Restructure & refactor codebase

internal/glance/config-fields.go

@@ -0,0 +1,221 @@
+package glance
+
+import (
+	"fmt"
+	"html/template"
+	"os"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+
+	"gopkg.in/yaml.v3"
+)
+
+var hslColorFieldPattern = regexp.MustCompile(`^(?:hsla?\()?(\d{1,3})(?: |,)+(\d{1,3})%?(?: |,)+(\d{1,3})%?\)?$`)
+
+const (
+	hslHueMax        = 360
+	hslSaturationMax = 100
+	hslLightnessMax  = 100
+)
+
+type hslColorField struct {
+	Hue        uint16
+	Saturation uint8
+	Lightness  uint8
+}
+
+func (c *hslColorField) String() string {
+	return fmt.Sprintf("hsl(%d, %d%%, %d%%)", c.Hue, c.Saturation, c.Lightness)
+}
+
+func (c *hslColorField) AsCSSValue() template.CSS {
+	return template.CSS(c.String())
+}
+
+func (c *hslColorField) UnmarshalYAML(node *yaml.Node) error {
+	var value string
+
+	if err := node.Decode(&value); err != nil {
+		return err
+	}
+
+	matches := hslColorFieldPattern.FindStringSubmatch(value)
+
+	if len(matches) != 4 {
+		return fmt.Errorf("invalid HSL color format: %s", value)
+	}
+
+	hue, err := strconv.ParseUint(matches[1], 10, 16)
+	if err != nil {
+		return err
+	}
+
+	if hue > hslHueMax {
+		return fmt.Errorf("HSL hue must be between 0 and %d", hslHueMax)
+	}
+
+	saturation, err := strconv.ParseUint(matches[2], 10, 8)
+	if err != nil {
+		return err
+	}
+
+	if saturation > hslSaturationMax {
+		return fmt.Errorf("HSL saturation must be between 0 and %d", hslSaturationMax)
+	}
+
+	lightness, err := strconv.ParseUint(matches[3], 10, 8)
+	if err != nil {
+		return err
+	}
+
+	if lightness > hslLightnessMax {
+		return fmt.Errorf("HSL lightness must be between 0 and %d", hslLightnessMax)
+	}
+
+	c.Hue = uint16(hue)
+	c.Saturation = uint8(saturation)
+	c.Lightness = uint8(lightness)
+
+	return nil
+}
+
+var durationFieldPattern = regexp.MustCompile(`^(\d+)(s|m|h|d)$`)
+
+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 := durationFieldPattern.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
+}
+
+var optionalEnvFieldPattern = regexp.MustCompile(`(^|.)\$\{([A-Z_]+)\}`)
+
+type optionalEnvField string
+
+func (f *optionalEnvField) UnmarshalYAML(node *yaml.Node) error {
+	var value string
+
+	err := node.Decode(&value)
+	if err != nil {
+		return err
+	}
+
+	replaced := optionalEnvFieldPattern.ReplaceAllStringFunc(value, func(match string) string {
+		if err != nil {
+			return ""
+		}
+
+		groups := optionalEnvFieldPattern.FindStringSubmatch(match)
+
+		if len(groups) != 3 {
+			return match
+		}
+
+		prefix, key := groups[1], groups[2]
+
+		if prefix == `\` {
+			if len(match) >= 2 {
+				return match[1:]
+			} else {
+				return ""
+			}
+		}
+
+		value, found := os.LookupEnv(key)
+		if !found {
+			err = fmt.Errorf("environment variable %s not found", key)
+			return ""
+		}
+
+		return prefix + value
+	})
+
+	if err != nil {
+		return err
+	}
+
+	*f = optionalEnvField(replaced)
+
+	return nil
+}
+
+func (f *optionalEnvField) String() string {
+	return string(*f)
+}
+
+type customIconField struct {
+	URL        string
+	IsFlatIcon bool
+	// TODO: along with whether the icon is flat, we also need to know
+	// whether the icon is black or white by default in order to properly
+	// invert the color based on the theme being light or dark
+}
+
+func (i *customIconField) UnmarshalYAML(node *yaml.Node) error {
+	var value string
+	if err := node.Decode(&value); err != nil {
+		return err
+	}
+
+	prefix, icon, found := strings.Cut(value, ":")
+	if !found {
+		i.URL = value
+		return nil
+	}
+
+	switch prefix {
+	case "si":
+		i.URL = "https://cdn.jsdelivr.net/npm/simple-icons@latest/icons/" + icon + ".svg"
+		i.IsFlatIcon = true
+	case "di":
+		// syntax: di:<icon_name>[.svg|.png]
+		// if the icon name is specified without extension, it is assumed to be wanting the SVG icon
+		// otherwise, specify the extension of either .svg or .png to use either of the CDN offerings
+		// any other extension will be interpreted as .svg
+		basename, ext, found := strings.Cut(icon, ".")
+		if !found {
+			ext = "svg"
+			basename = icon
+		}
+
+		if ext != "svg" && ext != "png" {
+			ext = "svg"
+		}
+
+		i.URL = "https://cdn.jsdelivr.net/gh/walkxcode/dashboard-icons@master/" + ext + "/" + basename + "." + ext
+	default:
+		i.URL = value
+	}
+
+	return nil
+}