package aluminum

import "bytes"
import "image"
import _ "embed"
import _ "image/png"
import "image/color"
import "git.tebibyte.media/tomo/tomo"
import "golang.org/x/image/font/basicfont"
import "git.tebibyte.media/tomo/tomo/data"
import "git.tebibyte.media/tomo/tomo/theme"
import "git.tebibyte.media/tomo/tomo/input"
import "git.tebibyte.media/tomo/tomo/event"
import "git.tebibyte.media/tomo/tomo/canvas"

//go:embed assets/mime-generic-medium.png
var genericMimeIconsMedium []byte
//go:embed assets/mime-medium.png
var mimeIconsMedium []byte

func hex (color uint32) (c color.RGBA) {
	c.A = uint8(color)
	c.B = uint8(color >>  8)
	c.G = uint8(color >> 16)
	c.R = uint8(color >> 24)
	return
}

func border (top, right, bottom, left uint32, width ...int) tomo.Border {
	return tomo.Border {
		Width: tomo.I(width...),
		Color: [4]color.Color {
			hex(top),    hex(right),
			hex(bottom), hex(left),
		},
	}
}

var engravedBorder = border(0xc3c3c5FF, 0xe3e3e3FF, 0xe9e9e9ff, 0xc2c2c2ff, 1)
var gapBorder      = border(0x697c7cFF, 0x566767FF, 0x566767ff, 0x697c7cff, 1)
var focusedBorder  = border(0x5f8bc4FF, 0x5f8bc4FF, 0x5f8bc4ff, 0x5f8bc4ff, 1)
var buttonBorder   = border(0xf9fafcFF, 0xc2c8d3FF, 0xa4afc0ff, 0xf5f6f8ff, 1)
var sunkenShadow   = border(0xa4afc0FF, 0xa4afc0FF, 0xa4afc0ff, 0xa4afc0ff, 1, 0, 0, 1)
var outerShadow    = border(0xa4afc0FF, 0xa4afc0FF, 0xa4afc0ff, 0xa4afc0ff, 0, 1, 1, 0)

var buttonColor        = hex(0xe9eaeaFF)
var buttonColorPressed = hex(0xe3e4e4FF)
var buttonColorFocused = hex(0xe4e6e8FF)
var buttonColorHovered = hex(0xf1f3f5FF)
var dotColor           = hex(0x7391c080)
var inputColor         = hex(0xe3e4e4FF)
var textColor          = hex(0x000000FF)
var backgroundColor    = hex(0xd6d6d6FF)
var gutterColor        = hex(0xbfc6d1FF)
var gutterColorHovered = hex(0xc5cbd6FF)

type Theme struct {
	unpackedIcons bool
	icons            iconSet[theme.Icon]
	mimeIcons        iconSet[string]
	genericMimeIcons iconSet[string]
	appIcons         iconSet[string]
	genericAppIcons  iconSet[tomo.ApplicationRole]
}

func (this *Theme) RGBA (id theme.Color) (r, g, b, a uint32) {
	switch id {
	case theme.ColorBackground: return backgroundColor  .RGBA()
	case theme.ColorForeground: return textColor        .RGBA()
	case theme.ColorRaised:     return buttonColor      .RGBA()
	case theme.ColorSunken:     return inputColor       .RGBA()
	case theme.ColorAccent:     return hex(0x5f8bc4FF)  .RGBA()
	default:                    return color.Transparent.RGBA()
	}
}

func (this *Theme) Apply (object tomo.Object, role theme.Role) event.Cookie {
	box := object.GetBox()

	if textBox, ok := box.(tomo.TextBox); ok {
		textBox.SetDotColor(dotColor)
		textBox.SetTextColor(textColor)
		textBox.SetFace(basicfont.Face7x13)
	}

	if containerBox, ok := box.(tomo.ContainerBox); ok {
		containerBox.SetGap(image.Pt(8, 8))
	}

	switch role.Object {
	case "Button":
		pressed := false
		hovered := false

		updateStyle := func () {
			border := []tomo.Border {
				engravedBorder,
				gapBorder,
				buttonBorder,
			}
			padding := tomo.I(4, 8)
			box.SetColor(buttonColor)

			if box.Focused() {
				box.SetColor(buttonColorFocused)
				border[1] = focusedBorder
			}
			if pressed {
				box.SetColor(buttonColorPressed)
				padding   = tomo.I(5, 8, 4, 9)
				border[2] = sunkenShadow
			} else if hovered {
				box.SetColor(buttonColorHovered)
			}
			box.SetBorder(border...)
			box.SetPadding(padding)
		}
		updateStyle()
		return event.MultiCookie (
			box.OnMouseDown(func (button input.Button) {
				if button != input.ButtonLeft { return }
				pressed = true
				updateStyle()
			}),
			box.OnMouseUp(func (button input.Button) {
				if button != input.ButtonLeft { return }
				pressed = false
				updateStyle()
			}),
			box.OnFocusEnter(updateStyle),
			box.OnFocusLeave(updateStyle),
			box.OnMouseEnter(func () {
				hovered = true
				updateStyle()
			}),
			box.OnMouseLeave(func () {
				hovered = false
				updateStyle()
			}))

	case "TextInput", "NumberInput":
		box.SetPadding(tomo.I(5, 4, 4, 5))
		updateStyle := func () {
			border := []tomo.Border {
				engravedBorder,
				gapBorder,
				sunkenShadow,
			}
			box.SetColor(inputColor)

			if box.Focused() {
				border[1] = focusedBorder
			}

			box.SetBorder(border...)
		}
		updateStyle()
		return event.MultiCookie (
			box.OnFocusEnter(updateStyle),
			box.OnFocusLeave(updateStyle))

	case "Container":
		if role.Variant == "outer" {
			box.SetColor(backgroundColor)
			box.SetPadding(tomo.I(8))
		}

	case "Heading":
		if textBox, ok := box.(tomo.TextBox); ok {
			textBox.SetAlign(tomo.AlignMiddle, tomo.AlignMiddle)
		}

	case "Separator":
		box.SetBorder(engravedBorder)

	case "Slider":
		pressed := false
		hovered := false

		if role.Variant == "vertical" {
			box.SetMinimumSize(image.Pt(0, 48))
		} else {
			box.SetMinimumSize(image.Pt(48, 0))
		}

		updateStyle := func () {
			border := []tomo.Border {
				engravedBorder,
				gapBorder,
				sunkenShadow,
			}
			box.SetColor(gutterColor)

			if box.Focused() {
				border[1] = focusedBorder
			}
			if hovered && !pressed {
				box.SetColor(gutterColorHovered)
			}

			box.SetBorder(border...)
		}
		updateStyle()
		return event.MultiCookie (
			box.OnFocusEnter(updateStyle),
			box.OnFocusLeave(updateStyle),
			box.OnMouseDown(func (button input.Button) {
				pressed = true
				updateStyle()
			}),
			box.OnMouseUp(func (button input.Button) {
				pressed = false
				updateStyle()
			}),
			box.OnMouseEnter(func () {
				hovered = true
				updateStyle()
			}),
			box.OnMouseLeave(func () {
				hovered = false
				updateStyle()
			}))

	case "SliderHandle":
		box.SetMinimumSize(image.Pt(12, 12))
		border := []tomo.Border {
			outerShadow,
			gapBorder,
			buttonBorder,
		}
		box.SetBorder(border...)
		box.SetColor(buttonColor)
	}
	return event.MultiCookie()
}

func (this *Theme) Icon (id theme.Icon, size theme.IconSize) canvas.Texture {
	this.ensureIcons()
	return this.icons.Get(id, size)
}

func (this *Theme) MimeIcon (mime data.Mime, size theme.IconSize) canvas.Texture {
	this.ensureIcons()
	texture := this.mimeIcons.Get(mime.String(), size)
	if texture != nil {
		return texture
	} else {
		return this.genericMimeIcons.Get(mime.Type, size)
	}
}

func (this *Theme) ApplicationIcon (id theme.ApplicationIcon, size theme.IconSize) canvas.Texture {
	this.ensureIcons()
	texture := this.appIcons.Get(id.Name, size)
	if texture != nil {
		return texture
	} else {
		return this.genericAppIcons.Get(id.Role, size)
	}
}

func (this *Theme) ensureIcons () {
	if this.unpackedIcons { return }
	this.unpackedIcons = true

	// this.icons.Init () // TODO
	this.mimeIcons.Init (
		nil, // TODO
		bytes.NewReader(mimeIconsMedium),
		nil, // TODO
		32, 12,

		// TODO
	)
	this.genericMimeIcons.Init (
		nil, // TODO
		bytes.NewReader(genericMimeIconsMedium),
		nil, // TODO
		1, 5,

		i(0, 0, "text"),
		i(1, 0, "image"),
		i(2, 0, "audio"),
		i(3, 0, "video"),
		i(4, 0, "application"),
	)
	// this.appIcons.Init () // TODO
	// this.genericAppIcons.Init () // TODO
}