import fs from 'fs'
import path from 'path'

/**
 * 读取根目录的 config-bianliang.env 并注入到 process.env
 * - 仅在变量未设置时写入，绝不覆盖真实环境变量或 .env 值
 * - 支持以 # 开头的注释，空行会被忽略
 * - 行格式 KEY=VALUE，等号右侧原样接收（去除收尾空白）
 */
export function loadPortableEnvIfPresent(): void {
  try {
    const root = process.cwd()
    const envFile = path.join(root, 'config-bianliang.env')
    if (!fs.existsSync(envFile)) return

    const content = fs.readFileSync(envFile, 'utf8')
    const lines = content.split(/\r?\n/)

    for (const rawLine of lines) {
      const line = rawLine.trim()
      if (!line || line.startsWith('#')) continue
      const eqIndex = line.indexOf('=')
      if (eqIndex <= 0) continue

      const key = line.slice(0, eqIndex).trim()
      const value = line.slice(eqIndex + 1).trim()

      if (!key) continue

      if (process.env[key] === undefined || process.env[key] === '') {
        process.env[key] = value
      }
    }
  } catch {
    // 静默失败，避免影响运行
  }
}

const configLoader = { loadPortableEnvIfPresent }

export default configLoader