import { z } from 'zod';
import dotenv from 'dotenv';
import path from 'node:path';

dotenv.config({ path: path.resolve(__dirname, '../../../.env') });

const envSchema = z.object({
  DATABASE_URL: z.string().min(1),
  ENCRYPTION_KEY: z.string().length(64, 'ENCRYPTION_KEY must be 64 hex characters (32 bytes)'),
  AI_API_KEY: z.string().optional(),
  AI_BASE_URL: z.string().url().default('https://openrouter.ai/api/v1'),
  AI_MODEL: z.string().default('openrouter/free'),
  // Legacy alias — still accepted
  OPENAI_API_KEY: z.string().optional(),
  API_KEY: z.string().optional(),
  PORT: z.coerce.number().default(3000),
  PUBLIC_BASE_URL: z.string().url().optional(),
  NODE_ENV: z.enum(['development', 'production', 'test']).default('development'),
});

const parsed = envSchema.safeParse(process.env);

if (!parsed.success) {
  console.error('Invalid environment variables:', parsed.error.flatten().fieldErrors);
  process.exit(1);
}

const data = parsed.data;

function resolveDatabaseUrl(url: string): string {
  if (!url.startsWith('file:')) return url;
  const filePath = url.slice('file:'.length);
  if (path.isAbsolute(filePath)) return url;
  return `file:${path.resolve(__dirname, '../../../', filePath)}`;
}

export const config = {
  ...data,
  DATABASE_URL: resolveDatabaseUrl(data.DATABASE_URL),
  AI_API_KEY: data.AI_API_KEY ?? data.OPENAI_API_KEY,
};