const express = require('express');
const cors = require('cors');
const Database = require('better-sqlite3');
const { v4: uuidv4 } = require('uuid');
const path = require('path');
const fs = require('fs');

const app = express();
const PORT = process.env.PORT || 3000;

const MAX_PROFILES = 5;
const DEFAULT_PROFILE_NAMES = {
  1: 'Profil 1',
  2: 'Profil 2',
  3: 'Profil 3',
  4: 'Profil 4',
  5: 'Profil 5'
};
const PROFILE_SCOPE_COOKIE = 'fb_tracker_scope';
const PROFILE_SCOPE_MAX_AGE = 60 * 60 * 24 * 30; // 30 days
const FACEBOOK_TRACKING_PARAM_PREFIXES = ['__cft__', '__tn__', '__eep__', 'mibextid'];
const SEARCH_POST_HIDE_THRESHOLD = 3;
const SEARCH_POST_RETENTION_DAYS = 90;

const screenshotDir = path.join(__dirname, 'data', 'screenshots');
if (!fs.existsSync(screenshotDir)) {
  fs.mkdirSync(screenshotDir, { recursive: true });
}

// Middleware - Enhanced CORS for extension
app.use(cors({
  origin: (origin, callback) => {
    callback(null, origin || false);
  },
  methods: ['GET', 'POST', 'PUT', 'PATCH', 'DELETE', 'OPTIONS'],
  allowedHeaders: ['Content-Type', 'Authorization'],
  credentials: true
}));
// Allow larger payloads because screenshots from high-res monitors can easily exceed 10 MB
app.use(express.json({ limit: '30mb' }));

// Additional CORS headers for extension compatibility
app.use((req, res, next) => {
  const origin = req.headers.origin;
  const host = req.headers.host;
  const fallbackOrigin = host ? `${isSecureRequest(req) ? 'https' : 'http'}://${host}` : '*';
  res.header('Access-Control-Allow-Origin', origin || fallbackOrigin);
  res.header('Access-Control-Allow-Methods', 'GET, POST, PUT, PATCH, DELETE, OPTIONS');
  res.header('Access-Control-Allow-Headers', 'Content-Type, Authorization');
  res.header('Access-Control-Allow-Credentials', 'true');

  if (req.method === 'OPTIONS') {
    res.sendStatus(204);
    return;
  }

  next();
});

// Assign per-browser profile scopes via cookies
app.use(ensureProfileScope);

// Database setup
const dbPath = path.join(__dirname, 'data', 'tracker.db');
const db = new Database(dbPath);

function parseCookies(header) {
  if (!header || typeof header !== 'string') {
    return {};
  }

  return header.split(';').reduce((acc, part) => {
    const index = part.indexOf('=');
    if (index === -1) {
      const key = part.trim();
      if (key) {
        acc[key] = '';
      }
      return acc;
    }

    const key = part.slice(0, index).trim();
    const value = part.slice(index + 1).trim();
    if (key) {
      acc[key] = decodeURIComponent(value);
    }
    return acc;
  }, {});
}

function isSecureRequest(req) {
  if (req.secure) {
    return true;
  }
  const forwardedProto = req.headers['x-forwarded-proto'];
  if (typeof forwardedProto === 'string') {
    return forwardedProto.split(',').map(value => value.trim().toLowerCase()).includes('https');
  }
  return false;
}

function buildScopeCookieValue(scopeId, req) {
  const secure = isSecureRequest(req);
  const attributes = [
    `${PROFILE_SCOPE_COOKIE}=${encodeURIComponent(scopeId)}`,
    'Path=/',
    `Max-Age=${PROFILE_SCOPE_MAX_AGE}`
  ];

  if (secure) {
    attributes.push('Secure', 'SameSite=None');
  } else {
    attributes.push('SameSite=Lax');
  }

  return attributes.join('; ');
}

function appendScopeCookie(res, value) {
  const existing = res.getHeader('Set-Cookie');
  if (!existing) {
    res.setHeader('Set-Cookie', value);
  } else if (Array.isArray(existing)) {
    res.setHeader('Set-Cookie', [...existing, value]);
  } else {
    res.setHeader('Set-Cookie', [existing, value]);
  }
}

function ensureProfileScope(req, res, next) {
  const cookies = parseCookies(req.headers.cookie);
  let scopeId = cookies[PROFILE_SCOPE_COOKIE];

  if (!scopeId) {
    scopeId = uuidv4();
  }

  appendScopeCookie(res, buildScopeCookieValue(scopeId, req));

  req.profileScope = scopeId;
  next();
}

function getScopedProfileNumber(scopeId) {
  if (!scopeId) {
    return null;
  }
  const row = db.prepare('SELECT profile_number FROM profile_state_scoped WHERE scope_id = ?').get(scopeId);
  if (!row) {
    return null;
  }
  return sanitizeProfileNumber(row.profile_number);
}

function setScopedProfileNumber(scopeId, profileNumber) {
  if (!scopeId || !profileNumber) {
    return;
  }

  db.prepare(`
    INSERT INTO profile_state_scoped (scope_id, profile_number)
    VALUES (?, ?)
    ON CONFLICT(scope_id) DO UPDATE SET profile_number = excluded.profile_number
  `).run(scopeId, profileNumber);
}

function clampTargetCount(value) {
  const parsed = parseInt(value, 10);
  if (Number.isNaN(parsed)) {
    return 1;
  }
  return Math.min(MAX_PROFILES, Math.max(1, parsed));
}

function validateTargetCount(value) {
  const parsed = parseInt(value, 10);
  if (Number.isNaN(parsed) || parsed < 1 || parsed > MAX_PROFILES) {
    return null;
  }
  return parsed;
}

function sanitizeProfileNumber(value) {
  const parsed = parseInt(value, 10);
  if (Number.isNaN(parsed) || parsed < 1 || parsed > MAX_PROFILES) {
    return null;
  }
  return parsed;
}

function normalizeDeadline(value) {
  if (!value && value !== 0) {
    return null;
  }

  if (value instanceof Date) {
    if (!Number.isNaN(value.getTime())) {
      return value.toISOString();
    }
    return null;
  }

  if (typeof value === 'string') {
    const trimmed = value.trim();
    if (!trimmed) {
      return null;
    }

    const parsed = new Date(trimmed);
    if (!Number.isNaN(parsed.getTime())) {
      return parsed.toISOString();
    }
    return null;
  }

  if (typeof value === 'number') {
    const parsed = new Date(value);
    if (!Number.isNaN(parsed.getTime())) {
      return parsed.toISOString();
    }
    return null;
  }

  return null;
}

function getProfileName(profileNumber) {
  return DEFAULT_PROFILE_NAMES[profileNumber] || `Profil ${profileNumber}`;
}

function normalizeCreatorName(value) {
  if (typeof value !== 'string') {
    return null;
  }

  const trimmed = value.trim();
  if (!trimmed) {
    return null;
  }

  return trimmed.slice(0, 160);
}

function normalizeFacebookPostUrl(rawValue) {
  if (typeof rawValue !== 'string') {
    return null;
  }

  let value = rawValue.trim();
  if (!value) {
    return null;
  }

  const trackingIndex = value.indexOf('__cft__');
  if (trackingIndex !== -1) {
    value = value.slice(0, trackingIndex);
  }

  value = value.replace(/[?&]$/, '');

  let parsed;
  try {
    parsed = new URL(value);
  } catch (error) {
    try {
      parsed = new URL(value, 'https://www.facebook.com');
    } catch (fallbackError) {
      return null;
    }
  }

  if (!parsed.hostname.toLowerCase().endsWith('facebook.com')) {
    return null;
  }

  const cleanedParams = new URLSearchParams();
  parsed.searchParams.forEach((paramValue, paramKey) => {
    const lowerKey = paramKey.toLowerCase();
    if (FACEBOOK_TRACKING_PARAM_PREFIXES.some((prefix) => lowerKey.startsWith(prefix)) || lowerKey === 'set' || lowerKey === 'comment_id') {
      return;
    }
    if (lowerKey === 'hoisted_section_header_type') {
      return;
    }
    cleanedParams.append(paramKey, paramValue);
  });

  const multiPermalinkId = cleanedParams.get('multi_permalinks');
  if (multiPermalinkId) {
    cleanedParams.delete('multi_permalinks');

    const groupMatch = parsed.pathname.match(/^\/groups\/([A-Za-z0-9\.\-_]+)/);
    if (groupMatch && /^[0-9]+$/.test(multiPermalinkId)) {
      parsed.pathname = `/groups/${groupMatch[1]}/posts/${multiPermalinkId}`;
    } else if (groupMatch) {
      parsed.pathname = `/groups/${groupMatch[1]}/permalink/${multiPermalinkId}`;
    }
  }

  const search = cleanedParams.toString();
  const formatted = `${parsed.origin}${parsed.pathname}${search ? `?${search}` : ''}`;
  return formatted.replace(/[?&]$/, '');
}

function getRequiredProfiles(targetCount) {
  const count = clampTargetCount(targetCount);
  return Array.from({ length: count }, (_, index) => index + 1);
}

function buildProfileStatuses(requiredProfiles, checks) {
  const validChecks = checks
    .map(check => {
      const profileNumber = sanitizeProfileNumber(check.profile_number);
      if (!profileNumber) {
        return null;
      }
      return {
        ...check,
        profile_number: profileNumber,
        profile_name: getProfileName(profileNumber)
      };
    })
    .filter(Boolean);

  const completedSet = new Set(validChecks.map(check => check.profile_number));
  const checkByProfile = new Map(validChecks.map(check => [check.profile_number, check]));

  const statuses = requiredProfiles.map((profileNumber, index) => {
    const prerequisites = requiredProfiles.slice(0, index);
    const prerequisitesMet = prerequisites.every(num => completedSet.has(num));
    const isChecked = completedSet.has(profileNumber);
    return {
      profile_number: profileNumber,
      profile_name: getProfileName(profileNumber),
      status: isChecked ? 'done' : (prerequisitesMet ? 'available' : 'locked'),
      checked_at: isChecked && checkByProfile.get(profileNumber)
        ? checkByProfile.get(profileNumber).checked_at
        : null
    };
  });

  return {
    statuses,
    completedChecks: validChecks,
    completedSet
  };
}

function recalcCheckedCount(postId) {
  const post = db.prepare('SELECT id, target_count, checked_count FROM posts WHERE id = ?').get(postId);
  if (!post) {
    return null;
  }

  const checks = db.prepare('SELECT id, profile_number, checked_at FROM checks WHERE post_id = ?').all(postId);
  const requiredProfiles = getRequiredProfiles(post.target_count);
  const { statuses } = buildProfileStatuses(requiredProfiles, checks);
  const checkedCount = statuses.filter(status => status.status === 'done').length;

  const updates = [];
  const params = [];

  if (post.checked_count !== checkedCount) {
    updates.push('checked_count = ?');
    params.push(checkedCount);
  }

  if (post.target_count !== requiredProfiles.length) {
    updates.push('target_count = ?');
    params.push(requiredProfiles.length);
  }

  if (updates.length) {
    updates.push('last_change = CURRENT_TIMESTAMP');
    params.push(postId);
    db.prepare(`UPDATE posts SET ${updates.join(', ')} WHERE id = ?`).run(...params);
  }

  return checkedCount;
}

// Initialize database tables
db.exec(`
  CREATE TABLE IF NOT EXISTS posts (
    id TEXT PRIMARY KEY,
    url TEXT NOT NULL UNIQUE,
    title TEXT,
    target_count INTEGER NOT NULL,
    checked_count INTEGER DEFAULT 0,
    screenshot_path TEXT,
    created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
    last_change DATETIME DEFAULT CURRENT_TIMESTAMP
  );
`);

db.exec(`
  CREATE TABLE IF NOT EXISTS checks (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    post_id TEXT NOT NULL,
    profile_number INTEGER,
    checked_at DATETIME DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (post_id) REFERENCES posts(id)
  );
`);

db.exec(`
  CREATE TABLE IF NOT EXISTS profile_state (
    id INTEGER PRIMARY KEY CHECK (id = 1),
    profile_number INTEGER NOT NULL
  );
`);

db.exec(`
  CREATE TABLE IF NOT EXISTS profile_state_scoped (
    scope_id TEXT PRIMARY KEY,
    profile_number INTEGER NOT NULL
  );
`);

db.exec(`
  CREATE TABLE IF NOT EXISTS ai_settings (
    id INTEGER PRIMARY KEY CHECK (id = 1),
    active_credential_id INTEGER,
    prompt_prefix TEXT,
    enabled INTEGER DEFAULT 0,
    updated_at DATETIME DEFAULT CURRENT_TIMESTAMP
  );
`);

db.exec(`
  CREATE TABLE IF NOT EXISTS ai_credentials (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    name TEXT NOT NULL,
    provider TEXT NOT NULL,
    api_key TEXT NOT NULL,
    model TEXT,
    created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
    updated_at DATETIME DEFAULT CURRENT_TIMESTAMP
  );
`);

db.exec(`
  CREATE TABLE IF NOT EXISTS profile_friends (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    profile_number INTEGER NOT NULL,
    friend_names TEXT NOT NULL,
    updated_at DATETIME DEFAULT CURRENT_TIMESTAMP,
    UNIQUE(profile_number)
  );
`);

db.exec(`
  CREATE TABLE IF NOT EXISTS search_seen_posts (
    url TEXT PRIMARY KEY,
    seen_count INTEGER NOT NULL DEFAULT 1,
    manually_hidden INTEGER NOT NULL DEFAULT 0,
    first_seen_at DATETIME DEFAULT CURRENT_TIMESTAMP,
    last_seen_at DATETIME DEFAULT CURRENT_TIMESTAMP
  );
`);

db.exec(`
  CREATE INDEX IF NOT EXISTS idx_search_seen_posts_last_seen_at
  ON search_seen_posts(last_seen_at);
`);

const ensureColumn = (table, column, definition) => {
  const columns = db.prepare(`PRAGMA table_info(${table})`).all();
  if (!columns.some(col => col.name === column)) {
    db.exec(`ALTER TABLE ${table} ADD COLUMN ${definition}`);
  }
};

ensureColumn('posts', 'checked_count', 'checked_count INTEGER DEFAULT 0');
ensureColumn('posts', 'screenshot_path', 'screenshot_path TEXT');
ensureColumn('posts', 'created_by_profile', 'created_by_profile INTEGER');
ensureColumn('posts', 'deadline_at', 'deadline_at DATETIME');
ensureColumn('posts', 'created_by_name', 'created_by_name TEXT');
ensureColumn('posts', 'last_change', 'last_change DATETIME');
ensureColumn('posts', 'is_successful', 'is_successful INTEGER DEFAULT 0');
ensureColumn('ai_settings', 'active_credential_id', 'active_credential_id INTEGER');
ensureColumn('ai_settings', 'prompt_prefix', 'prompt_prefix TEXT');
ensureColumn('ai_settings', 'enabled', 'enabled INTEGER DEFAULT 0');
ensureColumn('ai_credentials', 'is_active', 'is_active INTEGER DEFAULT 1');
ensureColumn('ai_credentials', 'priority', 'priority INTEGER DEFAULT 0');
ensureColumn('ai_credentials', 'base_url', 'base_url TEXT');
ensureColumn('search_seen_posts', 'manually_hidden', 'manually_hidden INTEGER NOT NULL DEFAULT 0');
db.prepare(`
  UPDATE posts
  SET last_change = COALESCE(
    last_change,
    (SELECT MAX(checked_at) FROM checks WHERE checks.post_id = posts.id),
    created_at,
    CURRENT_TIMESTAMP
  )
  WHERE last_change IS NULL
`).run();

function touchPost(postId) {
  if (!postId) {
    return;
  }
  try {
    db.prepare('UPDATE posts SET last_change = CURRENT_TIMESTAMP WHERE id = ?').run(postId);
  } catch (error) {
    console.warn(`Failed to update last_change for post ${postId}:`, error.message);
  }
}

function normalizeExistingPostUrls() {
  const rows = db.prepare('SELECT id, url FROM posts').all();
  let updatedCount = 0;

  for (const row of rows) {
    const cleaned = normalizeFacebookPostUrl(row.url);
    if (!cleaned || cleaned === row.url) {
      continue;
    }

    const conflict = db.prepare('SELECT id FROM posts WHERE url = ?').get(cleaned);
    if (conflict && conflict.id !== row.id) {
      console.warn(`Skipping URL normalization for post ${row.id} due to existing post ${conflict.id}`);
      continue;
    }

    try {
      db.prepare('UPDATE posts SET url = ? WHERE id = ?').run(cleaned, row.id);
      updatedCount += 1;
    } catch (error) {
      if (error && error.code === 'SQLITE_CONSTRAINT_UNIQUE') {
        console.warn(`Skipping URL normalization for post ${row.id} because the cleaned URL is already used.`);
        continue;
      }
      console.warn(`Failed to normalize URL for post ${row.id}:`, error.message);
    }
  }

  if (updatedCount) {
    console.log(`Normalized URLs for ${updatedCount} stored posts.`);
  }
}

normalizeExistingPostUrls();

function cleanupExpiredSearchPosts() {
  try {
    const threshold = `-${SEARCH_POST_RETENTION_DAYS} day`;
    db.prepare(`
      DELETE FROM search_seen_posts
      WHERE last_seen_at < DATETIME('now', ?)
    `).run(threshold);
  } catch (error) {
    console.warn('Failed to cleanup expired search posts:', error.message);
  }
}

function collectNormalizedFacebookUrls(primaryUrl, candidates = []) {
  const normalized = [];

  const pushNormalized = (value) => {
    const normalizedUrl = normalizeFacebookPostUrl(value);
    if (normalizedUrl && !normalized.includes(normalizedUrl)) {
      normalized.push(normalizedUrl);
    }
  };

  if (primaryUrl) {
    pushNormalized(primaryUrl);
  }

  if (Array.isArray(candidates)) {
    for (const candidate of candidates) {
      pushNormalized(candidate);
    }
  }

  return normalized;
}

function removeSearchSeenEntries(urls) {
  if (!Array.isArray(urls) || urls.length === 0) {
    return;
  }

  const uniqueValidUrls = Array.from(new Set(urls.filter(url => typeof url === 'string' && url.trim())));
  if (!uniqueValidUrls.length) {
    return;
  }

  const stmt = db.prepare('DELETE FROM search_seen_posts WHERE url = ?');
  const runDeletion = db.transaction((values) => {
    for (const value of values) {
      stmt.run(value);
    }
  });

  try {
    runDeletion(uniqueValidUrls);
  } catch (error) {
    console.warn('Failed to remove search seen entries:', error.message);
  }
}

cleanupExpiredSearchPosts();

const selectSearchSeenStmt = db.prepare('SELECT url, seen_count, manually_hidden, first_seen_at, last_seen_at FROM search_seen_posts WHERE url = ?');
const insertSearchSeenStmt = db.prepare(`
  INSERT INTO search_seen_posts (url, seen_count, manually_hidden, first_seen_at, last_seen_at)
  VALUES (?, ?, ?, CURRENT_TIMESTAMP, CURRENT_TIMESTAMP)
`);
const updateSearchSeenStmt = db.prepare(`
  UPDATE search_seen_posts
  SET seen_count = ?, manually_hidden = ?, last_seen_at = CURRENT_TIMESTAMP
  WHERE url = ?
`);
const deleteSearchSeenStmt = db.prepare('DELETE FROM search_seen_posts WHERE url = ?');
const selectTrackedPostStmt = db.prepare('SELECT id FROM posts WHERE url = ?');

const checkIndexes = db.prepare("PRAGMA index_list('checks')").all();
for (const idx of checkIndexes) {
  if (idx.unique) {
    // Skip auto indexes created from PRIMARY KEY/UNIQUE constraints; SQLite refuses to drop them
    if (idx.origin !== 'c' || (idx.name && idx.name.startsWith('sqlite_autoindex'))) {
      continue;
    }

    const info = db.prepare(`PRAGMA index_info('${idx.name}')`).all();
    const columns = info.map(i => i.name).join(',');
    if (columns === 'post_id,profile_number' || columns === 'profile_number,post_id') {
      db.exec(`DROP INDEX IF EXISTS "${idx.name}"`);
    }
  }
}

function sqliteTimestampToUTC(timestamp) {
  if (!timestamp) {
    return null;
  }
  // SQLite CURRENT_TIMESTAMP returns UTC time in format "YYYY-MM-DD HH:MM:SS"
  // Convert to ISO-8601 with Z suffix to indicate UTC
  return timestamp.replace(' ', 'T') + 'Z';
}

function mapPostRow(post) {
  if (!post) {
    return null;
  }

  const checks = db.prepare('SELECT id, profile_number, checked_at FROM checks WHERE post_id = ? ORDER BY checked_at ASC').all(post.id);
  const requiredProfiles = getRequiredProfiles(post.target_count);
  const { statuses, completedChecks } = buildProfileStatuses(requiredProfiles, checks);
  const checkedCount = statuses.filter(status => status.status === 'done').length;
  const screenshotFile = post.screenshot_path ? path.join(screenshotDir, post.screenshot_path) : null;
  const screenshotPath = screenshotFile && fs.existsSync(screenshotFile)
    ? `/api/posts/${post.id}/screenshot`
    : null;

  let postLastChange = post.last_change;

  if (post.checked_count !== checkedCount || post.target_count !== requiredProfiles.length) {
    const updates = [];
    const params = [];

    if (post.checked_count !== checkedCount) {
      updates.push('checked_count = ?');
      params.push(checkedCount);
    }

    if (post.target_count !== requiredProfiles.length) {
      updates.push('target_count = ?');
      params.push(requiredProfiles.length);
    }

    updates.push('last_change = CURRENT_TIMESTAMP');
    params.push(post.id);
    db.prepare(`UPDATE posts SET ${updates.join(', ')} WHERE id = ?`).run(...params);

    const refreshed = db.prepare('SELECT last_change FROM posts WHERE id = ?').get(post.id);
    if (refreshed && refreshed.last_change) {
      postLastChange = refreshed.last_change;
    }
  }

  const nextRequired = statuses.find(status => status.status === 'available');
  const creatorProfile = sanitizeProfileNumber(post.created_by_profile);
  const creatorName = normalizeCreatorName(post.created_by_name);

  // Convert SQLite timestamps to UTC ISO-8601 format
  const checksWithUTC = completedChecks.map(check => ({
    ...check,
    checked_at: sqliteTimestampToUTC(check.checked_at)
  }));

  const statusesWithUTC = statuses.map(status => ({
    ...status,
    checked_at: sqliteTimestampToUTC(status.checked_at)
  }));

  return {
    ...post,
    created_at: sqliteTimestampToUTC(post.created_at),
    target_count: requiredProfiles.length,
    checked_count: checkedCount,
    last_change: sqliteTimestampToUTC(postLastChange),
    checks: checksWithUTC,
    is_complete: checkedCount >= requiredProfiles.length,
    screenshot_path: screenshotPath,
    required_profiles: requiredProfiles,
    profile_statuses: statusesWithUTC,
    next_required_profile: nextRequired ? nextRequired.profile_number : null,
    created_by_profile: creatorProfile,
    created_by_profile_name: creatorProfile ? getProfileName(creatorProfile) : null,
    created_by_name: creatorName,
    deadline_at: post.deadline_at || null
  };
}

// Get all posts
app.get('/api/posts', (req, res) => {
  try {
    const posts = db.prepare(`
      SELECT *
      FROM posts
      ORDER BY created_at DESC
    `).all();

    res.json(posts.map(mapPostRow));
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

// Get post by URL
app.get('/api/posts/by-url', (req, res) => {
  try {
    const { url } = req.query;
    if (!url) {
      return res.status(400).json({ error: 'URL parameter required' });
    }

    const normalizedUrl = normalizeFacebookPostUrl(url);
    if (!normalizedUrl) {
      return res.status(400).json({ error: 'URL parameter must be a valid Facebook link' });
    }

    const post = db.prepare('SELECT * FROM posts WHERE url = ?').get(normalizedUrl);

    if (!post) {
      return res.json(null);
    }

    res.json(mapPostRow(post));
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

app.post('/api/search-posts', (req, res) => {
  try {
    const { url, candidates, skip_increment, force_hide } = req.body || {};

    const normalizedUrls = collectNormalizedFacebookUrls(url, candidates);
    if (!normalizedUrls.length) {
      return res.status(400).json({ error: 'url must be a valid Facebook link' });
    }

    cleanupExpiredSearchPosts();

    let isTracked = false;
    for (const candidate of normalizedUrls) {
      const tracked = selectTrackedPostStmt.get(candidate);
      if (tracked) {
        isTracked = true;
        deleteSearchSeenStmt.run(candidate);
      }
    }

    if (isTracked) {
      return res.json({ seen_count: 0, should_hide: false, tracked: true });
    }

    let existingRow = null;
    let existingUrl = null;

    for (const candidate of normalizedUrls) {
      const row = selectSearchSeenStmt.get(candidate);
      if (row) {
        existingRow = row;
        existingUrl = candidate;
        break;
      }
    }

    const targetUrl = existingUrl || normalizedUrls[0];
    const existingManualHidden = existingRow ? !!existingRow.manually_hidden : false;

    if (force_hide) {
      const desiredCount = Math.max(existingRow ? existingRow.seen_count : 0, SEARCH_POST_HIDE_THRESHOLD);
      const urlsToUpdate = Array.from(new Set(normalizedUrls));

      for (const candidate of urlsToUpdate) {
        const row = selectSearchSeenStmt.get(candidate);
        const candidateCount = row ? Math.max(row.seen_count, desiredCount) : desiredCount;
        if (row) {
          updateSearchSeenStmt.run(candidateCount, 1, candidate);
        } else {
          insertSearchSeenStmt.run(candidate, candidateCount, 1);
        }
      }

      return res.json({ seen_count: desiredCount, should_hide: true, manually_hidden: true });
    }

    if (skip_increment) {
      if (!existingRow) {
        return res.json({ seen_count: 0, should_hide: false, manually_hidden: false });
      }
      const seenCount = existingRow.seen_count;
      const shouldHide = seenCount >= SEARCH_POST_HIDE_THRESHOLD || existingManualHidden;
      return res.json({ seen_count: seenCount, should_hide: shouldHide, manually_hidden: existingManualHidden });
    }

    let seenCount = existingRow ? existingRow.seen_count + 1 : 1;
    const manualHidden = existingManualHidden;

    if (existingRow) {
      updateSearchSeenStmt.run(seenCount, manualHidden ? 1 : 0, targetUrl);
    } else {
      insertSearchSeenStmt.run(targetUrl, seenCount, manualHidden ? 1 : 0);
    }

    const shouldHide = seenCount >= SEARCH_POST_HIDE_THRESHOLD || manualHidden;
    res.json({ seen_count: seenCount, should_hide: shouldHide, manually_hidden: manualHidden });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

app.delete('/api/search-posts', (req, res) => {
  try {
    db.prepare('DELETE FROM search_seen_posts').run();
    res.json({ success: true });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

app.get('/api/profile-state', (req, res) => {
  try {
    const scopeId = req.profileScope;
    let profileNumber = getScopedProfileNumber(scopeId);
    if (!profileNumber) {
      profileNumber = 1;
      setScopedProfileNumber(scopeId, profileNumber);
    }

    res.json({ profile_number: profileNumber });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

app.post('/api/profile-state', (req, res) => {
  try {
    const { profile_number } = req.body;
    if (typeof profile_number === 'undefined') {
      return res.status(400).json({ error: 'profile_number is required' });
    }

    const parsed = parseInt(profile_number, 10);
    if (Number.isNaN(parsed) || parsed < 1 || parsed > 5) {
      return res.status(400).json({ error: 'profile_number must be between 1 and 5' });
    }

    const scopeId = req.profileScope;
    const sanitized = sanitizeProfileNumber(parsed) || 1;
    setScopedProfileNumber(scopeId, sanitized);

    res.json({ profile_number: sanitized });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

app.post('/api/posts/:postId/screenshot', (req, res) => {
  try {
    const { postId } = req.params;
    const { imageData } = req.body;

    const post = db.prepare('SELECT * FROM posts WHERE id = ?').get(postId);
    if (!post) {
      return res.status(404).json({ error: 'Post not found' });
    }

    if (!imageData || typeof imageData !== 'string') {
      return res.status(400).json({ error: 'imageData is required' });
    }

    const match = imageData.match(/^data:(image\/\w+);base64,(.+)$/);
    if (!match) {
      return res.status(400).json({ error: 'Invalid image data format' });
    }

    const mimeType = match[1];
    const base64 = match[2];
    const extension = mimeType === 'image/jpeg' ? 'jpg' : 'png';
    const buffer = Buffer.from(base64, 'base64');
    const fileName = `${postId}.${extension}`;
    const filePath = path.join(screenshotDir, fileName);

    if (post.screenshot_path && post.screenshot_path !== fileName) {
      const existingPath = path.join(screenshotDir, post.screenshot_path);
      if (fs.existsSync(existingPath)) {
        try {
          fs.unlinkSync(existingPath);
        } catch (error) {
          console.warn('Failed to remove previous screenshot:', error.message);
        }
      }
    }

    fs.writeFileSync(filePath, buffer);
    db.prepare('UPDATE posts SET screenshot_path = ?, last_change = CURRENT_TIMESTAMP WHERE id = ?').run(fileName, postId);

    const updatedPost = db.prepare('SELECT * FROM posts WHERE id = ?').get(postId);
    res.json(mapPostRow(updatedPost));
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

app.get('/api/posts/:postId/screenshot', (req, res) => {
  try {
    const { postId } = req.params;
    const post = db.prepare('SELECT screenshot_path FROM posts WHERE id = ?').get(postId);

    // Placeholder path (mounted in Docker container)
    const placeholderPath = path.join(__dirname, 'noScreenshot.png');

    if (!post || !post.screenshot_path) {
      // Return placeholder image
      if (fs.existsSync(placeholderPath)) {
        res.set('Cache-Control', 'public, max-age=86400');
        return res.sendFile(placeholderPath);
      }
      return res.status(404).json({ error: 'Screenshot not found' });
    }

    const filePath = path.join(screenshotDir, post.screenshot_path);
    if (!fs.existsSync(filePath)) {
      // Return placeholder image
      if (fs.existsSync(placeholderPath)) {
        res.set('Cache-Control', 'public, max-age=86400');
        return res.sendFile(placeholderPath);
      }
      return res.status(404).json({ error: 'Screenshot not found' });
    }

    res.set('Cache-Control', 'no-store');
    res.sendFile(filePath);
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

// Create new post
app.post('/api/posts', (req, res) => {
  try {
    const {
      url,
      title,
      target_count,
      created_by_profile,
      created_by_name,
      profile_number,
      deadline_at
    } = req.body;

    const validatedTargetCount = validateTargetCount(typeof target_count === 'undefined' ? 1 : target_count);

    const normalizedUrl = normalizeFacebookPostUrl(url);

    if (!normalizedUrl) {
      return res.status(400).json({ error: 'URL must be a valid Facebook link' });
    }

    if (!validatedTargetCount) {
      return res.status(400).json({ error: 'target_count must be between 1 and 5' });
    }

    const id = uuidv4();

    let creatorProfile = sanitizeProfileNumber(created_by_profile);
    if (!creatorProfile) {
      creatorProfile = sanitizeProfileNumber(profile_number) || null;
    }

    let normalizedDeadline = null;
    if (typeof deadline_at !== 'undefined' && deadline_at !== null && String(deadline_at).trim() !== '') {
      normalizedDeadline = normalizeDeadline(deadline_at);
      if (!normalizedDeadline) {
        return res.status(400).json({ error: 'deadline_at must be a valid date string' });
      }
    }

    const creatorDisplayName = normalizeCreatorName(created_by_name);

    const stmt = db.prepare(`
      INSERT INTO posts (id, url, title, target_count, checked_count, screenshot_path, created_by_profile, created_by_name, deadline_at, last_change)
      VALUES (?, ?, ?, ?, 0, NULL, ?, ?, ?, CURRENT_TIMESTAMP)
    `);
    stmt.run(id, normalizedUrl, title || '', validatedTargetCount, creatorProfile, creatorDisplayName, normalizedDeadline);

    const post = db.prepare('SELECT * FROM posts WHERE id = ?').get(id);

    removeSearchSeenEntries([normalizedUrl]);

    res.json(mapPostRow(post));
  } catch (error) {
    if (error.message.includes('UNIQUE constraint failed')) {
      res.status(409).json({ error: 'Post with this URL already exists' });
    } else {
      res.status(500).json({ error: error.message });
    }
  }
});

app.put('/api/posts/:postId', (req, res) => {
  try {
    const { postId } = req.params;
    const { target_count, title, created_by_profile, created_by_name, deadline_at, url } = req.body || {};

    const updates = [];
    const params = [];
    let normalizedUrlForCleanup = null;

    if (typeof target_count !== 'undefined') {
      const validatedTargetCount = validateTargetCount(target_count);
      if (!validatedTargetCount) {
        return res.status(400).json({ error: 'target_count must be between 1 and 5' });
      }
      updates.push('target_count = ?');
      params.push(validatedTargetCount);
    }

    if (typeof title !== 'undefined') {
      updates.push('title = ?');
      params.push(title || '');
    }

    if (typeof created_by_profile !== 'undefined') {
      const sanitized = sanitizeProfileNumber(created_by_profile);
      if (created_by_profile !== null && typeof created_by_profile !== 'undefined' && !sanitized) {
        return res.status(400).json({ error: 'created_by_profile must be between 1 and 5 or null' });
      }
      updates.push('created_by_profile = ?');
      params.push(sanitized || null);
    }

    if (typeof created_by_name !== 'undefined') {
      const normalizedName = normalizeCreatorName(created_by_name);
      updates.push('created_by_name = ?');
      params.push(normalizedName);
    }

    if (typeof deadline_at !== 'undefined') {
      let normalizedDeadline = null;
      const rawDeadline = deadline_at;
      if (rawDeadline !== null && String(rawDeadline).trim() !== '') {
        normalizedDeadline = normalizeDeadline(rawDeadline);
        if (!normalizedDeadline) {
          return res.status(400).json({ error: 'deadline_at must be a valid date string' });
        }
      }
      updates.push('deadline_at = ?');
      params.push(normalizedDeadline);
    }

    if (typeof url !== 'undefined') {
      const normalizedUrl = normalizeFacebookPostUrl(url);
      if (!normalizedUrl) {
        return res.status(400).json({ error: 'url must be a valid Facebook link' });
      }
      updates.push('url = ?');
      params.push(normalizedUrl);
      normalizedUrlForCleanup = normalizedUrl;
    }

    if (!updates.length) {
      return res.status(400).json({ error: 'No valid fields to update' });
    }

    updates.push('last_change = CURRENT_TIMESTAMP');
    params.push(postId);

    const stmt = db.prepare(`UPDATE posts SET ${updates.join(', ')} WHERE id = ?`);
    let result;
    try {
      result = stmt.run(...params);
    } catch (error) {
      if (error && error.code === 'SQLITE_CONSTRAINT_UNIQUE') {
        return res.status(409).json({ error: 'Post with this URL already exists' });
      }
      throw error;
    }

    if (result.changes === 0) {
      return res.status(404).json({ error: 'Post not found' });
    }

    recalcCheckedCount(postId);

    const updatedPost = db.prepare('SELECT * FROM posts WHERE id = ?').get(postId);

    if (normalizedUrlForCleanup) {
      removeSearchSeenEntries([normalizedUrlForCleanup]);
    }

    res.json(mapPostRow(updatedPost));
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

// Check a post for a profile
app.post('/api/posts/:postId/check', (req, res) => {
  try {
    const { postId } = req.params;
    const { profile_number } = req.body;

    const post = db.prepare('SELECT * FROM posts WHERE id = ?').get(postId);
    if (!post) {
      return res.status(404).json({ error: 'Post not found' });
    }

    // Check if deadline has passed
    if (post.deadline_at) {
      const deadline = new Date(post.deadline_at);
      if (new Date() > deadline) {
        return res.status(400).json({ error: 'Deadline ist abgelaufen' });
      }
    }

    const requiredProfiles = getRequiredProfiles(post.target_count);
    let didChange = false;
    if (post.target_count !== requiredProfiles.length) {
      db.prepare('UPDATE posts SET target_count = ?, last_change = CURRENT_TIMESTAMP WHERE id = ?').run(requiredProfiles.length, postId);
      post.target_count = requiredProfiles.length;
      didChange = true;
    }

    let profileValue = sanitizeProfileNumber(profile_number);
    if (!profileValue) {
      const storedProfile = getScopedProfileNumber(req.profileScope);
      profileValue = storedProfile || requiredProfiles[0];
    }

    if (!requiredProfiles.includes(profileValue)) {
      return res.status(409).json({ error: 'Dieses Profil ist für diesen Beitrag nicht erforderlich.' });
    }

    const existingCheck = db.prepare(
      'SELECT id FROM checks WHERE post_id = ? AND profile_number = ?'
    ).get(postId, profileValue);

    if (existingCheck) {
      const existingPost = db.prepare('SELECT * FROM posts WHERE id = ?').get(postId);
      return res.json(mapPostRow(existingPost));
    }

    // Allow creator to check immediately, regardless of profile number
    const isCreator = post.created_by_profile === profileValue;

    if (requiredProfiles.length > 0 && !isCreator) {
      const prerequisiteProfiles = requiredProfiles.slice(0, requiredProfiles.indexOf(profileValue));
      if (prerequisiteProfiles.length) {
        const completedRows = db.prepare('SELECT profile_number FROM checks WHERE post_id = ?').all(postId);
        const completedSet = new Set(
          completedRows
            .map(row => sanitizeProfileNumber(row.profile_number))
            .filter(Boolean)
        );

        const missingPrerequisites = prerequisiteProfiles.filter(num => !completedSet.has(num));
        if (missingPrerequisites.length) {
          return res.status(409).json({
            error: 'Vorherige Profile müssen zuerst bestätigen.',
            missing_profiles: missingPrerequisites
          });
        }
      }
    }

    const insertStmt = db.prepare('INSERT INTO checks (post_id, profile_number) VALUES (?, ?)');
    insertStmt.run(postId, profileValue);
    didChange = true;
    recalcCheckedCount(postId);
    if (didChange) {
      touchPost(postId);
    }

    const updatedPost = db.prepare('SELECT * FROM posts WHERE id = ?').get(postId);

    res.json(mapPostRow(updatedPost));
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

// Check by URL (for web interface auto-check)
app.post('/api/check-by-url', (req, res) => {
  try {
    const { url, profile_number } = req.body;

    if (!url) {
      return res.status(400).json({ error: 'URL is required' });
    }

    const normalizedUrl = normalizeFacebookPostUrl(url);
    if (!normalizedUrl) {
      return res.status(400).json({ error: 'URL must be a valid Facebook link' });
    }

    const post = db.prepare('SELECT * FROM posts WHERE url = ?').get(normalizedUrl);
    if (!post) {
      return res.status(404).json({ error: 'Post not found' });
    }

    // Check if deadline has passed
    if (post.deadline_at) {
      const deadline = new Date(post.deadline_at);
      if (new Date() > deadline) {
        return res.status(400).json({ error: 'Deadline ist abgelaufen' });
      }
    }

    const requiredProfiles = getRequiredProfiles(post.target_count);
    let didChange = false;
    if (post.target_count !== requiredProfiles.length) {
      db.prepare('UPDATE posts SET target_count = ?, last_change = CURRENT_TIMESTAMP WHERE id = ?').run(requiredProfiles.length, post.id);
      post.target_count = requiredProfiles.length;
      didChange = true;
    }

    let profileValue = sanitizeProfileNumber(profile_number);
    if (!profileValue) {
      const storedProfile = getScopedProfileNumber(req.profileScope);
      profileValue = storedProfile || requiredProfiles[0];
    }

    if (!requiredProfiles.includes(profileValue)) {
      return res.status(409).json({ error: 'Dieses Profil ist für diesen Beitrag nicht erforderlich.' });
    }

    const existingCheck = db.prepare(
      'SELECT id FROM checks WHERE post_id = ? AND profile_number = ?'
    ).get(post.id, profileValue);

    if (existingCheck) {
      const updatedPost = db.prepare('SELECT * FROM posts WHERE id = ?').get(post.id);
      return res.json(mapPostRow(updatedPost));
    }

    // Allow creator to check immediately, regardless of profile number
    const isCreator = post.created_by_profile === profileValue;

    if (requiredProfiles.length > 0 && !isCreator) {
      const prerequisiteProfiles = requiredProfiles.slice(0, requiredProfiles.indexOf(profileValue));
      if (prerequisiteProfiles.length) {
        const completedRows = db.prepare('SELECT profile_number FROM checks WHERE post_id = ?').all(post.id);
        const completedSet = new Set(
          completedRows
            .map(row => sanitizeProfileNumber(row.profile_number))
            .filter(Boolean)
        );

        const missingPrerequisites = prerequisiteProfiles.filter(num => !completedSet.has(num));
        if (missingPrerequisites.length) {
          return res.status(409).json({
            error: 'Vorherige Profile müssen zuerst bestätigen.',
            missing_profiles: missingPrerequisites
          });
        }
      }
    }

    db.prepare('INSERT INTO checks (post_id, profile_number) VALUES (?, ?)').run(post.id, profileValue);
    didChange = true;
    recalcCheckedCount(post.id);
    if (didChange) {
      touchPost(post.id);
    }

    const updatedPost = db.prepare('SELECT * FROM posts WHERE id = ?').get(post.id);

    res.json(mapPostRow(updatedPost));
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

app.post('/api/posts/:postId/profile-status', (req, res) => {
  try {
    const { postId } = req.params;
    const { profile_number, status } = req.body || {};

    const post = db.prepare('SELECT * FROM posts WHERE id = ?').get(postId);
    if (!post) {
      return res.status(404).json({ error: 'Post not found' });
    }

    // Check if deadline has passed (only for setting to 'done')
    if (status === 'done' && post.deadline_at) {
      const deadline = new Date(post.deadline_at);
      if (new Date() > deadline) {
        return res.status(400).json({ error: 'Deadline ist abgelaufen' });
      }
    }

    const requiredProfiles = getRequiredProfiles(post.target_count);
    let didChange = false;
    if (post.target_count !== requiredProfiles.length) {
      db.prepare('UPDATE posts SET target_count = ?, last_change = CURRENT_TIMESTAMP WHERE id = ?').run(requiredProfiles.length, post.id);
      post.target_count = requiredProfiles.length;
      didChange = true;
    }

    const profileValue = sanitizeProfileNumber(profile_number);
    if (!profileValue) {
      return res.status(400).json({ error: 'Valid profile_number required' });
    }

    if (!requiredProfiles.includes(profileValue)) {
      return res.status(409).json({ error: 'Dieses Profil ist für diesen Beitrag nicht erforderlich.' });
    }

    const normalizedStatus = status === 'done' ? 'done' : 'pending';

    if (normalizedStatus === 'done') {
      // Allow creator to check immediately, regardless of profile number
      const isCreator = post.created_by_profile === profileValue;

      if (!isCreator) {
        const prerequisiteProfiles = requiredProfiles.slice(0, requiredProfiles.indexOf(profileValue));
        if (prerequisiteProfiles.length) {
          const completedRows = db.prepare('SELECT profile_number FROM checks WHERE post_id = ?').all(postId);
          const completedSet = new Set(
            completedRows
              .map(row => sanitizeProfileNumber(row.profile_number))
              .filter(Boolean)
          );

          const missingPrerequisites = prerequisiteProfiles.filter(num => !completedSet.has(num));
          if (missingPrerequisites.length) {
            return res.status(409).json({
              error: 'Vorherige Profile müssen zuerst bestätigen.',
              missing_profiles: missingPrerequisites
            });
          }
        }
      }

      const existingCheck = db.prepare(
        'SELECT id FROM checks WHERE post_id = ? AND profile_number = ?'
      ).get(postId, profileValue);

      if (!existingCheck) {
        db.prepare('INSERT INTO checks (post_id, profile_number) VALUES (?, ?)').run(postId, profileValue);
        didChange = true;
      }
    } else {
      db.prepare('DELETE FROM checks WHERE post_id = ? AND profile_number = ?').run(postId, profileValue);
      didChange = true;
    }

    recalcCheckedCount(postId);
    if (didChange) {
      touchPost(postId);
    }

    const updatedPost = db.prepare('SELECT * FROM posts WHERE id = ?').get(postId);
    res.json(mapPostRow(updatedPost));
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

// Update post URL or success status
app.patch('/api/posts/:postId', (req, res) => {
  try {
    const { postId } = req.params;
    const { url, is_successful } = req.body;

    // Check if post exists
    const post = db.prepare('SELECT id FROM posts WHERE id = ?').get(postId);
    if (!post) {
      return res.status(404).json({ error: 'Post not found' });
    }

    if (url !== undefined) {
      const normalizedUrl = normalizeFacebookPostUrl(url);
      if (!normalizedUrl) {
        return res.status(400).json({ error: 'Invalid Facebook URL' });
      }

      // Check for URL conflicts
      const conflict = db.prepare('SELECT id FROM posts WHERE url = ? AND id != ?').get(normalizedUrl, postId);
      if (conflict) {
        return res.status(409).json({ error: 'URL already used by another post' });
      }

      // Update URL
      db.prepare('UPDATE posts SET url = ? WHERE id = ?').run(normalizedUrl, postId);
      removeSearchSeenEntries([normalizedUrl]);
      return res.json({ success: true, url: normalizedUrl });
    }

    if (is_successful !== undefined) {
      const successValue = is_successful ? 1 : 0;
      db.prepare('UPDATE posts SET is_successful = ? WHERE id = ?').run(successValue, postId);

      const updatedPost = db.prepare('SELECT * FROM posts WHERE id = ?').get(postId);
      return res.json(mapPostRow(updatedPost));
    }

    return res.status(400).json({ error: 'No valid update parameter provided' });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

// Delete post
app.delete('/api/posts/:postId', (req, res) => {
  try {
    const { postId } = req.params;

    const post = db.prepare('SELECT screenshot_path FROM posts WHERE id = ?').get(postId);

    db.prepare('DELETE FROM checks WHERE post_id = ?').run(postId);
    const result = db.prepare('DELETE FROM posts WHERE id = ?').run(postId);

    if (result.changes === 0) {
      return res.status(404).json({ error: 'Post not found' });
    }

    if (post && post.screenshot_path) {
      const filePath = path.join(screenshotDir, post.screenshot_path);
      if (fs.existsSync(filePath)) {
        try {
          fs.unlinkSync(filePath);
        } catch (error) {
          console.warn('Failed to remove screenshot:', error.message);
        }
      }
    }

    res.json({ success: true });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

// AI Credentials endpoints
app.get('/api/ai-credentials', (req, res) => {
  try {
    const credentials = db.prepare('SELECT id, name, provider, model, base_url, is_active, priority, created_at, updated_at FROM ai_credentials ORDER BY priority ASC, id ASC').all();
    res.json(credentials);
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

app.post('/api/ai-credentials', (req, res) => {
  try {
    const { name, provider, api_key, model, base_url } = req.body;

    const trimmedName = typeof name === 'string' ? name.trim() : '';
    const trimmedProvider = typeof provider === 'string' ? provider.trim() : '';
    const trimmedApiKey = typeof api_key === 'string' ? api_key.trim() : '';
    const trimmedModel = typeof model === 'string' ? model.trim() : '';
    const rawBaseUrl = typeof base_url === 'string' ? base_url.trim() : '';
    const normalizedBaseUrl = (trimmedProvider === 'openai' && rawBaseUrl)
      ? rawBaseUrl.replace(/\/+$/, '')
      : '';

    if (!trimmedName || !trimmedProvider) {
      return res.status(400).json({ error: 'Name und Provider sind erforderlich' });
    }

    if (normalizedBaseUrl && !/^https?:\/\//i.test(normalizedBaseUrl)) {
      return res.status(400).json({ error: 'Basis-URL muss mit http:// oder https:// beginnen' });
    }

    let finalApiKey = trimmedApiKey;
    if (!finalApiKey) {
      if (trimmedProvider === 'openai' && normalizedBaseUrl) {
        finalApiKey = '';
      } else {
        return res.status(400).json({ error: 'API-Schlüssel wird benötigt' });
      }
    }

    const result = db.prepare(`
      INSERT INTO ai_credentials (name, provider, api_key, model, base_url)
      VALUES (?, ?, ?, ?, ?)
    `).run(
      trimmedName,
      trimmedProvider,
      finalApiKey,
      trimmedModel || null,
      normalizedBaseUrl || null
    );

    const credential = db.prepare('SELECT id, name, provider, model, base_url, is_active, created_at, updated_at FROM ai_credentials WHERE id = ?').get(result.lastInsertRowid);
    res.json(credential);
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

app.put('/api/ai-credentials/:id', (req, res) => {
  try {
    const { id } = req.params;
    const { name, provider, api_key, model, base_url } = req.body;

    const credentialId = parseInt(id, 10);
    const existing = db.prepare('SELECT * FROM ai_credentials WHERE id = ?').get(credentialId);

    if (!existing) {
      return res.status(404).json({ error: 'Credential nicht gefunden' });
    }

    const trimmedName = typeof name === 'string' ? name.trim() : existing.name;
    const trimmedProvider = typeof provider === 'string' ? provider.trim() : existing.provider;
    if (!trimmedName || !trimmedProvider) {
      return res.status(400).json({ error: 'Name und Provider sind erforderlich' });
    }
    const trimmedModel = typeof model === 'string' ? model.trim() : existing.model || '';
    const rawBaseUrl = typeof base_url === 'string' ? base_url.trim() : (existing.base_url || '');
    const normalizedBaseUrl = (trimmedProvider === 'openai' && rawBaseUrl)
      ? rawBaseUrl.replace(/\/+$/, '')
      : '';

    let apiKeyProvided = api_key !== undefined;
    let trimmedApiKey = typeof api_key === 'string' ? api_key.trim() : '';

    if (!apiKeyProvided) {
      trimmedApiKey = existing.api_key;
    } else if (!trimmedApiKey && !(trimmedProvider === 'openai' && normalizedBaseUrl)) {
      return res.status(400).json({ error: 'API-Schlüssel wird benötigt' });
    }

    if (normalizedBaseUrl && !/^https?:\/\//i.test(normalizedBaseUrl)) {
      return res.status(400).json({ error: 'Basis-URL muss mit http:// oder https:// beginnen' });
    }

    if (trimmedProvider === 'openai' && !trimmedApiKey && !normalizedBaseUrl) {
      return res.status(400).json({ error: 'Für OpenAI wird ein API-Schlüssel benötigt, wenn keine Basis-URL angegeben ist' });
    }

    db.prepare(`
      UPDATE ai_credentials
      SET name = ?, provider = ?, api_key = ?, model = ?, base_url = ?, updated_at = CURRENT_TIMESTAMP
      WHERE id = ?
    `).run(
      trimmedName,
      trimmedProvider,
      trimmedApiKey,
      trimmedModel || null,
      normalizedBaseUrl || null,
      credentialId
    );

    const credential = db.prepare('SELECT id, name, provider, model, base_url, is_active, created_at, updated_at FROM ai_credentials WHERE id = ?').get(credentialId);
    res.json(credential);
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

app.patch('/api/ai-credentials/:id', (req, res) => {
  try {
    const { id } = req.params;
    const { is_active } = req.body;

    if (is_active === undefined) {
      return res.status(400).json({ error: 'is_active is required' });
    }

    db.prepare(`
      UPDATE ai_credentials
      SET is_active = ?, updated_at = CURRENT_TIMESTAMP
      WHERE id = ?
    `).run(is_active, id);

    const credential = db.prepare('SELECT id, name, provider, model, base_url, is_active, priority, created_at, updated_at FROM ai_credentials WHERE id = ?').get(id);
    res.json(credential);
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

app.post('/api/ai-credentials/reorder', (req, res) => {
  try {
    const { order } = req.body; // Array of IDs in new order

    if (!Array.isArray(order)) {
      return res.status(400).json({ error: 'order must be an array' });
    }

    // Update priorities based on order
    order.forEach((id, index) => {
      db.prepare('UPDATE ai_credentials SET priority = ? WHERE id = ?').run(index, id);
    });

    const credentials = db.prepare('SELECT id, name, provider, model, base_url, is_active, priority, created_at, updated_at FROM ai_credentials ORDER BY priority ASC, id ASC').all();
    res.json(credentials);
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

app.delete('/api/ai-credentials/:id', (req, res) => {
  try {
    const { id } = req.params;

    // Check if this credential is active
    const settings = db.prepare('SELECT active_credential_id FROM ai_settings WHERE id = 1').get();
    if (settings && settings.active_credential_id === parseInt(id)) {
      return res.status(400).json({ error: 'Cannot delete active credential' });
    }

    db.prepare('DELETE FROM ai_credentials WHERE id = ?').run(id);
    res.json({ success: true });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

// AI Settings endpoints
app.get('/api/ai-settings', (req, res) => {
  try {
    let settings = db.prepare('SELECT * FROM ai_settings WHERE id = 1').get();

    if (!settings) {
      settings = {
        id: 1,
        active_credential_id: null,
        prompt_prefix: 'Schreibe einen freundlichen, authentischen Kommentar auf Deutsch zu folgendem Facebook-Post. Der Kommentar soll natürlich wirken und maximal 2-3 Sätze lang sein:\n\n',
        enabled: 0,
        updated_at: null
      };
    }

    // Get active credential if set
    let activeCredential = null;
    if (settings.active_credential_id) {
      activeCredential = db.prepare('SELECT id, name, provider, model FROM ai_credentials WHERE id = ?').get(settings.active_credential_id);
    }

    res.json({
      ...settings,
      active_credential: activeCredential
    });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

app.put('/api/ai-settings', (req, res) => {
  try {
    const { active_credential_id, prompt_prefix, enabled } = req.body;

    const existing = db.prepare('SELECT * FROM ai_settings WHERE id = 1').get();

    if (existing) {
      db.prepare(`
        UPDATE ai_settings
        SET active_credential_id = ?, prompt_prefix = ?, enabled = ?, updated_at = CURRENT_TIMESTAMP
        WHERE id = 1
      `).run(active_credential_id || null, prompt_prefix, enabled ? 1 : 0);
    } else {
      db.prepare(`
        INSERT INTO ai_settings (id, active_credential_id, prompt_prefix, enabled, updated_at)
        VALUES (1, ?, ?, ?, CURRENT_TIMESTAMP)
      `).run(active_credential_id || null, prompt_prefix, enabled ? 1 : 0);
    }

    const updated = db.prepare('SELECT * FROM ai_settings WHERE id = 1').get();

    let activeCredential = null;
    if (updated.active_credential_id) {
      activeCredential = db.prepare('SELECT id, name, provider, model FROM ai_credentials WHERE id = ?').get(updated.active_credential_id);
    }

    res.json({
      ...updated,
      active_credential: activeCredential
    });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

function sanitizeAIComment(text) {
  if (!text) {
    return '';
  }

  return text
    .replace(/<think>[\s\S]*?<\/think>/gi, '')
    .replace(/\s{2,}/g, ' ')
    .trim();
}

async function tryGenerateComment(credential, promptPrefix, postText) {
  const provider = credential.provider;
  const apiKey = credential.api_key;
  const model = credential.model;

  let comment = '';

  if (provider === 'gemini') {
    // Gemini API
    const modelName = model || 'gemini-2.0-flash-exp';
    const prompt = promptPrefix + postText;

    const response = await fetch(
      `https://generativelanguage.googleapis.com/v1beta/models/${modelName}:generateContent?key=${apiKey}`,
      {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          contents: [{
            parts: [{ text: prompt }]
          }]
        })
      }
    );

    if (!response.ok) {
      const errorData = await response.json();
      throw new Error(`Gemini API error: ${errorData.error?.message || response.statusText}`);
    }

    const data = await response.json();
    comment = data.candidates?.[0]?.content?.parts?.[0]?.text || '';

  } else if (provider === 'openai') {
    // OpenAI/ChatGPT API
    const modelName = model || 'gpt-3.5-turbo';
    const prompt = promptPrefix + postText;

    const baseUrl = (credential.base_url || 'https://api.openai.com/v1').trim().replace(/\/+$/, '');
    const endpoint = baseUrl.endsWith('/chat/completions') ? baseUrl : `${baseUrl}/chat/completions`;

    const headers = {
      'Content-Type': 'application/json'
    };
    if (apiKey) {
      headers['Authorization'] = `Bearer ${apiKey}`;
    }

    const response = await fetch(endpoint, {
      method: 'POST',
      headers,
      body: JSON.stringify({
        model: modelName,
        messages: [{ role: 'user', content: prompt }],
        max_tokens: 150
      })
    });

    if (!response.ok) {
      const errorData = await response.json();
      const message = errorData.error?.message || response.statusText;
      throw new Error(`OpenAI API error: ${message}`);
    }

    const data = await response.json();
    comment = data.choices?.[0]?.message?.content || '';

  } else if (provider === 'claude') {
    // Anthropic Claude API
    const modelName = model || 'claude-3-5-haiku-20241022';
    const prompt = promptPrefix + postText;

    const response = await fetch('https://api.anthropic.com/v1/messages', {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        'x-api-key': apiKey,
        'anthropic-version': '2023-06-01'
      },
      body: JSON.stringify({
        model: modelName,
        max_tokens: 150,
        messages: [{ role: 'user', content: prompt }]
      })
    });

    if (!response.ok) {
      const errorData = await response.json();
      throw new Error(`Claude API error: ${errorData.error?.message || response.statusText}`);
    }

    const data = await response.json();
    comment = data.content?.[0]?.text || '';

  } else {
    throw new Error(`Unsupported AI provider: ${provider}`);
  }

  return sanitizeAIComment(comment);
}

app.post('/api/ai/generate-comment', async (req, res) => {
  try {
    const { postText, profileNumber, preferredCredentialId } = req.body;

    if (!postText) {
      return res.status(400).json({ error: 'postText is required' });
    }

    const settings = db.prepare('SELECT * FROM ai_settings WHERE id = 1').get();

    if (!settings || !settings.enabled) {
      return res.status(400).json({ error: 'AI comment generation is not enabled' });
    }

    // Get all active credentials, ordered by priority
    const credentials = db.prepare('SELECT * FROM ai_credentials WHERE is_active = 1 ORDER BY priority ASC, id ASC').all();

    if (!credentials || credentials.length === 0) {
      return res.status(400).json({ error: 'No active AI credentials available' });
    }

    let orderedCredentials = credentials;
    if (typeof preferredCredentialId !== 'undefined' && preferredCredentialId !== null) {
      const parsedPreferredId = Number(preferredCredentialId);
      if (!Number.isNaN(parsedPreferredId)) {
        const idx = credentials.findIndex(credential => credential.id === parsedPreferredId);
        if (idx > 0) {
          const preferred = credentials[idx];
          orderedCredentials = [preferred, ...credentials.slice(0, idx), ...credentials.slice(idx + 1)];
        }
      }
    }

    let promptPrefix = settings.prompt_prefix || '';

    // Get friend names for the profile if available
    if (profileNumber) {
      const friends = db.prepare('SELECT friend_names FROM profile_friends WHERE profile_number = ?').get(profileNumber);
      if (friends && friends.friend_names) {
        promptPrefix = promptPrefix.replace('{FREUNDE}', friends.friend_names);
      } else {
        promptPrefix = promptPrefix.replace('{FREUNDE}', '');
      }
    } else {
      promptPrefix = promptPrefix.replace('{FREUNDE}', '');
    }

    // Try each active credential until one succeeds
    let lastError = null;
    for (const credential of orderedCredentials) {
      try {
        console.log(`Trying credential: ${credential.name} (ID: ${credential.id})`);
        const comment = await tryGenerateComment(credential, promptPrefix, postText);
        console.log(`Success with credential: ${credential.name}`);
        return res.json({ comment, usedCredential: credential.name });
      } catch (error) {
        console.error(`Failed with credential ${credential.name}:`, error.message);
        lastError = error;
        // Continue to next credential
      }
    }

    // If we get here, all credentials failed
    throw lastError || new Error('All AI credentials failed');

  } catch (error) {
    console.error('AI comment generation error:', error);
    res.status(500).json({ error: error.message });
  }
});

// ============================================================================
// PROFILE FRIENDS API
// ============================================================================

// Get friends for a profile
app.get('/api/profile-friends/:profileNumber', (req, res) => {
  try {
    const profileNumber = parseInt(req.params.profileNumber);
    const friends = db.prepare('SELECT * FROM profile_friends WHERE profile_number = ?').get(profileNumber);

    if (!friends) {
      return res.json({ profile_number: profileNumber, friend_names: '' });
    }

    res.json(friends);
  } catch (error) {
    console.error('Error fetching profile friends:', error);
    res.status(500).json({ error: error.message });
  }
});

// Update friends for a profile
app.put('/api/profile-friends/:profileNumber', (req, res) => {
  try {
    const profileNumber = parseInt(req.params.profileNumber);
    const { friend_names } = req.body;

    if (friend_names === undefined) {
      return res.status(400).json({ error: 'friend_names is required' });
    }

    const existing = db.prepare('SELECT * FROM profile_friends WHERE profile_number = ?').get(profileNumber);

    if (existing) {
      db.prepare('UPDATE profile_friends SET friend_names = ?, updated_at = CURRENT_TIMESTAMP WHERE profile_number = ?')
        .run(friend_names, profileNumber);
    } else {
      db.prepare('INSERT INTO profile_friends (profile_number, friend_names) VALUES (?, ?)')
        .run(profileNumber, friend_names);
    }

    const updated = db.prepare('SELECT * FROM profile_friends WHERE profile_number = ?').get(profileNumber);
    res.json(updated);
  } catch (error) {
    console.error('Error updating profile friends:', error);
    res.status(500).json({ error: error.message });
  }
});

// Health check
app.get('/health', (req, res) => {
  res.json({ status: 'ok' });
});

app.listen(PORT, '0.0.0.0', () => {
  console.log(`Server running on port ${PORT}`);
});