/**
 * Environment validation utilities using Yup
 */
import { existsSync } from 'fs';
import { join } from 'path';
import { config } from 'dotenv';
import * as yup from 'yup';

// Function to find and load environment variables
function loadEnvFiles() {
  const cwd = process.cwd();
  const possiblePaths = [
    // Current working directory
    join(cwd, '.env'),
    join(cwd, '.env.local'),
    // Root of the workspace (common pattern)
    join(cwd, '../../.env'),
    join(cwd, '../../../.env'),
    // Config library directory
    join(__dirname, '../.env'),
    join(__dirname, '../../.env'),
    join(__dirname, '../../../.env'),
  ];

  // Try to load each possible .env file
  for (const envPath of possiblePaths) {
    if (existsSync(envPath)) {
      console.log(`📄 Loading environment from: ${envPath}`);
      config({ path: envPath });
      break; // Use the first .env file found
    }
  }

  // Also try to load environment-specific files
  const environment = process.env.NODE_ENV || 'development';
  const envSpecificPaths = [
    join(cwd, `.env.${environment}`),
    join(cwd, `.env.${environment}.local`),
  ];

  for (const envPath of envSpecificPaths) {
    if (existsSync(envPath)) {
      console.log(`📄 Loading ${environment} environment from: ${envPath}`);
      config({ path: envPath, override: false }); // Don't override existing vars
    }
  }
}

// Load environment variables
loadEnvFiles();

/**
 * Creates a Yup schema for environment variable validation
 */
export function createEnvSchema(shape: Record<string, any>) {
  return yup.object(shape);
}

/**
 * Validates environment variables against a Yup schema
 */
export function validateEnv(schema: yup.ObjectSchema<any>, env = process.env): any {
  try {
    const result = schema.validateSync(env, { abortEarly: false });
    return result;
  } catch (error) {
    if (error instanceof yup.ValidationError) {
      console.error('❌ Invalid environment variables:');
      error.inner.forEach(err => {
        console.error(`  ${err.path}: ${err.message}`);
      });
    }
    throw new Error('Environment validation failed');
  }
}

/**
 * Manually load environment variables from a specific path
 */
export function loadEnv(path?: string) {
  if (path) {
    console.log(`📄 Manually loading environment from: ${path}`);
    config({ path });
  } else {
    loadEnvFiles();
  }
}

/**
 * Helper functions for common validation patterns
 */
export const envValidators = {
  // String with default
  str: (defaultValue?: string, description?: string) => yup.string().default(defaultValue || ''),

  // String with choices (enum)
  strWithChoices: (choices: string[], defaultValue?: string, description?: string) =>
    yup
      .string()
      .oneOf(choices)
      .default(defaultValue || choices[0]),

  // Required string
  requiredStr: (description?: string) => yup.string().required('Required'),

  // Port number
  port: (defaultValue?: number, description?: string) =>
    yup
      .number()
      .integer()
      .min(1)
      .max(65535)
      .transform((val, originalVal) => {
        if (typeof originalVal === 'string') {
          return parseInt(originalVal, 10);
        }
        return val;
      })
      .default(defaultValue || 3000),

  // Number with default
  num: (defaultValue?: number, description?: string) =>
    yup
      .number()
      .transform((val, originalVal) => {
        if (typeof originalVal === 'string') {
          return parseFloat(originalVal);
        }
        return val;
      })
      .default(defaultValue || 0),

  // Boolean with default
  bool: (defaultValue?: boolean, description?: string) =>
    yup
      .boolean()
      .transform((val, originalVal) => {
        if (typeof originalVal === 'string') {
          return originalVal === 'true' || originalVal === '1';
        }
        return val;
      })
      .default(defaultValue || false),

  // URL validation
  url: (defaultValue?: string, description?: string) =>
    yup
      .string()
      .url()
      .default(defaultValue || 'http://localhost'),

  // Email validation
  email: (description?: string) => yup.string().email(),
};

/**
 * Legacy compatibility - creates a cleanEnv-like function
 */
export function cleanEnv(
  env: Record<string, string | undefined>,
  validators: Record<string, any>
): any {
  const schema = createEnvSchema(validators);
  return validateEnv(schema, env);
}