package tins2021

import (
	"image/color"

	"opslag.de/schobers/geom"
	"opslag.de/schobers/zntg/ui"
)

type BitmapFont struct {
	texture ui.Texture
	height  float32
	runes   map[rune]*geom.RectangleF32
}

var AllCharacters = []rune(`ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789 ,.?!;:+-=_()[]{}"'@#$%^&*<>\/`)
var AlphaCharacters = []rune("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz")
var LowerCaseAlphaCharacters = []rune("abcdefghijklmnopqrstuvwxyz")
var NumericCharacters = []rune("0123456789")
var SpecialCharacters = []rune(` ,.?!;:+-=_()[]{}"'@#$%^&*<>\/`)
var UpperCaseAlphaCharacters = []rune("ABCDEFGHIJKLMNOPQRSTUVWXYZ")

func NewBitmapFont(renderer ui.Renderer, font ui.Font, set ...rune) (*BitmapFont, error) {
	texture, err := renderer.TextTexture(font, color.White, string(set))
	if err != nil {
		return nil, err
	}
	runes := map[rune]*geom.RectangleF32{}
	height := float32(texture.Height())
	var left float32
	for _, r := range set {
		width := font.WidthOf(string([]rune{r}))
		right := left + width
		rect := geom.RectF32(left, 0, right, height)
		runes[r] = &rect
		left = right
	}
	return &BitmapFont{texture, font.Height(), runes}, nil
}

func (f *BitmapFont) Destroy() error  { return f.texture.Destroy() }
func (f *BitmapFont) Height() float32 { return f.height }

func (f *BitmapFont) Measure(t string) geom.RectangleF32 {
	if len(t) == 0 {
		return geom.RectF32(0, 0, 0, 0)
	}
	var minY, maxY float32
	var width float32
	var first int
	for i, r := range t {
		rect := f.runes[r]
		if rect == nil {
			continue
		}
		width = rect.Dx()
		minY, maxY = rect.Min.Y, rect.Max.Y
		first = i
		break
	}
	for _, r := range t[first+1:] {
		rect := f.runes[r]
		if rect == nil {
			continue
		}
		width += rect.Dx()
		if minY > rect.Min.Y {
			minY = rect.Min.Y
		}
		if maxY < rect.Max.Y {
			maxY = rect.Max.Y
		}
	}
	return geom.RectF32(0, minY, width, maxY)
}

func (f *BitmapFont) Text(renderer ui.Renderer, pos geom.PointF32, color color.Color, text string) {
	f.text(renderer, pos.X, pos.Y, color, text)
}

func (f *BitmapFont) TextAlign(renderer ui.Renderer, pos geom.PointF32, color color.Color, text string, align ui.HorizontalAlignment) {
	left := pos.X
	width := f.WidthOf(text)
	switch align {
	case ui.AlignCenter:
		left -= .5 * width
	case ui.AlignRight:
		left -= width
	}
	f.text(renderer, left, pos.Y, color, text)
}

func (f *BitmapFont) text(renderer ui.Renderer, left, top float32, color color.Color, text string) {
	for _, r := range text {
		src := f.runes[r]
		if src == nil {
			continue
		}
		renderer.DrawTexturePointOptions(f.texture, geom.PtF32(left, top), ui.DrawOptions{Tint: color, Source: src})
		left += src.Dx()
	}
}

func (f *BitmapFont) WidthOf(t string) float32 {
	return f.Measure(t).Dx()
}