Behavision/desktop/main.go

// Command behavision-desktop is the store-facing application: a tray icon, a
// window, and the supervisor for the recognition engine.
//
// It is one process rather than three because the tray, the window and the
// supervisor all need the same state, and because a user who quits the tray
// expects recognition to stop. It is deliberately NOT a Windows service: a
// service runs in session 0 and cannot draw a tray icon, and spawning a child
// process needs no elevation while controlling a service does.
package main

import (
	"context"
	"embed"
	"log"
	runtime2 "runtime"

	"github.com/wailsapp/wails/v2"
	"github.com/wailsapp/wails/v2/pkg/options"
	"github.com/wailsapp/wails/v2/pkg/options/assetserver"
	"github.com/wailsapp/wails/v2/pkg/options/windows"
	"github.com/wailsapp/wails/v2/pkg/runtime"
)

//go:embed all:frontend/dist
var assets embed.FS

func main() {
	app := NewApp()
	tray := newTray(app)

	// One process per PC, enforced by the OS rather than by hoping.
	//
	// The window hides to the tray on close, so the ordinary next thing a shop
	// assistant does is double-click the desktop shortcut again to get it
	// back. Without this lock that started a SECOND complete copy: a second
	// tray icon, a second engine supervisor on the same SQLite WAL and the
	// same port - the "start twice" failure the agent package exists to
	// prevent, on the one binary that never had the guard. Seen on a Windows
	// install as a row of Behavision icons in the tray. A second launch now
	// only brings the existing window to the front, which is what the person
	// wanted in the first place.
	var ctxRef context.Context
	single := &options.SingleInstanceLock{
		UniqueId: "ai.loyaly.behavision.desktop",
		OnSecondInstanceLaunch: func(options.SecondInstanceData) {
			if ctxRef != nil {
				// The same four calls the tray uses, and for the same reasons:
				// this runs on Wails' own listener goroutine rather than the
				// window's thread, and the launching process holds the
				// foreground, so without the flip the window comes back behind
				// it. Double-clicking the desktop icon while it is already
				// running is the single most common way anyone reaches this.
				go openWindow(ctxRef)
			}
		},
	}

	err := wails.Run(&options.App{
		SingleInstanceLock: single,
		Title:              "Behavision",
		Width:              1280,
		Height:             820,
		// Small enough to still be usable on a cramped shop-counter monitor.
		MinWidth:    1024,
		MinHeight:   640,
		AssetServer: &assetserver.Options{Assets: assets},
		// Closing the window hides it rather than quitting: the engine must
		// keep recognising after a shop assistant clicks the X, and the tray
		// is where they get the window back.
		// Windows hides on close because the tray is how the window comes
		// back and how recognition is stopped. macOS has no tray here (see
		// tray_run_darwin.go), so hiding would leave a running engine with no
		// window, no tray and no way to reach either - force-quit or nothing.
		// Closing the window therefore quits, which also stops the engine
		// through OnShutdown. Same rule as the tray's Quit: never leave it
		// watching with no visible control.
		HideWindowOnClose: runtime2.GOOS == "windows",
		OnStartup: func(ctx context.Context) {
			ctxRef = ctx
			app.startup(ctx)
			tray.start(ctx)
		},
		OnBeforeClose: func(ctx context.Context) bool {
			if runtime2.GOOS != "windows" {
				return false // let it close, and OnShutdown stops the engine
			}
			// WindowHide, not Hide. They are different calls on Windows -
			// WindowHide locks the OS thread for the Win32 work and Hide does
			// not - and the tray's reopen uses WindowShow, so hiding through
			// the other one leaves the pair mismatched. Same call, opposite
			// direction.
			runtime.WindowHide(ctx)
			return true // prevent the close; the tray is how it comes back
		},
		OnShutdown: func(ctx context.Context) {
			tray.stop()
			app.proxy.stop()
			app.StopEngine()
		},
		Bind: []any{app},
		Windows: &windows.Options{
			WebviewIsTransparent: false,
			WindowIsTranslucent:  false,
			// A shop PC is not a developer machine; a stray right-click that
			// opens devtools looks like the software is broken.
			DisableWindowIcon: false,
		},
	})
	if err != nil {
		log.Fatalf("behavision-desktop: %v", err)
	}
}