package main

import (
	"github.com/lamperi/e4bot/spotify"
	"html/template"
	"log"
	"net/http"
	"strings"
)

var (
	cachedTemplates = template.Must(template.ParseFiles("web/index.html"))
	spotifyClient   *spotify.SpotifyClient
)

func indexHandler(w http.ResponseWriter, r *http.Request) {
	if r.URL.Path != "/" {
		http.Error(w, "Not Found", http.StatusNotFound)
		return
	}

	data := struct {
		Username string
		Songs    []*struct {
			RoundID   int
			RoundName string
			Title     string
			Artist    string
			URL       string
			Sync      bool
		}
	}{
		"",
		make([]*struct {
			RoundID   int
			RoundName string
			Title     string
			Artist    string
			URL       string
			Sync      bool
		}, 0),
	}

	session, err := getSession(r)
	if session != nil {
		query := `
		SELECT r.id, r.section, e.artist, e.title, e.spotify_url, e.synced
		FROM public.round r
		LEFT JOIN public.entry e ON r.id = e.round_id
		LEFT JOIN public."user" u ON u.id = e.user_id AND lower(u.username) = lower($1)
		ORDER BY r.start ASC`
		rows, err := getDb().Query(query, session.username)
		if err != nil {
			log.Println("Error while executing query", err)
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		defer rows.Close()
		for i := 0; rows.Next(); i++ {
			row := &struct {
				RoundID   int
				RoundName string
				Title     string
				Artist    string
				URL       string
				Sync      bool
			}{}
			data.Songs = append(data.Songs, row)
			var (
				artist, title, url *string
				sync               *bool
			)
			err = rows.Scan(&data.Songs[i].RoundID, &data.Songs[i].RoundName, &artist, &title, &url, &sync)
			if err != nil {
				log.Println("Error while scanning cursor", err)
				http.Error(w, err.Error(), http.StatusInternalServerError)
				return
			}
			if artist != nil {
				row.Artist = *artist
			}
			if title != nil {
				row.Title = *title
			}
			if url != nil {
				row.URL = *url
			}
			if sync != nil {
				row.Sync = *sync
			}
		}
		data.Username = session.username
	}

	var templates = cachedTemplates
	if true {
		templates = template.Must(template.ParseFiles("web/index.html"))
	}

	err = templates.ExecuteTemplate(w, "index.html", data)
	if err != nil {
		log.Println("Error while rendering template", err)
		http.Error(w, err.Error(), http.StatusInternalServerError)
	}
}

func getTrackID(url string) string {
	const externalURLPrefix = "https://open.spotify.com/track/"
	const trackURIPrefix = "spotify:track:"
	if strings.HasPrefix(url, externalURLPrefix) {
		return strings.Split(url, externalURLPrefix)[1]
	} else if strings.HasPrefix(url, trackURIPrefix) {
		return strings.Split(url, trackURIPrefix)[1]
	}
	return url
}

func updateHandler(w http.ResponseWriter, r *http.Request) {
	if r.URL.Path != "/update" {
		http.Error(w, "Forbidden", http.StatusForbidden)
		return
	}
	session, err := getSession(r)
	if session == nil {
		http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
		return
	}

	err = r.ParseForm()
	if err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}
	round := r.Form.Get("round")
	artist := r.Form.Get("artist")
	title := r.Form.Get("title")
	url := r.Form.Get("url")

	if artist == "" && title == "" && url != "" {
		log.Println("Resolving Spotify URL")
		trackID := getTrackID(url)
		err := spotifyClient.Authenticate()
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		track, err := spotifyClient.GetTrack(trackID)

		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		log.Printf("Found Track with name %v and artists %v\n", track.Name, track.Artists)
		for index, trackArtist := range track.Artists {
			if index == 0 {
				artist = trackArtist.Name
			} else if index == 1 {
				artist = artist + " feat. " + trackArtist.Name
			} else {
				artist = artist + ", " + trackArtist.Name
			}
		}
		title = track.Name
		url = track.ExternalUrls.Spotify
	}

	query := `
	INSERT INTO public.entry
	SELECT id, $2, $3, $4, $5, false
	FROM public."user" u
	WHERE lower(u.username) = lower($1)
	ON CONFLICT (user_id, round_id) DO UPDATE SET artist = EXCLUDED.artist, title = EXCLUDED.title, spotify_url = EXCLUDED.spotify_url, synced = EXCLUDED.synced`
	res, err := getDb().Exec(query, session.username, round, artist, title, url)

	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	affected, err := res.RowsAffected()
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	if affected != 1 {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	log.Printf("Updated song for round %s, artist: %s, title: %s, URL: %s",
		round, artist, title, url)

	http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
}

func loginHandler(w http.ResponseWriter, r *http.Request) {
	err := r.ParseForm()
	if err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}
	username := r.Form.Get("username")
	password := r.Form.Get("password")
	remember := r.Form.Get("remember")
	longer := remember == "remember-me"

	cookie, err := tryLogin(username, password, longer)

	if err != nil {
		log.Println("Error while trying to login", err.Error())
		http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
		return
	}

	http.SetCookie(w, &cookie)
	http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
}

func webStart(listenAddr string, spot *spotify.SpotifyClient) {
	spotifyClient = spot

	mux := http.NewServeMux()

	fs := http.FileServer(http.Dir("web"))
	mux.Handle("/css/", fs)
	mux.Handle("/fonts/", fs)
	mux.Handle("/js/", fs)
	mux.Handle("/favicon.ico", fs)
	mux.HandleFunc("/", indexHandler)
	mux.HandleFunc("/update", updateHandler)
	mux.HandleFunc("/login", loginHandler)

	http.ListenAndServe(listenAddr, mux)
}