using System;
using System.IO;
using System.Threading.Tasks;
using MediaBrowser.Common.Configuration;
using MediaBrowser.Controller.Plugins;
using Microsoft.Extensions.Logging;

using Microsoft.Extensions.Hosting;

namespace JellyfinPlugin
{
    public class HtmlPatcher : IHostedService
    {
        private readonly IApplicationPaths _appPaths;
        private readonly ILogger<HtmlPatcher> _logger;

        public HtmlPatcher(IApplicationPaths appPaths, ILogger<HtmlPatcher> logger)
        {
            _appPaths = appPaths;
            _logger = logger;
        }

        public Task StartAsync(CancellationToken cancellationToken)
        {
            PatchHtml();
            return Task.CompletedTask;
        }

        public Task StopAsync(CancellationToken cancellationToken)
        {
            return Task.CompletedTask;
        }

        private void PatchHtml()
        {
            try
            {
                // Znajdujemy ścieżkę do web UI Jellyfina.
                // W większości instalacji linuksowych (np. Debian/Ubuntu) to:
                string[] possiblePaths = {
                    Path.Combine(_appPaths.ProgramDataPath, "web"),
                    "/usr/share/jellyfin/web",
                    "/jellyfin/jellyfin-web", // Docker
                };

                string webPath = string.Empty;
                foreach (var path in possiblePaths)
                {
                    if (Directory.Exists(path) && File.Exists(Path.Combine(path, "index.html")))
                    {
                        webPath = path;
                        break;
                    }
                }

                if (string.IsNullOrEmpty(webPath))
                {
                    _logger.LogWarning("Failed to find Jellyfin Web directory. Manual installation of the client script is required.");
                    return;
                }

                string indexPath = Path.Combine(webPath, "index.html");
                string indexContent = File.ReadAllText(indexPath);

                string scriptTag = "<script src=\"/BlackBarRemover/ClientScript.js\"></script>";

                if (!indexContent.Contains("BlackBarRemover/ClientScript.js"))
                {
                    indexContent = indexContent.Replace("</body>", $"    {scriptTag}\n</body>");
                    File.WriteAllText(indexPath, indexContent);
                    _logger.LogInformation("Successfully injected BlackBarRemover script into index.html at {Path}", indexPath);
                }
                else
                {
                    _logger.LogInformation("BlackBarRemover client script is already injected into index.html");
                }
            }
            catch (UnauthorizedAccessException)
            {
                _logger.LogWarning("Permission denied to modify index.html. Change Jellyfin Web file permissions or add the script manually in Custom CSS.");
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "An error occurred while injecting the script into index.html.");
            }
        }

        public void Dispose()
        {
        }
    }
}