package http

import (
	"fmt"
	"net/http"
	"net/url"
	"path"
	"path/filepath"
	"sort"
	"strings"

	"github.com/debridmediamanager.com/zurg/internal/torrent"
	"github.com/debridmediamanager.com/zurg/pkg/logutil"
)

func HandleDirectoryListing(w http.ResponseWriter, r *http.Request, t *torrent.TorrentManager) {
	log := logutil.NewLogger().Named("http")

	requestPath := path.Clean(r.URL.Path)

	var output *string
	var err error

	filteredSegments := removeEmptySegments(strings.Split(requestPath, "/"))
	switch {
	case len(filteredSegments) == 1:
		output, err = handleRoot(t)
	case len(filteredSegments) == 2:
		output, err = handleListOfTorrents(requestPath, t)
	case len(filteredSegments) == 3:
		output, err = handleSingleTorrent(requestPath, t)
	default:
		log.Warnf("Request %s %s not found", r.Method, requestPath)
		http.Error(w, "Not Found", http.StatusNotFound)
		return
	}
	if err != nil {
		if strings.Contains(err.Error(), "cannot find") {
			http.Error(w, "Not Found", http.StatusNotFound)
			return
		}
		log.Errorf("Error processing request: %v", err)
		http.Error(w, "Server error", http.StatusInternalServerError)
		return
	}

	if output != nil {
		w.Header().Set("Content-Type", "text/html; charset=\"utf-8\"")
		w.WriteHeader(http.StatusOK)
		fmt.Fprint(w, *output)
	}
}

func handleRoot(t *torrent.TorrentManager) (*string, error) {
	htmlDoc := "<ol>"
	directories := t.DirectoryMap.Keys()
	sort.Strings(directories)
	for _, directory := range directories {
		directoryPath := url.PathEscape(directory)
		htmlDoc += fmt.Sprintf("<li><a href=\"/http/%s/\">%s</a></li>", directoryPath, directory)
	}

	return &htmlDoc, nil
}

func handleListOfTorrents(requestPath string, t *torrent.TorrentManager) (*string, error) {
	basePath := path.Base(requestPath)
	torrents, ok := t.DirectoryMap.Get(basePath)
	if !ok {
		return nil, fmt.Errorf("cannot find directory %s", basePath)
	}

	htmlDoc := "<ol>"

	var allTorrents []*torrent.Torrent
	torrents.IterCb(func(_ string, tor *torrent.Torrent) {
		if tor.InProgress() {
			return
		}
		allTorrents = append(allTorrents, tor)
	})
	sort.Slice(allTorrents, func(i, j int) bool {
		return allTorrents[i].AccessKey < allTorrents[j].AccessKey
	})

	for _, tor := range allTorrents {
		htmlDoc = htmlDoc + fmt.Sprintf("<li><a href=\"%s/\">%s</a></li>", filepath.Join(requestPath, url.PathEscape(tor.AccessKey)), tor.AccessKey)
	}
	return &htmlDoc, nil
}

func handleSingleTorrent(requestPath string, t *torrent.TorrentManager) (*string, error) {
	basePath := path.Base(path.Dir(requestPath))
	torrents, ok := t.DirectoryMap.Get(basePath)
	if !ok {
		return nil, fmt.Errorf("cannot find directory %s", basePath)
	}
	accessKey := path.Base(requestPath)
	tor, ok := torrents.Get(accessKey)
	if !ok {
		return nil, fmt.Errorf("cannot find torrent %s", accessKey)
	}

	htmlDoc := "<ol>"
	filenames := tor.SelectedFiles.Keys()
	sort.Strings(filenames)
	for _, filename := range filenames {
		file, _ := tor.SelectedFiles.Get(filename)
		if file == nil || !strings.HasPrefix(file.Link, "http") {
			// will be caught by torrent manager's repairAll
			// just skip it for now
			continue
		}
		filePath := filepath.Join(requestPath, url.PathEscape(filename))
		htmlDoc += fmt.Sprintf("<li><a href=\"%s\">%s</a></li>", filePath, filename)
	}
	return &htmlDoc, nil
}