Initial commit

internal/widget/fields.go

@@ -0,0 +1,152 @@
+package widget
+
+import (
+	"fmt"
+	"html/template"
+	"os"
+	"regexp"
+	"strconv"
+	"time"
+
+	"gopkg.in/yaml.v3"
+)
+
+var HSLColorPattern = regexp.MustCompile(`^(?:hsla?\()?(\d{1,3})(?: |,)+(\d{1,3})%?(?: |,)+(\d{1,3})%?\)?$`)
+var EnvFieldPattern = regexp.MustCompile(`^\${([A-Z_]+)}$`)
+
+const (
+	HSLHueMax        = 360
+	HSLSaturationMax = 100
+	HSLLightnessMax  = 100
+)
+
+type HSLColorField struct {
+	Hue        uint16
+	Saturation uint8
+	Lightness  uint8
+}
+
+func (c *HSLColorField) String() string {
+	return fmt.Sprintf("hsl(%d, %d%%, %d%%)", c.Hue, c.Saturation, c.Lightness)
+}
+
+func (c *HSLColorField) AsCSSValue() template.CSS {
+	return template.CSS(c.String())
+}
+
+func (c *HSLColorField) UnmarshalYAML(node *yaml.Node) error {
+	var value string
+
+	if err := node.Decode(&value); err != nil {
+		return err
+	}
+
+	matches := HSLColorPattern.FindStringSubmatch(value)
+
+	if len(matches) != 4 {
+		return fmt.Errorf("invalid HSL color format: %s", value)
+	}
+
+	hue, err := strconv.ParseUint(matches[1], 10, 16)
+
+	if err != nil {
+		return err
+	}
+
+	if hue > HSLHueMax {
+		return fmt.Errorf("HSL hue must be between 0 and %d", HSLHueMax)
+	}
+
+	saturation, err := strconv.ParseUint(matches[2], 10, 8)
+
+	if err != nil {
+		return err
+	}
+
+	if saturation > HSLSaturationMax {
+		return fmt.Errorf("HSL saturation must be between 0 and %d", HSLSaturationMax)
+	}
+
+	lightness, err := strconv.ParseUint(matches[3], 10, 8)
+
+	if err != nil {
+		return err
+	}
+
+	if lightness > HSLLightnessMax {
+		return fmt.Errorf("HSL lightness must be between 0 and %d", HSLLightnessMax)
+	}
+
+	c.Hue = uint16(hue)
+	c.Saturation = uint8(saturation)
+	c.Lightness = uint8(lightness)
+
+	return nil
+}
+
+var DurationPattern = regexp.MustCompile(`^(\d+)(s|m|h|d)$`)
+
+type DurationField time.Duration
+
+func (d *DurationField) UnmarshalYAML(node *yaml.Node) error {
+	var value string
+
+	if err := node.Decode(&value); err != nil {
+		return err
+	}
+
+	matches := DurationPattern.FindStringSubmatch(value)
+
+	if len(matches) != 3 {
+		return fmt.Errorf("invalid duration format: %s", value)
+	}
+
+	duration, err := strconv.Atoi(matches[1])
+
+	if err != nil {
+		return err
+	}
+
+	switch matches[2] {
+	case "s":
+		*d = DurationField(time.Duration(duration) * time.Second)
+	case "m":
+		*d = DurationField(time.Duration(duration) * time.Minute)
+	case "h":
+		*d = DurationField(time.Duration(duration) * time.Hour)
+	case "d":
+		*d = DurationField(time.Duration(duration) * 24 * time.Hour)
+	}
+
+	return nil
+}
+
+type OptionalEnvString string
+
+func (f *OptionalEnvString) UnmarshalYAML(node *yaml.Node) error {
+	var value string
+
+	err := node.Decode(&value)
+
+	if err != nil {
+		return err
+	}
+
+	matches := EnvFieldPattern.FindStringSubmatch(value)
+
+	if len(matches) != 2 {
+		*f = OptionalEnvString(value)
+
+		return nil
+	}
+
+	value, found := os.LookupEnv(matches[1])
+
+	if !found {
+		return fmt.Errorf("environment variable %s not found", matches[1])
+	}
+
+	*f = OptionalEnvString(value)
+
+	return nil
+}