const { z } = require("zod");

const booleanString = z.enum(["true", "false"]).default("false").transform((value) => value === "true");

const envSchema = z.object({
  NODE_ENV: z.enum(["development", "test", "production"]).default("development"),
  PORT: z.coerce.number().int().min(1).max(65535).default(3070),
  DB_HOST: z.string().min(1),
  DB_PORT: z.coerce.number().int().min(1).max(65535).default(3306),
  DB_NAME: z.string().min(1),
  DB_USER: z.string().min(1),
  DB_PASSWORD: z.string(),
  JWT_SECRET: z.string().min(32, "JWT_SECRET must contain at least 32 characters"),
  JWT_ISSUER: z.string().min(1).default("zumri-api"),
  JWT_AUDIENCE: z.string().min(1).default("zumri-clients"),
  ACCESS_TOKEN_TTL: z.string().default("15m"),
  REFRESH_TOKEN_TTL_DAYS: z.coerce.number().int().positive().default(7),
  REMEMBER_ME_REFRESH_TOKEN_TTL_DAYS: z.coerce.number().int().positive().default(30),
  LOGIN_OTP_TTL_SECONDS: z.coerce.number().int().positive().default(900),
  LOGIN_OTP_MAX_ATTEMPTS: z.coerce.number().int().min(1).max(10).default(5),
  REDIS_HOST: z.string().min(1),
  REDIS_PORT: z.coerce.number().int().min(1).max(65535).default(6379),
  REDIS_PASSWORD: z.string().optional(),
  FRONTEND_URL: z.string().url(),
  TRUST_PROXY: z.coerce.number().int().min(0).max(10).default(0),
  JSON_BODY_LIMIT: z.string().default("1mb"),
  API_RATE_LIMIT_WINDOW_MS: z.coerce.number().int().positive().default(900000),
  API_RATE_LIMIT_MAX: z.coerce.number().int().positive().default(300),
  SENSITIVE_RATE_LIMIT_WINDOW_MS: z.coerce.number().int().positive().default(900000),
  SENSITIVE_RATE_LIMIT_MAX: z.coerce.number().int().positive().default(20),
  RUN_CRON: booleanString,
  ENABLE_MAIL: booleanString,
  ENABLE_S3: booleanString,
  SHUTDOWN_TIMEOUT_MS: z.coerce.number().int().positive().default(10000),
  CACHE: booleanString,
  MAIL_HOST: z.string().min(1).optional(), MAIL_PORT: z.coerce.number().int().positive().optional(),
  MAIL_SECURE: z.enum(["true", "false"]).optional(), MAIL_USER: z.string().optional(),
  MAIL_PASS: z.string().optional(), MAIL_FROM: z.string().optional(),
  AWS_REGION: z.string().optional(), AWS_ACCESS_KEY_ID: z.string().optional(),
  AWS_SECRET_ACCESS_KEY: z.string().optional(), AWS_S3_BUCKET_NAME: z.string().optional(),
  S3_ENDPOINT: z.string().url().optional(), S3_FORCE_PATH_STYLE: booleanString,
  S3_SIGNED_URL_TTL_SECONDS: z.coerce.number().int().min(60).max(86400).default(900),
  S3_MAX_UPLOAD_BYTES: z.coerce.number().int().positive().default(5242880),
  EMAIL_QUEUE_CONCURRENCY: z.coerce.number().int().positive().default(5),
  DOCUMENT_QUEUE_CONCURRENCY: z.coerce.number().int().positive().default(2),
  NOTIFICATION_RETENTION_DAYS: z.coerce.number().int().positive().default(90),
  INVENTORY_RESERVATION_TTL_MINUTES: z.coerce.number().int().positive().default(15),
  CHECKOUT_TTL_MINUTES: z.coerce.number().int().positive().default(15),
  CART_MAX_ITEM_QUANTITY: z.coerce.number().int().positive().default(100),
  RETURN_WINDOW_DAYS: z.coerce.number().int().positive().default(30),
  PAYHERE_MERCHANT_ID: z.string().optional(), PAYHERE_MERCHANT_SECRET: z.string().optional(),
  PAYHERE_NOTIFY_URL: z.string().url().optional(), PAYHERE_RETURN_URL: z.string().url().optional(), PAYHERE_CANCEL_URL: z.string().url().optional(),
  LOYALTY_RECONCILIATION_BATCH_SIZE: z.coerce.number().int().positive().max(1000).default(100),
  LOG_RETENTION_DAYS: z.coerce.number().int().positive().default(30),
  DOCS_USER: z.string().optional(), DOCS_PASS: z.string().optional(),
  GOOGLE_CLIENT_ID: z.string().optional(), APPLE_CLIENT_ID: z.string().optional(),
}).superRefine((env, context) => {
  const requireFeature = (enabled, names) => {
    if (!enabled) return;
    for (const name of names) {
      if (!env[name]) context.addIssue({ code: "custom", path: [name], message: `${name} is required when enabled` });
    }
  };
  requireFeature(env.ENABLE_MAIL, ["MAIL_HOST", "MAIL_PORT", "MAIL_USER", "MAIL_PASS", "MAIL_FROM"]);
  requireFeature(env.ENABLE_S3, ["AWS_REGION", "AWS_ACCESS_KEY_ID", "AWS_SECRET_ACCESS_KEY", "AWS_S3_BUCKET_NAME"]);
});

let validatedEnv;
const validateEnvironment = (source = process.env) => {
  const result = envSchema.safeParse(source);
  if (!result.success) {
    const names = [...new Set(result.error.issues.map((issue) => issue.path.join(".") || "environment"))];
    throw new Error(`Invalid environment configuration: ${names.join(", ")}`);
  }
  validatedEnv = result.data;
  return validatedEnv;
};
const getEnvironment = () => validatedEnv || validateEnvironment();
const getOptionalFeatureStatus = (env = process.env) => ({
  mail: Boolean(env.MAIL_HOST && env.MAIL_PORT && env.MAIL_USER && env.MAIL_PASS && env.MAIL_FROM),
  s3: Boolean(env.AWS_REGION && env.AWS_ACCESS_KEY_ID && env.AWS_SECRET_ACCESS_KEY && env.AWS_S3_BUCKET_NAME),
  docs: Boolean(env.DOCS_USER && env.DOCS_PASS),
});

module.exports = { validateEnvironment, getEnvironment, getOptionalFeatureStatus };