Files
karma/internal/transform/colors.go
Łukasz Mierzwa 50cd656cf3 fix(backend): use randomcolor fork
Forked code doesn't require any locks
2021-07-05 22:20:33 +01:00

110 lines
2.9 KiB
Go

package transform
import (
"crypto/sha1"
"image/color"
"io"
"math/rand"
"github.com/prymitive/karma/internal/config"
"github.com/prymitive/karma/internal/models"
"github.com/prymitive/karma/internal/slices"
"github.com/prymitive/randomcolor"
"github.com/rs/zerolog/log"
plcolors "gopkg.in/go-playground/colors.v1"
)
func labelToSeed(key string, val string) int64 {
h := sha1.New()
_, _ = io.WriteString(h, key)
_, _ = io.WriteString(h, val)
var seed int64
for _, i := range h.Sum(nil) {
seed += int64(i)
}
return seed
}
func colorFromKeyVal(key, val string) color.Color {
r := rand.New(rand.NewSource(labelToSeed(key, val)))
return randomcolor.New(r, randomcolor.Random, randomcolor.LIGHT)
}
func rgbToBrightness(r, g, b uint8) int32 {
return ((int32(r) * 299) + (int32(g) * 587) + (int32(b) * 114)) / 1000
}
func parseCustomColor(colorStore models.LabelsColorMap, key, val, customColor string) {
color, err := plcolors.Parse(customColor)
if err != nil {
log.Warn().
Err(err).
Str("key", key).
Str("value", val).
Msg("Failed to parse custom color")
return
}
rgb := color.ToRGB()
bc := models.Color{
Red: rgb.R,
Green: rgb.G,
Blue: rgb.B,
Alpha: 255,
}
brightness := rgbToBrightness(bc.Red, bc.Green, bc.Blue)
if _, found := colorStore[key]; !found {
colorStore[key] = make(map[string]models.LabelColors)
}
colorStore[key][val] = models.LabelColors{
Brightness: brightness,
Background: bc.ToString(),
}
}
// ColorLabel update karmaColorMap object with a color object generated
// from label key and value passed here
// It's used to generate unique colors for configured labels
func ColorLabel(colorStore models.LabelsColorMap, key string, val string) {
// first handle custom colors
_, ok := config.Config.Labels.Color.Custom[key]
if ok {
for _, colorRule := range config.Config.Labels.Color.Custom[key] {
if colorRule.Value == val {
parseCustomColor(colorStore, key, val, colorRule.Color)
return
}
if colorRule.CompiledRegex != nil && colorRule.CompiledRegex.MatchString(val) {
parseCustomColor(colorStore, key, val, colorRule.Color)
return
}
}
}
// if no custom color is found then generate unique colors if needed
if slices.StringInSlice(config.Config.Labels.Color.Unique, key) {
if _, found := colorStore[key]; !found {
colorStore[key] = make(map[string]models.LabelColors)
}
if _, found := colorStore[key][val]; !found {
color := colorFromKeyVal(key, val)
red, green, blue, alpha := color.RGBA()
bc := models.Color{
Red: uint8(red >> 8),
Green: uint8(green >> 8),
Blue: uint8(blue >> 8),
Alpha: uint8(alpha >> 8),
}
// check if color is bright or dark and pick the right background
// uses https://www.w3.org/WAI/ER/WD-AERT/#color-contrast method
brightness := rgbToBrightness(bc.Red, bc.Green, bc.Blue)
colorStore[key][val] = models.LabelColors{
Brightness: brightness,
Background: bc.ToString(),
}
}
}
}