener('DOMContentLoaded', function () {
        if (AniWorld.AnimeSettingsManager && AniWorld.AnimeSettingsManager.init) {
            AniWorld.AnimeSettingsManager.init();
        }
    });
}