package graphics

import (
	"math/rand"
	rl "github.com/gen2brain/raylib-go/raylib"
)

var (
	FlourescentHues = []float32{
		0,   // hot magenta-red
		30,  // neon orange
		60,  // acid yellow
		120, // laser green
		180, // cyan
		210, // electric blue
		270, // ultraviolet purple
	}
	FlourescentColors = makeFlourescentColors()
)

func makeFlourescentColors() []rl.Color {
	fc := make([]rl.Color, len(FlourescentHues))
	for i, hue := range(FlourescentHues) {
		fc[i] = rl.ColorFromHSV(hue, 1.0, 1.0)
	}
	return fc
}

type ColorCycle interface {
	Next() rl.Color
}

type ArrayBackedColorCycle struct {
	colors []rl.Color
	index int
}

func NewFixedColorCycle(colors []rl.Color) ArrayBackedColorCycle {
	return ArrayBackedColorCycle {
		colors: colors,
		index: 0,
	}
}

func (c ArrayBackedColorCycle) Shuffle(seed int64) ColorCycle {
	r := rand.New(rand.NewSource(seed))
	cprime := &ArrayBackedColorCycle {
		colors: make([]rl.Color, len(c.colors)),
		index: 0,
	}
	r.Shuffle(len(c.colors), func(i, j int) {
		cprime.colors[i] = c.colors[j]
	})
	return cprime
}

func (c *ArrayBackedColorCycle) Next() rl.Color {
	color := c.colors[c.index]
	c.index = (c.index + 1) % len(c.colors)
	return color
}