package main

import (
	"context"
	"log"
	"os"
	"path/filepath"

	"github.com/wailsapp/wails/v2/pkg/runtime"

	"github.com/waste-go/internal/crypto"
	"github.com/waste-go/internal/ipc"
	"github.com/waste-go/internal/netmgr"
	"github.com/waste-go/internal/proto"
)

const wsPort = 17338

// App is the Wails application backend.
// It embeds the daemon directly — no subprocess needed.
// The React frontend connects to the daemon's WebSocket IPC at ws://127.0.0.1:17338,
// exactly as it does in browser-daemon mode.
type App struct {
	ctx context.Context
	mgr *netmgr.Manager
}

func newApp() *App {
	return &App{}
}

// startup is called when the Wails window is ready. It initialises the daemon,
// starts the WebSocket IPC listener, sets up the system tray, and begins
// forwarding message/file events to the webview as OS notifications.
func (a *App) startup(ctx context.Context) {
	a.ctx = ctx

	dir := dataDir()
	id, err := crypto.LoadOrCreate(dir, "")
	if err != nil {
		log.Printf("app: identity: %v", err)
		runtime.MessageDialog(ctx, runtime.MessageDialogOptions{
			Type:    runtime.ErrorDialog,
			Title:   "waste — startup error",
			Message: "Failed to load identity: " + err.Error(),
		})
		return
	}
	log.Printf("app: peer id: %s  alias: %s", id.PeerID().Short(), id.Alias)

	a.mgr = netmgr.New(netmgr.Config{
		MasterIdentity: id,
		StoreDir:       dir,
	})

	// Forward daemon events to the webview and generate OS notifications.
	go a.watchEvents()

	// Start the WebSocket IPC server; the webview connects here (daemon mode).
	go func() {
		if err := ipc.RunWS(a.mgr, wsPort); err != nil {
			log.Printf("app: IPC: %v", err)
		}
	}()

	log.Printf("app: WebSocket IPC listening on 127.0.0.1:%d", wsPort)

	// System tray (Linux/Windows; no-op on macOS — see tray_darwin.go).
	a.startTray()
}

// shutdown is called when the Wails app exits.
func (a *App) shutdown(ctx context.Context) {
	if a.mgr != nil {
		a.mgr.LeaveAll()
	}
}

// watchEvents subscribes to all daemon events and emits OS notifications for
// incoming messages and completed file transfers. The "notify" event is received
// by the frontend via Wails EventsOn and displayed using the browser Notification API.
func (a *App) watchEvents() {
	if a.mgr == nil {
		return
	}
	events := a.mgr.Subscribe()
	defer a.mgr.Unsubscribe(events)

	for evt := range events {
		switch evt.Type {
		case proto.EvtMessageReceived:
			if evt.Message == nil {
				continue
			}
			// Don't notify for messages sent by the local peer.
			if a.mgr.MasterIdentity() != nil && evt.Message.From == a.mgr.MasterIdentity().PeerID() {
				continue
			}
			runtime.EventsEmit(a.ctx, "notify", map[string]string{
				"title": "waste — new message",
				"body":  evt.Message.Text,
			})

		case proto.EvtFileComplete:
			runtime.EventsEmit(a.ctx, "notify", map[string]string{
				"title": "waste — file received",
				"body":  filepath.Base(evt.Path),
			})
		}
	}
}

// dataDir returns the OS-appropriate config directory for identity and stores.
// macOS: ~/Library/Application Support/waste
// Linux: ~/.config/waste
// Windows: %APPDATA%\waste
func dataDir() string {
	base, err := os.UserConfigDir()
	if err != nil {
		if home, err := os.UserHomeDir(); err == nil {
			return filepath.Join(home, ".waste")
		}
		return ".waste"
	}
	dir := filepath.Join(base, "waste")
	if err := os.MkdirAll(dir, 0o700); err != nil {
		log.Printf("app: mkdir %s: %v", dir, err)
	}
	return dir
}