//go:build darwin && !ios && !server

package application

/*

#cgo CFLAGS: -mmacosx-version-min=10.13 -x objective-c
#cgo LDFLAGS: -framework Cocoa -mmacosx-version-min=10.13

#include "application_darwin.h"
#include "application_darwin_delegate.h"
#include "webview_window_darwin.h"
#include <stdlib.h>

extern void registerListener(unsigned int event);

#import <Cocoa/Cocoa.h>
#import <Foundation/Foundation.h>

static AppDelegate *appDelegate = nil;

static void init(void) {
    [NSApplication sharedApplication];
    appDelegate = [[AppDelegate alloc] init];
    [NSApp setDelegate:appDelegate];

	[NSEvent addLocalMonitorForEventsMatchingMask:NSEventMaskLeftMouseDown handler:^NSEvent * _Nullable(NSEvent * _Nonnull event) {
		NSWindow* eventWindow = [event window];
		if (eventWindow == nil ) {
			return event;
        }
		WebviewWindowDelegate* windowDelegate = (WebviewWindowDelegate*)[eventWindow delegate];
		if (windowDelegate == nil) {
			return event;
		}
		if ([windowDelegate respondsToSelector:@selector(handleLeftMouseDown:)]) {
			[windowDelegate handleLeftMouseDown:event];
		}
		return event;
	}];

	[NSEvent addLocalMonitorForEventsMatchingMask:NSEventMaskLeftMouseUp handler:^NSEvent * _Nullable(NSEvent * _Nonnull event) {
		NSWindow* eventWindow = [event window];
		if (eventWindow == nil ) {
			return event;
        }
		WebviewWindowDelegate* windowDelegate = (WebviewWindowDelegate*)[eventWindow delegate];
		if (windowDelegate == nil) {
			return event;
		}
		if ([windowDelegate respondsToSelector:@selector(handleLeftMouseUp:)]) {
			[windowDelegate handleLeftMouseUp:eventWindow];
		}
		return event;
	}];

	NSDistributedNotificationCenter *center = [NSDistributedNotificationCenter defaultCenter];
	[center addObserver:appDelegate selector:@selector(themeChanged:) name:@"AppleInterfaceThemeChangedNotification" object:nil];

	// Register the custom URL scheme handler
	StartCustomProtocolHandler();
}

static bool isDarkMode(void) {
	NSUserDefaults* userDefaults = [NSUserDefaults standardUserDefaults];
	if (userDefaults == nil) {
		return false;
	}

	NSString *interfaceStyle = [userDefaults stringForKey:@"AppleInterfaceStyle"];
	if (interfaceStyle == nil) {
		return false;
	}

	return [interfaceStyle isEqualToString:@"Dark"];
}

static char* getAccentColor(void) {
	@autoreleasepool {
		NSColor *accentColor;
		if (@available(macOS 10.14, *)) {
			accentColor = [NSColor controlAccentColor];
		} else {
			// Fallback to system blue for older macOS versions
			accentColor = [NSColor systemBlueColor];
		}
		// Convert to RGB color space
		NSColor *rgbColor = [accentColor colorUsingColorSpace:[NSColorSpace sRGBColorSpace]];
		if (rgbColor == nil) {
			rgbColor = accentColor;
		}
		// Get RGB components
		CGFloat red, green, blue, alpha;
		[rgbColor getRed:&red green:&green blue:&blue alpha:&alpha];
		// Convert to 0-255 range and format as rgb() string
		int r = (int)(red * 255);
		int g = (int)(green * 255);
		int b = (int)(blue * 255);
		NSString *colorString = [NSString stringWithFormat:@"rgb(%d,%d,%d)", r, g, b];
		return strdup([colorString UTF8String]);
	}
}

static void setApplicationShouldTerminateAfterLastWindowClosed(bool shouldTerminate) {
	// Get the NSApp delegate
	AppDelegate *appDelegate = (AppDelegate*)[NSApp delegate];
	// Set the applicationShouldTerminateAfterLastWindowClosed boolean
	appDelegate.shouldTerminateWhenLastWindowClosed = shouldTerminate;
}

static void setActivationPolicy(int policy) {
    [NSApp setActivationPolicy:policy];
}

static void activateIgnoringOtherApps() {
	[NSApp activateIgnoringOtherApps:YES];
}

static void run(void) {
    @autoreleasepool {
        [NSApp run];
        [appDelegate release];
		[NSApp abortModal];
    }
}

// destroyApp destroys the application
static void destroyApp(void) {
	[NSApp terminate:nil];
}

// Set the application menu
static void setApplicationMenu(void *menu) {
	NSMenu *nsMenu = (__bridge NSMenu *)menu;
	[NSApp setMainMenu:menu];
}

// Get the application name
static char* getAppName(void) {
	NSString *appName = [NSRunningApplication currentApplication].localizedName;
	if( appName == nil ) {
		appName = [[NSProcessInfo processInfo] processName];
	}
	return strdup([appName UTF8String]);
}

// get the current window ID
static unsigned int getCurrentWindowID(void) {
	// AppKit must be accessed on the main thread. This function may be called
	// from arbitrary Go goroutines, so we hop to the main queue when needed.
	__block unsigned int result = 0;
	if (NSApp == nil) {
		return result;
	}
	void (^resolve)(void) = ^{
		NSWindow *window = [NSApp keyWindow];
		if (window == nil) {
			window = [NSApp mainWindow];
		}
		if (window == nil) {
			return;
		}
		WebviewWindowDelegate *delegate = (WebviewWindowDelegate*)[window delegate];
		if (delegate != nil) {
			result = delegate.windowId;
		}
	};
	if ([NSThread isMainThread]) {
		resolve();
	} else {
		dispatch_sync(dispatch_get_main_queue(), resolve);
	}
	return result;
}

// Set the application icon
static void setApplicationIcon(void *icon, int length) {
    // On main thread
	dispatch_async(dispatch_get_main_queue(), ^{
		NSImage *image = [[NSImage alloc] initWithData:[NSData dataWithBytes:icon length:length]];
		[NSApp setApplicationIconImage:image];
	});
}

// Hide the application
static void hide(void) {
	[NSApp hide:nil];
}

// Show the application
static void show(void) {
	[NSApp unhide:nil];
}

static const char* serializationNSDictionary(void *dict) {
	@autoreleasepool {
		NSDictionary *nsDict = (__bridge NSDictionary *)dict;

		if ([NSJSONSerialization isValidJSONObject:nsDict]) {
			NSError *error;
			NSData *data = [NSJSONSerialization dataWithJSONObject:nsDict options:kNilOptions error:&error];
			NSString *result = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];

			return strdup([result UTF8String]);
		}
	}

	return nil;
}

static void startSingleInstanceListener(const char *uniqueID) {
	// Convert to NSString
	NSString *uid = [NSString stringWithUTF8String:uniqueID];
	[[NSDistributedNotificationCenter defaultCenter] addObserver:appDelegate
          selector:@selector(handleSecondInstanceNotification:) name:uid object:nil];
}
*/
import "C"
import (
	"sync"
	"time"
	"unsafe"

	"encoding/json"

	"github.com/wailsapp/wails/v3/internal/assetserver/webview"
	"github.com/wailsapp/wails/v3/internal/operatingsystem"
	"github.com/wailsapp/wails/v3/pkg/events"
)

type macosApp struct {
	applicationMenu unsafe.Pointer
	parent          *App
}

func (m *macosApp) isDarkMode() bool {
	return bool(C.isDarkMode())
}

func (m *macosApp) getAccentColor() string {
	accentColorC := C.getAccentColor()
	defer C.free(unsafe.Pointer(accentColorC))
	return C.GoString(accentColorC)
}

func getNativeApplication() *macosApp {
	return globalApplication.impl.(*macosApp)
}

func (m *macosApp) hide() {
	C.hide()
}

func (m *macosApp) show() {
	C.show()
}

func (m *macosApp) on(eventID uint) {
	C.registerListener(C.uint(eventID))
}

func (m *macosApp) setIcon(icon []byte) {
	C.setApplicationIcon(unsafe.Pointer(&icon[0]), C.int(len(icon)))
}

func (m *macosApp) name() string {
	appName := C.getAppName()
	defer C.free(unsafe.Pointer(appName))
	return C.GoString(appName)
}

func (m *macosApp) getCurrentWindowID() uint {
	return uint(C.getCurrentWindowID())
}

func (m *macosApp) setApplicationMenu(menu *Menu) {
	if menu == nil {
		// Create a default menu for mac
		menu = DefaultApplicationMenu()
	}
	menu.Update()

	// Convert impl to macosMenu object
	m.applicationMenu = (menu.impl).(*macosMenu).nsMenu
	C.setApplicationMenu(m.applicationMenu)
}

func (m *macosApp) run() error {
	if m.parent.options.SingleInstance != nil {
		cUniqueID := C.CString(m.parent.options.SingleInstance.UniqueID)
		defer C.free(unsafe.Pointer(cUniqueID))
		C.startSingleInstanceListener(cUniqueID)
	}
	// Add a hook to the ApplicationDidFinishLaunching event
	m.parent.Event.OnApplicationEvent(
		events.Mac.ApplicationDidFinishLaunching,
		func(*ApplicationEvent) {
			C.setApplicationShouldTerminateAfterLastWindowClosed(
				C.bool(m.parent.options.Mac.ApplicationShouldTerminateAfterLastWindowClosed),
			)
			C.setActivationPolicy(C.int(m.parent.options.Mac.ActivationPolicy))
			C.activateIgnoringOtherApps()
		},
	)
	m.setupCommonEvents()
	// setup event listeners
	for eventID := range m.parent.applicationEventListeners {
		m.on(eventID)
	}
	C.run()
	return nil
}

func (m *macosApp) destroy() {
	C.destroyApp()
}

func (m *macosApp) GetFlags(options Options) map[string]any {
	if options.Flags == nil {
		options.Flags = make(map[string]any)
	}
	return options.Flags
}

func newPlatformApp(app *App) *macosApp {
	C.init()
	return &macosApp{
		parent: app,
	}
}

//export processApplicationEvent
func processApplicationEvent(eventID C.uint, data unsafe.Pointer) {
	event := newApplicationEvent(events.ApplicationEventType(eventID))

	if data != nil {
		dataCStrJSON := C.serializationNSDictionary(data)
		if dataCStrJSON != nil {
			defer C.free(unsafe.Pointer(dataCStrJSON))

			dataJSON := C.GoString(dataCStrJSON)
			var result map[string]any
			err := json.Unmarshal([]byte(dataJSON), &result)

			if err != nil {
				panic(err)
			}

			event.Context().setData(result)
		}
	}

	switch event.Id {
	case uint(events.Mac.ApplicationDidChangeTheme):
		isDark := globalApplication.Env.IsDarkMode()
		event.Context().setIsDarkMode(isDark)
	}
	applicationEvents <- event
}

//export processWindowEvent
func processWindowEvent(windowID C.uint, eventID C.uint) {
	windowEvents <- &windowEvent{
		WindowID: uint(windowID),
		EventID:  uint(eventID),
	}
}

//export processMessage
func processMessage(windowID C.uint, message *C.char, origin *C.char, isMainFrame bool) {
	o := ""
	if origin != nil {
		o = C.GoString(origin)
	}
	windowMessageBuffer <- &windowMessage{
		windowId: uint(windowID),
		message:  C.GoString(message),
		originInfo: &OriginInfo{
			Origin:      o,
			IsMainFrame: isMainFrame,
		},
	}
}

//export processURLRequest
func processURLRequest(windowID C.uint, wkUrlSchemeTask unsafe.Pointer) {
	window, ok := globalApplication.Window.GetByID(uint(windowID))
	if !ok || window == nil {
		globalApplication.debug("could not find window with id", "windowID", windowID)
		return
	}

	webviewRequests <- &webViewAssetRequest{
		Request:    webview.NewRequest(wkUrlSchemeTask),
		windowId:   uint(windowID),
		windowName: window.Name(),
	}
}

//export processWindowKeyDownEvent
func processWindowKeyDownEvent(windowID C.uint, acceleratorString *C.char) {
	windowKeyEvents <- &windowKeyEvent{
		windowId:          uint(windowID),
		acceleratorString: C.GoString(acceleratorString),
	}
}

//export processDragItems
func processDragItems(windowID C.uint, arr **C.char, length C.int, x C.int, y C.int) {
	var filenames []string
	// Convert the C array to a Go slice
	goSlice := (*[1 << 30]*C.char)(unsafe.Pointer(arr))[:length:length]
	for _, str := range goSlice {
		filenames = append(filenames, C.GoString(str))
	}

	globalApplication.debug(
		"[DragDropDebug] processDragItems called",
		"windowID",
		windowID,
		"fileCount",
		len(filenames),
		"x",
		x,
		"y",
		y,
	)
	targetWindow, ok := globalApplication.Window.GetByID(uint(windowID))
	if !ok || targetWindow == nil {
		println("Error: processDragItems could not find window with ID:", uint(windowID))
		return
	}

	globalApplication.debug(
		"[DragDropDebug] processDragItems: Calling targetWindow.InitiateFrontendDropProcessing",
	)
	targetWindow.InitiateFrontendDropProcessing(filenames, int(x), int(y))
}

//export macosOnDragEnter
func macosOnDragEnter(windowID C.uint) {
	window, ok := globalApplication.Window.GetByID(uint(windowID))
	if !ok || window == nil {
		return
	}

	// Call JavaScript to show drag entered state
	window.ExecJS("window._wails.handleDragEnter();")
}

//export macosOnDragExit
func macosOnDragExit(windowID C.uint) {
	window, ok := globalApplication.Window.GetByID(uint(windowID))
	if !ok || window == nil {
		return
	}

	// Call JavaScript to clean up drag state
	window.ExecJS("window._wails.handleDragLeave();")
}

var (
	// Pre-allocated buffer for drag JS calls to avoid allocations
	dragOverJSBuffer = make([]byte, 128) // Increased for safety
	dragOverJSMutex  sync.Mutex          // Protects dragOverJSBuffer
	dragOverJSPrefix = []byte("window._wails.handleDragOver(")

	// Cache window references to avoid repeated lookups
	windowImplCache sync.Map // windowID -> *macosWebviewWindow

	// Per-window drag throttle state
	dragThrottle sync.Map // windowID -> *dragThrottleState
)

type dragThrottleState struct {
	mu           sync.Mutex // Protects all fields below
	lastX, lastY int
	timer        *time.Timer
	pendingX     int
	pendingY     int
	hasPending   bool
}

// clearWindowDragCache removes cached references for a window
func clearWindowDragCache(windowID uint) {
	windowImplCache.Delete(windowID)

	// Cancel any pending timer
	if throttleVal, ok := dragThrottle.Load(windowID); ok {
		if throttle, ok := throttleVal.(*dragThrottleState); ok {
			throttle.mu.Lock()
			if throttle.timer != nil {
				throttle.timer.Stop()
			}
			throttle.mu.Unlock()
		}
	}
	dragThrottle.Delete(windowID)
}

// writeInt writes an integer to a byte slice and returns the number of bytes written
func writeInt(buf []byte, n int) int {
	if n < 0 {
		if len(buf) == 0 {
			return 0
		}
		buf[0] = '-'
		return 1 + writeInt(buf[1:], -n)
	}
	if n == 0 {
		if len(buf) == 0 {
			return 0
		}
		buf[0] = '0'
		return 1
	}

	// Count digits
	tmp := n
	digits := 0
	for tmp > 0 {
		digits++
		tmp /= 10
	}

	// Bounds check
	if digits > len(buf) {
		return 0
	}

	// Write digits in reverse
	for i := digits - 1; i >= 0; i-- {
		buf[i] = byte('0' + n%10)
		n /= 10
	}
	return digits
}

//export macosOnDragOver
func macosOnDragOver(windowID C.uint, x C.int, y C.int) {
	winID := uint(windowID)
	intX, intY := int(x), int(y)

	// Get or create throttle state
	throttleKey := winID
	throttleVal, _ := dragThrottle.LoadOrStore(throttleKey, &dragThrottleState{
		lastX: intX,
		lastY: intY,
	})
	throttle := throttleVal.(*dragThrottleState)

	throttle.mu.Lock()

	// Update pending position
	throttle.pendingX = intX
	throttle.pendingY = intY
	throttle.hasPending = true

	// If timer is already running, just update the pending position
	if throttle.timer != nil {
		throttle.mu.Unlock()
		return
	}

	// Apply 5-pixel threshold for immediate update
	dx := intX - throttle.lastX
	dy := intY - throttle.lastY
	if dx < 0 {
		dx = -dx
	}
	if dy < 0 {
		dy = -dy
	}

	// Check if we should send an immediate update
	shouldSendNow := dx >= 5 || dy >= 5

	if shouldSendNow {
		// Update last position
		throttle.lastX = intX
		throttle.lastY = intY
		throttle.hasPending = false

		// Send this update immediately (unlock before JS call to avoid deadlock)
		throttle.mu.Unlock()
		sendDragUpdate(winID, intX, intY)
		throttle.mu.Lock()
	}

	// Start 50ms timer for next update (whether we sent now or not)
	throttle.timer = time.AfterFunc(50*time.Millisecond, func() {
		// Execute on main thread to ensure UI updates
		InvokeSync(func() {
			throttle.mu.Lock()
			// Clear timer reference
			throttle.timer = nil

			// Send pending update if any
			if throttle.hasPending {
				pendingX, pendingY := throttle.pendingX, throttle.pendingY
				throttle.lastX = pendingX
				throttle.lastY = pendingY
				throttle.hasPending = false
				throttle.mu.Unlock()
				sendDragUpdate(winID, pendingX, pendingY)
			} else {
				throttle.mu.Unlock()
			}
		})
	})
	throttle.mu.Unlock()
}

// sendDragUpdate sends the actual drag update to JavaScript
func sendDragUpdate(winID uint, x, y int) {
	// Try cached implementation first
	var darwinImpl *macosWebviewWindow
	var needsExecJS bool

	if cached, found := windowImplCache.Load(winID); found {
		darwinImpl = cached.(*macosWebviewWindow)
		if darwinImpl != nil && darwinImpl.nsWindow != nil {
			needsExecJS = true
		} else {
			// Invalid cache entry, remove it
			windowImplCache.Delete(winID)
		}
	}

	if !needsExecJS {
		// Fallback to full lookup
		window, ok := globalApplication.Window.GetByID(winID)
		if !ok || window == nil {
			return
		}

		// Type assert to WebviewWindow
		webviewWindow, ok := window.(*WebviewWindow)
		if !ok || webviewWindow == nil {
			return
		}

		// Get implementation
		darwinImpl, ok = webviewWindow.impl.(*macosWebviewWindow)
		if !ok {
			return
		}

		// Cache for next time
		windowImplCache.Store(winID, darwinImpl)
		needsExecJS = true
	}

	if !needsExecJS || darwinImpl == nil {
		return
	}

	// Protect shared buffer access
	dragOverJSMutex.Lock()

	// Build JS string with zero allocations
	// Format: "window._wails.handleDragOver(X,Y)"
	// Max length with int32 coords: 30 + 11 + 1 + 11 + 1 + 1 = 55 bytes
	n := copy(dragOverJSBuffer[:], dragOverJSPrefix)
	n += writeInt(dragOverJSBuffer[n:], x)
	if n < len(dragOverJSBuffer) {
		dragOverJSBuffer[n] = ','
		n++
	}
	n += writeInt(dragOverJSBuffer[n:], y)
	if n < len(dragOverJSBuffer) {
		dragOverJSBuffer[n] = ')'
		n++
	}
	if n < len(dragOverJSBuffer) {
		dragOverJSBuffer[n] = 0 // null terminate for C
	} else {
		// Buffer overflow - this should not happen with 128 byte buffer
		dragOverJSMutex.Unlock()
		return
	}

	// Call JavaScript with zero allocations
	darwinImpl.execJSDragOver(dragOverJSBuffer[:n+1]) // Include null terminator
	dragOverJSMutex.Unlock()
}

//export processMenuItemClick
func processMenuItemClick(menuID C.uint) {
	menuItemClicked <- uint(menuID)
}

//export shouldQuitApplication
func shouldQuitApplication() C.bool {
	// TODO: This should be configurable
	return C.bool(globalApplication.shouldQuit())
}

//export cleanup
func cleanup() {
	globalApplication.cleanup()
}

func (a *App) logPlatformInfo() {
	info, err := operatingsystem.Info()
	if err != nil {
		a.error("error getting OS info: %w", err)
		return
	}

	a.info("Platform Info:", info.AsLogSlice()...)

}

func (a *App) platformEnvironment() map[string]any {
	return map[string]any{}
}

func fatalHandler(errFunc func(error)) {
	return
}

//export HandleOpenFile
func HandleOpenFile(filePath *C.char) {
	goFilepath := C.GoString(filePath)
	// Create new application event context
	eventContext := newApplicationEventContext()
	eventContext.setOpenedWithFile(goFilepath)
	// EmitEvent application started event
	applicationEvents <- &ApplicationEvent{
		Id:  uint(events.Common.ApplicationOpenedWithFile),
		ctx: eventContext,
	}
}

//export HandleOpenURL
func HandleOpenURL(urlCString *C.char) {
	urlString := C.GoString(urlCString)
	eventContext := newApplicationEventContext()
	eventContext.setURL(urlString)

	// Emit the standard event with the URL string as data
	applicationEvents <- &ApplicationEvent{
		Id:  uint(events.Common.ApplicationLaunchedWithUrl),
		ctx: eventContext,
	}
}