const Database = require('better-sqlite3');
const path = require('path');
const fs = require('fs');

const dataDir = path.join(__dirname, '..', '..', 'data');
const dbPath = path.join(dataDir, 'content.db');

// Ensure data directory exists
if (!fs.existsSync(dataDir)) {
    fs.mkdirSync(dataDir, { recursive: true });
}

let db;

function getDb() {
    if (!db) {
        console.log('[SQLite] Opening database at', dbPath);
        db = new Database(dbPath);
        // Optimize performance
        db.pragma('journal_mode = WAL');
        db.pragma('synchronous = NORMAL');
        initSchema();
    }
    return db;
}

function initSchema() {
    if (!db) throw new Error('Database not initialized');

    // Categories (Groups)
    db.exec(`
        CREATE TABLE IF NOT EXISTS categories (
            id TEXT PRIMARY KEY, -- Composite key: sourceId:categoryId
            source_id INTEGER NOT NULL,
            category_id TEXT NOT NULL,
            type TEXT NOT NULL, -- 'live', 'movie', 'series'
            name TEXT NOT NULL,
            parent_id TEXT, -- For nested categories
            is_hidden INTEGER DEFAULT 0,
            data JSON -- Extra provider data
        );
        CREATE INDEX IF NOT EXISTS idx_categories_source_type ON categories(source_id, type);
    `);

    // Playlist Items (Channels, Movies, Series, Episodes)
    db.exec(`
        CREATE TABLE IF NOT EXISTS playlist_items (
            id TEXT PRIMARY KEY, -- Composite key: sourceId:itemId
            source_id INTEGER NOT NULL,
            item_id TEXT NOT NULL, -- Original ID from provider
            type TEXT NOT NULL, -- 'live', 'movie', 'series', 'episode'
            name TEXT NOT NULL,
            category_id TEXT, -- maps to categories.category_id (not our composite id)
            parent_id TEXT, -- For episodes -> series_id
            
            -- Common Media Fields
            stream_icon TEXT,
            stream_url TEXT, -- Direct link if available
            container_extension TEXT,
            
            -- VOD/Series Specific
            rating REAL,
            year TEXT,
            added_at TEXT,
            
            -- App State
            is_hidden INTEGER DEFAULT 0,
            is_favorite INTEGER DEFAULT 0,
            
            data JSON -- Full original JSON object
        );
        CREATE INDEX IF NOT EXISTS idx_items_source_type ON playlist_items(source_id, type);
        CREATE INDEX IF NOT EXISTS idx_items_category ON playlist_items(source_id, category_id);
    `);

    // EPG Programs
    // Optimized for range queries
    db.exec(`
        CREATE TABLE IF NOT EXISTS epg_programs (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            channel_id TEXT NOT NULL, -- matches playlist_items.id if possible, or mapping key
            source_id INTEGER NOT NULL,
            start_time INTEGER NOT NULL, -- Unix timestamp (ms)
            end_time INTEGER NOT NULL,   -- Unix timestamp (ms)
            title TEXT,
            description TEXT,
            data JSON
        );
        CREATE INDEX IF NOT EXISTS idx_epg_channel_time ON epg_programs(channel_id, start_time, end_time);
        CREATE INDEX IF NOT EXISTS idx_epg_cleanup ON epg_programs(end_time); -- For deleting old programs
    `);

    // Sync Status
    db.exec(`
        CREATE TABLE IF NOT EXISTS sync_status (
            source_id INTEGER NOT NULL,
            type TEXT NOT NULL, -- 'live', 'vod', 'series', 'epg'
            last_sync INTEGER NOT NULL,
            status TEXT, -- 'success', 'error', 'syncing'
            error TEXT,
            PRIMARY KEY (source_id, type)
        );
    `);

    console.log('[SQLite] Schema initialized');
}

module.exports = {
    getDb,
    initSchema
};