import { readFileSync } from "fs";

function env(key: string, fallback?: string): string {
  const val = process.env[key] ?? fallback;
  if (val === undefined) throw new Error(`Missing required env var: ${key}`);
  return val;
}

function envOptional(key: string, fallback = ""): string {
  return process.env[key] ?? fallback;
}

export const config = {
  port: parseInt(envOptional("PORT", "4100")),
  host: envOptional("HOST", "0.0.0.0"),

  // JWT
  jwtSecret: env("JWT_SECRET"),
  jwtExpiresIn: envOptional("JWT_EXPIRES_IN", "7d"),

  // Database
  dbUrl: env("DATABASE_URL"),

  // Redis
  redisUrl: envOptional("REDIS_URL", "redis://localhost:6379"),

  // Encryption key for LiteLLM virtual keys stored in DB (32-byte hex)
  encryptionKey: env("ENCRYPTION_KEY"),

  // LiteLLM
  litellmUrl: envOptional("LITELLM_URL", "http://litellm:4000"),
  litellmMasterKey: env("LITELLM_MASTER_KEY"),

  // Self-referencing URL for MCP demux (used in LiteLLM MCP server registration)
  agilitonAccountUrl: envOptional("AGILITON_ACCOUNT_URL", "http://agiliton-account:4100"),

  // Shared secret used by LiteLLM when calling /mcp/demux/:id/mcp
  mcpBridgeSecret: env("MCP_BRIDGE_SECRET"),

  // Google OAuth
  googleClientId: env("GOOGLE_CLIENT_ID"),
  googleClientSecret: env("GOOGLE_CLIENT_SECRET"),

  // Microsoft OAuth
  msClientId: envOptional("MS_CLIENT_ID"),
  msTenantId: envOptional("MS_TENANT_ID", "common"),

  // Default budget per customer (USD, 30 days)
  defaultBudgetUsd: parseFloat(envOptional("DEFAULT_BUDGET_USD", "30.0")),
  defaultBudgetDuration: envOptional("DEFAULT_BUDGET_DURATION", "30d"),
  defaultRpmLimit: parseInt(envOptional("DEFAULT_RPM_LIMIT", "30")),
  defaultModels: envOptional(
    "DEFAULT_MODELS",
    "claude-sonnet-4-6,claude-opus-4-6,grok-heavy"
  ).split(","),

  // WebSocket MCP bridge timeout (ms)
  mcpBridgeTimeoutMs: parseInt(envOptional("MCP_BRIDGE_TIMEOUT_MS", "15000")),
} as const;