import { pool } from './pool';

async function initDB() {
  const client = await pool.connect();
  try {
    await client.query('BEGIN');

    console.log('Creating tables...');

    // 1. Catalogue Module
    await client.query(`
      CREATE TABLE IF NOT EXISTS drugs (
        id VARCHAR(50) PRIMARY KEY,
        generic_name VARCHAR(255) NOT NULL,
        atc_code VARCHAR(50),
        schedule VARCHAR(20),
        is_nti BOOLEAN DEFAULT false,
        pregnancy_category VARCHAR(10)
      );
    `);

    await client.query(`
      CREATE TABLE IF NOT EXISTS products (
        id VARCHAR(50) PRIMARY KEY,
        drug_id VARCHAR(50) REFERENCES drugs(id),
        brand_name VARCHAR(255) NOT NULL,
        manufacturer VARCHAR(255),
        strength VARCHAR(50),
        form VARCHAR(50),
        mrp DECIMAL(10, 2),
        dpco_ceiling DECIMAL(10, 2)
      );
    `);

    // 2. Inventory Module
    await client.query(`
      CREATE TABLE IF NOT EXISTS batches (
        batch_no VARCHAR(100) PRIMARY KEY,
        product_id VARCHAR(50) REFERENCES products(id),
        expiry DATE NOT NULL,
        qty_on_hand INTEGER NOT NULL CHECK (qty_on_hand >= 0),
        purchase_price DECIMAL(10, 2),
        status VARCHAR(50) DEFAULT 'available'
      );
    `);

    await client.query(`
      CREATE TABLE IF NOT EXISTS stock_movements (
        id SERIAL PRIMARY KEY,
        batch_no VARCHAR(100) REFERENCES batches(batch_no),
        movement_type VARCHAR(50) NOT NULL, -- 'receipt', 'dispense', 'adjustment'
        qty_delta INTEGER NOT NULL,
        reference_id VARCHAR(100),
        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
      );
    `);

    // 3. Dispensing & Audit
    await client.query(`
      CREATE TABLE IF NOT EXISTS dispensing_records (
        id VARCHAR(50) PRIMARY KEY,
        subject_ref VARCHAR(100) NOT NULL,
        tenant_id VARCHAR(50) NOT NULL,
        dispensed_by VARCHAR(100) NOT NULL,
        prescription_id VARCHAR(50),
        total_amount DECIMAL(10, 2) DEFAULT 0,
        payment_method VARCHAR(50) DEFAULT 'cash',
        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
      );
    `);

    await client.query(`
      CREATE TABLE IF NOT EXISTS overrides_log (
        id SERIAL PRIMARY KEY,
        dispensing_id VARCHAR(50) REFERENCES dispensing_records(id),
        code VARCHAR(50) NOT NULL,
        reason TEXT NOT NULL,
        actor_user_id VARCHAR(100) NOT NULL,
        occurred_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
      );
    `);

    await client.query(`
      CREATE TABLE IF NOT EXISTS h1_registers (
        id VARCHAR(50) PRIMARY KEY,
        dispensing_id VARCHAR(50) REFERENCES dispensing_records(id),
        patient_name VARCHAR(255) NOT NULL,
        prescriber_name VARCHAR(255),
        drug_name VARCHAR(255) NOT NULL,
        batch_no VARCHAR(100),
        qty INTEGER NOT NULL,
        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
      );
    `);

    await client.query(`
      CREATE TABLE IF NOT EXISTS order_drafts (
        id VARCHAR(50) PRIMARY KEY,
        subject_ref VARCHAR(100),
        prescription_ref VARCHAR(50),
        items JSONB,
        status VARCHAR(20) DEFAULT 'draft',
        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
        updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
      );
    `);

    await client.query(`
      CREATE TABLE IF NOT EXISTS audit_logs (
        id SERIAL PRIMARY KEY,
        call_id VARCHAR(100),
        actor_user_id VARCHAR(100),
        task_type VARCHAR(50),
        details JSONB,
        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
      );
    `);

    // 4. Phase 2: Prescriptions
    await client.query(`
      CREATE TABLE IF NOT EXISTS prescriptions (
        id VARCHAR(50) PRIMARY KEY,
        image_path TEXT NOT NULL,
        image_hash VARCHAR(64) NOT NULL,
        status VARCHAR(20) DEFAULT 'processing',
        extracted_data JSONB,
        confirmed_data JSONB,
        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
      );
    `);

    console.log('Seeding initial data...');
    // Seed Dummy Data for UI
    await client.query(`
      INSERT INTO drugs (id, generic_name, schedule) VALUES 
      ('drg_001', 'Losartan Potassium', 'H'),
      ('drg_002', 'Sertraline', 'H')
      ON CONFLICT (id) DO NOTHING;
    `);

    await client.query(`
      INSERT INTO products (id, drug_id, brand_name, form, mrp) VALUES 
      ('prd_4410', 'drg_001', 'Losar 50', 'tablet', 78.50),
      ('prd_5510', 'drg_002', 'Sertra 50', 'tablet', 110.00)
      ON CONFLICT (id) DO NOTHING;
    `);

    // Add batches. Let's add a near-expiry batch so the UI alert triggers
    await client.query(`
      INSERT INTO batches (batch_no, product_id, expiry, qty_on_hand, purchase_price) VALUES 
      ('B4421', 'prd_4410', CURRENT_DATE + INTERVAL '15 days', 240, 50.00),
      ('B4630', 'prd_5510', CURRENT_DATE + INTERVAL '200 days', 500, 80.00)
      ON CONFLICT (batch_no) DO NOTHING;
    `);

    await client.query('COMMIT');
    console.log('Database initialization and seeding completed successfully!');
  } catch (error) {
    await client.query('ROLLBACK');
    console.error('Error initializing database:', error);
  } finally {
    client.release();
    pool.end();
  }
}

initDB();