package web

import (
	"context"
	"embed"
	"html/template"
	"io/fs"
	"log"
	"net/http"
	"sync"
	"time"

	"gitea.kazu634.com/kazu634/tver/internal/store"
)

//go:embed templates/*.html static/*
var assets embed.FS

type page struct {
	Title         string
	Newer         *newerView
	Queue         *queueView
	Subscriptions *subscriptionsView
}

type JobStore interface {
	Enqueue(context.Context, store.Episode, string) (store.Job, bool, error)
	EpisodeStatuses(context.Context, []string) (map[string]string, error)
	ListJobs(context.Context, string, int) ([]store.Job, error)
	GetJob(context.Context, int64) (store.Job, error)
	Retry(context.Context, int64) error
	RetryEpisode(context.Context, string) error
	CancelQueued(context.Context, int64) error
	SubscribedSeries(context.Context, []string) (map[string]bool, error)
	RegisterSubscription(context.Context, string, string, []store.Episode, bool) (bool, error)
	ListSubscriptions(context.Context) ([]store.Subscription, error)
	SetSubscriptionEnabled(context.Context, string, bool) error
	DeleteSubscription(context.Context, string) (bool, error)
}

type server struct {
	fetcher NewerFetcher
	jobs    JobStore
	now     func() time.Time
	logger  *log.Logger
	zone    *time.Location
	tmpl    *template.Template
	cacheMu sync.Mutex
	cache   map[string]cacheEntry
}

func NewHandler(fetcher NewerFetcher, jobs JobStore, now func() time.Time, logger *log.Logger) http.Handler {
	tmpl := template.Must(template.ParseFS(assets, "templates/*.html"))
	staticFiles, err := fs.Sub(assets, "static")
	if err != nil {
		panic(err)
	}
	zone, err := time.LoadLocation("Asia/Tokyo")
	if err != nil {
		panic(err)
	}
	s := &server{fetcher: fetcher, jobs: jobs, now: now, logger: logger, zone: zone, tmpl: tmpl, cache: make(map[string]cacheEntry)}
	mux := http.NewServeMux()
	mux.Handle("GET /static/", http.StripPrefix("/static/", http.FileServerFS(staticFiles)))
	mux.HandleFunc("GET /healthz", func(w http.ResponseWriter, _ *http.Request) {
		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
		_, _ = w.Write([]byte("ok\n"))
	})
	mux.HandleFunc("GET /{$}", s.home)
	mux.HandleFunc("GET /newer", s.newerFragment)
	mux.HandleFunc("POST /episodes/enqueue", s.enqueue)
	mux.HandleFunc("POST /episodes/retry", s.retryEpisode)
	mux.HandleFunc("GET /queue", s.queuePage)
	mux.HandleFunc("GET /queue/list", s.queueFragment)
	mux.HandleFunc("POST /jobs/{id}/retry", s.retryJob)
	mux.HandleFunc("POST /jobs/{id}/cancel", s.cancelJob)
	mux.HandleFunc("GET /subscriptions", s.subscriptionsPage)
	mux.HandleFunc("GET /subscriptions/list", s.subscriptionsFragment)
	mux.HandleFunc("GET /subscriptions/choice", s.subscriptionChoice)
	mux.HandleFunc("POST /subscriptions/register", s.registerSubscription)
	mux.HandleFunc("POST /subscriptions/{id}/pause", s.pauseSubscription)
	mux.HandleFunc("POST /subscriptions/{id}/resume", s.resumeSubscription)
	mux.HandleFunc("POST /subscriptions/{id}/delete", s.deleteSubscription)
	for path, title := range map[string]string{
		"GET /library": "ライブラリ",
	} {
		mux.HandleFunc(path, func(w http.ResponseWriter, _ *http.Request) {
			w.Header().Set("Content-Type", "text/html; charset=utf-8")
			if err := s.tmpl.ExecuteTemplate(w, "layout", page{Title: title}); err != nil {
				http.Error(w, "template error", http.StatusInternalServerError)
			}
		})
	}
	return mux
}