package view

import (
	"encoding/json"
	"fmt"
	"html/template"
	"net/http"
	"strings"

	"arimelody.me/arimelody.me/admin"
	"arimelody.me/arimelody.me/global"
	"arimelody.me/arimelody.me/music/model"
)

type (
    gatewayTrack struct {
        *model.Track
        Lyrics template.HTML
        Number int
    }

    gatewayRelease struct {
        *model.Release
        Tracks []gatewayTrack
    }
)

// HTTP HANDLERS

func ServeRelease() http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path == "/" {
			http.NotFound(w, r)
			return
		}

		releaseID := r.URL.Path[1:]
		var release = global.GetRelease(releaseID)
		if release == nil {
			http.NotFound(w, r)
			return
		}

		// only allow authorised users to view unreleased releases
		authorised := admin.GetSession(r) != nil
		if !release.IsReleased() && !authorised {
			admin.MustAuthorise(ServeRelease()).ServeHTTP(w, r)
			return
		}

		w.Header().Add("Content-Type", "application/json")
		err := json.NewEncoder(w).Encode(release)
		if err != nil {
			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
			return
		}
	})
}

func ServeGateway() http.Handler {
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        if r.URL.Path == "/" {
            http.Redirect(w, r, "/music", http.StatusPermanentRedirect)
            return
        }

        id := r.URL.Path[1:]
        release := global.GetRelease(id)
        if release == nil {
            http.NotFound(w, r)
            return
        }

        tracks := []gatewayTrack{}
        for i, track := range release.Tracks {
            tracks = append([]gatewayTrack{{
                Track: track,
                Lyrics: template.HTML(strings.Replace(track.Lyrics, "\n", "<br>", -1)),
                Number: len(release.Tracks) - i,
            }}, tracks...)
        }

        // only allow authorised users to view unreleased releases
        authorised := admin.GetSession(r) != nil
        if !release.IsReleased() && !authorised {
            admin.MustAuthorise(ServeGateway()).ServeHTTP(w, r)
            return
        }

        lrw := global.LoggingResponseWriter{ResponseWriter: w, Code: http.StatusOK}

        global.ServeTemplate("music-gateway.html", gatewayRelease{release, tracks}).ServeHTTP(&lrw, r)

        if lrw.Code != http.StatusOK {
            fmt.Printf("Error rendering music gateway for %s\n", id)
            return
        }
    })
}