// 1 march 2014
package ui

import (
	"fmt"
	"unsafe"
)

// #cgo LDFLAGS: -lobjc -framework Foundation -framework AppKit
// #include "objc_darwin.h"
import "C"

type sysData struct {
	cSysData

	id	C.id
}

type classData struct {
	make		func(parentWindow C.id) C.id
	show		func(what C.id)
	hide			func(what C.id)
	settextsel		C.SEL
	textsel		C.SEL
}

var (
	_NSWindow = objc_getClass("NSWindow")

	_initWithContentRect = sel_getUid("initWithContentRect:styleMask:backing:defer:")
	_makeKeyAndOrderFront = sel_getUid("makeKeyAndOrderFront:")
	_orderOut = sel_getUid("orderOut:")
	_setHidden = sel_getUid("setHidden:")
	_setTitle = sel_getUid("setTitle:")
	_setStringValue = sel_getUid("setStringValue:")
	_setFrame = sel_getUid("setFrame:")
	_state = sel_getUid("state")
	_title = sel_getUid("title")
	_stringValue = sel_getUid("stringValue")
	// TODO others
	_setFrameDisplay = sel_getUid("setFrame:display:")
)

func controlShow(what C.id) {
	C.objc_msgSend_bool(what, _setHidden, C.BOOL(C.NO))
}

func controlHide(what C.id) {
	C.objc_msgSend_bool(what, _setHidden, C.BOOL(C.YES))
}

var classTypes = [nctypes]*classData{
	c_window:		&classData{
		make:		func(parentWindow C.id) C.id {
			const (
				NSBorderlessWindowMask = 0
				NSTitledWindowMask = 1 << 0
				NSClosableWindowMask = 1 << 1
				NSMiniaturizableWindowMask = 1 << 2
				NSResizableWindowMask = 1 << 3
				NSTexturedBackgroundWindowMask = 1 << 8
			)

			// we have to specify a content rect to start; it will be overridden soon though
			win := objc_alloc(_NSWindow)
			return objc_msgSend_rect_uint_uint_bool(win,
				_initWithContentRect,
				0, 0, 100, 100,
				NSTitledWindowMask | NSClosableWindowMask | NSClosableWindowMask | NSResizableWindowMask,
				2,					// NSBackingStoreBuffered - the only backing store method that Apple says we should use (the others are legacy)
				C.BOOL(C.YES))			// defer creation of device until we show the window
		},
		show:		func(what C.id) {
			C.objc_msgSend_id(what, _makeKeyAndOrderFront, what)
		},
		hide:			func(what C.id) {
			C.objc_msgSend_id(what, _orderOut, what)
		},
		settextsel:		_setTitle,
		textsel:		_title,
	},
	c_button:			&classData{
	},
	c_checkbox:		&classData{
	},
	c_combobox:		&classData{
	},
	c_lineedit:		&classData{
	},
	c_label:			&classData{
	},
	c_listbox:			&classData{
	},
	c_progressbar:		&classData{
	},
}

func (s *sysData) make(initText string, window *sysData) error {
	var parentWindow C.id

	ct := classTypes[s.ctype]
	if ct.make == nil {
		println(s.ctype, "not implemented")
		return nil
	}
	if window != nil {
		parentWindow = window.id
	}
	ret := make(chan C.id)
	defer close(ret)
	uitask <- func() {
		ret <- ct.make(parentWindow)
	}
	s.id = <-ret
	err := s.setText(initText)
	if err != nil {
		return fmt.Errorf("error setting initial text of new window/control: %v", err)
	}
	return nil
}

func (s *sysData) show() error {
if classTypes[s.ctype].show == nil { return nil }
	ret := make(chan struct{})
	defer close(ret)
	uitask <- func() {
		classTypes[s.ctype].show(s.id)
		ret <- struct{}{}
	}
	<-ret
	return nil
}

func (s *sysData) hide() error {
if classTypes[s.ctype].hide == nil { return nil }
	ret := make(chan struct{})
	defer close(ret)
	uitask <- func() {
		classTypes[s.ctype].hide(s.id)
		ret <- struct{}{}
	}
	<-ret
	return nil
}

func (s *sysData) setText(text string) error {
var zero C.SEL
if classTypes[s.ctype].settextsel == zero { return nil }
	ret := make(chan struct{})
	defer close(ret)
	uitask <- func() {
		C.objc_msgSend_id(s.id, classTypes[s.ctype].settextsel, toNSString(text))
		ret <- struct{}{}
	}
	<-ret
	return nil
}

func (s *sysData) setRect(x int, y int, width int, height int) error {
if classTypes[s.ctype].make == nil { return nil }
	objc_msgSend_rect(s.id, _setFrame, x, y, width, height)
	return nil
}

func (s *sysData) isChecked() bool {
if classTypes[s.ctype].make == nil { return false }
	const (
		NSOnState = 1
	)

	ret := make(chan bool)
	defer close(ret)
	uitask <- func() {
		k := C.objc_msgSend_noargs(s.id, _state)
		ret <- uintptr(unsafe.Pointer(k)) == NSOnState
	}
	return <-ret
}

func (s *sysData) text() string {
var zero C.SEL
if classTypes[s.ctype].textsel == zero { return "" }
	ret := make(chan string)
	defer close(ret)
	uitask <- func() {
		str := C.objc_msgSend_noargs(s.id, classTypes[s.ctype].textsel)
		ret <- fromNSString(str)
	}
	return <-ret
}

func (s *sysData) append(what string) error {
	// TODO
	return nil
}

func (s *sysData) insertBefore(what string, before int) error {
	// TODO
	return nil
}

func (s *sysData) selectedIndex() int {
	// TODO
	return -1
}

func (s *sysData) selectedIndices() []int {
	// TODO
	return nil
}

func (s *sysData) selectedTexts() []string {
	// TODO
	return nil
}

func (s *sysData) setWindowSize(width int, height int) error {
	ret := make(chan struct{})
	defer close(ret)
	uitask <- func() {
		// we need to get the top left point
		objc_msgSend_rect_bool(s.id, _setFrameDisplay,
			x, y, width, height,
			C.BOOL(C.YES))		// TODO set to NO to prevent subviews from being redrawn before they are resized?
		ret <- struct{}{}
	}
	<-ret
	return nil
}

func (s *sysData) delete(index int) error {
	// TODO
	return nil
}

func (s *sysData) setProgress(percent int) {
	// TODO
}