import { PrismaClient } from '@prisma/client';
import { PrismaPg } from '@prisma/adapter-pg';
import { Pool } from 'pg';

const globalForPrisma = globalThis as unknown as {
  prisma: PrismaClient | undefined;
};

function createPrismaClient() {
  // In development without a database, we'll create a mock-friendly client
  // For production or when DATABASE_URL is set, use the real adapter
  const connectionString = process.env.DATABASE_URL;
  
  if (!connectionString) {
    console.warn('DATABASE_URL not set - database features will not work');
    // Return a client that will throw clear errors when used
    return new PrismaClient({
      // This will fail on actual DB operations but allows imports to work
      adapter: new PrismaPg(new Pool({ connectionString: 'postgresql://localhost:5432/dummy' })),
    });
  }
  
  const pool = new Pool({ connectionString });
  const adapter = new PrismaPg(pool);
  
  return new PrismaClient({
    adapter,
    log: process.env.NODE_ENV === 'development' ? ['query', 'error', 'warn'] : ['error'],
  });
}

export const db = globalForPrisma.prisma ?? createPrismaClient();

if (process.env.NODE_ENV !== 'production') {
  globalForPrisma.prisma = db;
}

export default db;