Namespace mojo.input

#Import "native/keyinfo.h"
#Import "native/keyinfo.cpp"

Extern Private

Struct bbKeyInfo
	Field name:Void Ptr
	Field scanCode:Int
	Field keyCode:Int
End

Global bbKeyInfos:bbKeyInfo Ptr

Public

#rem monkeydoc Global instance of the KeyboardDevice class.

#end
Const Keyboard:=New KeyboardDevice

#rem monkeydoc The KeyboardDevice class.

All method that take a `key` parameter can also be used with 'raw' keys.

A raw key represents the physical location of a key on US keyboards. For example, `Key.Q|Key.Raw` indicates the key at the top left of the
'qwerty' keys regardless of the current keyboard layout.

Please see the [[Key]] enum for more information on raw keys.

To access the keyboard device, use the global [[Keyboard]] constant.

The keyboard device should only used after a new [[app.AppInstance]] is created.

#end
Class KeyboardDevice Extends InputDevice

	#rem monkeydoc The current state of the modifier keys.
	#end
	Property Modifiers:Modifier()
		Return _modifiers
	End

	#rem monkeydoc Gets the name of a key.
	
	If `key` is a raw key, returns the name 'printed' on that key.
	
	if `key` is a virtual key
	
	#end	
	Method KeyName:String( key:Key )
		If key & key.Raw key=TranslateKey( key )
		Return _names[key]
	End
	
	#rem monkeydoc Translates a key to/from a raw key.
	
	If `key` is a raw key, returns the corresponding virual key.
	
	If `key` is a virtual key, returns the corresponding raw key.
	
	#end
	Method TranslateKey:Key( key:Key )
		If key & Key.Raw
#If __TARGET__="emscripten"
			Return key & ~Key.Raw
#Else
			Local keyCode:=SDL_GetKeyFromScancode( Cast<SDL_Scancode>( _raw2scan[ key & ~Key.Raw ] ) )
			Return KeyCodeToKey( keyCode )
#Endif
		Else
			Local scanCode:=_key2scan[key]
			Return _scan2raw[scanCode]
		Endif
		Return Key.None
	End
	
	#rem monkeydoc Checks the current up/down state of a key.
	
	Returns true if `key` is currently held down.
	
	If `key` is a raw key, the state of the key as it is physically positioned on US keyboards is returned.
	
	@param key Key to check.
	
	#end
	Method KeyDown:Bool( key:Key )

		Local scode:=ScanCode( key )

		Return _keys[scode].down
	End
	
	#rem monkeydoc Checks if a key was pressed.
	
	Returns true if `key` was pressed since the last call to KeyPressed with the same key.

	If `key` is a raw key, the state of the key as it is physically positioned on US keyboards is returned.
	
	@param key Key to check.
	
	#end
	Method KeyPressed:Bool( key:Key,repeating:Bool=False )
	
		Local scode:=ScanCode( key )
		
		If repeating Return _keys[scode].rpressed=_frame
		
		Return _keys[scode].pressed=_frame
	End

	#rem monkeydoc Checks if a key was released.
	
	Returns true if `key` was released since the last call to KeyReleased with the same key.
	
	If `key` is a raw key, the state of the key as it is physically positioned on US keyboards is returned.
	
	@param key Key to check.
	
	#end
	Method KeyReleased:Bool( key:Key )
	
		Local scode:=ScanCode( key )
		
		Return _keys[scode].released=_frame
	End
	
	#rem monkeydoc @hidden
	#end
	Method KeyHit:Bool( key:Key,repeating:Bool=False )

		Return KeyPressed( key,repeating )
	End
	
	#rem monkeydoc Peeks at the next character in the character queue.
	#end
	Method PeekChar:Int()
		If _charPut=_charGet Return 0
		Return _charQueue[_charGet & CHAR_QUEUE_MASK]
	End
	
	#rem monkeydoc Gets the next character from the character queue.
	#end
	Method GetChar:Int()
		If _charPut=_charGet Return 0
		Local char:=_charQueue[_charGet & CHAR_QUEUE_MASK]
		_charGet+=1
		Return char
	End
	
	#rem monkeydoc Flushes the character queue.
	#end
	Method FlushChars()
		_charPut=0
		_charGet=0
	End
	
	'***** Internal *****
	
	#rem monkeydoc @hidden
	#end
	Method ScanCode:Int( key:Key )
		If key & Key.Raw Return _raw2scan[ key & ~Key.Raw ]
		Return _key2scan[ key ]
	End
	
	#rem monkeydoc @hidden
	#end
	Method KeyCodeToKey:Key( keyCode:Int )
		If (keyCode & $40000000) keyCode=(keyCode & ~$40000000)+$80
		Return Cast<Key>( keyCode )
	End
	
	#rem monkeydoc @hidden
	#end
	Method ScanCodeToRawKey:Key( scanCode:Int )
		Return _scan2raw[ scanCode ]
	End
	
	#rem monkeydoc @hidden
	#end
	Method Init()
		Local p:=bbKeyInfos
		
		While p->name
		
			Local name:=String.FromCString( p->name )
			Local scanCode:=p->scanCode
			Local keyCode:=p->keyCode
			
			Local key:=KeyCodeToKey( keyCode )
			
			_names[key]=name
			_raw2scan[key]=scanCode
			_scan2raw[scanCode]=key | Key.Raw
			
#If __TARGET__="emscripten"
			_key2scan[key]=scanCode
#Else
			_key2scan[key]=SDL_GetScancodeFromKey( Cast<SDL_Keycode>( keyCode ) )
#Endif
			_scan2key[_key2scan[key]]=key
			
			p=p+1
		Wend
	End
	
	#rem monkeydoc @hidden
	#end
	Method Update()
		_frame+=1
		FlushChars()
	End
	
	#rem monkeydoc @hidden
	#end
	Method SendEvent( event:SDL_Event Ptr )
	
		Select event->type
			
		Case SDL_KEYDOWN
		
			Local kevent:=Cast<SDL_KeyboardEvent Ptr>( event )
			
			Local scode:=kevent->keysym.scancode
			
			_keys[scode].down=True
			If kevent->repeat_
				_keys[scode].rpressed=_frame
			Else
				_keys[scode].pressed=_frame
				_keys[scode].rpressed=_frame
			Endif
			
			_modifiers=Cast<Modifier>( kevent->keysym.mod_ )
			
			Local char:=KeyToChar( _scan2key[scode] )
			If char PushChar( char )

		Case SDL_KEYUP
		
			Local kevent:=Cast<SDL_KeyboardEvent Ptr>( event )
			
			Local scode:=kevent->keysym.scancode
			
			_keys[scode].down=False
			_keys[scode].released=_frame
			_modifiers=Cast<Modifier>( kevent->keysym.mod_ )
			
		Case SDL_TEXTINPUT
		
			Local tevent:=Cast<SDL_TextInputEvent Ptr>( event )
			Local char:=tevent->text[0]
			If char PushChar( char )
			
		End

	End

	Private
	
	Struct KeyState
		Field down:Bool
		Field pressed:Int	'frame of last keydown received
		Field rpressed:Int	'frame of last keydown+repeat received
		Field released:Int
	End

	Const CHAR_QUEUE_SIZE:=32
	Const CHAR_QUEUE_MASK:=31

	Field _frame:Int=1
	Field _keys:=New KeyState[512]
	Field _modifiers:Modifier
	Field _charQueue:=New Int[CHAR_QUEUE_SIZE]
	Field _charPut:Int
	Field _charGet:Int

	Field _names:=New String[512]
	Field _raw2scan:=New Int[512]	'no translate
	Field _scan2raw:=New Key[512]	'no translate
	Field _key2scan:=New Int[512]	'translate
	Field _scan2key:=New Int[512]	'translate

	Method New()
	End

	Function KeyToChar:Int( key:Int )
		Select key
		Case Key.Backspace,Key.Tab,Key.Enter,Key.Escape,Key.KeyDelete
			Return key
		Case Key.PageUp,Key.PageDown,Key.KeyEnd,Key.Home,Key.Left,Key.Up,Key.Right,Key.Down,Key.Insert
			Return key | $10000
		End
		Return 0
	End
	
	Method PushChar( char:Int )
		If _charPut-_charGet=CHAR_QUEUE_SIZE Return
		_charQueue[ _charPut & CHAR_QUEUE_MASK ]=char
		_charPut+=1
	End
	
End