using System.Collections.Concurrent;
using System.Text.Json;

namespace Dpz.Core.Web.Library;

public class AssetService
{
    private readonly IWebHostEnvironment _environment;
    private static readonly ConcurrentDictionary<string, string> Manifest = new(
        StringComparer.OrdinalIgnoreCase
    );

    public AssetService(IWebHostEnvironment environment, ILogger<AssetService> logger)
    {
        _environment = environment;
        if (!Manifest.IsEmpty)
        {
            return;
        }
        var manifestPath = Path.Combine(_environment.WebRootPath, "assets-manifest.json");
        if (File.Exists(manifestPath))
        {
            try
            {
                var json = File.ReadAllText(manifestPath);
                var manifest =
                    JsonSerializer.Deserialize<Dictionary<string, string>>(json)
                    ?? new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
                InitManifest(manifest);
            }
            catch (Exception ex)
            {
                logger.LogError(ex, "加载资源清单失败");
            }
        }
    }

    private static void InitManifest(Dictionary<string, string> manifest)
    {
        foreach (var (key, value) in manifest)
        {
            Manifest.TryAdd(key, value);
        }
    }

    public string GetPath(string path)
    {
        // 在开发环境中，返回原始路径
        if (_environment.IsDevelopment())
        {
            return path;
        }

        // 规范化路径键：移除 ~ 和开头的 /
        var key = path.TrimStart('~').TrimStart('/');

        if (Manifest.TryGetValue(key, out var hashedPath))
        {
            return "/" + hashedPath;
        }

        // 如果在清单中未找到，返回原始路径
        return path;
    }
}