init

2025-06-18 01:00:00 -04:00
commit f84b511895
228 changed files with 42509 additions and 0 deletions
--- a/jdenticon/config.go
+++ b/jdenticon/config.go
@@ -0,0 +1,235 @@
+package jdenticon
+
+import (
+	"fmt"
+	"regexp"
+)
+
+// Config holds configuration options for identicon generation.
+type Config struct {
+	// HueRestrictions specifies the hues (in degrees) that are allowed for the identicon.
+	// If empty, any hue can be used. Values should be between 0 and 360.
+	HueRestrictions []float64
+	
+	// ColorLightnessRange specifies the lightness range for colored shapes [min, max].
+	// Values should be between 0.0 and 1.0. Default: [0.4, 0.8]
+	ColorLightnessRange [2]float64
+	
+	// GrayscaleLightnessRange specifies the lightness range for grayscale shapes [min, max].
+	// Values should be between 0.0 and 1.0. Default: [0.3, 0.9]
+	GrayscaleLightnessRange [2]float64
+	
+	// ColorSaturation controls the saturation of colored shapes.
+	// Values should be between 0.0 and 1.0. Default: 0.5
+	ColorSaturation float64
+	
+	// GrayscaleSaturation controls the saturation of grayscale shapes.
+	// Values should be between 0.0 and 1.0. Default: 0.0
+	GrayscaleSaturation float64
+	
+	// BackgroundColor sets the background color for the identicon.
+	// Accepts hex colors like "#fff", "#ffffff", "#ffffff80" (with alpha).
+	// If empty, the background will be transparent.
+	BackgroundColor string
+	
+	// Padding controls the padding around the identicon as a percentage of the size.
+	// Values should be between 0.0 and 0.5. Default: 0.08
+	Padding float64
+}
+
+// DefaultConfig returns a default configuration that matches jdenticon-js defaults.
+func DefaultConfig() Config {
+	return Config{
+		HueRestrictions:         nil, // No restrictions
+		ColorLightnessRange:     [2]float64{0.4, 0.8},
+		GrayscaleLightnessRange: [2]float64{0.3, 0.9},
+		ColorSaturation:         0.5,
+		GrayscaleSaturation:     0.0,
+		BackgroundColor:         "", // Transparent
+		Padding:                 0.08,
+	}
+}
+
+// ConfigOption represents a configuration option function.
+type ConfigOption func(*Config) error
+
+// WithHueRestrictions sets the allowed hues in degrees (0-360).
+func WithHueRestrictions(hues []float64) ConfigOption {
+	return func(c *Config) error {
+		for _, hue := range hues {
+			if hue < 0 || hue >= 360 {
+				return fmt.Errorf("hue must be between 0 and 360, got %f", hue)
+			}
+		}
+		c.HueRestrictions = make([]float64, len(hues))
+		copy(c.HueRestrictions, hues)
+		return nil
+	}
+}
+
+// WithColorLightnessRange sets the lightness range for colored shapes.
+func WithColorLightnessRange(min, max float64) ConfigOption {
+	return func(c *Config) error {
+		if min < 0 || min > 1 || max < 0 || max > 1 {
+			return fmt.Errorf("lightness values must be between 0 and 1, got min=%f max=%f", min, max)
+		}
+		if min > max {
+			return fmt.Errorf("minimum lightness cannot be greater than maximum, got min=%f max=%f", min, max)
+		}
+		c.ColorLightnessRange = [2]float64{min, max}
+		return nil
+	}
+}
+
+// WithGrayscaleLightnessRange sets the lightness range for grayscale shapes.
+func WithGrayscaleLightnessRange(min, max float64) ConfigOption {
+	return func(c *Config) error {
+		if min < 0 || min > 1 || max < 0 || max > 1 {
+			return fmt.Errorf("lightness values must be between 0 and 1, got min=%f max=%f", min, max)
+		}
+		if min > max {
+			return fmt.Errorf("minimum lightness cannot be greater than maximum, got min=%f max=%f", min, max)
+		}
+		c.GrayscaleLightnessRange = [2]float64{min, max}
+		return nil
+	}
+}
+
+// WithColorSaturation sets the saturation for colored shapes.
+func WithColorSaturation(saturation float64) ConfigOption {
+	return func(c *Config) error {
+		if saturation < 0 || saturation > 1 {
+			return fmt.Errorf("saturation must be between 0 and 1, got %f", saturation)
+		}
+		c.ColorSaturation = saturation
+		return nil
+	}
+}
+
+// WithGrayscaleSaturation sets the saturation for grayscale shapes.
+func WithGrayscaleSaturation(saturation float64) ConfigOption {
+	return func(c *Config) error {
+		if saturation < 0 || saturation > 1 {
+			return fmt.Errorf("saturation must be between 0 and 1, got %f", saturation)
+		}
+		c.GrayscaleSaturation = saturation
+		return nil
+	}
+}
+
+// WithBackgroundColor sets the background color.
+func WithBackgroundColor(color string) ConfigOption {
+	return func(c *Config) error {
+		if color != "" {
+			if err := validateHexColor(color); err != nil {
+				return fmt.Errorf("invalid background color: %w", err)
+			}
+		}
+		c.BackgroundColor = color
+		return nil
+	}
+}
+
+// WithPadding sets the padding around the identicon.
+func WithPadding(padding float64) ConfigOption {
+	return func(c *Config) error {
+		if padding < 0 || padding > 0.5 {
+			return fmt.Errorf("padding must be between 0 and 0.5, got %f", padding)
+		}
+		c.Padding = padding
+		return nil
+	}
+}
+
+// Configure creates a new configuration with the given options.
+func Configure(options ...ConfigOption) (Config, error) {
+	config := DefaultConfig()
+	
+	for _, option := range options {
+		if err := option(&config); err != nil {
+			return Config{}, err
+		}
+	}
+	
+	return config, nil
+}
+
+// validateHexColor validates that a color string is a valid hex color.
+func validateHexColor(color string) error {
+	hexColorPattern := regexp.MustCompile(`^#[0-9a-fA-F]{3,8}$`)
+	if !hexColorPattern.MatchString(color) {
+		return fmt.Errorf("color must be a hex color like #fff, #ffffff, or #ffffff80")
+	}
+	
+	// Validate length - must be 3, 4, 6, or 8 characters after #
+	length := len(color) - 1
+	if length != 3 && length != 4 && length != 6 && length != 8 {
+		return fmt.Errorf("hex color must be 3, 4, 6, or 8 characters after #")
+	}
+	
+	return nil
+}
+
+// ParseColor normalizes a hex color string to the full #RRGGBB or #RRGGBBAA format.
+func ParseColor(color string) (string, error) {
+	if color == "" {
+		return "", nil
+	}
+	
+	if err := validateHexColor(color); err != nil {
+		return "", err
+	}
+	
+	// Normalize short forms to full forms
+	switch len(color) {
+	case 4: // #RGB -> #RRGGBB
+		r, g, b := color[1], color[2], color[3]
+		return fmt.Sprintf("#%c%c%c%c%c%c", r, r, g, g, b, b), nil
+	case 5: // #RGBA -> #RRGGBBAA
+		r, g, b, a := color[1], color[2], color[3], color[4]
+		return fmt.Sprintf("#%c%c%c%c%c%c%c%c", r, r, g, g, b, b, a, a), nil
+	case 7, 9: // #RRGGBB or #RRGGBBAA - already normalized
+		return color, nil
+	default:
+		return "", fmt.Errorf("unsupported color format")
+	}
+}
+
+// GetHue returns the hue for the given original hue value, taking into account hue restrictions.
+func (c *Config) GetHue(originalHue float64) float64 {
+	if len(c.HueRestrictions) == 0 {
+		return originalHue
+	}
+	
+	// Map originalHue [0,1] to one of the restricted hues
+	index := int(originalHue * 0.999 * float64(len(c.HueRestrictions)))
+	if index >= len(c.HueRestrictions) {
+		index = len(c.HueRestrictions) - 1
+	}
+	
+	hue := c.HueRestrictions[index]
+	// Convert degrees to [0,1] range and normalize
+	return ((hue/360.0)+1.0) - float64(int((hue/360.0)+1.0))
+}
+
+// GetColorLightness returns a lightness value within the color lightness range.
+func (c *Config) GetColorLightness(value float64) float64 {
+	return c.getLightness(value, c.ColorLightnessRange)
+}
+
+// GetGrayscaleLightness returns a lightness value within the grayscale lightness range.
+func (c *Config) GetGrayscaleLightness(value float64) float64 {
+	return c.getLightness(value, c.GrayscaleLightnessRange)
+}
+
+// getLightness maps a value [0,1] to the specified lightness range.
+func (c *Config) getLightness(value float64, lightnessRange [2]float64) float64 {
+	result := lightnessRange[0] + value*(lightnessRange[1]-lightnessRange[0])
+	if result < 0 {
+		return 0
+	}
+	if result > 1 {
+		return 1
+	}
+	return result
+}