#include <AppKit/AppKit.h>

#include <thread>

#include "boo/IApplication.hpp"
#include "boo/graphicsdev/Metal.hpp"
#include "lib/Common.hpp"
#include "lib/mac/CocoaCommon.hpp"

#include <logvisor/logvisor.hpp>

#if !__has_feature(objc_arc)
#error ARC Required
#endif

/* If set, application will terminate once client thread reaches end;
 * main() will not get back control. Otherwise, main will get back control
 * but App will not terminate in the normal Cocoa manner (possibly resulting
 * in CoreAnimation warnings). */
#define COCOA_TERMINATE 1

namespace boo { class ApplicationCocoa; }
@interface AppDelegate : NSObject <NSApplicationDelegate> {
  boo::ApplicationCocoa* m_app;
@public
}
- (id)initWithApp:(boo::ApplicationCocoa*)app;
@end

namespace boo {
static logvisor::Module Log("boo::ApplicationCocoa");

std::shared_ptr<IWindow> _WindowCocoaNew(SystemStringView title, MetalContext* metalCtx);

class ApplicationCocoa : public IApplication {
public:
  IApplicationCallback& m_callback;
  AppDelegate* m_appDelegate;
private:
  const SystemString m_uniqueName;
  const SystemString m_friendlyName;
  const SystemString m_pname;
  const std::vector<SystemString> m_args;

  NSPanel* aboutPanel;

  /* All windows */
  std::unordered_map<uintptr_t, std::weak_ptr<IWindow>> m_windows;

  MetalContext m_metalCtx;
#if 0
  GLContext m_glCtx;
#endif

  void _deletedWindow(IWindow* window) override {
    m_windows.erase(window->getPlatformHandle());
  }

public:
  ApplicationCocoa(IApplicationCallback& callback,
                   SystemStringView uniqueName,
                   SystemStringView friendlyName,
                   SystemStringView pname,
                   const std::vector<SystemString>& args,
                   std::string_view gfxApi,
                   uint32_t samples,
                   uint32_t anisotropy,
                   bool deepColor)
    : m_callback(callback),
      m_uniqueName(uniqueName),
      m_friendlyName(friendlyName),
      m_pname(pname),
      m_args(args) {
    m_metalCtx.m_sampleCount = samples;
    m_metalCtx.m_anisotropy = anisotropy;
    m_metalCtx.m_pixelFormat = deepColor ? MTLPixelFormatRGBA16Float : MTLPixelFormatBGRA8Unorm;
#if 0
    m_glCtx.m_sampleCount = samples;
    m_glCtx.m_anisotropy = anisotropy;
    m_glCtx.m_deepColor = deepColor;
#endif

    [[NSApplication sharedApplication] setActivationPolicy:NSApplicationActivationPolicyRegular];

    /* Delegate (OS X callbacks) */
    m_appDelegate = [[AppDelegate alloc] initWithApp:this];
    [[NSApplication sharedApplication] setDelegate:m_appDelegate];

    /* App menu */
    NSMenu* rootMenu = [[NSMenu alloc] initWithTitle:@"main"];
    NSMenu* appMenu = [[NSMenu alloc] initWithTitle:[NSString stringWithUTF8String:m_friendlyName.c_str()]];
    NSMenuItem* fsItem = [appMenu addItemWithTitle:@"Toggle Full Screen"
                                            action:@selector(toggleFs:)
                                     keyEquivalent:@"f"];
    [fsItem setKeyEquivalentModifierMask:NSEventModifierFlagCommand];
    [appMenu addItem:[NSMenuItem separatorItem]];
    NSMenuItem* quitItem = [appMenu addItemWithTitle:[NSString stringWithFormat:@"Quit %s", m_friendlyName.c_str()]
                                              action:@selector(quitApp:)
                                       keyEquivalent:@"q"];
    [quitItem setKeyEquivalentModifierMask:NSEventModifierFlagCommand];
    [[rootMenu addItemWithTitle:[NSString stringWithUTF8String:m_friendlyName.c_str()]
                         action:nil keyEquivalent:@""] setSubmenu:appMenu];
    [[NSApplication sharedApplication] setMainMenu:rootMenu];

    m_metalCtx.m_dev = MTLCreateSystemDefaultDevice();
    if (!m_metalCtx.m_dev)
      Log.report(logvisor::Fatal, FMT_STRING("Unable to create metal device"));
    m_metalCtx.m_q = [m_metalCtx.m_dev newCommandQueue];
    while (![m_metalCtx.m_dev supportsTextureSampleCount:m_metalCtx.m_sampleCount])
      m_metalCtx.m_sampleCount = flp2(m_metalCtx.m_sampleCount - 1);
    Log.report(logvisor::Info, FMT_STRING("using Metal renderer"));

    [[NSApplication sharedApplication] activateIgnoringOtherApps:YES];
  }

  EPlatformType getPlatformType() const override {
    return EPlatformType::Cocoa;
  }

  std::thread m_clientThread;
  int m_clientReturn = 0;
  bool m_terminateNow = false;

  int run() override {
    /* Spawn client thread */
    m_clientThread = std::thread([&]() {
      std::string thrName = std::string(getFriendlyName()) + " Client Thread";
      logvisor::RegisterThreadName(thrName.c_str());

      /* Run app */
      m_clientReturn = m_callback.appMain(this);

      /* Cleanup */
      for (auto& w : m_windows)
        if (std::shared_ptr<IWindow> window = w.second.lock())
          window->closeWindow();

#if COCOA_TERMINATE
      /* Continue termination */
      dispatch_sync(dispatch_get_main_queue(),
                    ^{
                      /* Ends modal run loop and continues Cocoa termination */
                      [NSApp replyToApplicationShouldTerminate:YES];

                      /* If this is reached, application didn't spawn any windows
                       * and must be explicitly terminated */
                      m_terminateNow = true;
                      [NSApp terminate:nil];
                    });
#else
      /* Return control to main() */
      dispatch_sync(dispatch_get_main_queue(),
      ^{
          [[NSApplication sharedApplication] stop:nil];
      });
#endif
    });

    /* Already in Cocoa's event loop; return now */
    return 0;
  }

  void quit() {
    [NSApp terminate:nil];
  }

  SystemStringView getUniqueName() const override {
    return m_uniqueName;
  }

  SystemStringView getFriendlyName() const override {
    return m_friendlyName;
  }

  SystemStringView getProcessName() const override {
    return m_pname;
  }

  const std::vector<SystemString>& getArgs() const override {
    return m_args;
  }

  std::shared_ptr<IWindow> newWindow(std::string_view title) override {
    auto newWindow = _WindowCocoaNew(title, &m_metalCtx);
    m_windows[newWindow->getPlatformHandle()] = newWindow;
    return newWindow;
  }

  /* Last GL context */
#if 0
  NSOpenGLContext* m_lastGLCtx = nullptr;
#endif
};

#if 0
void _CocoaUpdateLastGLCtx(NSOpenGLContext* lastGLCtx)
{
    static_cast<ApplicationCocoa*>(APP)->m_lastGLCtx = lastGLCtx;
}
#endif

IApplication* APP = nullptr;

int ApplicationRun(IApplication::EPlatformType platform,
                   IApplicationCallback& cb,
                   SystemStringView uniqueName,
                   SystemStringView friendlyName,
                   SystemStringView pname,
                   const std::vector<SystemString>& args,
                   std::string_view gfxApi,
                   uint32_t samples,
                   uint32_t anisotropy,
                   bool deepColor,
                   bool singleInstance) {
  std::string thrName = std::string(friendlyName) + " Main Thread";
  logvisor::RegisterThreadName(thrName.c_str());
  @autoreleasepool {
    if (!APP) {
      if (platform != IApplication::EPlatformType::Cocoa &&
          platform != IApplication::EPlatformType::Auto)
        return 1;
      /* Never deallocated to ensure window destructors have access */
      APP = new ApplicationCocoa(cb, uniqueName, friendlyName, pname, args,
                                 gfxApi, samples, anisotropy, deepColor);
    }
#if __MAC_OS_X_VERSION_MAX_ALLOWED >= 101400
    if ([NSApp respondsToSelector:@selector(setAppearance:)])
      [NSApp setAppearance:[NSAppearance appearanceNamed:NSAppearanceNameDarkAqua]];
#endif
    [NSApp run];
    ApplicationCocoa* appCocoa = static_cast<ApplicationCocoa*>(APP);
    if (appCocoa->m_clientThread.joinable())
      appCocoa->m_clientThread.join();
    return appCocoa->m_clientReturn;
  }
}

}

@implementation AppDelegate
- (id)initWithApp:(boo::ApplicationCocoa*)app {
  self = [super init];
  m_app = app;
  return self;
}

- (void)applicationDidFinishLaunching:(NSNotification*)notification {
  (void) notification;
  m_app->run();
}

#if COCOA_TERMINATE

- (NSApplicationTerminateReply)applicationShouldTerminate:(NSApplication*)app {
  (void) app;
  if (m_app->m_terminateNow)
    return NSTerminateNow;
  m_app->m_callback.appQuitting(m_app);
  return NSTerminateLater;
}

#else
- (NSApplicationTerminateReply)applicationShouldTerminate:(NSApplication*)app
{
    (void)app;
    m_app->m_callback.appQuitting(m_app);
    return NSTerminateCancel;
}
#endif

- (BOOL)application:(NSApplication*)sender openFile:(NSString*)filename {
  std::vector<boo::SystemString> strVec;
  strVec.push_back(boo::SystemString([filename UTF8String]));
  m_app->m_callback.appFilesOpen(boo::APP, strVec);
  return true;
}

- (void)application:(NSApplication*)sender openFiles:(NSArray*)filenames {
  std::vector<boo::SystemString> strVec;
  strVec.reserve([filenames count]);
  for (NSString* str in filenames)
    strVec.push_back(boo::SystemString([str UTF8String]));
  m_app->m_callback.appFilesOpen(boo::APP, strVec);
}

- (BOOL)applicationShouldTerminateAfterLastWindowClosed:(NSApplication*)sender {
  (void) sender;
  return YES;
}

- (IBAction)toggleFs:(id)sender {
  (void) sender;
  [[NSApp keyWindow] toggleFullScreen:nil];
}

- (IBAction)quitApp:(id)sender {
  (void) sender;
  [NSApp terminate:nil];
}
@end