package color

import (
	"encoding/hex"
	"errors"
	"fmt"
	"strings"
)

type RGB struct {
	Red   int
	Green int
	Blue  int
}

func MustParseHex(hexColor string) *RGB {
	c, err := ParseHex(hexColor)
	if err != nil {
		panic(err)
	}
	return c
}

func ParseHex(hexColor string) (*RGB, error) {
	hexColor = strings.TrimPrefix(hexColor, "#")

	// Convert to individual parts
	var rh, gh, bh string
	switch len(hexColor) {
	case 3:
		rh, gh, bh = hexColor[:1]+hexColor[:1], hexColor[1:2]+hexColor[1:2], hexColor[2:3]+hexColor[2:3]
	case 6:
		rh, gh, bh = hexColor[0:2], hexColor[2:4], hexColor[4:6]
	default:
		return nil, errors.New("invalid hex string")
	}

	// Convert to bytes
	rb, err := hex.DecodeString(rh)
	if err != nil {
		return nil, err
	}
	gb, err := hex.DecodeString(gh)
	if err != nil {
		return nil, err
	}
	bb, err := hex.DecodeString(bh)
	if err != nil {
		return nil, err
	}

	return &RGB{
		Red:   int(rb[0]),
		Green: int(gb[0]),
		Blue:  int(bb[0]),
	}, nil
}

// String returns an r;g;b representation of an RGB
func (r *RGB) String() string {
	return r.format()
}

func (r *RGB) format() string {
	return fmt.Sprintf("%d;%d;%d", r.Red, r.Green, r.Blue)
}