GoDoxy/internal/docker/label.go

package docker

import (
	"fmt"
	"strings"

	"github.com/yusing/go-proxy/internal/gperr"
	"github.com/yusing/go-proxy/internal/utils/strutils"
)

type LabelMap = map[string]any

var ErrInvalidLabel = gperr.New("invalid label")

func ParseLabels(labels map[string]string) (LabelMap, gperr.Error) {
	nestedMap := make(LabelMap)
	errs := gperr.NewBuilder("labels error")

	ExpandWildcard(labels)

	for lbl, value := range labels {
		parts := strutils.SplitRune(lbl, '.')
		if parts[0] != NSProxy {
			continue
		}
		if len(parts) == 1 {
			errs.Add(ErrInvalidLabel.Subject(lbl))
			continue
		}
		parts = parts[1:]
		currentMap := nestedMap

		for i, k := range parts {
			if i == len(parts)-1 {
				// Last element, set the value
				currentMap[k] = value
			} else {
				// If the key doesn't exist, create a new map
				if _, exists := currentMap[k]; !exists {
					currentMap[k] = make(LabelMap)
				}
				// Move deeper into the nested map
				m, ok := currentMap[k].(LabelMap)
				if !ok && currentMap[k] != "" {
					errs.Add(gperr.Errorf("expect mapping, got %T", currentMap[k]).Subject(lbl))
					continue
				} else if !ok {
					m = make(LabelMap)
					currentMap[k] = m
				}
				currentMap = m
			}
		}
	}

	return nestedMap, errs.Error()
}

func ExpandWildcard(labels map[string]string) {
	aliasLabels := make([]string, 0, len(labels))
	wildcardLabels := make(map[string]string)

	for lbl, value := range labels {
		parts := strings.SplitN(lbl, ".", 3) // Split into proxy, alias, rest
		if parts[0] != NSProxy || len(parts) < 2 {
			continue
		}
		alias := parts[1] // alias or wildcard alias
		if alias == WildcardAlias {
			delete(labels, lbl)
			if len(parts) < 3 { // invalid wildcard label (no suffix)
				continue
			}
			wildcardLabels[parts[2]] = value
		} else {
			// Extract just the alias part (first segment after proxy)
			aliasLabels = append(aliasLabels, alias)
		}
	}

	for lbl, v := range wildcardLabels {
		for _, alias := range aliasLabels {
			labels[fmt.Sprintf("%s.%s.%s", NSProxy, alias, lbl)] = v
		}
	}
}