package handlers

import (
	"dwelling-radio/internal/configuration"
	"dwelling-radio/internal/radio"
	"dwelling-radio/pkg/logging"
	"dwelling-radio/pkg/utils"
	"embed"
	"encoding/json"
	"html/template"
	"io/fs"
	"net/http"
	"time"

	"github.com/Joker/jade"
)

const FormatISO8601 = "2006-01-02T15:04:05-0700"

var compiledTemplates map[string]*template.Template

//go:embed web/assets
var assetsDir embed.FS

//go:embed web/templates
var templatesDir embed.FS

type NotFoundData struct {
	MainSite string
}

type IndexData struct {
	MainSite string
	Status   *radio.IcecastStatus
	Songs    []radio.Song
}

type RadioHandlers struct {
	conf   *configuration.Configuration
	logErr *logging.Logger
}

func NewRadioHandlers(conf *configuration.Configuration, lErr *logging.Logger) *RadioHandlers {
	compileTemplates(lErr)

	return &RadioHandlers{
		conf:   conf,
		logErr: lErr}
}

func (h *RadioHandlers) AssetsFS() http.FileSystem {
	f, _ := fs.Sub(assetsDir, "web/assets")
	return http.FS(f)
}

func (h *RadioHandlers) Robots(w http.ResponseWriter, r *http.Request) {
	fc, _ := assetsDir.ReadFile("web/assets/robots.txt")
	w.Write(fc)
}

func (h *RadioHandlers) Index(w http.ResponseWriter, r *http.Request) {
	status, err := radio.IcecastGetStatus(h.conf.Icecast.URL)
	if err != nil {
		h.logErr.Println("failed to get Icecast status:", err)
	} else {
		if tim, err := time.Parse(time.RFC1123Z, status.ServerStartDate); err == nil {
			status.ServerStartDate = utils.ToClientTimezone(tim, r).Format(time.RFC1123)
		}

		if tim, err := time.Parse(FormatISO8601, status.ServerStartISO8601); err == nil {
			status.ServerStartISO8601 = utils.ToClientTimezone(tim, r).Format(FormatISO8601)
		}
	}

	songs, err := radio.IcecastLastPlayedSongs(h.conf.ListLastNSongs,
		h.conf.Icecast.Playlist)
	if err != nil {
		h.logErr.Println("cannot retrieve last songs:", err)
	} else {
		for i := 0; i < len(songs); i++ {
			if tim, err := time.Parse(radio.SongTimeFormat, songs[i].Time); err == nil {
				songs[i].Time = utils.ToClientTimezone(tim, r).Format("15:04")
			}
		}
	}

	if err := web.Template("index").Execute(w, &IndexData{
		MainSite: utils.MainSite(r.Host),
		Status:   status,
		Songs:    songs,
	}); err != nil {
		h.logErr.Fatalln("failed to execute Index template:", err)
		http.Error(w, "cannot execute Index template", http.StatusInternalServerError)
	}
}

func (h *RadioHandlers) Stats(w http.ResponseWriter, r *http.Request) {
	status, err := radio.IcecastGetStatus(h.conf.Icecast.URL)
	if err != nil {
		h.logErr.Println("cannot retrieve Icecast status:", err)
		http.Error(w, "cannot retrieve Icecast status", http.StatusInternalServerError)
		return
	}

	if tim, err := time.Parse(time.RFC1123Z, status.ServerStartDate); err == nil {
		status.ServerStartDate = utils.ToClientTimezone(tim, r).Format(time.RFC1123)
	}

	if tim, err := time.Parse(FormatISO8601, status.ServerStartISO8601); err == nil {
		status.ServerStartISO8601 = utils.ToClientTimezone(tim, r).Format(FormatISO8601)
	}

	w.Header().Add("Content-Type", "application/json")
	json.NewEncoder(w).Encode(status)
}

func (h *RadioHandlers) LastSong(w http.ResponseWriter, r *http.Request) {
	song, err := radio.IcecastLastSong(h.conf.Icecast.Playlist)
	if err != nil {
		h.logErr.Println("cannot retrieve last songs:", err)
	}

	if song.Time == "" {
		w.WriteHeader(http.StatusNotFound)
		return
	}

	if tim, err := time.Parse(radio.SongTimeFormat, song.Time); err == nil {
		song.Time = utils.ToClientTimezone(tim, r).Format("15:04")
	}

	w.Header().Add("Content-Type", "application/json")
	json.NewEncoder(w).Encode(song)
}

func (h *RadioHandlers) Playlist(w http.ResponseWriter, _ *http.Request) {
	w.Header().Add("Content-Disposition", "attachment; filename=\"radio.arav.top.m3u\"")
	fc, _ := assetsDir.ReadFile("web/assets/radio.arav.top.m3u")
	w.Write(fc)
}

func compileTemplates(lErr *logging.Logger) {
	compiledTemplates = make(map[string]*template.Template)

	t, _ := fs.Sub(templatesDir, "web/templates")
	templatesFS := http.FS(t)

	indexStr, err := jade.ParseFileFromFileSystem("index.jade", templatesFS)
	if err != nil {
		lErr.Fatalln(err)
	}

	indexTpl, err := template.New("index").Parse(indexStr)
	if err != nil {
		lErr.Fatalln(err)
	}

	compiledTemplates["index"] = indexTpl
}