XplorePlane/XP.Common/PdfViewer/Implementations/PdfViewerService.cs

using System;
using System.IO;
using XP.Common.Localization;
using XP.Common.Logging.Interfaces;
using XP.Common.PdfViewer.Exceptions;
using XP.Common.PdfViewer.Interfaces;
using XP.Common.PdfViewer.ViewModels;
using XP.Common.PdfViewer.Views;

namespace XP.Common.PdfViewer.Implementations
{
    /// <summary>
    /// PDF 查看服务实现 | PDF viewer service implementation
    /// 基于 Telerik RadPdfViewer 实现 | Based on Telerik RadPdfViewer
    /// </summary>
    public class PdfViewerService : IPdfViewerService
    {
        private readonly ILoggerService _logger;
        private readonly IPdfPrintService _printService;
        private bool _disposed;

        public PdfViewerService(ILoggerService logger, IPdfPrintService printService)
        {
            _logger = logger?.ForModule<PdfViewerService>()
                ?? throw new ArgumentNullException(nameof(logger));
            _printService = printService
                ?? throw new ArgumentNullException(nameof(printService));
        }

        /// <summary>
        /// 通过文件路径打开 PDF 阅读器窗口 | Open PDF viewer window by file path
        /// </summary>
        /// <param name="filePath">PDF 文件路径 | PDF file path</param>
        /// <exception cref="FileNotFoundException">文件不存在 | File not found</exception>
        /// <exception cref="PdfLoadException">PDF 格式无效 | Invalid PDF format</exception>
        public void OpenViewer(string filePath)
        {
            ObjectDisposedException.ThrowIf(_disposed, this);

            // 1. 验证文件路径存在 | Validate file path exists
            if (string.IsNullOrWhiteSpace(filePath))
            {
                throw new ArgumentNullException(nameof(filePath),
                    "文件路径不能为空 | File path cannot be null or empty");
            }

            if (!File.Exists(filePath))
            {
                _logger.Error(new FileNotFoundException(filePath),
                    "文件不存在 | File not found: {FilePath}", filePath);
                throw new FileNotFoundException(
                    $"文件不存在 | File not found: {filePath}", filePath);
            }

            try
            {
                // 2. 创建 PdfViewerWindowViewModel | Create PdfViewerWindowViewModel
                var viewModel = new PdfViewerWindowViewModel(filePath, _printService, _logger);

                // 3. 创建 PdfViewerWindow 并设置 DataContext | Create PdfViewerWindow and set DataContext
                var window = new PdfViewerWindow
                {
                    DataContext = viewModel
                };

                // 4. 记录 Info 日志 | Log info
                _logger.Info("打开 PDF 阅读器窗口 | Opening PDF viewer window: {FileName}",
                    Path.GetFileName(filePath));

                // 5. 显示窗口（非模态）| Show window (non-modal)
                window.Show();
            }
            catch (Exception ex) when (ex is not FileNotFoundException
                                    and not ArgumentNullException
                                    and not PdfLoadException)
            {
                _logger.Error(ex, "PDF 文件加载失败 | PDF file load failed: {FilePath}", filePath);
                throw new PdfLoadException(
                    "PDF 文件加载失败 | PDF file load failed", filePath, ex);
            }
        }

        /// <summary>
        /// 通过文件流打开 PDF 阅读器窗口 | Open PDF viewer window by stream
        /// </summary>
        /// <param name="stream">PDF 文件流 | PDF file stream</param>
        /// <param name="title">窗口标题（可选）| Window title (optional)</param>
        /// <exception cref="ArgumentNullException">流为 null | Stream is null</exception>
        /// <exception cref="PdfLoadException">PDF 格式无效 | Invalid PDF format</exception>
        public void OpenViewer(Stream stream, string? title = null)
        {
            ObjectDisposedException.ThrowIf(_disposed, this);

            // 1. 验证 stream 非 null | Validate stream is not null
            ArgumentNullException.ThrowIfNull(stream, nameof(stream));

            try
            {
                // 2. 创建 ViewModel | Create ViewModel
                var viewModel = new PdfViewerWindowViewModel(stream, title, _printService, _logger);

                // 3. 创建 PdfViewerWindow 并设置 DataContext | Create PdfViewerWindow and set DataContext
                var window = new PdfViewerWindow
                {
                    DataContext = viewModel
                };

                // 4. 记录 Info 日志 | Log info
                var displayTitle = title ?? LocalizationHelper.Get("PdfViewer_Title");
                _logger.Info("打开 PDF 阅读器窗口（流模式）| Opening PDF viewer window (stream mode): {Title}",
                    displayTitle);

                // 5. 显示窗口（非模态）| Show window (non-modal)
                window.Show();
            }
            catch (Exception ex) when (ex is not ArgumentNullException
                                    and not PdfLoadException)
            {
                _logger.Error(ex, "PDF 文件加载失败（流模式）| PDF file load failed (stream mode)");
                throw new PdfLoadException(
                    "PDF 文件加载失败 | PDF file load failed", null, ex);
            }
        }

        #region IDisposable 模式 | IDisposable Pattern

        /// <summary>
        /// 释放资源 | Dispose resources
        /// </summary>
        public void Dispose()
        {
            Dispose(disposing: true);
            GC.SuppressFinalize(this);
        }

        /// <summary>
        /// 释放资源的核心方法 | Core dispose method
        /// </summary>
        /// <param name="disposing">是否由 Dispose() 调用 | Whether called by Dispose()</param>
        protected virtual void Dispose(bool disposing)
        {
            if (_disposed)
            {
                return;
            }

            if (disposing)
            {
                // 释放托管资源 | Dispose managed resources
                _logger.Info("PdfViewerService 已释放 | PdfViewerService disposed");
            }

            _disposed = true;
        }

        /// <summary>
        /// 终结器安全网 | Finalizer safety net
        /// 确保未显式释放时仍能清理非托管资源 | Ensures unmanaged resources are cleaned up if not explicitly disposed
        /// </summary>
        ~PdfViewerService()
        {
            Dispose(disposing: false);
        }

        #endregion
    }
}