import { Agent as HttpAgent } from 'node:http'
import { Agent as HttpsAgent } from 'node:https'
import react from '@vitejs/plugin-react'
import { defineConfig, loadEnv, type ProxyOptions } from 'vite'

// https://vite.dev/config/
export default defineConfig(({ mode }) => {
  const env = loadEnv(mode, process.cwd(), '')
  const proxy: Record<string, ProxyOptions> = {}

  if (env.CALDAV_URL) {
    const target = new URL(env.CALDAV_URL)
    const basePath = target.pathname.replace(/\/$/, '')

    // Credentials never reach the client bundle: the dev server injects
    // Basic auth on the proxied request, browser code only ever calls /caldav/.
    const headers: Record<string, string> = {}
    if (env.CALDAV_USERNAME && env.CALDAV_PASSWORD) {
      const token = Buffer.from(`${env.CALDAV_USERNAME}:${env.CALDAV_PASSWORD}`).toString('base64')
      headers.Authorization = `Basic ${token}`
    }

    proxy['/caldav'] = {
      target: target.origin,
      changeOrigin: true,
      rewrite: (path) => path.replace(/^\/caldav/, basePath),
      headers,
      // The CalDAV server answers every request with `Connection: close`,
      // but http-proxy's default agent still pools/reuses sockets — that
      // races with the server closing them and intermittently surfaces as
      // a 503 (ECONNRESET) here. A fresh connection per request avoids it.
      agent: target.protocol === 'https:'
        ? new HttpsAgent({ keepAlive: false })
        : new HttpAgent({ keepAlive: false }),
    }
  }

  return {
    plugins: [react()],
    server: { proxy },
  }
})