client/Services/Printing/PdfPrintJobExecutor.cs

using CloudPrint.Client.Models;
using System.Diagnostics;
using System.IO;

namespace CloudPrint.Client.Services.Printing;

public sealed class PdfPrintJobExecutor : IPrintJobExecutor
{
    private readonly IWindowsPrintQueueService _queueService;

    public PdfPrintJobExecutor(IWindowsPrintQueueService queueService)
    {
        _queueService = queueService;
    }

    public bool CanHandle(PrintJob job)
    {
        return string.Equals(Path.GetExtension(job.FilePath), ".pdf", StringComparison.OrdinalIgnoreCase);
    }

    public async Task ExecuteAsync(PrintJob job, IProgress<int>? progress, CancellationToken cancellationToken = default)
    {
        PrintFileGuards.EnsurePrintableFile(job);
        progress?.Report(10);

        var sumatraPath = FindSumatraPdfExecutable();
        if (!string.IsNullOrWhiteSpace(sumatraPath))
        {
            await PrintWithSumatraAsync(sumatraPath, job, cancellationToken).ConfigureAwait(true);
        }
        else
        {
            await PrintWithShellAsync(job, cancellationToken).ConfigureAwait(true);
        }

        CaptureWindowsJob(job);

        progress?.Report(100);
    }

    private void CaptureWindowsJob(PrintJob job)
    {
        var documentName = Path.GetFileName(job.FilePath);
        var queueJob = _queueService.FindLatestJob(job.PrinterName, documentName);
        if (queueJob is null)
        {
            return;
        }

        job.WindowsJobId = queueJob.JobId;
        job.WindowsJobStatus = queueJob.Status;
    }

    private static async Task PrintWithSumatraAsync(string sumatraPath, PrintJob job, CancellationToken cancellationToken)
    {
        var startInfo = new ProcessStartInfo
        {
            FileName = sumatraPath,
            Arguments = $"-print-to \"{job.PrinterName}\" -silent -exit-when-done \"{job.FilePath}\"",
            CreateNoWindow = true,
            UseShellExecute = false
        };

        using var process = Process.Start(startInfo) ?? throw new InvalidOperationException("启动 SumatraPDF 失败");
        await process.WaitForExitAsync(cancellationToken).ConfigureAwait(true);
        if (process.ExitCode != 0)
        {
            throw new InvalidOperationException($"SumatraPDF 打印失败，退出码：{process.ExitCode}");
        }
    }

    private static async Task PrintWithShellAsync(PrintJob job, CancellationToken cancellationToken)
    {
        var startInfo = new ProcessStartInfo
        {
            FileName = job.FilePath,
            Verb = "printto",
            Arguments = $"\"{job.PrinterName}\"",
            UseShellExecute = true,
            CreateNoWindow = true,
            WindowStyle = ProcessWindowStyle.Hidden
        };

        using var process = Process.Start(startInfo)
            ?? throw new InvalidOperationException("无法调用系统默认 PDF 打印程序，请安装 SumatraPDF 或配置 PDF 默认打印程序");
        await process.WaitForExitAsync(cancellationToken).ConfigureAwait(true);
    }

    private static string? FindSumatraPdfExecutable()
    {
        var candidates = new[]
        {
            Environment.GetEnvironmentVariable("SUMATRA_PDF_PATH"),
            @"C:\Program Files\SumatraPDF\SumatraPDF.exe",
            @"C:\Program Files (x86)\SumatraPDF\SumatraPDF.exe"
        };

        return candidates.FirstOrDefault(path => !string.IsNullOrWhiteSpace(path) && File.Exists(path));
    }
}