package pixel

import (
	"github.com/faiface/pixel/pixelgl"
	"github.com/go-gl/glfw/v3.2/glfw"
)

// Pressed returns whether a button is currently pressed down.
func (w *Window) Pressed(button Button) bool {
	return w.currInp.buttons[button]
}

// JustPressed returns whether a button has just been pressed down.
func (w *Window) JustPressed(button Button) bool {
	return w.currInp.buttons[button] && !w.prevInp.buttons[button]
}

// JustReleased returns whether a button has just been released up.
func (w *Window) JustReleased(button Button) bool {
	return !w.currInp.buttons[button] && w.prevInp.buttons[button]
}

// MousePosition returns the current mouse position relative to the window.
func (w *Window) MousePosition() Vec {
	var x, y, width, height float64
	pixelgl.Do(func() {
		x, y = w.window.GetCursorPos()
		wi, hi := w.window.GetSize()
		width, height = float64(wi), float64(hi)
	})

	// transform to OpenGL coordinates
	x = (x - width/2) / (width / 2)
	y = (height/2 - y) / (height / 2)

	return V(x, y)
}

// MouseScroll returns the scroll amount (in both axis) since the last call to Window.Update.
func (w *Window) MouseScroll() Vec {
	return w.currInp.scroll
}

// Button is a keyboard or mouse button. Why distinguish?
type Button int

// List of all mouse buttons.
const (
	MouseButton1      = Button(glfw.MouseButton1)
	MouseButton2      = Button(glfw.MouseButton2)
	MouseButton3      = Button(glfw.MouseButton3)
	MouseButton4      = Button(glfw.MouseButton4)
	MouseButton5      = Button(glfw.MouseButton5)
	MouseButton6      = Button(glfw.MouseButton6)
	MouseButton7      = Button(glfw.MouseButton7)
	MouseButton8      = Button(glfw.MouseButton8)
	MouseButtonLast   = Button(glfw.MouseButtonLast)
	MouseButtonLeft   = Button(glfw.MouseButtonLeft)
	MouseButtonRight  = Button(glfw.MouseButtonRight)
	MouseButtonMiddle = Button(glfw.MouseButtonMiddle)
)

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

func (w *Window) initInput() {
	pixelgl.Do(func() {
		w.window.SetMouseButtonCallback(func(_ *glfw.Window, button glfw.MouseButton, action glfw.Action, mod glfw.ModifierKey) {
			switch action {
			case glfw.Press:
				w.currInp.buttons[Button(button)] = true
			case glfw.Release:
				w.currInp.buttons[Button(button)] = false
			}
		})

		w.window.SetKeyCallback(func(_ *glfw.Window, key glfw.Key, scancode int, action glfw.Action, mods glfw.ModifierKey) {
			switch action {
			case glfw.Press:
				w.currInp.buttons[Button(key)] = true
			case glfw.Release:
				w.currInp.buttons[Button(key)] = false
			}
		})

		w.window.SetScrollCallback(func(_ *glfw.Window, xoff, yoff float64) {
			w.currInp.scroll += V(xoff, yoff)
		})
	})
}

func (w *Window) updateInput() {
	// copy temp to prev
	w.prevInp = w.tempInp

	// zero current scroll (but keep what was added in callbacks outside of this function)
	w.currInp.scroll -= w.tempInp.scroll

	// get events (usually calls callbacks, but callbacks can be called outside too)
	pixelgl.Do(func() {
		glfw.PollEvents()
	})

	// cache current state to temp (so that if there are callbacks outside this function, everything works)
	w.tempInp = w.currInp
}