package storage

import (
	"context"
	"fmt"
	"strings"
)

const PublishAttachmentKeyPrefix = "publish-attachments/"

const MaxPublishAttachments = 20

func NormalizeImageKeys(single string, list []string) []string {
	out := make([]string, 0, len(list)+1)
	seen := make(map[string]struct{}, len(list)+1)
	add := func(key string) {
		key = strings.TrimSpace(key)
		if key == "" {
			return
		}
		if _, ok := seen[key]; ok {
			return
		}
		seen[key] = struct{}{}
		out = append(out, key)
	}
	add(single)
	for _, key := range list {
		add(key)
	}
	if len(out) > MaxPublishAttachments {
		return out[:MaxPublishAttachments]
	}
	return out
}

func ValidatePublishAttachmentKey(key string) error {
	key = strings.TrimSpace(key)
	if key == "" {
		return nil
	}
	if !strings.HasPrefix(key, PublishAttachmentKeyPrefix) {
		return fmt.Errorf("invalid publish attachment key")
	}
	return nil
}

// PurgePublishAttachment deletes an ephemeral publish attachment; ignores empty/invalid keys.
func PurgePublishAttachment(ctx context.Context, store ObjectDeleter, key string) error {
	key = strings.TrimSpace(key)
	if key == "" {
		return nil
	}
	if err := ValidatePublishAttachmentKey(key); err != nil {
		return nil
	}
	if store == nil {
		return nil
	}
	return store.DeleteObject(ctx, key)
}

// PurgePublishAttachments deletes multiple ephemeral publish attachments.
func PurgePublishAttachments(ctx context.Context, store ObjectDeleter, keys []string) {
	for _, key := range keys {
		_ = PurgePublishAttachment(ctx, store, key)
	}
}