// Copyright 2016 The G3N Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Package window abstracts the OpenGL Window manager
// Currently only "glfw" is supported
package window

import (
	"github.com/g3n/engine/core"
	"github.com/go-gl/glfw/v3.2/glfw"
)

// IWindowManager is the interface for all window managers
type IWindowManager interface {
	ScreenResolution(interface{}) (width, height int)
	CreateWindow(width, height int, title string, full bool) (IWindow, error)
	SetSwapInterval(interval int)
	PollEvents()
	Terminate()
}

// IWindow is the interface for all windows
type IWindow interface {
	core.IDispatcher
	MakeContextCurrent()
	FramebufferSize() (width int, height int)
	Size() (width int, height int)
	SetSize(width int, height int)
	Pos() (xpos, ypos int)
	SetPos(xpos, ypos int)
	SetTitle(title string)
	SetStandardCursor(cursor StandardCursor)
	SetInputMode(InputMode, int)
	SetCursorPos(xpos, ypos float64)
	ShouldClose() bool
	SetShouldClose(bool)
	FullScreen() bool
	SetFullScreen(bool)
	SwapBuffers()
	Destroy()
}

// Key corresponds to a keyboard key.
type Key int

// Keycodes (from glfw)
const (
	KeyUnknown      = Key(glfw.KeyUnknown)
	KeySpace        = Key(glfw.KeySpace)
	KeyApostrophe   = Key(glfw.KeyApostrophe)
	KeyComma        = Key(glfw.KeyComma)
	KeyMinus        = Key(glfw.KeyMinus)
	KeyPeriod       = Key(glfw.KeyPeriod)
	KeySlash        = Key(glfw.KeySlash)
	Key0            = Key(glfw.Key0)
	Key1            = Key(glfw.Key1)
	Key2            = Key(glfw.Key2)
	Key3            = Key(glfw.Key3)
	Key4            = Key(glfw.Key4)
	Key5            = Key(glfw.Key5)
	Key6            = Key(glfw.Key6)
	Key7            = Key(glfw.Key7)
	Key8            = Key(glfw.Key8)
	Key9            = Key(glfw.Key9)
	KeySemicolon    = Key(glfw.KeySemicolon)
	KeyEqual        = Key(glfw.KeyEqual)
	KeyA            = Key(glfw.KeyA)
	KeyB            = Key(glfw.KeyB)
	KeyC            = Key(glfw.KeyC)
	KeyD            = Key(glfw.KeyD)
	KeyE            = Key(glfw.KeyE)
	KeyF            = Key(glfw.KeyF)
	KeyG            = Key(glfw.KeyG)
	KeyH            = Key(glfw.KeyH)
	KeyI            = Key(glfw.KeyI)
	KeyJ            = Key(glfw.KeyJ)
	KeyK            = Key(glfw.KeyK)
	KeyL            = Key(glfw.KeyL)
	KeyM            = Key(glfw.KeyM)
	KeyN            = Key(glfw.KeyN)
	KeyO            = Key(glfw.KeyO)
	KeyP            = Key(glfw.KeyP)
	KeyQ            = Key(glfw.KeyQ)
	KeyR            = Key(glfw.KeyR)
	KeyS            = Key(glfw.KeyS)
	KeyT            = Key(glfw.KeyT)
	KeyU            = Key(glfw.KeyU)
	KeyV            = Key(glfw.KeyV)
	KeyW            = Key(glfw.KeyW)
	KeyX            = Key(glfw.KeyX)
	KeyY            = Key(glfw.KeyY)
	KeyZ            = Key(glfw.KeyZ)
	KeyLeftBracket  = Key(glfw.KeyLeftBracket)
	KeyBackslash    = Key(glfw.KeyBackslash)
	KeyRightBracket = Key(glfw.KeyRightBracket)
	KeyGraveAccent  = Key(glfw.KeyGraveAccent)
	KeyWorld1       = Key(glfw.KeyWorld1)
	KeyWorld2       = Key(glfw.KeyWorld2)
	KeyEscape       = Key(glfw.KeyEscape)
	KeyEnter        = Key(glfw.KeyEnter)
	KeyTab          = Key(glfw.KeyTab)
	KeyBackspace    = Key(glfw.KeyBackspace)
	KeyInsert       = Key(glfw.KeyInsert)
	KeyDelete       = Key(glfw.KeyDelete)
	KeyRight        = Key(glfw.KeyRight)
	KeyLeft         = Key(glfw.KeyLeft)
	KeyDown         = Key(glfw.KeyDown)
	KeyUp           = Key(glfw.KeyUp)
	KeyPageUp       = Key(glfw.KeyPageUp)
	KeyPageDown     = Key(glfw.KeyPageDown)
	KeyHome         = Key(glfw.KeyHome)
	KeyEnd          = Key(glfw.KeyEnd)
	KeyCapsLock     = Key(glfw.KeyCapsLock)
	KeyScrollLock   = Key(glfw.KeyScrollLock)
	KeyNumLock      = Key(glfw.KeyNumLock)
	KeyPrintScreen  = Key(glfw.KeyPrintScreen)
	KeyPause        = Key(glfw.KeyPause)
	KeyF1           = Key(glfw.KeyF1)
	KeyF2           = Key(glfw.KeyF2)
	KeyF3           = Key(glfw.KeyF3)
	KeyF4           = Key(glfw.KeyF4)
	KeyF5           = Key(glfw.KeyF5)
	KeyF6           = Key(glfw.KeyF6)
	KeyF7           = Key(glfw.KeyF7)
	KeyF8           = Key(glfw.KeyF8)
	KeyF9           = Key(glfw.KeyF9)
	KeyF10          = Key(glfw.KeyF10)
	KeyF11          = Key(glfw.KeyF11)
	KeyF12          = Key(glfw.KeyF12)
	KeyF13          = Key(glfw.KeyF13)
	KeyF14          = Key(glfw.KeyF14)
	KeyF15          = Key(glfw.KeyF15)
	KeyF16          = Key(glfw.KeyF16)
	KeyF17          = Key(glfw.KeyF17)
	KeyF18          = Key(glfw.KeyF18)
	KeyF19          = Key(glfw.KeyF19)
	KeyF20          = Key(glfw.KeyF20)
	KeyF21          = Key(glfw.KeyF21)
	KeyF22          = Key(glfw.KeyF22)
	KeyF23          = Key(glfw.KeyF23)
	KeyF24          = Key(glfw.KeyF24)
	KeyF25          = Key(glfw.KeyF25)
	KeyKP0          = Key(glfw.KeyKP0)
	KeyKP1          = Key(glfw.KeyKP1)
	KeyKP2          = Key(glfw.KeyKP2)
	KeyKP3          = Key(glfw.KeyKP3)
	KeyKP4          = Key(glfw.KeyKP4)
	KeyKP5          = Key(glfw.KeyKP5)
	KeyKP6          = Key(glfw.KeyKP6)
	KeyKP7          = Key(glfw.KeyKP7)
	KeyKP8          = Key(glfw.KeyKP8)
	KeyKP9          = Key(glfw.KeyKP9)
	KeyKPDecimal    = Key(glfw.KeyKPDecimal)
	KeyKPDivide     = Key(glfw.KeyKPDivide)
	KeyKPMultiply   = Key(glfw.KeyKPMultiply)
	KeyKPSubtract   = Key(glfw.KeyKPSubtract)
	KeyKPAdd        = Key(glfw.KeyKPAdd)
	KeyKPEnter      = Key(glfw.KeyKPEnter)
	KeyKPEqual      = Key(glfw.KeyKPEqual)
	KeyLeftShift    = Key(glfw.KeyLeftShift)
	KeyLeftControl  = Key(glfw.KeyLeftControl)
	KeyLeftAlt      = Key(glfw.KeyLeftAlt)
	KeyLeftSuper    = Key(glfw.KeyLeftSuper)
	KeyRightShift   = Key(glfw.KeyRightShift)
	KeyRightControl = Key(glfw.KeyRightControl)
	KeyRightAlt     = Key(glfw.KeyRightAlt)
	KeyRightSuper   = Key(glfw.KeyRightSuper)
	KeyMenu         = Key(glfw.KeyMenu)
	KeyLast         = Key(glfw.KeyLast)
)

// ModifierKey corresponds to a modifier key.
type ModifierKey int

// Modifier keys
const (
	ModShift   = ModifierKey(glfw.ModShift)
	ModControl = ModifierKey(glfw.ModControl)
	ModAlt     = ModifierKey(glfw.ModAlt)
	ModSuper   = ModifierKey(glfw.ModSuper)
)

// MouseButton corresponds to a mouse button.
type MouseButton int

// Mouse buttons
const (
	MouseButton1      = MouseButton(glfw.MouseButton1)
	MouseButton2      = MouseButton(glfw.MouseButton2)
	MouseButton3      = MouseButton(glfw.MouseButton3)
	MouseButton4      = MouseButton(glfw.MouseButton4)
	MouseButton5      = MouseButton(glfw.MouseButton5)
	MouseButton6      = MouseButton(glfw.MouseButton6)
	MouseButton7      = MouseButton(glfw.MouseButton7)
	MouseButton8      = MouseButton(glfw.MouseButton8)
	MouseButtonLast   = MouseButton(glfw.MouseButtonLast)
	MouseButtonLeft   = MouseButton(glfw.MouseButtonLeft)
	MouseButtonRight  = MouseButton(glfw.MouseButtonRight)
	MouseButtonMiddle = MouseButton(glfw.MouseButtonMiddle)
)

// StandardCursor corresponds to a standard cursor icon.
type StandardCursor int

// Standard cursors
const (
	ArrowCursor     = StandardCursor(glfw.ArrowCursor)
	IBeamCursor     = StandardCursor(glfw.IBeamCursor)
	CrosshairCursor = StandardCursor(glfw.CrosshairCursor)
	HandCursor      = StandardCursor(glfw.HandCursor)
	HResizeCursor   = StandardCursor(glfw.HResizeCursor)
	VResizeCursor   = StandardCursor(glfw.VResizeCursor)
)

// Action corresponds to a key or button action.
type Action int

const (
	// Release indicates that key or mouse button was released
	Release = Action(glfw.Release)
	// Press indicates that key or mouse button was pressed
	Press = Action(glfw.Press)
	// Repeat indicates that key was held down until it repeated
	Repeat = Action(glfw.Repeat)
)

// InputMode corresponds to an input mode.
type InputMode int

// Input modes
const (
	CursorMode             = InputMode(glfw.CursorMode)             // See Cursor mode values
	StickyKeysMode         = InputMode(glfw.StickyKeysMode)         // Value can be either 1 or 0
	StickyMouseButtonsMode = InputMode(glfw.StickyMouseButtonsMode) // Value can be either 1 or 0
)

// Cursor mode values
const (
	CursorNormal   = glfw.CursorNormal
	CursorHidden   = glfw.CursorHidden
	CursorDisabled = glfw.CursorDisabled
)

//
// Window event names using for dispatch and subscribe
//
const (
	OnWindowPos  = "win.OnWindowPos"
	OnWindowSize = "win.OnWindowSize"
	OnKeyUp      = "win.OnKeyUp"
	OnKeyDown    = "win.OnKeyDown"
	OnKeyRepeat  = "win.OnKeyRepeat"
	OnChar       = "win.OnChar"
	OnCursor     = "win.OnCursor"
	OnMouseUp    = "win.OnMouseUp"
	OnMouseDown  = "win.OnMouseDown"
	OnScroll     = "win.OnScroll"
	OnFrame      = "win.OnFrame"
)

// PosEvent describes a windows position changed event
type PosEvent struct {
	W    IWindow
	Xpos int
	Ypos int
}

// SizeEvent describers a window size changed event
type SizeEvent struct {
	W      IWindow
	Width  int
	Height int
}

// KeyEvent describes a window key event
type KeyEvent struct {
	W        IWindow
	Keycode  Key
	Scancode int
	Action   Action
	Mods     ModifierKey
}

// CharEvent describes a window char event
type CharEvent struct {
	W    IWindow
	Char rune
	Mods ModifierKey
}

// MouseEvent describes a mouse event over the window
type MouseEvent struct {
	W      IWindow
	Xpos   float32
	Ypos   float32
	Button MouseButton
	Action Action
	Mods   ModifierKey
}

// CursorEvent describes a cursor position changed event
type CursorEvent struct {
	W    IWindow
	Xpos float32
	Ypos float32
}

// ScrollEvent describes a scroll event
type ScrollEvent struct {
	W       IWindow
	Xoffset float32
	Yoffset float32
}

// Manager returns the window manager for the specified type.
// Currently only "glfw" type is supported.
func Manager(wtype string) (IWindowManager, error) {

	if wtype != "glfw" {
		panic("Unsupported window manager")
	}
	return Glfw()
}