package main

import (
	"os"
	"fmt"
	"net"
	"net/http"
	"strings"
	"time"

	"code.gitea.io/sdk/gitea"
	"github.com/urfave/cli/v2"
	log "github.com/sirupsen/logrus"
)

const (
	//PagesBranch "pages"
	// TODO: Change back for testing
	PagesBranch = "main"
)

func handleSubdomain(domain string, cname string, path string, giteaClient *gitea.Client, w http.ResponseWriter) {
	hostParts := strings.Split(domain, ".")
	username := hostParts[0]

	// Strip the leading /
	if path[:1] == "/" {
		path = path[1:]
	}

	_, path, err := RepoFromPath(
		username,
		domain,
		cname,
		path,
		giteaClient,
		
	)
	if err != nil {
		log.Errorf("Failed to get repo: %s", err)
		w.WriteHeader(404)
		return
	}

	serveFile(username, path, giteaClient, w)
}

func Handler(pagesDomain string, giteaClient *gitea.Client) http.HandlerFunc {
	return func(w http.ResponseWriter, req *http.Request) {
		w.Header().Set("Server", "rio")

		if strings.HasSuffix(req.Host, pagesDomain){
			log.Debug("Domain can be directly handled")
			handleSubdomain(req.Host, "", req.URL.Path, giteaClient, w)
			return
		}
		
		cname, err := lookupCNAME(req.Host)
		if err != nil {
			log.Warningf("CNAME request failed, we don't handle %s", req.Host)
			w.WriteHeader(400)
			return
		}
		log.Debugf("Got CNAME %s", cname)

		if strings.HasSuffix(cname, pagesDomain) {
			log.Debugf("%s is alias of %s", req.Host, cname)
			handleSubdomain(cname, cname, req.URL.Path, giteaClient, w)
			return
		}

		log.Errorf("Not handling %s", req.Host)
		w.WriteHeader(404)
	}
}

func runServer(ctx *cli.Context) error {
	giteaUrl := ctx.String("gitea-url")
	addr := ctx.String("listen-host") + ":" + ctx.String("listen-port")
	domain := ctx.String("pages-domain")

	log.SetLevel(log.DebugLevel)
	httpClient := http.Client{Timeout: 10 * time.Second}
	client, err := gitea.NewClient(
		giteaUrl,
		gitea.SetHTTPClient(&httpClient),
		gitea.SetToken(""),
		gitea.SetUserAgent("rio"),
	)

	listener, err := net.Listen("tcp", addr)
	if err != nil {
		fmt.Errorf("Failed to create listener: %v", err)
		return err
	}
	if err := http.Serve(listener, Handler(domain, client)); err != nil {
		fmt.Printf("Listening failed")
		return err
	}

	return nil
}

func main() {
	app := &cli.App{
		Action: runServer,
		Flags: []cli.Flag{
			&cli.StringFlag{
				Name: "gitea-url",
				Usage: "The (HTTPS) URL to the serving Gitea instance",
				EnvVars: []string{"GITEA_URL"},
				Required: true,
			},
			&cli.StringFlag{
				Name: "listen-host",
				Usage: "The host to listen on",
				EnvVars: []string{"HOST"},
				Value: "127.0.0.1",
			},
			&cli.StringFlag{
				Name: "listen-port",
				Usage: "The port to listen on",
				EnvVars: []string{"PORT"},
				Value: "8888",
			},
			&cli.StringFlag{
				Name: "pages-domain",
				Usage: "The domain on which the server is reachable",
				EnvVars: []string{"PAGES_DOMAIN"},
				Required: true,
			},
		},
	}

	if err := app.Run(os.Args); err != nil {
		log.Fatalf("Failed to run app: %s", err)
	}
}