server/db.js

import { createClient } from '@supabase/supabase-js';
import Database from 'better-sqlite3';
import dotenv from 'dotenv';
import path from 'path';
import fs from 'fs';
import WebSocket from 'ws';

// Polyfill WebSocket for Supabase Realtime in Node.js < 22
globalThis.WebSocket = WebSocket;

dotenv.config();

// Detect mode
const supabaseUrl = process.env.SUPABASE_URL;
const supabaseKey = process.env.SUPABASE_SERVICE_ROLE_KEY || process.env.SUPABASE_KEY;

// We use Supabase if keys are provided and don't look like default placeholders
const useSupabase = supabaseUrl && 
                    supabaseKey && 
                    !supabaseUrl.includes('YOUR_PROJECT_ID') && 
                    !supabaseKey.includes('your-supabase');

export const dbMode = useSupabase ? 'supabase' : 'sqlite';

console.log(`[Database] Initializing in Mode: ${dbMode.toUpperCase()}`);

// =========================================================================
// SQLITE SETUP (Local development fallback)
// =========================================================================
let sqliteDb = null;

if (dbMode === 'sqlite') {
  const dbPath = path.resolve(process.env.SQLITE_DB_PATH || 'database.db');
  console.log(`[Database] SQLite file location: ${dbPath}`);
  sqliteDb = new Database(dbPath);
  
  // Create tables in SQLite if they don't exist
  sqliteDb.exec(`
    CREATE TABLE IF NOT EXISTS streams (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      start_time TEXT DEFAULT CURRENT_TIMESTAMP,
      end_time TEXT,
      title TEXT,
      twitch_stream_id TEXT UNIQUE,
      category TEXT,
      backfill_status TEXT DEFAULT 'pending',
      twitch_vod_id TEXT
    );

    CREATE TABLE IF NOT EXISTS messages (
      id TEXT PRIMARY KEY,
      stream_id INTEGER,
      username TEXT NOT NULL,
      display_name TEXT,
      message TEXT NOT NULL,
      timestamp TEXT DEFAULT CURRENT_TIMESTAMP,
      is_streamer INTEGER DEFAULT 0,
      is_mod INTEGER DEFAULT 0,
      is_sub INTEGER DEFAULT 0
    );

    CREATE INDEX IF NOT EXISTS idx_messages_stream_id ON messages(stream_id);
    CREATE INDEX IF NOT EXISTS idx_messages_username ON messages(username);
    CREATE INDEX IF NOT EXISTS idx_messages_timestamp ON messages(timestamp);

    CREATE TABLE IF NOT EXISTS voice_words (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      stream_id INTEGER,
      word TEXT NOT NULL,
      timestamp TEXT DEFAULT CURRENT_TIMESTAMP
    );

    CREATE INDEX IF NOT EXISTS idx_voice_words_stream_id ON voice_words(stream_id);
    CREATE INDEX IF NOT EXISTS idx_voice_words_word ON voice_words(word);

    CREATE TABLE IF NOT EXISTS mod_actions (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      stream_id INTEGER,
      action_type TEXT NOT NULL,
      moderator TEXT NOT NULL,
      target_user TEXT,
      duration INTEGER,
      reason TEXT,
      message_text TEXT,
      timestamp TEXT DEFAULT CURRENT_TIMESTAMP
    );

    CREATE INDEX IF NOT EXISTS idx_mod_actions_stream_id ON mod_actions(stream_id);
    CREATE INDEX IF NOT EXISTS idx_mod_actions_timestamp ON mod_actions(timestamp);

    CREATE TABLE IF NOT EXISTS settings (
      key TEXT PRIMARY KEY,
      value TEXT NOT NULL
    );

    CREATE TABLE IF NOT EXISTS stream_viewers (
      stream_id INTEGER,
      username TEXT NOT NULL,
      display_name TEXT,
      has_chatted INTEGER DEFAULT 0,
      is_mod INTEGER DEFAULT 0,
      is_sub INTEGER DEFAULT 0,
      first_seen TEXT,
      PRIMARY KEY (stream_id, username)
    );

    CREATE TABLE IF NOT EXISTS chat_users (
      username TEXT PRIMARY KEY,
      display_name TEXT,
      is_mod INTEGER DEFAULT 0,
      is_sub INTEGER DEFAULT 0,
      is_vip INTEGER DEFAULT 0,
      last_seen TEXT NOT NULL
    );
  `);
  console.log('[Database] SQLite Tables & Indexes initialized.');

  // Migrations for SQLite
  try {
    const columnsStreams = sqliteDb.prepare("PRAGMA table_info(streams)").all();
    if (!columnsStreams.some(c => c.name === 'twitch_stream_id')) {
      sqliteDb.exec("ALTER TABLE streams ADD COLUMN twitch_stream_id TEXT");
      try {
        sqliteDb.exec("CREATE UNIQUE INDEX IF NOT EXISTS idx_streams_twitch_stream_id ON streams(twitch_stream_id)");
      } catch (idxErr) {
        // ignore
      }
      console.log("[Database] SQLite Migrated: Added twitch_stream_id to streams");
    }
    if (!columnsStreams.some(c => c.name === 'category')) {
      sqliteDb.exec("ALTER TABLE streams ADD COLUMN category TEXT");
      console.log("[Database] SQLite Migrated: Added category to streams");
    }
    if (!columnsStreams.some(c => c.name === 'backfill_status')) {
      sqliteDb.exec("ALTER TABLE streams ADD COLUMN backfill_status TEXT DEFAULT 'pending'");
      console.log("[Database] SQLite Migrated: Added backfill_status to streams");
    }
    if (!columnsStreams.some(c => c.name === 'twitch_vod_id')) {
      sqliteDb.exec("ALTER TABLE streams ADD COLUMN twitch_vod_id TEXT");
      console.log("[Database] SQLite Migrated: Added twitch_vod_id to streams");
    }

    const columnsModActions = sqliteDb.prepare("PRAGMA table_info(mod_actions)").all();
    if (!columnsModActions.some(c => c.name === 'reaction_time')) {
      sqliteDb.exec("ALTER TABLE mod_actions ADD COLUMN reaction_time REAL");
      console.log("[Database] SQLite Migrated: Added reaction_time to mod_actions");
    }
  } catch (err) {
    console.error("[Database] SQLite Migration error:", err.message);
  }
}

// =========================================================================
// SUPABASE CLIENT (Cloud production mode)
// =========================================================================
export const supabase = useSupabase ? createClient(supabaseUrl, supabaseKey) : null;

// Gaps larger than 2 hours (in ms) will trigger a new stream session automatically
const STREAM_SESSION_GAP = 2 * 60 * 60 * 1000;
let activeStreamCache = null;
let lastMessageTime = null;

// =========================================================================
// HELPER METHODS (Dually implemented for SQLite & Supabase)
// =========================================================================

/**
 * Get active stream or auto-start a new one
 */
export async function getOrStartActiveStream() {
  const now = new Date();

  // 1. Check cache first
  if (activeStreamCache) {
    if (lastMessageTime && (now - lastMessageTime < STREAM_SESSION_GAP)) {
      lastMessageTime = now;
      return activeStreamCache;
    } else if (lastMessageTime) {
      console.log('[Database] Stream session gap exceeded. Closing old stream.');
      await endActiveStream(activeStreamCache.id);
      activeStreamCache = null;
    }
  }

  // 2. Fetch from DB
  if (dbMode === 'sqlite') {
    const row = sqliteDb.prepare('SELECT * FROM streams WHERE end_time IS NULL ORDER BY start_time DESC LIMIT 1').get();
    if (row) {
      activeStreamCache = row;
      lastMessageTime = now;
      return activeStreamCache;
    }

    // Auto-create new stream in SQLite
    console.log('[Database] No active stream found. Auto-starting new stream in SQLite.');
    const title = `Stream ${now.toLocaleDateString('ru-RU')} - ${now.toLocaleTimeString('ru-RU', { hour: '2-digit', minute: '2-digit' })}`;
    const info = sqliteDb.prepare("INSERT INTO streams (title, start_time, backfill_status) VALUES (?, ?, 'live')").run(title, now.toISOString());
    
    activeStreamCache = {
      id: info.lastInsertRowid,
      title,
      start_time: now.toISOString(),
      end_time: null,
      twitch_stream_id: null,
      category: null,
      backfill_status: 'live'
    };
    lastMessageTime = now;
    return activeStreamCache;

  } else {
    // Supabase Mode
    const { data: activeStreams, error } = await supabase
      .from('streams')
      .select('*')
      .is('end_time', null)
      .order('start_time', { ascending: false })
      .limit(1);

    if (error) {
      console.error('[Supabase] Error fetching active stream:', error);
      return null;
    }

    if (activeStreams && activeStreams.length > 0) {
      activeStreamCache = activeStreams[0];
      lastMessageTime = now;
      return activeStreamCache;
    }

    // Auto-create new stream in Supabase
    console.log('[Database] No active stream found. Auto-starting new stream in Supabase.');
    const title = `Stream ${now.toLocaleDateString('ru-RU')} - ${now.toLocaleTimeString('ru-RU', { hour: '2-digit', minute: '2-digit' })}`;
    const { data: newStream, error: createError } = await supabase
      .from('streams')
      .insert([{ title, start_time: now.toISOString(), backfill_status: 'live' }])
      .select()
      .single();

    if (createError) {
      console.error('[Supabase] Error starting stream:', createError);
      return null;
    }

    activeStreamCache = newStream;
    lastMessageTime = now;
    return activeStreamCache;
  }
}

/**
 * Get the current active stream without starting a new one
 */
export async function getActiveStream() {
  if (activeStreamCache) {
    return activeStreamCache;
  }

  if (dbMode === 'sqlite') {
    const row = sqliteDb.prepare('SELECT * FROM streams WHERE end_time IS NULL ORDER BY start_time DESC LIMIT 1').get();
    if (row) {
      activeStreamCache = row;
    }
    return row || null;
  } else {
    const { data: activeStreams, error } = await supabase
      .from('streams')
      .select('*')
      .is('end_time', null)
      .order('start_time', { ascending: false })
      .limit(1);

    if (error) {
      console.error('[Supabase] Error fetching active stream:', error);
      return null;
    }

    if (activeStreams && activeStreams.length > 0) {
      activeStreamCache = activeStreams[0];
      return activeStreamCache;
    }
    return null;
  }
}


/**
 * Check if a stream with given twitch_stream_id already exists in the database
 */
export async function checkIfStreamExists(twitchStreamId) {
  if (dbMode === 'sqlite') {
    const row = sqliteDb.prepare('SELECT id FROM streams WHERE twitch_stream_id = ?').get(twitchStreamId);
    return !!row;
  } else {
    const { data, error } = await supabase
      .from('streams')
      .select('id')
      .eq('twitch_stream_id', twitchStreamId)
      .limit(1);
    if (error) {
      console.error('[Supabase] Error checking if stream exists:', error);
      return false;
    }
    return data && data.length > 0;
  }
}

/**
 * Sync active stream session with Twitch API data (status, category, started_at)
 */
export async function syncActiveStream(twitchStreamId, title, category, startTimeIso) {
  if (dbMode === 'sqlite') {
    // Check if stream with this twitch_stream_id exists
    let stream = sqliteDb.prepare('SELECT * FROM streams WHERE twitch_stream_id = ?').get(twitchStreamId);
    if (stream) {
      if (stream.end_time) {
        sqliteDb.prepare("UPDATE streams SET end_time = NULL, category = ?, title = ?, backfill_status = 'live' WHERE id = ?").run(category, title, stream.id);
        stream.end_time = null;
        stream.category = category;
        stream.title = title;
      } else {
        sqliteDb.prepare("UPDATE streams SET category = ?, title = ?, backfill_status = 'live' WHERE id = ?").run(category, title, stream.id);
        stream.category = category;
        stream.title = title;
      }
      activeStreamCache = stream;
      lastMessageTime = new Date();
      return stream;
    }

    // If it doesn't exist, check if there is an active stream with no twitch_stream_id
    let activeStream = sqliteDb.prepare('SELECT * FROM streams WHERE end_time IS NULL AND twitch_stream_id IS NULL ORDER BY start_time DESC LIMIT 1').get();
    if (activeStream) {
      sqliteDb.prepare("UPDATE streams SET twitch_stream_id = ?, category = ?, title = ?, backfill_status = 'live' WHERE id = ?").run(twitchStreamId, category, title, activeStream.id);
      activeStream.twitch_stream_id = twitchStreamId;
      activeStream.category = category;
      activeStream.title = title;
      activeStreamCache = activeStream;
      lastMessageTime = new Date();
      return activeStream;
    }

    // Otherwise, create a new stream session
    const info = sqliteDb.prepare("INSERT INTO streams (twitch_stream_id, title, category, start_time, backfill_status) VALUES (?, ?, ?, ?, 'live')").run(twitchStreamId, title, category, startTimeIso || new Date().toISOString());
    activeStreamCache = {
      id: info.lastInsertRowid,
      twitch_stream_id: twitchStreamId,
      title,
      category,
      start_time: startTimeIso || new Date().toISOString(),
      end_time: null,
      backfill_status: 'live'
    };
    lastMessageTime = new Date();
    return activeStreamCache;
  } else {
    // Supabase Mode
    let { data: existingStreams, error: fetchErr } = await supabase
      .from('streams')
      .select('*')
      .eq('twitch_stream_id', twitchStreamId)
      .limit(1);

    if (existingStreams && existingStreams.length > 0) {
      let stream = existingStreams[0];
      if (stream.end_time) {
        const { data: updated, error } = await supabase
          .from('streams')
          .update({ end_time: null, category, title, backfill_status: 'live' })
          .eq('id', stream.id)
          .select()
          .single();
        if (!error) stream = updated;
      } else {
        const { data: updated, error } = await supabase
          .from('streams')
          .update({ category, title, backfill_status: 'live' })
          .eq('id', stream.id)
          .select()
          .single();
        if (!error) stream = updated;
      }
      activeStreamCache = stream;
      lastMessageTime = new Date();
      return stream;
    }

    let { data: activeStreams } = await supabase
      .from('streams')
      .select('*')
      .is('end_time', null)
      .is('twitch_stream_id', null)
      .order('start_time', { ascending: false })
      .limit(1);

    if (activeStreams && activeStreams.length > 0) {
      let activeStream = activeStreams[0];
      const { data: updated, error } = await supabase
        .from('streams')
        .update({ twitch_stream_id: twitchStreamId, category, title, backfill_status: 'live' })
        .eq('id', activeStream.id)
        .select()
        .single();
      if (!error) activeStream = updated;
      activeStreamCache = activeStream;
      lastMessageTime = new Date();
      return activeStream;
    }

    const { data: newStream, error: insertErr } = await supabase
      .from('streams')
      .insert([{ twitch_stream_id: twitchStreamId, title, category, start_time: startTimeIso || new Date().toISOString(), backfill_status: 'live' }])
      .select()
      .single();

    if (insertErr) {
      console.error('[Supabase] Error syncing stream insertion:', insertErr);
      return null;
    }

    activeStreamCache = newStream;
    lastMessageTime = new Date();
    return activeStreamCache;
  }
}

/**
 * End an active stream
 */
export async function endActiveStream(streamId = null, endTime = null, twitchVodId = null) {
  const idToClose = streamId || (activeStreamCache ? activeStreamCache.id : null);
  if (!idToClose) return;

  const endTimeIso = endTime || new Date().toISOString();

  if (dbMode === 'sqlite') {
    if (twitchVodId) {
      sqliteDb.prepare("UPDATE streams SET end_time = ?, backfill_status = 'pending', twitch_vod_id = ? WHERE id = ?").run(endTimeIso, twitchVodId, idToClose);
    } else {
      sqliteDb.prepare("UPDATE streams SET end_time = ?, backfill_status = 'pending' WHERE id = ?").run(endTimeIso, idToClose);
    }
    console.log(`[Database] SQLite Stream ID ${idToClose} ended. VOD: ${twitchVodId || 'None'}`);
  } else {
    const updateData = { end_time: endTimeIso, backfill_status: 'pending' };
    if (twitchVodId) updateData.twitch_vod_id = twitchVodId;

    const { error } = await supabase
      .from('streams')
      .update(updateData)
      .eq('id', idToClose);
    if (error) {
      console.error('[Supabase] Error ending stream:', error);
    } else {
      console.log(`[Database] Supabase Stream ID ${idToClose} ended. VOD: ${twitchVodId || 'None'}`);
    }
  }

  if (activeStreamCache && activeStreamCache.id === idToClose) {
    activeStreamCache = null;
    lastMessageTime = null;
  }
}

/**
 * Find stream active at a specific timestamp
 */
export async function getStreamAtTimestamp(timestampIso) {
  const time = new Date(timestampIso);
  if (dbMode === 'sqlite') {
    const stream = sqliteDb.prepare(`
      SELECT * FROM streams 
      WHERE datetime(start_time) <= datetime(?) 
        AND (end_time IS NULL OR datetime(end_time) >= datetime(?))
      ORDER BY start_time DESC LIMIT 1
    `).get(timestampIso, timestampIso);
    return stream || null;
  } else {
    const { data, error } = await supabase
      .from('streams')
      .select('*')
      .lte('start_time', timestampIso)
      .order('start_time', { ascending: false });
      
    if (error) {
      console.error('[Supabase] Error finding stream at timestamp:', error);
      return null;
    }
    const stream = data.find(s => !s.end_time || new Date(s.end_time) >= time);
    return stream || null;
  }
}

/**
 * Log chat message
 */
export async function logChatMessage(msg) {
  const time = msg.timestamp || new Date().toISOString();
  let stream = null;
  if (msg.timestamp) {
    stream = await getStreamAtTimestamp(msg.timestamp);
  }
  if (!stream) {
    stream = await getActiveStream();
  }
  const streamId = stream ? stream.id : null;

  if (dbMode === 'sqlite') {
    try {
      sqliteDb.prepare(`
        INSERT INTO messages (id, stream_id, username, display_name, message, timestamp, is_streamer, is_mod, is_sub)
        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
      `).run(
        msg.id,
        streamId,
        msg.username.toLowerCase(),
        msg.displayName || msg.username,
        msg.message,
        msg.timestamp || new Date().toISOString(),
        msg.isStreamer ? 1 : 0,
        msg.isMod ? 1 : 0,
        msg.isSub ? 1 : 0
      );
    } catch (err) {
      // Ignore duplicate keys
      if (!err.message.includes('UNIQUE constraint failed')) {
        console.error('[Database] SQLite Error saving message:', err.message);
      }
    }
    
    // Update stream_viewers table
    try {
      sqliteDb.prepare(`
        INSERT INTO stream_viewers (stream_id, username, display_name, has_chatted, is_mod, is_sub, first_seen)
        VALUES (?, ?, ?, 1, ?, ?, ?)
        ON CONFLICT(stream_id, username) DO UPDATE SET 
          has_chatted = 1,
          is_mod = excluded.is_mod,
          is_sub = excluded.is_sub
      `).run(
        streamId,
        msg.username.toLowerCase(),
        msg.displayName || msg.username,
        msg.isMod ? 1 : 0,
        msg.isSub ? 1 : 0,
        msg.timestamp || new Date().toISOString()
      );
    } catch (err) {
      console.error('[Database] SQLite Error updating stream_viewers:', err.message);
    }
  } else {
    const { error } = await supabase
      .from('messages')
      .insert([{
        id: msg.id,
        stream_id: streamId,
        username: msg.username.toLowerCase(),
        display_name: msg.displayName || msg.username,
        message: msg.message,
        timestamp: msg.timestamp || new Date().toISOString(),
        is_streamer: msg.isStreamer || false,
        is_mod: msg.isMod || false,
        is_sub: msg.isSub || false
      }]);

    if (error && error.code !== '23505') {
      console.error('[Supabase] Error logging message:', error);
    }

    // Update stream_viewers
    const { error: viewerError } = await supabase
      .from('stream_viewers')
      .upsert({
        stream_id: streamId,
        username: msg.username.toLowerCase(),
        display_name: msg.displayName || msg.username,
        has_chatted: true,
        is_mod: msg.isMod || false,
        is_sub: msg.isSub || false,
        first_seen: msg.timestamp || new Date().toISOString()
      }, { onConflict: 'stream_id, username' });
      
    if (viewerError) {
      console.error('[Supabase] Error updating stream_viewers:', viewerError);
    }
  }
}

/**
 * Log chat messages in batch (performance optimized)
 */
export async function logChatMessagesBatch(messages) {
  if (!messages || messages.length === 0) return;

  // 1. Fetch all streams to search in-memory instead of making DB queries for each message
  const streams = await getStreamsList();
  const activeStream = await getActiveStream();

  const getStreamIdForTime = (timestampIso) => {
    if (!timestampIso) return activeStream ? activeStream.id : null;
    const time = new Date(timestampIso);
    const matchedStream = streams.find(s => {
      const start = new Date(s.start_time);
      const isAfterStart = start <= time;
      const isBeforeEnd = !s.end_time || new Date(s.end_time) >= time;
      return isAfterStart && isBeforeEnd;
    });
    return matchedStream ? matchedStream.id : (activeStream ? activeStream.id : null);
  };

  if (dbMode === 'sqlite') {
    const insertMsg = sqliteDb.prepare(`
      INSERT INTO messages (id, stream_id, username, display_name, message, timestamp, is_streamer)
      VALUES (?, ?, ?, ?, ?, ?, ?)
    `);

    const insertViewer = sqliteDb.prepare(`
      INSERT INTO stream_viewers (stream_id, username, display_name, has_chatted, is_mod, is_sub, first_seen)
      VALUES (?, ?, ?, 1, ?, ?, ?)
      ON CONFLICT(stream_id, username) DO UPDATE SET 
        has_chatted = 1,
        is_mod = excluded.is_mod,
        is_sub = excluded.is_sub
    `);

    const insertChatUser = sqliteDb.prepare(`
      INSERT INTO chat_users (username, display_name, is_mod, is_sub, is_vip, last_seen)
      VALUES (?, ?, ?, ?, ?, ?)
      ON CONFLICT(username) DO UPDATE SET
        display_name = excluded.display_name,
        is_mod = excluded.is_mod,
        is_sub = excluded.is_sub,
        is_vip = excluded.is_vip,
        last_seen = excluded.last_seen
      WHERE excluded.last_seen > chat_users.last_seen
    `);

    const runTransaction = sqliteDb.transaction((msgs) => {
      for (const msg of msgs) {
        const streamId = getStreamIdForTime(msg.timestamp);
        try {
          insertMsg.run(
            msg.id,
            streamId,
            msg.username.toLowerCase(),
            msg.displayName || msg.username,
            msg.message,
            msg.timestamp || new Date().toISOString(),
            msg.isStreamer ? 1 : 0
          );
        } catch (err) {
          if (!err.message.includes('UNIQUE constraint failed')) {
            console.error('[Database] SQLite Batch Error saving message:', err.message);
          }
        }

        try {
          insertViewer.run(
            streamId,
            msg.username.toLowerCase(),
            msg.displayName || msg.username,
            msg.isMod ? 1 : 0,
            msg.isSub ? 1 : 0,
            msg.timestamp || new Date().toISOString()
          );
        } catch (err) {
          console.error('[Database] SQLite Batch Error updating viewer:', err.message);
        }

        try {
          insertChatUser.run(
            msg.username.toLowerCase(),
            msg.displayName || msg.username,
            msg.isMod ? 1 : 0,
            msg.isSub ? 1 : 0,
            msg.isVip ? 1 : 0,
            msg.timestamp || new Date().toISOString()
          );
        } catch (err) {
          console.error('[Database] SQLite Batch Error updating chat_user:', err.message);
        }
      }
    });

    runTransaction(messages);
  } else {
    // Supabase Mode: Build batch lists
    const messagesToInsert = [];
    const viewersToUpsert = new Map(); // Use Map to unique-fy viewers by stream_id + username
    const chatUsersToUpsert = new Map();

    for (const msg of messages) {
      const streamId = getStreamIdForTime(msg.timestamp);
      const ts = msg.timestamp || new Date().toISOString();
      const username = msg.username.toLowerCase();
      
      messagesToInsert.push({
        id: msg.id,
        stream_id: streamId,
        username: username,
        display_name: msg.displayName || msg.username,
        message: msg.message,
        timestamp: ts,
        is_streamer: msg.isStreamer || false
      });

      const viewerKey = `${streamId || 'null'}-${username}`;
      viewersToUpsert.set(viewerKey, {
        stream_id: streamId,
        username: msg.username.toLowerCase(),
        display_name: msg.displayName || msg.username,
        has_chatted: true,
        is_mod: msg.isMod || false,
        is_sub: msg.isSub || false,
        first_seen: ts
      });

      const userKey = username;
      chatUsersToUpsert.set(userKey, {
        username: username,
        display_name: msg.displayName || msg.username,
        is_mod: msg.isMod || false,
        is_sub: msg.isSub || false,
        is_vip: msg.isVip || false,
        last_seen: ts
      });
    }

    // 1. Bulk upsert messages
    const { error: msgError } = await supabase
      .from('messages')
      .upsert(messagesToInsert, { onConflict: 'id' });

    if (msgError) {
      console.error('[Supabase] Bulk message upsert error:', msgError.message);
    }

    // 2. Bulk upsert viewers
    const uniqueViewers = Array.from(viewersToUpsert.values());
    const { error: viewerError } = await supabase
      .from('stream_viewers')
      .upsert(uniqueViewers, { onConflict: 'stream_id, username' });

    if (viewerError) {
      console.error('[Supabase] Bulk viewers upsert error:', viewerError.message);
    }

    // 3. Bulk upsert global chat_users safely based on last_seen
    const uniqueChatUsers = Array.from(chatUsersToUpsert.values());
    if (uniqueChatUsers.length > 0) {
      const { data: existingUsers } = await supabase
        .from('chat_users')
        .select('username, last_seen')
        .in('username', uniqueChatUsers.map(u => u.username));
      
      const existingMap = new Map((existingUsers || []).map(u => [u.username, new Date(u.last_seen).getTime()]));
      const toUpsert = uniqueChatUsers.filter(u => {
         const oldTime = existingMap.get(u.username) || 0;
         const newTime = new Date(u.last_seen).getTime();
         return newTime > oldTime;
      });

      if (toUpsert.length > 0) {
         const { error: chatUserError } = await supabase
            .from('chat_users')
            .upsert(toUpsert, { onConflict: 'username' });
         if (chatUserError) {
            console.error('[Supabase] Bulk chat_users upsert error:', chatUserError.message);
         }
      }
    }
  }
}

/**
 * Log only roles (used by role backfiller)
 */
export async function logRolesBatch(users) {
  if (!users || users.length === 0) return;

  const chatUsersToUpsert = new Map();
  for (const user of users) {
    const ts = user.timestamp || new Date().toISOString();
    const username = user.username.toLowerCase();
    
    chatUsersToUpsert.set(username, {
      username: username,
      display_name: user.displayName || user.username,
      is_mod: user.isMod || false,
      is_sub: user.isSub || false,
      is_vip: user.isVip || false,
      last_seen: ts
    });
  }

  const uniqueChatUsers = Array.from(chatUsersToUpsert.values());

  if (dbMode === 'sqlite') {
    const insertChatUser = sqliteDb.prepare(`
      INSERT INTO chat_users (username, display_name, is_mod, is_sub, is_vip, last_seen)
      VALUES (?, ?, ?, ?, ?, ?)
      ON CONFLICT(username) DO UPDATE SET
        display_name = excluded.display_name,
        is_mod = excluded.is_mod,
        is_sub = excluded.is_sub,
        is_vip = excluded.is_vip,
        last_seen = excluded.last_seen
      WHERE excluded.last_seen > chat_users.last_seen
    `);

    const runTransaction = sqliteDb.transaction((usersToInsert) => {
      for (const u of usersToInsert) {
        try {
          insertChatUser.run(
            u.username,
            u.display_name,
            u.is_mod ? 1 : 0,
            u.is_sub ? 1 : 0,
            u.is_vip ? 1 : 0,
            u.last_seen
          );
        } catch (err) {
          console.error('[Database] SQLite Error updating role for user:', u.username, err.message);
        }
      }
    });

    runTransaction(uniqueChatUsers);
  } else {
    // Supabase Mode
    const { data: existingUsers } = await supabase
      .from('chat_users')
      .select('username, last_seen')
      .in('username', uniqueChatUsers.map(u => u.username));
    
    const existingMap = new Map((existingUsers || []).map(u => [u.username, new Date(u.last_seen).getTime()]));
    
    // Always update roles (is_mod/is_sub/is_vip), but only advance last_seen if newer
    const toUpsert = uniqueChatUsers.map(u => {
       const oldTime = existingMap.get(u.username) || 0;
       const newTime = new Date(u.last_seen).getTime();
       return {
         ...u,
         // Keep last_seen as the newer of the two
         last_seen: newTime > oldTime ? u.last_seen : (existingUsers || []).find(e => e.username === u.username)?.last_seen || u.last_seen
       };
    });

    if (toUpsert.length > 0) {
       const { error: chatUserError } = await supabase
          .from('chat_users')
          .upsert(toUpsert, { onConflict: 'username' });
       if (chatUserError) {
          console.error('[Supabase] Bulk roles upsert error:', chatUserError.message);
       }
    }
  }
}


/**
 * Log voice words (bulk insert)
 */
export async function logVoiceWords(words, timestamp) {
  if (!words || words.length === 0) return;
  const time = timestamp || new Date().toISOString();
  let stream = null;
  if (timestamp) {
    stream = await getStreamAtTimestamp(timestamp);
  }
  if (!stream) {
    stream = await getActiveStream();
  }
  const clientId = process.env.TWITCH_CLIENT_ID;
  const clientSecret = process.env.TWITCH_CLIENT_SECRET;
  const twitchConfigured = !!(clientId && clientSecret && !clientId.includes('YOUR_') && !clientSecret.includes('YOUR_'));
  if (!stream && !twitchConfigured) {
    stream = await getOrStartActiveStream();
  }
  const streamId = stream ? stream.id : null;

  const cleanWords = words.map(w => w.toLowerCase().trim().replace(/[.,\/#!$%\^&\*;:{}=\-_`~()?]/g,"")).filter(w => w.length > 0);
  if (cleanWords.length === 0) return;

  if (dbMode === 'sqlite') {
    const insert = sqliteDb.prepare('INSERT INTO voice_words (stream_id, word, timestamp) VALUES (?, ?, ?)');
    const transaction = sqliteDb.transaction((recs) => {
      for (const word of recs) {
        insert.run(streamId, word, time);
      }
    });
    transaction(cleanWords);
  } else {
    const records = cleanWords.map(word => ({
      stream_id: streamId,
      word,
      timestamp: time
    }));
    const { error } = await supabase.from('voice_words').insert(records);
    if (error) {
      console.error('[Supabase] Error logging voice words:', error);
    }
  }
}

/**
 * Log moderator actions
 */
export async function logModAction(action) {
  const time = action.timestamp || new Date().toISOString();
  let stream = null;
  if (action.timestamp) {
    stream = await getStreamAtTimestamp(action.timestamp);
  }
  if (!stream) {
    stream = await getActiveStream();
  }
  const streamId = stream ? stream.id : null;

  // Prevent duplicate actions (e.g., from both EventSub and local IRC worker running together)
  let duplicateToUpdate = null;
  if (action.targetUser) {
    const targetUserLower = action.targetUser.toLowerCase();
    if (dbMode === 'sqlite') {
      const existing = sqliteDb.prepare(`
        SELECT id, moderator FROM mod_actions 
        WHERE action_type = ? 
          AND target_user = ? 
          AND abs(strftime('%s', timestamp) - strftime('%s', ?)) < 15
      `).get(action.actionType, targetUserLower, time);
      if (existing) {
        if (existing.moderator === 'TwitchIRC' && action.moderator !== 'TwitchIRC') {
          duplicateToUpdate = existing.id;
        } else {
          console.log(`[Database] Duplicate SQLite mod action ${action.actionType} for ${targetUserLower} ignored.`);
          return;
        }
      }
    } else {
      const timeMs = new Date(time).getTime();
      const startTimeRange = new Date(timeMs - 15000).toISOString();
      const endTimeRange = new Date(timeMs + 15000).toISOString();
      
      const { data: existing, error } = await supabase
        .from('mod_actions')
        .select('id, moderator')
        .eq('action_type', action.actionType)
        .eq('target_user', targetUserLower)
        .gte('timestamp', startTimeRange)
        .lte('timestamp', endTimeRange)
        .limit(1);
        
      if (!error && existing && existing.length > 0) {
        const first = existing[0];
        if (first.moderator === 'TwitchIRC' && action.moderator !== 'TwitchIRC') {
          duplicateToUpdate = first.id;
        } else {
          console.log(`[Database] Duplicate Supabase mod action ${action.actionType} for ${targetUserLower} ignored.`);
          return;
        }
      }
    }
  }

  // Try to auto-calculate reaction time if target user and message exist
  let reactionTime = null;
  if (action.targetUser) {
    const targetUserLower = action.targetUser.toLowerCase();
    let originalMsg = null;
    try {
      if (action.actionType === 'delete' && action.messageText) {
        if (dbMode === 'sqlite') {
          originalMsg = sqliteDb.prepare('SELECT timestamp FROM messages WHERE username = ? AND message = ? ORDER BY timestamp DESC LIMIT 1').get(targetUserLower, action.messageText);
        } else {
          const { data } = await supabase
            .from('messages')
            .select('timestamp')
            .eq('username', targetUserLower)
            .eq('message', action.messageText)
            .order('timestamp', { ascending: false })
            .limit(1);
          if (data && data.length > 0) originalMsg = data[0];
        }
      } else {
        if (dbMode === 'sqlite') {
          originalMsg = sqliteDb.prepare('SELECT timestamp FROM messages WHERE username = ? ORDER BY timestamp DESC LIMIT 1').get(targetUserLower);
        } else {
          const { data } = await supabase
            .from('messages')
            .select('timestamp')
            .eq('username', targetUserLower)
            .order('timestamp', { ascending: false })
            .limit(1);
          if (data && data.length > 0) originalMsg = data[0];
        }
      }

      if (originalMsg) {
        const origTime = new Date(originalMsg.timestamp);
        const actionTime = new Date(time);
        const diffSec = (actionTime - origTime) / 1000;
        if (diffSec >= 0 && diffSec < 1800) { // must be positive and within 30 minutes
          reactionTime = diffSec;
        }
      }
    } catch (e) {
      console.error('[Database] Failed to calculate reaction time:', e.message);
    }
  }

  if (dbMode === 'sqlite') {
    if (duplicateToUpdate) {
      sqliteDb.prepare(`
        UPDATE mod_actions 
        SET moderator = ?, reason = ?, reaction_time = ?
        WHERE id = ?
      `).run(
        action.moderator,
        action.reason || null,
        reactionTime,
        duplicateToUpdate
      );
      console.log(`[Database] Duplicate SQLite mod action ${action.actionType} updated with real moderator ${action.moderator}.`);
    } else {
      sqliteDb.prepare(`
        INSERT INTO mod_actions (stream_id, action_type, moderator, target_user, duration, reason, message_text, timestamp, reaction_time)
        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
      `).run(
        streamId,
        action.actionType,
        action.moderator,
        action.targetUser ? action.targetUser.toLowerCase() : null,
        action.duration || null,
        action.reason || null,
        action.messageText || null,
        time,
        reactionTime
      );
    }
  } else {
    if (duplicateToUpdate) {
      const { error } = await supabase
        .from('mod_actions')
        .update({
          moderator: action.moderator,
          reason: action.reason || null,
          reaction_time: reactionTime
        })
        .eq('id', duplicateToUpdate);
      if (error) {
        console.error('[Supabase] Error updating mod action duplicate:', error);
      } else {
        console.log(`[Database] Duplicate Supabase mod action ${action.actionType} updated with real moderator ${action.moderator}.`);
      }
    } else {
      const { error } = await supabase
        .from('mod_actions')
        .insert([{
          stream_id: streamId,
          action_type: action.actionType,
          moderator: action.moderator,
          target_user: action.targetUser ? action.targetUser.toLowerCase() : null,
          duration: action.duration || null,
          reason: action.reason || null,
          message_text: action.messageText || null,
          timestamp: time,
          reaction_time: reactionTime
        }]);
      if (error) {
        console.error('[Supabase] Error logging mod action:', error);
      }
    }
  }
}

/**
 * Get list of all streams
 */
export async function getStreamsList() {
  if (dbMode === 'sqlite') {
    return sqliteDb.prepare('SELECT * FROM streams ORDER BY start_time DESC').all();
  } else {
    const { data, error } = await supabase
      .from('streams')
      .select('*')
      .order('start_time', { ascending: false });
    if (error) {
      console.error('[Supabase] Error getting streams:', error);
      return [];
    }
    return data || [];
  }
}

/**
 * Get top active chatters
 */
export async function getTopChatters(streamId = null, limit = 50) {
  if (dbMode === 'sqlite') {
    let stmt;
    if (streamId) {
      stmt = sqliteDb.prepare(`
        SELECT 
          v.username, 
          u.display_name, 
          u.is_mod, 
          u.is_sub,
          u.is_vip,
          v.has_chatted,
          (SELECT COUNT(*) FROM messages m WHERE m.stream_id = v.stream_id AND m.username = v.username) as message_count
        FROM stream_viewers v
        LEFT JOIN chat_users u ON v.username = u.username
        WHERE v.stream_id = ? 
        GROUP BY v.username 
        ORDER BY message_count DESC 
        LIMIT ?
      `);
      return stmt.all(streamId, limit);
    } else {
      stmt = sqliteDb.prepare(`
        SELECT 
          m.username, 
          u.display_name, 
          u.is_mod, 
          u.is_sub,
          u.is_vip,
          COUNT(*) as message_count
        FROM messages m
        LEFT JOIN chat_users u ON m.username = u.username
        GROUP BY m.username 
        ORDER BY message_count DESC 
        LIMIT ?
      `);
      return stmt.all(limit);
    }
  } else {
    // Supabase Mode queries the views we created
    let query;
    if (streamId) {
      query = supabase
        .from('stream_chatter_stats')
        .select('*')
        .eq('stream_id', streamId)
        .order('message_count', { ascending: false })
        .limit(limit);
    } else {
      query = supabase
        .from('global_chatter_stats')
        .select('*')
        .order('message_count', { ascending: false })
        .limit(limit);
    }
    const { data, error } = await query;
    if (error) {
      console.error('[Supabase] Error getting top chatters:', error);
      return [];
    }
    return data || [];
  }
}

/**
 * Get overall summary statistics (true total metrics)
 */
export async function getStatsSummary(streamId = null) {
  if (dbMode === 'sqlite') {
    let msgCount, uniqueChatters, voiceCount, topChatter;
    
    if (streamId) {
      msgCount = sqliteDb.prepare('SELECT COUNT(*) as count FROM messages WHERE stream_id = ?').get(streamId).count;
      uniqueChatters = sqliteDb.prepare('SELECT COUNT(DISTINCT username) as count FROM messages WHERE stream_id = ?').get(streamId).count;
      voiceCount = sqliteDb.prepare('SELECT COUNT(*) as count FROM voice_words WHERE stream_id = ?').get(streamId).count;
      const row = sqliteDb.prepare('SELECT display_name FROM stream_viewers WHERE stream_id = ? AND has_chatted = 1 ORDER BY (SELECT COUNT(*) FROM messages m WHERE m.stream_id = ? AND m.username = stream_viewers.username) DESC LIMIT 1').get(streamId, streamId);
      topChatter = row ? row.display_name : '—';
    } else {
      msgCount = sqliteDb.prepare('SELECT COUNT(*) as count FROM messages').get().count;
      uniqueChatters = sqliteDb.prepare('SELECT COUNT(DISTINCT username) as count FROM messages').get().count;
      voiceCount = sqliteDb.prepare('SELECT COUNT(*) as count FROM voice_words').get().count;
      const row = sqliteDb.prepare('SELECT username FROM messages GROUP BY username ORDER BY COUNT(*) DESC LIMIT 1').get();
      topChatter = row ? row.username : '—';
    }
    
    return {
      messages: msgCount,
      uniqueChatters: uniqueChatters,
      mostActiveChatter: topChatter,
      voiceWordsCount: voiceCount
    };
  } else {
    // Supabase Mode
    let msgCountQuery = supabase.from('messages').select('*', { count: 'exact', head: true });
    let voiceCountQuery = supabase.from('voice_words').select('*', { count: 'exact', head: true });
    
    if (streamId) {
      msgCountQuery = msgCountQuery.eq('stream_id', streamId);
      voiceCountQuery = voiceCountQuery.eq('stream_id', streamId);
    }
    
    const { count: msgCount } = await msgCountQuery;
    const { count: voiceCount } = await voiceCountQuery;
    
    // Unique chatters count
    let uniqueChatters = 0;
    if (streamId) {
      const { count } = await supabase
        .from('stream_chatter_stats')
        .select('*', { count: 'exact', head: true })
        .eq('stream_id', streamId);
      uniqueChatters = count || 0;
    } else {
      const { count } = await supabase
        .from('global_chatter_stats')
        .select('*', { count: 'exact', head: true });
      uniqueChatters = count || 0;
    }
    
    // Top active chatter
    let topChatter = '—';
    if (streamId) {
      const { data } = await supabase
        .from('stream_chatter_stats')
        .select('display_name')
        .eq('stream_id', streamId)
        .order('message_count', { ascending: false })
        .limit(1);
      if (data && data.length > 0) topChatter = data[0].display_name;
    } else {
      const { data } = await supabase
        .from('global_chatter_stats')
        .select('username')
        .order('message_count', { ascending: false })
        .limit(1);
      if (data && data.length > 0) topChatter = data[0].username;
    }
    
    return {
      messages: msgCount || 0,
      uniqueChatters: uniqueChatters,
      mostActiveChatter: topChatter,
      voiceWordsCount: voiceCount || 0
    };
  }
}


/**
 * Get top spoken words
 */
export async function getSpokenWords(streamId = null, limit = 100) {
  if (dbMode === 'sqlite') {
    let stmt;
    if (streamId) {
      stmt = sqliteDb.prepare(`
        SELECT word, count(*) as word_count 
        FROM voice_words 
        WHERE stream_id = ? 
        GROUP BY word 
        ORDER BY word_count DESC 
        LIMIT ?
      `);
      return stmt.all(streamId, limit);
    } else {
      stmt = sqliteDb.prepare(`
        SELECT word, count(*) as word_count 
        FROM voice_words 
        GROUP BY word 
        ORDER BY word_count DESC 
        LIMIT ?
      `);
      return stmt.all(limit);
    }
  } else {
    let query;
    if (streamId) {
      query = supabase
        .from('stream_voice_word_stats')
        .select('word, word_count')
        .eq('stream_id', streamId)
        .order('word_count', { ascending: false })
        .limit(limit);
    } else {
      query = supabase
        .from('global_voice_word_stats')
        .select('word, word_count')
        .order('word_count', { ascending: false })
        .limit(limit);
    }
    const { data, error } = await query;
    if (error) {
      console.error('[Supabase] Error getting spoken words:', error);
      return [];
    }
    return data || [];
  }
}

/**
 * Get all messages written in chat (for client-side word count in JS)
 */
export async function getChatMessages(streamId = null) {
  const bots = ['streamelements', 'nightbot'];
  if (dbMode === 'sqlite') {
    if (streamId) {
      return sqliteDb.prepare('SELECT message, username, display_name, timestamp FROM messages WHERE stream_id = ? AND username NOT IN (?, ?)').all(streamId, ...bots);
    } else {
      return sqliteDb.prepare('SELECT message, username, display_name, timestamp FROM messages WHERE username NOT IN (?, ?)').all(...bots);
    }
  } else {
    let allData = [];
    let from = 0;
    const limit = 1000;
    
    while(true) {
      let query = supabase
        .from('messages')
        .select('message, username, display_name, timestamp')
        .not('username', 'in', `(${bots.map(b => `"${b}"`).join(',')})`)
        .range(from, from + limit - 1);

      if (streamId) {
        query = query.eq('stream_id', streamId);
      }
      
      const { data, error } = await query;
      
      if (error) {
        console.error('[Supabase] Error getting chat messages:', error);
        break;
      }
      
      if (data && data.length > 0) {
        allData = allData.concat(data);
        if (data.length < limit) break; // Fetched the last incomplete page
        from += limit;
      } else {
        break; // Empty page
      }
    }
    
    return allData;
  }
}

/**
 * Get log of moderator actions
 */
export async function getModActionsList(streamId = null, limit = 100) {
  if (dbMode === 'sqlite') {
    if (streamId) {
      return sqliteDb.prepare('SELECT * FROM mod_actions WHERE stream_id = ? ORDER BY timestamp DESC LIMIT ?').all(streamId, limit);
    } else {
      return sqliteDb.prepare('SELECT * FROM mod_actions ORDER BY timestamp DESC LIMIT ?').all(limit);
    }
  } else {
    let query = supabase
      .from('mod_actions')
      .select('*')
      .order('timestamp', { ascending: false })
      .limit(limit);

    if (streamId) {
      query = query.eq('stream_id', streamId);
    }
    const { data, error } = await query;
    if (error) {
      console.error('[Supabase] Error getting mod actions:', error);
      return [];
    }
    return data || [];
  }
}

/**
 * Settings Get Helper
 */
export async function getSetting(key) {
  if (dbMode === 'sqlite') {
    const row = sqliteDb.prepare('SELECT value FROM settings WHERE key = ?').get(key);
    return row ? row.value : null;
  } else {
    const { data, error } = await supabase
      .from('settings')
      .select('value')
      .eq('key', key)
      .single();
    if (error) {
      if (error.code !== 'PGRST116') {
        console.error(`[Supabase] Error getting setting ${key}:`, error);
      }
      return null;
    }
    return data ? data.value : null;
  }
}

/**
 * Settings Set Helper
 */
export async function setSetting(key, value) {
  if (dbMode === 'sqlite') {
    sqliteDb.prepare('INSERT INTO settings (key, value) VALUES (?, ?) ON CONFLICT(key) DO UPDATE SET value = ?').run(key, String(value), String(value));
  } else {
    const { error } = await supabase
      .from('settings')
      .upsert([{ key, value: String(value) }]);
    if (error) {
      console.error(`[Supabase] Error saving setting ${key}:`, error);
    }
  }
}

/**
 * Get all message timestamps for a stream (for activity chart)
 */
export async function getStreamMessageTimestamps(streamId) {
  if (dbMode === 'sqlite') {
    return sqliteDb.prepare('SELECT timestamp FROM messages WHERE stream_id = ? ORDER BY timestamp ASC').all(streamId);
  } else {
    let allData = [];
    let from = 0;
    const limit = 1000;
    
    while(true) {
      const { data, error } = await supabase
        .from('messages')
        .select('timestamp')
        .eq('stream_id', streamId)
        .order('timestamp', { ascending: true })
        .range(from, from + limit - 1);
      
      if (error) {
        console.error('[Supabase] Error fetching message timestamps:', error);
        break;
      }
      
      if (data && data.length > 0) {
        allData = allData.concat(data);
        if (data.length < limit) break;
        from += limit;
      } else {
        break;
      }
    }
    return allData;
  }
}

/**
 * Get raw moderator actions for summary aggregation
 */
export async function getModActionsSummaryRaw(streamId = null) {
  if (dbMode === 'sqlite') {
    if (streamId) {
      return sqliteDb.prepare('SELECT moderator, action_type FROM mod_actions WHERE stream_id = ?').all(streamId);
    } else {
      return sqliteDb.prepare('SELECT moderator, action_type FROM mod_actions').all();
    }
  } else {
    let allData = [];
    let from = 0;
    const limit = 1000;
    
    while(true) {
      let query = supabase.from('mod_actions').select('moderator, action_type').range(from, from + limit - 1);
      if (streamId) {
        query = query.eq('stream_id', streamId);
      }
      
      const { data, error } = await query;
      if (error) {
        console.error('[Supabase] Error getting mod actions summary:', error);
        break;
      }
      
      if (data && data.length > 0) {
        allData = allData.concat(data);
        if (data.length < limit) break;
        from += limit;
      } else {
        break;
      }
    }
    return allData;
  }
}

/**
 * Get aggregated moderator stats and radar scores for profiles
 */
export async function getModeratorProfilesData(streamId = null) {
  let actions = [];
  if (dbMode === 'sqlite') {
    if (streamId) {
      actions = sqliteDb.prepare('SELECT * FROM mod_actions WHERE stream_id = ?').all(streamId);
    } else {
      actions = sqliteDb.prepare('SELECT * FROM mod_actions').all();
    }
  } else {
    let query = supabase.from('mod_actions').select('*');
    if (streamId) {
      query = query.eq('stream_id', streamId);
    }
    const { data, error } = await query;
    if (error) {
      console.error('[Supabase] Error fetching mod actions for profiles:', error);
      return [];
    }
    actions = data || [];
  }

  const modData = {};
  for (const act of actions) {
    const mod = act.moderator;
    if (!modData[mod]) {
      modData[mod] = {
        moderator: mod,
        total_actions: 0,
        reaction_times: [],
        bans_count: 0,
        timeouts_count: 0,
        deletions_count: 0,
        unbans_count: 0
      };
    }

    const stats = modData[mod];
    stats.total_actions += 1;
    if (act.action_type === 'ban') stats.bans_count += 1;
    else if (act.action_type === 'timeout') stats.timeouts_count += 1;
    else if (act.action_type === 'delete') stats.deletions_count += 1;
    else if (act.action_type === 'unban') stats.unbans_count += 1;

    if (act.reaction_time !== null && act.reaction_time !== undefined) {
      stats.reaction_times.push(act.reaction_time);
    }
  }

  const profiles = Object.values(modData).map(stats => {
    const totalReactionTime = stats.reaction_times.reduce((sum, val) => sum + val, 0);
    const avgReactionTime = stats.reaction_times.length > 0 ? totalReactionTime / stats.reaction_times.length : null;

    // Normalizing scores (0 to 100)
    let scoreSpeed = 50;
    if (avgReactionTime !== null) {
      if (avgReactionTime <= 2) scoreSpeed = 100;
      else if (avgReactionTime >= 30) scoreSpeed = 10;
      else scoreSpeed = Math.round(100 - ((avgReactionTime - 2) * (90 / 28)));
    }

    const scoreActivity = Math.min(100, Math.round((stats.total_actions / 50) * 100));

    const strictCount = stats.bans_count + stats.timeouts_count;
    const scoreHarshness = stats.total_actions > 0 ? Math.round((strictCount / stats.total_actions) * 100) : 0;

    const scoreWatchfulness = stats.total_actions > 0 ? Math.round((stats.deletions_count / stats.total_actions) * 100) : 0;

    return {
      moderator: stats.moderator,
      total_actions: stats.total_actions,
      reaction_time_avg: avgReactionTime ? parseFloat(avgReactionTime.toFixed(2)) : null,
      bans_count: stats.bans_count,
      timeouts_count: stats.timeouts_count,
      deletions_count: stats.deletions_count,
      unbans_count: stats.unbans_count,
      scores: {
        speed: scoreSpeed,
        activity: scoreActivity,
        harshness: scoreHarshness,
        watchfulness: scoreWatchfulness
      }
    };
  });

  return profiles.sort((a, b) => b.total_actions - a.total_actions);
}

// ============================================================
// COVERAGE WINDOWS — track which time ranges were captured
// ============================================================

/**
 * Start a new coverage window (worker session started)
 */
export async function startCoverageWindow(streamId, source = 'live', coveredFrom = null, coveredTo = null) {
  const fromTime = coveredFrom || new Date().toISOString();
  if (dbMode === 'sqlite') {
    const result = sqliteDb.prepare(
      'INSERT INTO stream_coverage (stream_id, covered_from, covered_to, source) VALUES (?, ?, ?, ?)'
    ).run(streamId, fromTime, coveredTo, source);
    return result.lastInsertRowid;
  } else {
    const { data, error } = await supabase
      .from('stream_coverage')
      .insert({ stream_id: streamId, covered_from: fromTime, covered_to: coveredTo, source })
      .select('id')
      .single();
    if (error) console.error('[Supabase] startCoverageWindow error:', error.message);
    return data?.id || null;
  }
}

/**
 * Update coverage heartbeat (worker still running)
 */
export async function updateCoverageHeartbeat(coverageId) {
  const now = new Date().toISOString();
  if (dbMode === 'sqlite') {
    sqliteDb.prepare('UPDATE stream_coverage SET covered_to = ? WHERE id = ?').run(now, coverageId);
  } else {
    await supabase.from('stream_coverage').update({ covered_to: now }).eq('id', coverageId);
  }
}

/**
 * End a coverage window (worker session stopped)
 */
export async function endCoverageWindow(coverageId, coveredTo = null) {
  const toTime = coveredTo || new Date().toISOString();
  if (dbMode === 'sqlite') {
    sqliteDb.prepare('UPDATE stream_coverage SET covered_to = ? WHERE id = ?').run(toTime, coverageId);
  } else {
    await supabase.from('stream_coverage').update({ covered_to: toTime }).eq('id', coverageId);
  }
}

/**
 * Fetch VOD duration in seconds via Twitch GQL
 */
async function getVodDurationSeconds(vodId) {
  try {
    const res = await fetch('https://gql.twitch.tv/gql', {
      method: 'POST',
      headers: {
        'Client-Id': 'kimne78kx3ncx6brgo4mv6wki5h1ko',
        'Content-Type': 'application/json'
      },
      body: JSON.stringify({
        query: `query { video(id: "${vodId}") { lengthSeconds } }`
      })
    });
    const data = await res.json();
    return data?.data?.video?.lengthSeconds || null;
  } catch (e) {
    console.error('[GQL] getVodDurationSeconds error:', e.message);
    return null;
  }
}

/**
 * Compute uncovered gaps for a stream given its coverage windows.
 * Returns array of { from_offset, to_offset } in seconds from stream start.
 */
export async function getCoverageGaps(streamId, vodId, streamStartTime) {
  const startEpoch = new Date(streamStartTime).getTime() / 1000;

  // 1. Get VOD duration
  const durationSeconds = vodId ? await getVodDurationSeconds(vodId) : null;
  const vodEnd = durationSeconds != null ? startEpoch + durationSeconds : null;

  // 2. Get all coverage windows for this stream
  let windows = [];
  if (dbMode === 'sqlite') {
    windows = sqliteDb.prepare(
      'SELECT covered_from, covered_to FROM stream_coverage WHERE stream_id = ? AND covered_to IS NOT NULL ORDER BY covered_from ASC'
    ).all(streamId);
  } else {
    const { data } = await supabase
      .from('stream_coverage')
      .select('covered_from, covered_to')
      .eq('stream_id', streamId)
      .not('covered_to', 'is', null)
      .order('covered_from', { ascending: true });
    windows = data || [];
  }

  if (windows.length === 0) {
    // No coverage at all — backfill entire VOD
    if (vodEnd) return [{ from_offset: 0, to_offset: durationSeconds }];
    return [{ from_offset: 0, to_offset: null }];
  }

  // 3. Convert to [start_offset, end_offset] pairs (seconds from stream start)
  const intervals = windows.map(w => ({
    s: Math.max(0, Math.round(new Date(w.covered_from).getTime() / 1000 - startEpoch)),
    e: Math.round(new Date(w.covered_to).getTime() / 1000 - startEpoch)
  })).filter(w => w.e > w.s);

  // 4. Sort and merge overlapping intervals
  intervals.sort((a, b) => a.s - b.s);
  const merged = [];
  for (const iv of intervals) {
    if (merged.length === 0 || iv.s > merged[merged.length - 1].e + 30) {
      merged.push({ ...iv });
    } else {
      merged[merged.length - 1].e = Math.max(merged[merged.length - 1].e, iv.e);
    }
  }

  // 5. Find gaps
  const gaps = [];
  const THRESHOLD = 60; // ignore gaps < 60 seconds

  // Gap before first coverage window
  if (merged[0].s > THRESHOLD) {
    gaps.push({ from_offset: 0, to_offset: merged[0].s });
  }

  // Gaps between windows
  for (let i = 0; i < merged.length - 1; i++) {
    const gapSize = merged[i + 1].s - merged[i].e;
    if (gapSize > THRESHOLD) {
      gaps.push({ from_offset: merged[i].e, to_offset: merged[i + 1].s });
    }
  }

  // Gap after last coverage window (to end of VOD)
  const lastEnd = merged[merged.length - 1].e;
  if (vodEnd) {
    const remainingSeconds = durationSeconds - lastEnd;
    if (remainingSeconds > THRESHOLD) {
      gaps.push({ from_offset: lastEnd, to_offset: durationSeconds });
    }
  } else {
    // Unknown VOD duration — backfill from last known point to end
    gaps.push({ from_offset: lastEnd, to_offset: null });
  }

  return gaps;
}

/**
 * Get list of VOD streams waiting for backfill
 */
export async function getPendingBackfillStreams() {
  if (dbMode === 'sqlite') {
    const streams = sqliteDb.prepare("SELECT * FROM streams WHERE backfill_status = 'pending' AND twitch_vod_id IS NOT NULL ORDER BY start_time ASC").all();
    for (const stream of streams) {
      stream.gaps = await getCoverageGaps(stream.id, stream.twitch_vod_id, stream.start_time);
    }
    return streams;
  } else {
    const { data: streams, error } = await supabase
      .from('streams')
      .select('*')
      .eq('backfill_status', 'pending')
      .not('twitch_vod_id', 'is', null)
      .order('start_time', { ascending: true });

    if (error) {
      console.error('[Supabase] Error getting pending backfill streams:', error);
      return [];
    }

    if (streams) {
      for (const stream of streams) {
        stream.gaps = await getCoverageGaps(stream.id, stream.twitch_vod_id, stream.start_time);
      }
    }
    return streams || [];
  }
}

/**
 * Mark a stream as backfilled and completed
 */
export async function markStreamBackfilled(streamId = null, twitchStreamId = null) {
  if (dbMode === 'sqlite') {
    if (streamId) {
      sqliteDb.prepare("UPDATE streams SET backfill_status = 'completed' WHERE id = ?").run(streamId);
    } else if (twitchStreamId) {
      sqliteDb.prepare("UPDATE streams SET backfill_status = 'completed' WHERE twitch_stream_id = ?").run(twitchStreamId);
    }
  } else {
    const query = supabase.from('streams').update({ backfill_status: 'completed' });
    let res;
    if (streamId) {
      res = await query.eq('id', streamId);
    } else if (twitchStreamId) {
      res = await query.eq('twitch_stream_id', twitchStreamId);
    }
    if (res && res.error) {
      console.error('[Supabase] Error marking stream as backfilled:', res.error);
    }
  }
}

/**
 * Reset backfill status and optionally delete existing data for rebuild
 */
export async function resetStreamBackfill(streamId, mode = 'gap_fill') {
  if (dbMode === 'sqlite') {
    if (mode === 'full_rebuild') {
      sqliteDb.prepare("DELETE FROM messages WHERE stream_id = ?").run(streamId);
      sqliteDb.prepare("DELETE FROM voice_words WHERE stream_id = ?").run(streamId);
      console.log(`[Database] SQLite Stream ID ${streamId} data cleared for full rebuild.`);
    }
    sqliteDb.prepare("UPDATE streams SET backfill_status = 'pending' WHERE id = ?").run(streamId);
    console.log(`[Database] SQLite Stream ID ${streamId} reset to pending.`);
  } else {
    if (mode === 'full_rebuild') {
      const { error: msgErr } = await supabase.from('messages').delete().eq('stream_id', streamId);
      const { error: voiceErr } = await supabase.from('voice_words').delete().eq('stream_id', streamId);
      if (msgErr || voiceErr) {
        console.error('[Supabase] Error clearing data for rebuild:', msgErr, voiceErr);
      } else {
        console.log(`[Database] Supabase Stream ID ${streamId} data cleared for full rebuild.`);
      }
    }
    const { error: streamErr } = await supabase.from('streams').update({ backfill_status: 'pending' }).eq('id', streamId);
    if (streamErr) {
      console.error('[Supabase] Error resetting stream to pending:', streamErr);
    } else {
      console.log(`[Database] Supabase Stream ID ${streamId} reset to pending.`);
    }
  }
}

/**
 * Delete stream and all its messages, words, and mod actions
 */
export async function deleteStream(streamId) {
  if (dbMode === 'sqlite') {
    sqliteDb.prepare("DELETE FROM messages WHERE stream_id = ?").run(streamId);
    sqliteDb.prepare("DELETE FROM voice_words WHERE stream_id = ?").run(streamId);
    sqliteDb.prepare("DELETE FROM mod_actions WHERE stream_id = ?").run(streamId);
    sqliteDb.prepare("DELETE FROM streams WHERE id = ?").run(streamId);
    console.log(`[Database] SQLite Stream ID ${streamId} fully deleted.`);
  } else {
    const { error: msgErr } = await supabase.from('messages').delete().eq('stream_id', streamId);
    const { error: voiceErr } = await supabase.from('voice_words').delete().eq('stream_id', streamId);
    const { error: modErr } = await supabase.from('mod_actions').delete().eq('stream_id', streamId);
    const { error: streamErr } = await supabase.from('streams').delete().eq('id', streamId);
    
    if (msgErr || voiceErr || modErr || streamErr) {
      console.error('[Supabase] Error deleting stream:', msgErr, voiceErr, modErr, streamErr);
    } else {
      console.log(`[Database] Supabase Stream ID ${streamId} fully deleted.`);
    }
  }
}

/**
 * Update metadata (title/category) of a stream
 */
export async function updateStreamMetadata(streamId, title, category) {
  if (dbMode === 'sqlite') {
    sqliteDb.prepare("UPDATE streams SET title = ?, category = ? WHERE id = ?").run(title, category, streamId);
    console.log(`[Database] SQLite Stream ID ${streamId} updated: Title="${title}", Category="${category}"`);
  } else {
    const { error } = await supabase
      .from('streams')
      .update({ title, category })
      .eq('id', streamId);
      
    if (error) {
      console.error('[Supabase] Error updating stream metadata:', error);
    } else {
      console.log(`[Database] Supabase Stream ID ${streamId} updated: Title="${title}", Category="${category}"`);
    }
  }
}

/**
 * Get system statistics (size, count of records)
 */
export async function getSystemStats() {
  let stats = {
    dbMode,
    totalStreams: 0,
    totalMessages: 0,
    totalVoiceWords: 0,
    dbSizeMb: 0
  };

  if (dbMode === 'sqlite') {
    stats.totalStreams = sqliteDb.prepare("SELECT count(*) as count FROM streams").get().count;
    stats.totalMessages = sqliteDb.prepare("SELECT count(*) as count FROM messages").get().count;
    stats.totalVoiceWords = sqliteDb.prepare("SELECT count(*) as count FROM voice_words").get().count;
    
    try {
      const dbPath = path.resolve('database.db');
      if (fs.existsSync(dbPath)) {
        const fileStats = fs.statSync(dbPath);
        stats.dbSizeMb = parseFloat((fileStats.size / (1024 * 1024)).toFixed(2));
      }
    } catch (err) {
      console.error('[Database] Error reading SQLite file size:', err.message);
    }
  } else {
    // Supabase count queries
    const { count: streamsCount, error: err1 } = await supabase.from('streams').select('*', { count: 'exact', head: true });
    const { count: messagesCount, error: err2 } = await supabase.from('messages').select('*', { count: 'exact', head: true });
    const { count: voiceWordsCount, error: err3 } = await supabase.from('voice_words').select('*', { count: 'exact', head: true });
    
    if (err1 || err2 || err3) {
      console.error('[Supabase] Error fetching system stats:', err1, err2, err3);
    }
    
    stats.totalStreams = streamsCount || 0;
    stats.totalMessages = messagesCount || 0;
    stats.totalVoiceWords = voiceWordsCount || 0;
  }
  return stats;
}

/**
 * Clean up streams with 0 messages AND 0 voice words
 */
export async function cleanupGhostStreams() {
  if (dbMode === 'sqlite') {
    const info = sqliteDb.prepare(`
      DELETE FROM streams 
      WHERE id NOT IN (SELECT DISTINCT stream_id FROM messages WHERE stream_id IS NOT NULL)
        AND id NOT IN (SELECT DISTINCT stream_id FROM voice_words WHERE stream_id IS NOT NULL)
    `).run();
    console.log(`[Database] SQLite Ghost streams cleaned up. Deleted ${info.changes} streams.`);
    return info.changes;
  } else {
    // Supabase mode - fetch all streams and check manually (safer for postgres count limitations)
    const { data: streams, error: fetchErr } = await supabase.from('streams').select('id');
    if (fetchErr || !streams) {
      console.error('[Supabase] Error fetching streams for cleanup:', fetchErr);
      return 0;
    }
    
    let deletedCount = 0;
    for (const stream of streams) {
      const { count: msgCount } = await supabase.from('messages').select('*', { count: 'exact', head: true }).eq('stream_id', stream.id);
      const { count: voiceCount } = await supabase.from('voice_words').select('*', { count: 'exact', head: true }).eq('stream_id', stream.id);
      
      if ((msgCount || 0) === 0 && (voiceCount || 0) === 0) {
        const { error: delErr } = await supabase.from('streams').delete().eq('id', stream.id);
        if (delErr) {
          console.error(`[Supabase] Error deleting empty stream ID ${stream.id}:`, delErr);
        } else {
          deletedCount++;
        }
      }
    }
    console.log(`[Database] Supabase Ghost streams cleaned up. Deleted ${deletedCount} streams.`);
    return deletedCount;
  }
}


/**
 * Log viewer join event (Lurker)
 */
export async function logViewerJoin(username) {
  const stream = await getActiveStream();
  if (!stream) return;

  const streamId = stream.id;
  const time = new Date().toISOString();

  if (dbMode === 'sqlite') {
    try {
      sqliteDb.prepare(`
        INSERT INTO stream_viewers (stream_id, username, display_name, has_chatted, is_mod, is_sub, first_seen)
        VALUES (?, ?, ?, 0, 0, 0, ?)
        ON CONFLICT(stream_id, username) DO NOTHING
      `).run(streamId, username.toLowerCase(), username, time);
    } catch (err) {
      console.error('[Database] SQLite Error logging viewer join:', err.message);
    }
  } else {
    const { error } = await supabase
      .from('stream_viewers')
      .insert([{
        stream_id: streamId,
        username: username.toLowerCase(),
        display_name: username,
        has_chatted: false,
        is_mod: false,
        is_sub: false,
        first_seen: time
      }], { onConflict: 'stream_id, username' });

    if (error && error.code !== '23505') {
      console.error('[Supabase] Error logging viewer join:', error);
    }
  }
}