package gallery

import (
	"net/url"
	"regexp"
	"strings"
)

var zipExportSuffix = regexp.MustCompile(`-\d{8}T\d{6}Z-1-\d+$`)

// URLPath escapes a relative image path for use in URL paths.
func URLPath(rel string) string {
	parts := strings.Split(rel, "/")
	for i, p := range parts {
		parts[i] = url.PathEscape(p)
	}
	return strings.Join(parts, "/")
}

func collectionFromRel(rel string) (key, label string) {
	parts := strings.Split(rel, "/")
	if len(parts) <= 2 {
		return "", ""
	}
	inner := strings.TrimSpace(parts[len(parts)-2])
	label = cleanCollectionName(inner)
	if label == "" {
		return "", ""
	}
	return collectionKey(label), label
}

func cleanCollectionName(name string) string {
	name = strings.TrimSpace(name)
	name = zipExportSuffix.ReplaceAllString(name, "")
	return strings.TrimSpace(name)
}

func collectionKey(label string) string {
	key := strings.ToLower(label)
	key = strings.ReplaceAll(key, " ", "-")
	key = strings.Map(func(r rune) rune {
		if (r >= 'a' && r <= 'z') || (r >= '0' && r <= '9') || r == '-' {
			return r
		}
		return -1
	}, key)
	return key
}

// CollectionLabel returns display name for a collection filter key.
func CollectionLabel(key string, images []Image) string {
	for _, img := range images {
		if img.CollectionKey == key {
			return img.Collection
		}
	}
	return key
}