package dav

import (
	"encoding/xml"
	"fmt"
	"net/http"
	"path"
	"path/filepath"
	"strings"

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

func HandlePropfindRequest(w http.ResponseWriter, r *http.Request, t *torrent.TorrentManager, c config.ConfigInterface) {
	log := logutil.NewLogger().Named("dav")

	requestPath := path.Clean(r.URL.Path)
	requestPath = strings.Trim(requestPath, "/")

	var output []byte
	var err error

	filteredSegments := strings.Split(requestPath, "/")

	switch {
	case len(filteredSegments) == 1 && filteredSegments[0] == "":
		output, err = handleRoot(w, r, c)
	case len(filteredSegments) == 1:
		output, err = handleListOfTorrents(requestPath, w, r, t, c)
	case len(filteredSegments) == 2:
		output, err = handleSingleTorrent(requestPath, w, r, 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 {
		respBody := fmt.Sprintf("<?xml version=\"1.0\" encoding=\"utf-8\"?>\n%s\n", output)
		w.Header().Set("Content-Type", "text/xml; charset=\"utf-8\"")
		w.WriteHeader(http.StatusMultiStatus)
		fmt.Fprint(w, respBody)
	}
}

func handleRoot(w http.ResponseWriter, r *http.Request, c config.ConfigInterface) ([]byte, error) {
	var responses []dav.Response
	responses = append(responses, dav.Directory(""))
	for _, directory := range c.GetDirectories() {
		responses = append(responses, dav.Directory(directory))
	}
	rootResponse := dav.MultiStatus{
		XMLNS:    "DAV:",
		Response: responses,
	}
	return xml.Marshal(rootResponse)
}

func handleListOfTorrents(requestPath string, w http.ResponseWriter, r *http.Request, t *torrent.TorrentManager, c config.ConfigInterface) ([]byte, error) {
	basePath := path.Base(requestPath)

	for _, directory := range c.GetDirectories() {
		if basePath == directory {
			var responses []dav.Response

			responses = append(responses, dav.Directory(basePath))

			for el := t.TorrentMap.Front(); el != nil; el = el.Next() {
				accessKey := el.Key
				torrent := el.Value
				if torrent.InProgress {
					continue
				}
				for _, dir := range torrent.Directories {
					if dir == basePath {
						path := filepath.Join(basePath, accessKey)
						responses = append(responses, dav.Directory(path))
						break
					}
				}
			}

			resp := &dav.MultiStatus{
				XMLNS:    "DAV:",
				Response: responses,
			}
			return xml.Marshal(resp)
		}
	}

	return nil, fmt.Errorf("cannot find directory when generating list: %s", requestPath)
}

func handleSingleTorrent(requestPath string, w http.ResponseWriter, r *http.Request, t *torrent.TorrentManager) ([]byte, error) {
	accessKey := path.Base(requestPath)
	torrent, exists := t.TorrentMap.Get(accessKey)
	if !exists {
		return nil, fmt.Errorf("cannot find torrent %s", accessKey)
	}

	var responses []dav.Response

	// initial response is the directory itself
	responses = append(responses, dav.Directory(requestPath))

	for el := torrent.SelectedFiles.Front(); el != nil; el = el.Next() {
		file := el.Value
		if file.Link == "" {
			// will be caught by torrent manager's repairAll
			// just skip it for now
			continue
		}
		filename := filepath.Base(file.Path)
		filePath := filepath.Join(requestPath, filename)
		responses = append(responses, dav.File(
			filePath,
			file.Bytes,
			convertRFC3339toRFC1123(torrent.LatestAdded),
			file.Link,
		))
	}

	resp := &dav.MultiStatus{
		XMLNS:    "DAV:",
		Response: responses,
	}
	return xml.Marshal(resp)
}