import Joi from 'joi';

import { logger } from './logger.ts';
import type { NodeEnvironment, ValidatedEnvironment } from '../types/index.ts';

type EnvBooleanString = 'true' | 'false';
type EnvLogLevel = ValidatedEnvironment['LOG_LEVEL'];

const envSchema = Joi.object({
  NODE_ENV: Joi.string()
    .valid('development', 'test', 'production', 'dev_stage')
    .default('development'),

  PORT: Joi.number().default(8080),
  NEXT_PUBLIC_BACK_API: Joi.string().uri().allow('').default(''),

  DB_HOST: Joi.string().default('localhost'),
  DB_PORT: Joi.number().default(5432),
  DB_NAME: Joi.string().default('db_tour_builder_platform'),
  DB_USER: Joi.string().default('postgres'),
  DB_PASS: Joi.string().allow('').default(''),

  SECRET_KEY: Joi.string()
    .min(16)
    .default('88dbeaf8-e906-405e-9e41-c3baadeda5c6'),

  ADMIN_PASS: Joi.string().default('88dbeaf8'),
  USER_PASS: Joi.string().default('c3baadeda5c6'),
  ADMIN_EMAIL: Joi.string().email().default('admin@flatlogic.com'),

  GOOGLE_CLIENT_ID: Joi.string().allow('').default(''),
  GOOGLE_CLIENT_SECRET: Joi.string().allow('').default(''),
  MS_CLIENT_ID: Joi.string().allow('').default(''),
  MS_CLIENT_SECRET: Joi.string().allow('').default(''),

  AWS_ACCESS_KEY_ID: Joi.string().allow('').default(''),
  AWS_SECRET_ACCESS_KEY: Joi.string().allow('').default(''),
  AWS_S3_BUCKET: Joi.string().allow('').default(''),
  AWS_S3_REGION: Joi.string().default('us-east-1'),
  AWS_S3_PREFIX: Joi.string().default('afeefb9d49f5b7977577876b99532ac7'),
  AWS_S3_CONNECTION_TIMEOUT: Joi.number().integer().positive().default(5000),
  AWS_S3_REQUEST_TIMEOUT: Joi.number().integer().positive().default(30000),
  AWS_S3_MAX_ATTEMPTS: Joi.number().integer().positive().default(3),
  AWS_S3_MAX_SOCKETS: Joi.number().integer().positive().default(50),
  AWS_S3_KEEP_ALIVE: Joi.string().valid('true', 'false').default('true'),
  AWS_S3_PRESIGN_EXPIRY: Joi.number().integer().positive().default(3600),

  FILE_STORAGE_PROVIDER: Joi.string()
    .trim()
    .lowercase()
    .valid('', 's3', 'gcloud', 'local')
    .default(''),
  GC_PROJECT_ID: Joi.string().allow('').default(''),
  GC_CLIENT_EMAIL: Joi.string().allow('').default(''),
  GC_PRIVATE_KEY: Joi.string().allow('').default(''),

  S3_CACHE_DIR: Joi.string().allow('').default(''),
  S3_CACHE_ENABLED: Joi.string().valid('true', 'false').default('true'),
  S3_CACHE_MAX_AGE: Joi.number().integer().positive().default(86400),

  FFMPEG_REVERSE_TIMEOUT_MS: Joi.number().integer().positive().default(600000),
  FFPROBE_TIMEOUT_MS: Joi.number().integer().positive().default(30000),
  FFMPEG_BREAKER_FAILURE_THRESHOLD: Joi.number()
    .integer()
    .positive()
    .default(3),
  FFMPEG_BREAKER_COOLDOWN_MS: Joi.number()
    .integer()
    .positive()
    .default(120000),
  FFMPEG_BREAKER_SUCCESS_THRESHOLD: Joi.number()
    .integer()
    .positive()
    .default(1),
  FILE_STORAGE_BREAKER_FAILURE_THRESHOLD: Joi.number()
    .integer()
    .positive()
    .default(5),
  FILE_STORAGE_BREAKER_COOLDOWN_MS: Joi.number()
    .integer()
    .positive()
    .default(30000),
  FILE_STORAGE_BREAKER_SUCCESS_THRESHOLD: Joi.number()
    .integer()
    .positive()
    .default(2),

  EMAIL_USER: Joi.string().allow('').default(''),
  EMAIL_PASS: Joi.string().allow('').default(''),
  EMAIL_TLS_REJECT_UNAUTHORIZED: Joi.string()
    .valid('true', 'false')
    .default('true'),

  PEXELS_KEY: Joi.string().allow('').default(''),

  LOG_LEVEL: Joi.string()
    .valid('fatal', 'error', 'warn', 'info', 'debug', 'trace')
    .default('info'),
  LOG_PRETTY: Joi.string().valid('true', 'false').default('false'),
}).unknown(true);

function isNodeEnvironment(value: unknown): value is NodeEnvironment {
  return (
    value === 'development' ||
    value === 'test' ||
    value === 'production' ||
    value === 'dev_stage'
  );
}

function isRecord(value: unknown): value is Record<string, unknown> {
  return Boolean(value) && typeof value === 'object' && !Array.isArray(value);
}

function isEnvBooleanString(value: unknown): value is EnvBooleanString {
  return value === 'true' || value === 'false';
}

function isEnvLogLevel(value: unknown): value is EnvLogLevel {
  return (
    value === 'fatal' ||
    value === 'error' ||
    value === 'warn' ||
    value === 'info' ||
    value === 'debug' ||
    value === 'trace'
  );
}

function readString(
  values: Record<string, unknown>,
  key: keyof ValidatedEnvironment,
  fallback: string,
): string {
  const value = values[key];
  return typeof value === 'string' ? value : fallback;
}

function readNumber(
  values: Record<string, unknown>,
  key: keyof ValidatedEnvironment,
  fallback: number,
): number {
  const value = values[key];
  return typeof value === 'number' ? value : fallback;
}

function toValidatedEnvironment(
  values: Record<string, unknown>,
): ValidatedEnvironment {
  const nodeEnv = values.NODE_ENV;
  const tlsRejectUnauthorized = values.EMAIL_TLS_REJECT_UNAUTHORIZED;
  const logLevel = values.LOG_LEVEL;
  const s3KeepAlive = values.AWS_S3_KEEP_ALIVE;
  const fileStorageProvider = values.FILE_STORAGE_PROVIDER;
  const s3CacheEnabled = values.S3_CACHE_ENABLED;
  const logPretty = values.LOG_PRETTY;

  return {
    NODE_ENV: isNodeEnvironment(nodeEnv) ? nodeEnv : 'development',
    PORT: readNumber(values, 'PORT', 8080),
    NEXT_PUBLIC_BACK_API: readString(values, 'NEXT_PUBLIC_BACK_API', ''),
    DB_HOST: readString(values, 'DB_HOST', 'localhost'),
    DB_PORT: readNumber(values, 'DB_PORT', 5432),
    DB_NAME: readString(values, 'DB_NAME', 'db_tour_builder_platform'),
    DB_USER: readString(values, 'DB_USER', 'postgres'),
    DB_PASS: readString(values, 'DB_PASS', ''),
    SECRET_KEY: readString(
      values,
      'SECRET_KEY',
      '88dbeaf8-e906-405e-9e41-c3baadeda5c6',
    ),
    ADMIN_PASS: readString(values, 'ADMIN_PASS', '88dbeaf8'),
    USER_PASS: readString(values, 'USER_PASS', 'c3baadeda5c6'),
    ADMIN_EMAIL: readString(values, 'ADMIN_EMAIL', 'admin@flatlogic.com'),
    GOOGLE_CLIENT_ID: readString(values, 'GOOGLE_CLIENT_ID', ''),
    GOOGLE_CLIENT_SECRET: readString(values, 'GOOGLE_CLIENT_SECRET', ''),
    MS_CLIENT_ID: readString(values, 'MS_CLIENT_ID', ''),
    MS_CLIENT_SECRET: readString(values, 'MS_CLIENT_SECRET', ''),
    AWS_ACCESS_KEY_ID: readString(values, 'AWS_ACCESS_KEY_ID', ''),
    AWS_SECRET_ACCESS_KEY: readString(values, 'AWS_SECRET_ACCESS_KEY', ''),
    AWS_S3_BUCKET: readString(values, 'AWS_S3_BUCKET', ''),
    AWS_S3_REGION: readString(values, 'AWS_S3_REGION', 'us-east-1'),
    AWS_S3_PREFIX: readString(
      values,
      'AWS_S3_PREFIX',
      'afeefb9d49f5b7977577876b99532ac7',
    ),
    AWS_S3_CONNECTION_TIMEOUT: readNumber(
      values,
      'AWS_S3_CONNECTION_TIMEOUT',
      5000,
    ),
    AWS_S3_REQUEST_TIMEOUT: readNumber(
      values,
      'AWS_S3_REQUEST_TIMEOUT',
      30000,
    ),
    AWS_S3_MAX_ATTEMPTS: readNumber(values, 'AWS_S3_MAX_ATTEMPTS', 3),
    AWS_S3_MAX_SOCKETS: readNumber(values, 'AWS_S3_MAX_SOCKETS', 50),
    AWS_S3_KEEP_ALIVE: isEnvBooleanString(s3KeepAlive) ? s3KeepAlive : 'true',
    AWS_S3_PRESIGN_EXPIRY: readNumber(
      values,
      'AWS_S3_PRESIGN_EXPIRY',
      3600,
    ),
    FILE_STORAGE_PROVIDER:
      fileStorageProvider === 's3' ||
      fileStorageProvider === 'gcloud' ||
      fileStorageProvider === 'local'
        ? fileStorageProvider
        : '',
    GC_PROJECT_ID: readString(values, 'GC_PROJECT_ID', ''),
    GC_CLIENT_EMAIL: readString(values, 'GC_CLIENT_EMAIL', ''),
    GC_PRIVATE_KEY: readString(values, 'GC_PRIVATE_KEY', ''),
    S3_CACHE_DIR: readString(values, 'S3_CACHE_DIR', ''),
    S3_CACHE_ENABLED: isEnvBooleanString(s3CacheEnabled)
      ? s3CacheEnabled
      : 'true',
    S3_CACHE_MAX_AGE: readNumber(values, 'S3_CACHE_MAX_AGE', 86400),
    FFMPEG_REVERSE_TIMEOUT_MS: readNumber(
      values,
      'FFMPEG_REVERSE_TIMEOUT_MS',
      600000,
    ),
    FFPROBE_TIMEOUT_MS: readNumber(values, 'FFPROBE_TIMEOUT_MS', 30000),
    FFMPEG_BREAKER_FAILURE_THRESHOLD: readNumber(
      values,
      'FFMPEG_BREAKER_FAILURE_THRESHOLD',
      3,
    ),
    FFMPEG_BREAKER_COOLDOWN_MS: readNumber(
      values,
      'FFMPEG_BREAKER_COOLDOWN_MS',
      120000,
    ),
    FFMPEG_BREAKER_SUCCESS_THRESHOLD: readNumber(
      values,
      'FFMPEG_BREAKER_SUCCESS_THRESHOLD',
      1,
    ),
    FILE_STORAGE_BREAKER_FAILURE_THRESHOLD: readNumber(
      values,
      'FILE_STORAGE_BREAKER_FAILURE_THRESHOLD',
      5,
    ),
    FILE_STORAGE_BREAKER_COOLDOWN_MS: readNumber(
      values,
      'FILE_STORAGE_BREAKER_COOLDOWN_MS',
      30000,
    ),
    FILE_STORAGE_BREAKER_SUCCESS_THRESHOLD: readNumber(
      values,
      'FILE_STORAGE_BREAKER_SUCCESS_THRESHOLD',
      2,
    ),
    EMAIL_USER: readString(values, 'EMAIL_USER', ''),
    EMAIL_PASS: readString(values, 'EMAIL_PASS', ''),
    EMAIL_TLS_REJECT_UNAUTHORIZED: isEnvBooleanString(tlsRejectUnauthorized)
      ? tlsRejectUnauthorized
      : 'true',
    PEXELS_KEY: readString(values, 'PEXELS_KEY', ''),
    LOG_LEVEL: isEnvLogLevel(logLevel) ? logLevel : 'info',
    LOG_PRETTY: isEnvBooleanString(logPretty) ? logPretty : 'false',
  };
}

function validateEnv(): ValidatedEnvironment {
  const result: Joi.ValidationResult<Record<string, unknown>> =
    envSchema.validate(process.env, {
    abortEarly: false,
    stripUnknown: false,
  });

  if (result.error) {
    const messages = result.error.details.map(
      (detail) => `  - ${detail.message}`,
    );
    logger.error({ errors: messages }, 'Environment validation failed');

    if (process.env.NODE_ENV === 'production') {
      process.exit(1);
    } else {
      logger.warn('Continuing with default values in non-production mode');
    }
  }

  const resultValue: unknown = result.value;
  return toValidatedEnvironment(isRecord(resultValue) ? resultValue : {});
}

export { envSchema, validateEnv };