using System.Collections.Generic;
using YooAsset;

namespace AOT.Patch
{
    /// <summary>
    /// YooAsset 远端地址查询（CDN）。
    /// </summary>
    public sealed class CdnRemoteService : IRemoteService
    {
        readonly string _primary;
        readonly string _fallback;

        public CdnRemoteService(string primaryRoot, string fallbackRoot = null)
        {
            _primary = TrimSlash(primaryRoot);
            _fallback = string.IsNullOrEmpty(fallbackRoot) ? _primary : TrimSlash(fallbackRoot);
        }

        public IReadOnlyList<string> GetRemoteUrls(string fileName)
        {
            return new[]
            {
                $"{_primary}/{fileName}",
                $"{_fallback}/{fileName}",
            };
        }

        static string TrimSlash(string root)
        {
            if (string.IsNullOrEmpty(root)) return string.Empty;
            return root.TrimEnd('/');
        }
    }
}