const { Pool } = require('pg');
require('dotenv').config();

let pool = null;

// ================================================================
// INICIALIZAR BANCO DE DADOS POSTGRESQL
// ================================================================

async function initDatabase() {
  const dbConfig = {
    host: process.env.DB_HOST || '10.99.0.3',
    port: process.env.DB_PORT || 5432,
    user: process.env.DB_USER || 'postgres',
    database: process.env.DB_NAME || 'dental_images',
    max: 20, // Max number of clients in the pool
    idleTimeoutMillis: 30000,
  };

  if (process.env.DB_PASSWORD) {
    dbConfig.password = process.env.DB_PASSWORD;
  }

  try {
    pool = new Pool(dbConfig);
    
    // Testa a conexão
    const client = await pool.connect();
    console.log(`✅ Conectado ao PostgreSQL (Host: ${dbConfig.host}, DB: ${dbConfig.database})`);
    client.release();
    
    // Criar as tabelas
    await createTables();
  } catch (error) {
    console.error('❌ Erro ao conectar ao PostgreSQL:', error.message);
    throw error;
  }
}

// ================================================================
// CRIAR TABELAS POSTGRESQL
// ================================================================

async function createTables() {
  const client = await pool.connect();
  
  try {
    // Tabela de usuários
    await client.query(`
      CREATE TABLE IF NOT EXISTS users (
        id SERIAL PRIMARY KEY,
        username VARCHAR(50) UNIQUE NOT NULL,
        email VARCHAR(100) UNIQUE NOT NULL,
        password_hash TEXT NOT NULL,
        clinic_name VARCHAR(100),
        pc_name VARCHAR(50),
        is_admin BOOLEAN DEFAULT false,
        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
      )
    `);
    console.log('✅ Tabela users criada/verificada no PostgreSQL');
    
    // Tabela de imagens
    await client.query(`
      CREATE TABLE IF NOT EXISTS images (
        id SERIAL PRIMARY KEY,
        image_guid VARCHAR(255) NOT NULL,
        patient_name TEXT,
        client_name VARCHAR(100),
        original_filename TEXT,
        filename TEXT NOT NULL,
        enabled BOOLEAN DEFAULT true,
        tooth_number VARCHAR(10),
        tooth_side VARCHAR(10),
        patient_name_resumed VARCHAR(50),
        original_image_id INT,
        rotation INT DEFAULT 0,
        flip_horizontal INT DEFAULT 0,
        flip_vertical INT DEFAULT 0,
        doctor VARCHAR(255),
        remark TEXT,
        thumb_filename TEXT,
        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
      )
    `);
    
    // Criação de índices no PostgreSQL
    await client.query('CREATE INDEX IF NOT EXISTS idx_images_enabled ON images(enabled)');
    await client.query('CREATE INDEX IF NOT EXISTS idx_images_original ON images(original_image_id)');
    await client.query('CREATE INDEX IF NOT EXISTS idx_image_guid ON images(image_guid)');
    await client.query('CREATE INDEX IF NOT EXISTS idx_client_name ON images(client_name)');
    await client.query('CREATE INDEX IF NOT EXISTS idx_created_at ON images(created_at)');
    
    // Garantir que a coluna exista caso a tabela já tenha sido criada antes
    await client.query('ALTER TABLE images ADD COLUMN IF NOT EXISTS thumb_filename TEXT;');
    await client.query('ALTER TABLE images ADD COLUMN IF NOT EXISTS clinic_name VARCHAR(100);');
    await client.query('ALTER TABLE images ADD COLUMN IF NOT EXISTS image_remark TEXT;');

    console.log('✅ Tabela images criada/verificada no PostgreSQL');
    
    // Tabela GTOs
    await client.query(`
      CREATE TABLE IF NOT EXISTS gtos (
        id SERIAL PRIMARY KEY,
        gto_number VARCHAR(100) NOT NULL,
        patient_name VARCHAR(255) NOT NULL,
        description TEXT,
        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
      )
    `);
    await client.query('CREATE INDEX IF NOT EXISTS idx_gtos_patient ON gtos(patient_name)');
    await client.query('ALTER TABLE gtos ADD COLUMN IF NOT EXISTS sent BOOLEAN DEFAULT FALSE;');
    await client.query('ALTER TABLE gtos ADD COLUMN IF NOT EXISTS sent_at TIMESTAMP;');
    console.log('✅ Tabela gtos criada/verificada no PostgreSQL');

    // Tabela de vínculo GTO-Images
    await client.query(`
      CREATE TABLE IF NOT EXISTS gto_images (
        id SERIAL PRIMARY KEY,
        gto_id INT NOT NULL REFERENCES gtos(id) ON DELETE CASCADE,
        image_id INT NOT NULL REFERENCES images(id) ON DELETE CASCADE,
        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
        UNIQUE(gto_id, image_id)
      )
    `);
    console.log('✅ Tabela gto_images criada/verificada no PostgreSQL');

    // Tabela de Clínicas / Dispositivos
    await client.query(`
      CREATE TABLE IF NOT EXISTS clinics_devices (
        id SERIAL PRIMARY KEY,
        clinic_name VARCHAR(255) NOT NULL,
        email VARCHAR(255) UNIQUE NOT NULL,
        password_hash TEXT NOT NULL,
        pc_name VARCHAR(100),
        machine_token UUID NOT NULL UNIQUE,
        last_ip VARCHAR(50),
        is_active BOOLEAN DEFAULT true,
        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
      )
    `);
    console.log('✅ Tabela clinics_devices criada/verificada no PostgreSQL');

    // Tabela de configurações do sistema (key-value)
    await client.query(`
      CREATE TABLE IF NOT EXISTS system_config (
        key VARCHAR(100) PRIMARY KEY,
        value TEXT,
        updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
      )
    `);
    console.log('✅ Tabela system_config criada/verificada no PostgreSQL');
    
    // Verificar colunas faltantes em users (migração)
    try {
      const res = await client.query(`
        SELECT column_name 
        FROM information_schema.columns 
        WHERE table_name = 'users' AND column_name = 'clinic_name'
      `);
      if (res.rows.length === 0) {
        console.log('⚠️ Adicionando novas colunas na tabela users...');
        await client.query(`
          ALTER TABLE users 
          ADD COLUMN clinic_name VARCHAR(100),
          ADD COLUMN pc_name VARCHAR(50),
          ADD COLUMN is_admin BOOLEAN DEFAULT false
        `);
      }
    } catch (e) {
      console.warn('⚠️ Erro ao migrar tabela users:', e.message);
    }

    // Criar administrador padrão se não houver usuários
    try {
      const res = await client.query('SELECT COUNT(*) as count FROM users');
      if (parseInt(res.rows[0].count) === 0) {
        console.log('⚠️ Nenhum usuário encontrado. Criando admin padrão (admin / admin1234)...');
        const bcrypt = require('bcrypt');
        const passwordHash = bcrypt.hashSync('admin1234', 10);
        await client.query(`
          INSERT INTO users (username, email, password_hash, clinic_name, pc_name, is_admin)
          VALUES ($1, $2, $3, $4, $5, true)
        `, ['admin', 'admin@dental.local', passwordHash, 'Admin Clinic', 'Admin PC']);
        console.log('✅ Usuário admin padrão criado com sucesso!');
      }
    } catch (error) {
      console.error('⚠️ Erro ao criar admin padrão:', error.message);
    }
    
  } catch (error) {
    console.error('❌ Erro ao criar tabelas no PostgreSQL:', error);
  } finally {
    client.release();
  }
}

// ================================================================
// FUNÇÕES DE CONSULTA (ENVOLVENDO O POOL DO PG)
// ================================================================

function get(query, params = []) {
  return new Promise(async (resolve, reject) => {
    try {
      const res = await pool.query(query, params);
      resolve(res.rows[0] || null);
    } catch (error) {
      reject(error);
    }
  });
}

function all(query, params = []) {
  return new Promise(async (resolve, reject) => {
    try {
      const res = await pool.query(query, params);
      resolve(res.rows || []);
    } catch (error) {
      reject(error);
    }
  });
}

function run(query, params = []) {
  return new Promise(async (resolve, reject) => {
    try {
      const res = await pool.query(query, params);
      
      // No PostgreSQL, se adicionamos RETURNING id, o id estará no res.rows[0]
      const insertedId = (res.rows && res.rows[0] && res.rows[0].id) ? res.rows[0].id : null;
      
      resolve({ 
        lastID: insertedId, 
        changes: res.rowCount 
      });
    } catch (error) {
      reject(error);
    }
  });
}

// ================================================================
// EXPORT
// ================================================================

module.exports = {
  initDatabase,
  get,
  all,
  run,
  get db() { return pool; }
};