package numbers

import (
	"github.com/veandco/go-sdl2/sdl"
)

const width = 60

var digitSegments = [][]int{
	{0, 1, 2, 4, 5, 6},
	{2, 5},
	{0, 2, 3, 4, 6},
	{0, 2, 3, 5, 6},
	{1, 2, 3, 5},
	{0, 1, 3, 5, 6},
	{0, 1, 3, 4, 5, 6},
	{0, 2, 5},
	{0, 1, 2, 3, 4, 5, 6},
	{0, 1, 2, 3, 5, 6},
}

func drawDigit(renderer *sdl.Renderer, d int, x, y int32) error {
	const (
		height    = 100
		thickness = 10
	)
	for _, segment := range digitSegments[d] {
		switch segment {
		case 0:
			renderer.FillRect(&sdl.Rect{X: x, Y: y, W: width, H: thickness})
		case 1:
			renderer.FillRect(&sdl.Rect{X: x, Y: y, W: thickness, H: height / 2})
		case 2:
			renderer.FillRect(&sdl.Rect{X: x + width - thickness, Y: y, W: thickness, H: height / 2})
		case 3:
			renderer.FillRect(&sdl.Rect{X: x, Y: y + height/2 - thickness/2, W: width, H: thickness})
		case 4:
			renderer.FillRect(&sdl.Rect{X: x, Y: y + height/2, W: thickness, H: height / 2})
		case 5:
			renderer.FillRect(&sdl.Rect{X: x + width - thickness, Y: y + height/2, W: thickness, H: height / 2})
		case 6:
			renderer.FillRect(&sdl.Rect{X: x, Y: y + height - thickness, W: width, H: thickness})
		}
	}
	return nil
}

func Draw(renderer *sdl.Renderer, n int, x, y int32) error {
	const padding = 20

	if err := renderer.SetDrawColor(245, 245, 245, 255); err != nil {
		return err
	}
	if n == 0 {
		return drawDigit(renderer, 0, x, y)
	}
	digits := make([]int, 0, 19)
	for ; n > 0; n /= 10 {
		digits = append(digits, n%10)
	}
	for i := len(digits) - 1; i >= 0; i-- {
		if err := drawDigit(renderer, digits[i], x, y); err != nil {
			return err
		}
		x += width + padding
	}
	return nil
}