/**
 * Migration Example: Applying Centralized RLS Policies
 *
 * This migration demonstrates how to replace vertical-specific RLS policies
 * with the centralized shared library policies.
 *
 * BEFORE: Each vertical had duplicated RLS functions and policies
 * AFTER: Use shared-libs centralized RLS policies
 */

import { Pool } from 'pg';
import {
  applyCompleteRlsPolicies,
  applyCompletePoliciesForSchema,
  batchApplyRlsPolicies,
  getSchemaRlsStatus,
} from '@erp-suite/core';

/**
 * Migration UP: Apply RLS policies to all tables
 */
export async function up(pool: Pool): Promise<void> {
  console.log('Starting RLS migration...');

  // STEP 1: Install RLS helper functions (run once per database)
  console.log('Installing RLS helper functions...');
  // Note: This would be done via SQL file first:
  // psql -d database -f apps/shared-libs/core/database/policies/rls-policies.sql

  // STEP 2: Apply RLS to ERP Core tables
  console.log('Applying RLS to ERP Core tables...');

  const coreSchemas = [
    {
      schema: 'core',
      tables: ['partners', 'addresses', 'product_categories', 'tags', 'sequences', 'attachments', 'notes'],
    },
    {
      schema: 'inventory',
      tables: ['products', 'warehouses', 'locations', 'lots', 'pickings', 'stock_moves'],
    },
    {
      schema: 'sales',
      tables: ['sales_orders', 'quotations', 'pricelists'],
    },
    {
      schema: 'purchase',
      tables: ['purchase_orders', 'rfqs', 'vendor_pricelists'],
    },
    {
      schema: 'financial',
      tables: ['accounts', 'invoices', 'payments', 'journal_entries'],
    },
  ];

  for (const { schema, tables } of coreSchemas) {
    await applyCompletePoliciesForSchema(pool, schema, tables);
    console.log(`  Applied RLS to ${schema} schema (${tables.length} tables)`);
  }

  // STEP 3: Apply RLS to vertical-specific tables
  console.log('Applying RLS to vertical tables...');

  // Example: Construccion vertical
  const construccionTables = [
    { schema: 'construction', table: 'projects', tenantColumn: 'constructora_id' },
    { schema: 'construction', table: 'estimates', tenantColumn: 'constructora_id' },
    { schema: 'construction', table: 'work_orders', tenantColumn: 'constructora_id' },
    { schema: 'hse', table: 'incidents', tenantColumn: 'constructora_id' },
  ];

  await batchApplyRlsPolicies(pool, construccionTables);
  console.log(`  Applied RLS to construccion vertical (${construccionTables.length} tables)`);

  // Example: Mecanicas-diesel vertical
  const mecanicasTables = [
    { schema: 'mechanics', table: 'work_orders' },
    { schema: 'mechanics', table: 'vehicles' },
    { schema: 'mechanics', table: 'parts' },
  ];

  await batchApplyRlsPolicies(pool, mecanicasTables);
  console.log(`  Applied RLS to mecanicas-diesel vertical (${mecanicasTables.length} tables)`);

  // STEP 4: Verify RLS application
  console.log('Verifying RLS policies...');
  const coreStatus = await getSchemaRlsStatus(pool, 'core');
  const enabledCount = coreStatus.filter(s => s.rlsEnabled).length;
  console.log(`  Core schema: ${enabledCount}/${coreStatus.length} tables have RLS enabled`);

  console.log('RLS migration completed successfully!');
}

/**
 * Migration DOWN: Remove RLS policies
 */
export async function down(pool: Pool): Promise<void> {
  console.log('Rolling back RLS migration...');

  // Import cleanup functions
  const { dropAllRlsPolicies, disableRls } = await import('@erp-suite/core');

  // Remove RLS from all tables
  const schemas = ['core', 'inventory', 'sales', 'purchase', 'financial', 'construction', 'hse', 'mechanics'];

  for (const schema of schemas) {
    const tablesQuery = `
      SELECT table_name
      FROM information_schema.tables
      WHERE table_schema = $1
      AND table_type = 'BASE TABLE'
    `;
    const result = await pool.query(tablesQuery, [schema]);

    for (const row of result.rows) {
      const table = row.table_name;
      try {
        const count = await dropAllRlsPolicies(pool, schema, table);
        if (count > 0) {
          await disableRls(pool, schema, table);
          console.log(`  Removed RLS from ${schema}.${table} (${count} policies)`);
        }
      } catch (error) {
        console.error(`  Error removing RLS from ${schema}.${table}:`, error.message);
      }
    }
  }

  console.log('RLS migration rollback completed!');
}

/**
 * Example usage in a migration framework
 */
export default {
  up,
  down,
};

// TypeORM migration class format
export class ApplyRlsPolicies1234567890123 {
  public async up(queryRunner: any): Promise<void> {
    // Get pool from queryRunner or create one
    const pool = queryRunner.connection.driver.master;
    await up(pool);
  }

  public async down(queryRunner: any): Promise<void> {
    const pool = queryRunner.connection.driver.master;
    await down(pool);
  }
}