const sqlite3 = require('sqlite3').verbose();
const path = require('path');

const dbPath = path.join(__dirname, '..', 'step_competition.db');
const db = new sqlite3.Database(dbPath);

// Initialize database schema
function initializeDatabase() {
  db.serialize(() => {
    // Teams table
    db.run(`
      CREATE TABLE IF NOT EXISTS teams (
        id INTEGER PRIMARY KEY AUTOINCREMENT,
        name TEXT NOT NULL UNIQUE,
        created_at DATETIME DEFAULT CURRENT_TIMESTAMP
      )
    `);

    // Participants table
    db.run(`
      CREATE TABLE IF NOT EXISTS participants (
        id INTEGER PRIMARY KEY AUTOINCREMENT,
        name TEXT NOT NULL,
        email TEXT UNIQUE,
        team_id INTEGER NOT NULL,
        created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
        FOREIGN KEY (team_id) REFERENCES teams(id)
      )
    `);

    // Daily steps table
    db.run(`
      CREATE TABLE IF NOT EXISTS daily_steps (
        id INTEGER PRIMARY KEY AUTOINCREMENT,
        participant_id INTEGER NOT NULL,
        date DATE NOT NULL,
        steps INTEGER NOT NULL DEFAULT 0,
        created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
        updated_at DATETIME DEFAULT CURRENT_TIMESTAMP,
        FOREIGN KEY (participant_id) REFERENCES participants(id),
        UNIQUE(participant_id, date)
      )
    `);

    // Daily monsters table
    db.run(`
      CREATE TABLE IF NOT EXISTS daily_monsters (
        id INTEGER PRIMARY KEY AUTOINCREMENT,
        date DATE NOT NULL UNIQUE,
        monster_name TEXT NOT NULL,
        monster_description TEXT,
        step_goal INTEGER NOT NULL,
        monster_icon TEXT DEFAULT '👹',
        created_at DATETIME DEFAULT CURRENT_TIMESTAMP
      )
    `);

    // Monster catches view - derived from actual step data
    // Drop the old table if it exists and recreate as a view
    db.run(`DROP TABLE IF EXISTS monster_catches`);
    db.run(`
      CREATE VIEW IF NOT EXISTS monster_catches AS
      SELECT
        dm.id as monster_id,
        dm.date,
        t.id as team_id,
        t.name as team_name,
        COALESCE(SUM(ds.steps), 0) as final_steps,
        dm.step_goal
      FROM daily_monsters dm
      CROSS JOIN teams t
      LEFT JOIN participants p ON t.id = p.team_id
      LEFT JOIN daily_steps ds ON p.id = ds.participant_id AND ds.date = dm.date
      GROUP BY dm.id, dm.date, t.id, t.name, dm.step_goal
      HAVING final_steps >= dm.step_goal
    `);

    // Create indexes for better query performance
    db.run(`CREATE INDEX IF NOT EXISTS idx_daily_steps_date ON daily_steps(date)`);
    db.run(`CREATE INDEX IF NOT EXISTS idx_daily_steps_participant ON daily_steps(participant_id)`);
    db.run(`CREATE INDEX IF NOT EXISTS idx_participants_team ON participants(team_id)`);
    db.run(`CREATE INDEX IF NOT EXISTS idx_daily_monsters_date ON daily_monsters(date)`);

    console.log('Database initialized successfully');
  });
}

// Helper function to run queries with promises
function runQuery(sql, params = []) {
  return new Promise((resolve, reject) => {
    db.run(sql, params, function(err) {
      if (err) reject(err);
      else resolve({ id: this.lastID, changes: this.changes });
    });
  });
}

function getQuery(sql, params = []) {
  return new Promise((resolve, reject) => {
    db.get(sql, params, (err, row) => {
      if (err) reject(err);
      else resolve(row);
    });
  });
}

function allQuery(sql, params = []) {
  return new Promise((resolve, reject) => {
    db.all(sql, params, (err, rows) => {
      if (err) reject(err);
      else resolve(rows);
    });
  });
}

module.exports = {
  db,
  initializeDatabase,
  runQuery,
  getQuery,
  allQuery
};