import { existsSync, readFileSync } from 'node:fs';
import path from 'node:path';

import { parse } from 'dotenv';

import {
  loadApiConfig,
  loadSchedulerConfig,
  loadWorkerConfig,
  type ApiRuntimeConfig,
  type SchedulerRuntimeConfig,
  type WorkerRuntimeConfig,
} from './runtime-config';

type ProcessName = 'api' | 'scheduler' | 'worker';

function findRepositoryRoot(startDirectory: string): string {
  let current = path.resolve(startDirectory);

  while (true) {
    if (existsSync(path.join(current, 'pnpm-workspace.yaml'))) return current;
    const parent = path.dirname(current);
    if (parent === current) throw new Error('无法定位项目根目录');
    current = parent;
  }
}

function readDevelopmentEnv(processName: ProcessName): NodeJS.ProcessEnv {
  const repositoryRoot = findRepositoryRoot(__dirname);
  const envFile = path.join(
    repositoryRoot,
    'deploy',
    'env',
    'development',
    `${processName}.env.local`,
  );

  if (!existsSync(envFile)) {
    throw new Error(`缺少本地开发配置：deploy/env/development/${processName}.env.local`);
  }

  return { ...process.env, ...parse(readFileSync(envFile)) };
}

function resolveProcessEnvironment(processName: ProcessName): NodeJS.ProcessEnv {
  // 生产环境只信任 systemd/Compose 注入的 process.env，绝不读取仓库内开发配置。
  return process.env.APP_ENV === 'production' ? process.env : readDevelopmentEnv(processName);
}

export function loadApiProcessConfig(): ApiRuntimeConfig {
  return loadApiConfig(resolveProcessEnvironment('api'));
}

export function loadSchedulerProcessConfig(): SchedulerRuntimeConfig {
  return loadSchedulerConfig(resolveProcessEnvironment('scheduler'));
}

export function loadWorkerProcessConfig(): WorkerRuntimeConfig {
  return loadWorkerConfig(resolveProcessEnvironment('worker'));
}