package main

import (
	"archive/tar"
	"bytes"
	"compress/gzip"
	"io"
	"log"
	"net"
	"net/http"
	"os"
	"strings"
)

func Middleware(next http.Handler) http.Handler {
	return http.HandlerFunc(
		func(w http.ResponseWriter, r *http.Request) {
			defer func() {
				r := recover()
				if r != nil {
					log.Println("panic", r)
					w.WriteHeader(500)
				}
			}()
			abort := false
			if flagAllow != "" {
				if GetIP(r) != flagAllow {
					HttpWriter(w, 403, "permission denyed")
					abort = true
				}
			}

			if !abort {
				next.ServeHTTP(w, r)
			}
			log.Printf("%s %s %s %s\n", GetIP(r), r.Method, r.URL, r.Header.Get("User-Agent"))
		},
	)
}

func bundle(buf io.Writer, paths []string, flat bool) error {
	gw := gzip.NewWriter(buf)
	defer gw.Close()
	tw := tar.NewWriter(gw)
	defer tw.Close()

	for _, file := range paths {
		if err := func(file string) error {
			f, err := os.Open(file)
			if err != nil {
				return err
			}
			defer f.Close()

			info, err := f.Stat()
			if err != nil {
				return err
			}

			header, err := tar.FileInfoHeader(info, info.Name())
			if err != nil {
				return err
			}

			// Use full path as name (FileInfoHeader only takes the basename)
			// If we don't do this the directory strucuture would
			// not be preserved
			// https://golang.org/src/archive/tar/common.go?#L626
			if !flat {
				if !strings.HasPrefix(file, "/") {
					file = "configui/" + file
				} else {
					file = "configui" + file
				}
				header.Name = file
			}

			// Write file header to the tar archive
			err = tw.WriteHeader(header)
			if err != nil {
				return err
			}

			// Copy file content to tar archive
			_, err = io.Copy(tw, f)
			if err != nil {
				return err
			}
			return nil

		}(file); err != nil {
			return err
		}
	}

	return nil
}

func HttpWriter(w http.ResponseWriter, status int, errStr string) {
	w.WriteHeader(status)
	w.Write([]byte(errStr))
}

func GetIP(r *http.Request) string {
	ip := r.Header.Get("X-Real-Ip")
	if ip == "" {
		ips := r.Header.Get("X-Forwarded-For")
		ipArr := strings.Split(ips, ",")
		ip = strings.Trim(ipArr[len(ipArr)-1], " ")
	}
	if ip == "" {
		var err error
		ip, _, err = net.SplitHostPort(r.RemoteAddr)
		if err != nil {
			ip = r.RemoteAddr
		}
	}
	return ip
}

func serve(w http.ResponseWriter, name string, data interface{}) error {
	buf := &bytes.Buffer{}
	err := tmpl.ExecuteTemplate(buf, "home", data)
	if err != nil {
		HttpWriter(w, 500, err.Error())
		return err
	}
	_, err = w.Write(buf.Bytes())
	return err
}