package common

import (
	"regexp"
	"strings"

	"github.com/lucasb-eyer/go-colorful"
)

// the values in colors must be lowercase so it matches with the color input
// this saves from having to call strings.ToLower(color) every time to check
var colors = []string{
	"aliceblue", "antiquewhite", "aqua", "aquamarine", "azure",
	"beige", "bisque", "black", "blanchedalmond", "blue",
	"blueviolet", "brown", "burlywood", "cadetblue", "chartreuse",
	"chocolate", "coral", "cornflowerblue", "cornsilk", "crimson",
	"cyan", "darkblue", "darkcyan", "darkgoldenrod", "darkgray",
	"darkgrey", "darkgreen", "darkkhaki", "darkmagenta", "darkolivegreen",
	"darkorange", "darkorchid", "darkred", "darksalmon", "darkseagreen",
	"darkslateblue", "darkslategray", "darkslategrey", "darkturquoise", "darkviolet",
	"deeppink", "deepskyblue", "dimgray", "dimgrey", "dodgerblue",
	"firebrick", "floralwhite", "forestgreen", "fuchsia", "gainsboro",
	"ghostwhite", "gold", "goldenrod", "gray", "grey",
	"green", "greenyellow", "honeydew", "hotpink", "indianred",
	"indigo", "ivory", "khaki", "lavender", "lavenderblush",
	"lawngreen", "lemonchiffon", "lightblue", "lightcoral", "lightcyan",
	"lightgoldenrodyellow", "lightgray", "lightgrey", "lightgreen", "lightpink",
	"lightsalmon", "lightseagreen", "lightskyblue", "lightslategray", "lightslategrey",
	"lightsteelblue", "lightyellow", "lime", "limegreen", "linen",
	"magenta", "maroon", "mediumaquamarine", "mediumblue", "mediumorchid",
	"mediumpurple", "mediumseagreen", "mediumslateblue", "mediumspringgreen", "mediumturquoise",
	"mediumvioletred", "midnightblue", "mintcream", "mistyrose", "moccasin",
	"navajowhite", "navy", "oldlace", "olive", "olivedrab",
	"orange", "orangered", "orchid", "palegoldenrod", "palegreen",
	"paleturquoise", "palevioletred", "papayawhip", "peachpuff", "peru",
	"pink", "plum", "powderblue", "purple", "rebeccapurple",
	"red", "rosybrown", "royalblue", "saddlebrown", "salmon",
	"sandybrown", "seagreen", "seashell", "sienna", "silver",
	"skyblue", "slateblue", "slategray", "slategrey", "snow",
	"springgreen", "steelblue", "tan", "teal", "thistle",
	"tomato", "turquoise", "violet", "wheat", "white",
	"whitesmoke", "yellow", "yellowgreen",
}

var (
	regexColor = regexp.MustCompile(`^#([0-9A-Fa-f]{3}){1,2}$`)
)

// IsValidColor takes a string s and compares it against a list of css color names.
// It also accepts hex codes in the form of #RGB and #RRGGBB
func IsValidColor(s string) bool {
	s = strings.ToLower(s)
	for _, c := range colors {
		if s == c {
			return true
		}
	}

	if regexColor.MatchString(s) {
		c, err := colorful.Hex(s)
		if err != nil {
			return false
		}
		total := c.R + c.G + c.B
		return total > 0.7 && c.B/total < 0.7
	}
	return false
}

// RandomColor returns a hex color code
func RandomColor() string {
	var color colorful.Color
	for !IsValidColor(color.Hex()) {
		color = colorful.FastHappyColor()
	}
	return color.Hex()
}