package api

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

	webui "jukebox_maker/web"

	"jukebox_maker/internal/config"
	"jukebox_maker/internal/copier"
	"jukebox_maker/internal/task"
	"jukebox_maker/internal/watcher"
)

type Deps struct {
	Config     *config.Config
	ConfigPath string
	Version    string
	Watcher    *watcher.Watcher
	Copier     *copier.Copier
	Tasks      *task.Store
	MediaPath  string
	MountPath  string
	// OnDiskInit вызывается при ручной инициализации диска через UI.
	OnDiskInit func(mountPath, diskID string)
}

type Server struct {
	deps      Deps
	dashboard *template.Template
	settings  *template.Template
	mux       *http.ServeMux
}

func New(deps Deps) (*Server, error) {
	dash, err := template.ParseFS(webui.FS, "templates/layout.html", "templates/dashboard.html")
	if err != nil {
		return nil, err
	}
	sett, err := template.ParseFS(webui.FS, "templates/layout.html", "templates/settings.html")
	if err != nil {
		return nil, err
	}

	s := &Server{deps: deps, dashboard: dash, settings: sett, mux: http.NewServeMux()}
	s.routes()
	return s, nil
}

func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	s.mux.ServeHTTP(w, r)
}

func (s *Server) routes() {
	s.mux.Handle("GET /static/", http.FileServerFS(webui.FS))

	s.mux.HandleFunc("GET /", s.handleDashboard)
	s.mux.HandleFunc("GET /settings", s.handleSettings)

	s.mux.HandleFunc("GET /health", s.handleHealth)
	s.mux.HandleFunc("GET /api/disks", s.handleDiskStatus)
	s.mux.HandleFunc("POST /api/disks/init", s.handleDiskInit)
	s.mux.HandleFunc("GET /api/sources", s.handleSources)
	s.mux.HandleFunc("GET /api/config", s.handleGetConfig)
	s.mux.HandleFunc("PUT /api/config", s.handlePutConfig)
	s.mux.HandleFunc("POST /api/disks/{diskID}/copy/start", s.handleCopyStart)
	s.mux.HandleFunc("POST /api/disks/{diskID}/copy/cancel", s.handleCopyCancel)
	s.mux.HandleFunc("GET /api/tasks/{id}", s.handleTaskGet)
}

func (s *Server) handleDashboard(w http.ResponseWriter, r *http.Request) {
	if r.URL.Path != "/" {
		http.NotFound(w, r)
		return
	}
	s.render(w, s.dashboard, map[string]any{"Title": "Dashboard", "Page": "dashboard"})
}

func (s *Server) handleSettings(w http.ResponseWriter, r *http.Request) {
	s.render(w, s.settings, map[string]any{"Title": "Settings", "Page": "settings"})
}

func (s *Server) handleHealth(w http.ResponseWriter, r *http.Request) {
	jsonOK(w, map[string]string{"status": "ok"})
}

func (s *Server) render(w http.ResponseWriter, tmpl *template.Template, data any) {
	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	payload := map[string]any{"Version": s.deps.Version}
	if incoming, ok := data.(map[string]any); ok {
		for k, v := range incoming {
			payload[k] = v
		}
	}
	if err := tmpl.ExecuteTemplate(w, "layout", payload); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
	}
}

func jsonOK(w http.ResponseWriter, v any) {
	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(v)
}

func jsonErr(w http.ResponseWriter, code int, msg string) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(code)
	json.NewEncoder(w).Encode(map[string]string{"error": msg})
}