client/Services/PrintService.cs

using System.Drawing.Printing;
using System.Management;
using CloudPrint.Client.Models;
using CloudPrint.Client.Services.Abstractions;
using CloudPrint.Client.Services.Printing;

namespace CloudPrint.Client.Services;

/// <summary>
/// 真实打印服务：枚举 Windows 打印机，按文件类型提交到图片/PDF/RAW 打印执行器。
/// </summary>
public sealed class PrintService : IPrintService
{
    private readonly IReadOnlyList<IPrintJobExecutor> _executors;
    private readonly IPrinterStatusReader _statusReader;
    private readonly IWindowsPrintQueueService _queueService;

    public PrintService()
        : this(CreateDefaultExecutors(), new WindowsPrinterStatusReader(), new WindowsPrintQueueService())
    {
    }

    private static IReadOnlyList<IPrintJobExecutor> CreateDefaultExecutors()
    {
        var queueService = new WindowsPrintQueueService();
        return new IPrintJobExecutor[]
        {
            new ImagePrintJobExecutor(queueService),
            new PdfPrintJobExecutor(queueService),
            new RawPrintJobExecutor()
        };
    }

    public PrintService(IEnumerable<IPrintJobExecutor> executors, IPrinterStatusReader statusReader, IWindowsPrintQueueService queueService)
    {
        _executors = executors.ToList();
        _statusReader = statusReader;
        _queueService = queueService;
        if (_executors.Count == 0)
        {
            throw new ArgumentException("至少需要一个打印执行器", nameof(executors));
        }
    }

    public IReadOnlyList<PrinterInfo> GetPrinters()
    {
        var printers = new List<PrinterInfo>();
        var index = 1;

        foreach (string printerName in PrinterSettings.InstalledPrinters)
        {
            if (IsVirtualPrinter(printerName))
            {
                continue;
            }

            var snapshot = _statusReader.Read(printerName);
            printers.Add(new PrinterInfo
            {
                Id = index++,
                Name = printerName,
                DisplayName = printerName,
                IsActive = true,
                Status = snapshot.Status,
                QueueCount = snapshot.QueueCount,
                StatusMessage = snapshot.Message,
                LastHeartbeat = DateTime.Now
            });
        }

        return printers;
    }

    public PrinterStatus GetPrinterStatus(string printerName)
    {
        if (string.IsNullOrWhiteSpace(printerName))
        {
            return PrinterStatus.Unknown;
        }

        return _statusReader.Read(printerName).Status;
    }

    public async Task<string> SubmitPrintJobAsync(PrintJob job, IProgress<int>? progress = null, CancellationToken cancellationToken = default)
    {
        ArgumentNullException.ThrowIfNull(job);

        job.StartedAt = DateTime.Now;
        job.MarkPrinting();
        progress?.Report(5);

        var executor = _executors.FirstOrDefault(item => item.CanHandle(job))
            ?? throw new NotSupportedException($"没有可用的打印执行器处理文件：{job.FilePath}");

        await executor.ExecuteAsync(job, progress, cancellationToken).ConfigureAwait(true);
        job.MarkCompleted();
        return job.JobNo;
    }

    public bool CancelPrintJob(string jobId)
    {
        return !string.IsNullOrWhiteSpace(jobId);
    }

    public bool CancelPrintJob(PrintJob job)
    {
        ArgumentNullException.ThrowIfNull(job);
        return job.WindowsJobId is > 0 && _queueService.CancelJob(job.PrinterName, job.WindowsJobId.Value);
    }

    public PrintJobStatus GetJobStatus(string jobId)
    {
        return string.IsNullOrWhiteSpace(jobId) ? PrintJobStatus.Failed : PrintJobStatus.Pending;
    }

    private static bool IsVirtualPrinter(string printerName)
    {
        if (string.IsNullOrWhiteSpace(printerName))
        {
            return true;
        }

        try
        {
            using var searcher = new ManagementObjectSearcher("SELECT Name, DriverName, PortName FROM Win32_Printer");
            foreach (ManagementObject printer in searcher.Get())
            {
                var name = Convert.ToString(printer["Name"]);
                if (!string.Equals(name, printerName, StringComparison.OrdinalIgnoreCase))
                {
                    continue;
                }

                var driverName = Convert.ToString(printer["DriverName"]) ?? string.Empty;
                var portName = Convert.ToString(printer["PortName"]) ?? string.Empty;
                return IsKnownVirtualPrinter(printerName, driverName, portName);
            }
        }
        catch
        {
            // If WMI is unavailable, fall back to conservative name-based filtering.
        }

        return IsKnownVirtualPrinter(printerName, string.Empty, string.Empty);
    }

    private static bool IsKnownVirtualPrinter(string printerName, string driverName, string portName)
    {
        var value = $"{printerName}|{driverName}|{portName}";
        return ContainsAny(value,
            "Microsoft Print to PDF",
            "Microsoft XPS Document Writer",
            "OneNote",
            "Fax",
            "Foxit PDF",
            "PDF Printer",
            "Print to Evernote",
            "Evernote",
            "XPS",
            "PORTPROMPT:",
            "FILE:",
            "NUL:");
    }

    private static bool ContainsAny(string value, params string[] candidates)
    {
        return candidates.Any(candidate => value.Contains(candidate, StringComparison.OrdinalIgnoreCase));
    }

}