import path from "path";
import dotenv from "dotenv";

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

function requireEnv(name: string): string {
  const value = process.env[name];
  if (!value) {
    throw new Error(`Missing required environment variable: ${name}`);
  }
  return value;
}

function optionalEnv(name: string): string | null {
  const value = process.env[name]?.trim();
  return value ? value : null;
}

function requireEnvUnlessMock(name: string, fallback: string): string {
  if (useMockDb) {
    return process.env[name]?.trim() || fallback;
  }
  return requireEnv(name);
}

function parseBoolean(value: string | undefined, fallback: boolean): boolean {
  if (value == null || value.trim() === "") {
    return fallback;
  }
  return value === "1" || value.toLowerCase() === "true";
}

const useMockDb =
  process.env.CALENDAR_RUN_MOCK_DB === "1" ||
  process.env.CALENDAR_RUN_MOCK_DB?.toLowerCase() === "true";

export const config = {
  useMockDb,
  db: useMockDb
    ? {
        host: "mock",
        port: 5432,
        database: "mock",
        user: "mock",
        password: "mock",
      }
    : {
        host: requireEnv("DB_HOST"),
        port: parseInt(requireEnv("DB_PORT"), 10),
        database: requireEnv("DB_NAME"),
        user: requireEnv("DB_USER"),
        password: requireEnv("DB_PASSWORD"),
      },
  apiPort: parseInt(process.env.PORT || process.env.API_PORT || "3001", 10),
  /** Одно значение или несколько через запятую (прод: https://домен) */
  corsOrigin: parseCorsOrigins(),
  appBaseUrl: process.env.APP_BASE_URL?.trim() || "http://localhost:5173",
  session: {
    secret: requireEnvUnlessMock("SESSION_SECRET", "mock-session-secret-change-me"),
    cookieName:
      process.env.SESSION_COOKIE_NAME?.trim() ||
      (process.env.NODE_ENV === "production" ? "__Host-sid" : "sid"),
    secure: parseBoolean(process.env.SESSION_COOKIE_SECURE, process.env.NODE_ENV === "production"),
    ttlDays: parseInt(process.env.SESSION_TTL_DAYS || "30", 10),
  },
  smtp: {
    host: optionalEnv("SMTP_HOST"),
    port: parseInt(process.env.SMTP_PORT || "587", 10),
    secure: parseBoolean(process.env.SMTP_SECURE, false),
    user: optionalEnv("SMTP_USER"),
    password: optionalEnv("SMTP_PASSWORD"),
    from: process.env.SMTP_FROM?.trim() || "Calendar Run <no-reply@example.com>",
  },
  turnstile: {
    secretKey: process.env.TURNSTILE_SECRET_KEY?.trim() || (useMockDb ? "mock-turnstile-secret" : ""),
    bypassToken: process.env.TURNSTILE_BYPASS_TOKEN?.trim() || (useMockDb ? "mock-turnstile-token" : ""),
  },
  securityProfile: process.env.SECURITY_PROFILE?.trim() || process.env.NODE_ENV || "development",
};

function parseCorsOrigins(): string | string[] {
  const raw = process.env.CORS_ORIGIN?.trim();
  if (!raw) {
    return "http://localhost:5173";
  }
  const parts = raw.split(",").map((s) => s.trim()).filter(Boolean);
  if (parts.length === 0) {
    return "http://localhost:5173";
  }
  if (parts.length === 1) {
    return parts[0]!;
  }
  return parts;
}