// 28 february 2014

package ui

import (
	"fmt"
	"unsafe"
)

// #cgo CFLAGS: -mmacosx-version-min=10.7 -DMACOSX_DEPLOYMENT_TARGET=10.7
// #cgo LDFLAGS: -mmacosx-version-min=10.7 -lobjc -framework Foundation -framework AppKit
// /* application compatibilty stuff via https://developer.apple.com/library/mac/documentation/DeveloperTools/Conceptual/cross_development/Configuring/configuring.html, http://www.cocoawithlove.com/2009/09/building-for-earlier-os-versions-in.html, http://opensource.apple.com/source/xnu/xnu-2422.1.72/EXTERNAL_HEADERS/AvailabilityMacros.h (via http://stackoverflow.com/questions/20485797/what-macro-to-use-to-identify-mavericks-osx-10-9-in-c-c-code), and Beelsebob and LookyLuke_ICBM on irc.freenode.net/#macdev */
// #include "objc_darwin.h"
import "C"

func uiinit() error {
	err := initCocoa()
	if err != nil {
		return err
	}

	return nil
}

func ui() {
	// Cocoa must run on the first thread created by the program, so we run our dispatcher on another thread instead
	go func() {
		<-Stop
		// TODO is this function thread-safe?
		C.breakMainLoop()
	}()

	C.cocoaMainLoop()
}

// we're going to call the appDelegate selector with waitUntilDone:YES so we don't have to worry about garbage collection
// we DO need to collect the two pointers together, though

type uipostmsg struct {
	w		*Window
	data		interface{}
}

//export appDelegate_uipost
func appDelegate_uipost(xmsg unsafe.Pointer) {
	msg := (*uipostmsg)(xmsg)
	msg.w.sysData.post(msg.data)
}

func uipost(w *Window, data interface{}) {
	msg := &uipostmsg{
		w:		w,
		data:		data,
	}
	C.uipost(appDelegate, unsafe.Pointer(msg))
}

func initCocoa() (err error) {
	makeAppDelegate()
	if C.initCocoa(appDelegate) != C.YES {
		return fmt.Errorf("error setting NSApplication activation policy (basically identifies our program as a separate program; needed for several things, such as Dock icon, application menu, window resizing, etc.) (unknown reason)")
	}
	return nil
}