DocumentService/DocumentService.Client/Clients/PdfOperationsClient.cs

using DocumentService.Client.Interfaces;
using DocumentService.Client.Models.Requests;
using Microsoft.Extensions.Logging;
using System.Net.Http;
using System.Net.Http.Headers;

namespace DocumentService.Client.Clients;

/// <summary>
/// Implementation of PDF operations client (merge, annotate, stamp).
/// </summary>
public class PdfOperationsClient(HttpClient httpClient, ILogger<PdfOperationsClient> logger) : BaseDocumentClient(httpClient, logger), IPdfOperationsClient
{

    // ==================== MERGE OPERATIONS ====================

    /// <inheritdoc />
    public async Task<Stream> MergeAsync(IEnumerable<Stream> pdfStreams, List<string?>? pageRanges = null, CancellationToken cancellationToken = default)
    {
        using var content = new MultipartFormDataContent();

        foreach (var stream in pdfStreams)
        {
            var streamContent = new StreamContent(stream);
            streamContent.Headers.ContentType = new MediaTypeHeaderValue("application/pdf");
            content.Add(streamContent, "files", $"file_{Guid.NewGuid()}.pdf");
        }

        return await SendMultipartContentForStreamAsync("/api/pdf/operations/merge", content, cancellationToken);
    }

    /// <inheritdoc />
    public async Task<Stream> MergeAsync(IEnumerable<byte[]> pdfByteArrays, List<string?>? pageRanges = null, CancellationToken cancellationToken = default)
    {
        var request = new MergePdfsBase64Request
        {
            Base64Pdfs = [.. pdfByteArrays.Select(ToBase64)],
            PageRanges = pageRanges
        };

        return await SendJsonForStreamAsync(
            "/api/pdf/operations/merge",
            request,
            cancellationToken);
    }

    // ==================== ANNOTATION OPERATIONS ====================

    /// <inheritdoc />
    public async Task<Stream> AnnotateAsync(Stream pdfStream, AddAnnotationBase64Request request, CancellationToken cancellationToken = default)
    {
        // For multipart, we need to send form data with all annotation parameters
        using var content = new MultipartFormDataContent();
        
        var streamContent = new StreamContent(pdfStream);
        streamContent.Headers.ContentType = new MediaTypeHeaderValue("application/pdf");
        content.Add(streamContent, "File", "document.pdf");

        // Add annotation parameters as form fields
        content.Add(new StringContent(request.AnnotationType.ToString()), "AnnotationType");
        content.Add(new StringContent(request.PageNumber.ToString()), "PageNumber");
        content.Add(new StringContent(request.X1.ToString()), "X1");
        content.Add(new StringContent(request.Y1.ToString()), "Y1");
        
        if (request.X2.HasValue)
            content.Add(new StringContent(request.X2.Value.ToString()), "X2");
        if (request.Y2.HasValue)
            content.Add(new StringContent(request.Y2.Value.ToString()), "Y2");
        if (request.Width.HasValue)
            content.Add(new StringContent(request.Width.Value.ToString()), "Width");
        if (request.Height.HasValue)
            content.Add(new StringContent(request.Height.Value.ToString()), "Height");
        if (!string.IsNullOrEmpty(request.Content))
            content.Add(new StringContent(request.Content), "Content");
        if (!string.IsNullOrEmpty(request.Author))
            content.Add(new StringContent(request.Author), "Author");
        if (!string.IsNullOrEmpty(request.Color))
            content.Add(new StringContent(request.Color), "Color");
        if (request.TextMarkupStyle.HasValue)
            content.Add(new StringContent(request.TextMarkupStyle.Value.ToString()), "TextMarkupStyle");
        
        content.Add(new StringContent(request.Origin.ToString()), "Origin");

        return await SendMultipartContentForStreamAsync("/api/pdf/operations/annotate", content, cancellationToken);
    }

    /// <inheritdoc />
    public async Task<Stream> AnnotateAsync(byte[] pdfBytes, AddAnnotationBase64Request request, CancellationToken cancellationToken = default)
    {
        var requestWithPdf = request with { Base64Pdf = ToBase64(pdfBytes) };

        return await SendJsonForStreamAsync(
            "/api/pdf/operations/annotate",
            requestWithPdf,
            cancellationToken);
    }

    // ==================== STAMP OPERATIONS ====================

    /// <inheritdoc />
    public async Task<Stream> StampAsync(Stream pdfStream, AddStampBase64Request request, CancellationToken cancellationToken = default)
    {
        // For multipart, we need to send form data with all stamp parameters
        using var content = new MultipartFormDataContent();
        
        var streamContent = new StreamContent(pdfStream);
        streamContent.Headers.ContentType = new MediaTypeHeaderValue("application/pdf");
        content.Add(streamContent, "File", "document.pdf");

        // Add stamp parameters as form fields
        content.Add(new StringContent(request.StampType.ToString()), "StampType");
        content.Add(new StringContent(request.X.ToString()), "X");
        content.Add(new StringContent(request.Y.ToString()), "Y");
        
        if (request.PageNumbers != null && request.PageNumbers.Length > 0)
        {
            foreach (var pageNum in request.PageNumbers)
            {
                content.Add(new StringContent(pageNum.ToString()), "PageNumbers");
            }
        }

        if (request.Width.HasValue)
            content.Add(new StringContent(request.Width.Value.ToString()), "Width");
        if (request.Height.HasValue)
            content.Add(new StringContent(request.Height.Value.ToString()), "Height");
        
        content.Add(new StringContent(request.Origin.ToString()), "Origin");
        
        if (!string.IsNullOrEmpty(request.Text))
            content.Add(new StringContent(request.Text), "Text");
        if (!string.IsNullOrEmpty(request.FontName))
            content.Add(new StringContent(request.FontName), "FontName");
        if (request.FontSize.HasValue)
            content.Add(new StringContent(request.FontSize.Value.ToString()), "FontSize");
        if (!string.IsNullOrEmpty(request.Color))
            content.Add(new StringContent(request.Color), "Color");
        if (request.Opacity.HasValue)
            content.Add(new StringContent(request.Opacity.Value.ToString()), "Opacity");
        if (request.Rotation.HasValue)
            content.Add(new StringContent(request.Rotation.Value.ToString()), "Rotation");
        
        content.Add(new StringContent(request.Placement.ToString()), "Placement");
        
        if (request.PredefinedType.HasValue)
            content.Add(new StringContent(request.PredefinedType.Value.ToString()), "PredefinedType");

        return await SendMultipartContentForStreamAsync("/api/pdf/operations/stamp", content, cancellationToken);
    }

    /// <inheritdoc />
    public async Task<Stream> StampAsync(byte[] pdfBytes, AddStampBase64Request request, CancellationToken cancellationToken = default)
    {
        var requestWithPdf = request with { Base64Pdf = ToBase64(pdfBytes) };

        return await SendJsonForStreamAsync(
            "/api/pdf/operations/stamp",
            requestWithPdf,
            cancellationToken);
    }
}