package main

import (
	"errors"
	"log"
	"net/http"
	"os"
	"path/filepath"
	"strings"

	"github.com/ewpt3ch/pkgstash/internal/cache"
)

func (s *Server) handlePackage(w http.ResponseWriter, req *http.Request) {

	// most mirrors don't have a *db.sig so we 404 it here instead of spamming the mirror
	if strings.HasSuffix(req.PathValue("file"), ".db.sig") {
		w.WriteHeader(http.StatusNotFound)
		return
	}

	// record the useragent from requestor
	log.Printf("Requestors UA: %s", req.Header.Get("User-Agent"))

	// build file paths from the request, they follow archlinux repo
	// <mirrorroot>/[core, extra, etc]/os/[x86_64, arm, etc]/package.pkg.tar.zst[.sig]
	repo := req.PathValue("repo")
	arch := req.PathValue("arch")
	file := req.PathValue("file")
	repoPath := filepath.Join(repo, "os", arch, file)     //path from mirror root to pkg or db file
	cachePath := filepath.Join(s.cfg.CacheRoot, repoPath) //absolute path for local read of the file

	if _, err := os.Stat(cachePath); err != nil {
		err = s.c.Fetch(repoPath)
		if err != nil {
			var upstreamErr *cache.UpstreamError
			if errors.As(err, &upstreamErr) {
				log.Printf("upstream error: %v", err)
				http.Error(w, "Not found upstream", upstreamErr.StatusCode)
				return
			}
			log.Printf("fetch error: %v", err)
			http.Error(w, "Failed to fetch from upstream", http.StatusBadGateway)
			return
		}

	}

	http.ServeFile(w, req, cachePath)
}