DocumentService/DocumentOperator.API/Controllers/PdfValidationController.cs

using DocumentOperator.Application.Common.DTOs;
using DocumentOperator.Application.ValidatePdf.Queries;
using DocumentOperator.Application.ValidatePdfA.Queries;
using MediatR;
using Microsoft.AspNetCore.Mvc;

namespace DocumentOperator.API.Controllers;

/// <summary>
/// PDF validation operations
/// </summary>
[ApiController]
[Route("api/pdf/validation")]
[Produces("application/json")]
public class PdfValidationController(IMediator Mediator) : ControllerBase
{
    /// <summary>
    /// Validates a PDF document and returns metadata (multipart/form-data)
    /// </summary>
    /// <param name="file">PDF file to validate</param>
    /// <param name="cancellationToken">Cancellation token</param>
    /// <returns>PDF metadata (page count, file size, PDF version, attachments)</returns>
    /// <response code="200">PDF is valid, metadata returned</response>
    /// <response code="400">Invalid PDF or file format</response>
    /// <response code="500">Internal server error during validation</response>
    [HttpPost("validate")]
    [Consumes("multipart/form-data")]
    [ProducesResponseType(typeof(PdfValidationResult), StatusCodes.Status200OK)]
    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status400BadRequest)]
    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status500InternalServerError)]
    public async Task<IActionResult> ValidateFromFile(
        IFormFile file,
        CancellationToken cancellationToken)
    {
        if (file == null || file.Length == 0)
        {
            return BadRequest(new ProblemDetails
            {
                Title = "Invalid file",
                Detail = "File is required and cannot be empty",
                Status = StatusCodes.Status400BadRequest
            });
        }

        // Convert IFormFile to byte array
        using var memoryStream = new MemoryStream();
        await file.CopyToAsync(memoryStream, cancellationToken);
        byte[] pdfBytes = memoryStream.ToArray();

        // Direct pass-through to MediatR
        var query = new ValidatePdfQuery { PdfBytes = pdfBytes };
        var result = await Mediator.Send(query, cancellationToken);
        
        return Ok(result);
    }

    /// <summary>
    /// Validates a PDF document and returns metadata (Base64 JSON)
    /// </summary>
    /// <param name="query">PDF as Base64 string</param>
    /// <param name="cancellationToken">Cancellation token</param>
    /// <returns>PDF metadata (page count, file size, PDF version, attachments)</returns>
    /// <response code="200">PDF is valid, metadata returned</response>
    /// <response code="400">Invalid PDF or Base64 format</response>
    /// <response code="500">Internal server error during validation</response>
    [HttpPost("validate")]
    [Consumes("application/json")]
    [ProducesResponseType(typeof(PdfValidationResult), StatusCodes.Status200OK)]
    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status400BadRequest)]
    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status500InternalServerError)]
    public async Task<IActionResult> ValidateFromBase64(
        [FromBody] ValidatePdfQuery query,
        CancellationToken cancellationToken)
    {
        // Direct pass-through to MediatR
        var result = await Mediator.Send(query, cancellationToken);
        
        return Ok(result);
    }

    /// <summary>
    /// Validates a PDF/A document and checks conformance level (multipart/form-data)
    /// </summary>
    /// <param name="file">PDF file to validate</param>
    /// <param name="cancellationToken">Cancellation token</param>
    /// <returns>PDF/A metadata (conformance level, errors, warnings)</returns>
    /// <response code="200">PDF/A validation completed, results returned</response>
    /// <response code="400">Invalid PDF or file format</response>
    /// <response code="500">Internal server error during validation</response>
    [HttpPost("validate-pdfa")]
    [Consumes("multipart/form-data")]
    [ProducesResponseType(typeof(PdfAValidationResult), StatusCodes.Status200OK)]
    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status400BadRequest)]
    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status500InternalServerError)]
    public async Task<IActionResult> ValidatePdfAFromFile(
        IFormFile file,
        CancellationToken cancellationToken)
    {
        if (file == null || file.Length == 0)
        {
            return BadRequest(new ProblemDetails
            {
                Title = "Invalid file",
                Detail = "File is required and cannot be empty",
                Status = StatusCodes.Status400BadRequest
            });
        }

        // Convert IFormFile to byte array
        using var memoryStream = new MemoryStream();
        await file.CopyToAsync(memoryStream, cancellationToken);
        byte[] pdfBytes = memoryStream.ToArray();

        // Direct pass-through to MediatR
        var query = new ValidatePdfAQuery { PdfBytes = pdfBytes };
        var result = await Mediator.Send(query, cancellationToken);
        
        return Ok(result);
    }

    /// <summary>
    /// Validates a PDF/A document and checks conformance level (Base64 JSON)
    /// </summary>
    /// <param name="query">PDF as Base64 string</param>
    /// <param name="cancellationToken">Cancellation token</param>
    /// <returns>PDF/A metadata (conformance level, errors, warnings)</returns>
    /// <response code="200">PDF/A validation completed, results returned</response>
    /// <response code="400">Invalid PDF or Base64 format</response>
    /// <response code="500">Internal server error during validation</response>
    [HttpPost("validate-pdfa")]
    [Consumes("application/json")]
    [ProducesResponseType(typeof(PdfAValidationResult), StatusCodes.Status200OK)]
    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status400BadRequest)]
    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status500InternalServerError)]
    public async Task<IActionResult> ValidatePdfAFromBase64(
        [FromBody] ValidatePdfAQuery query,
        CancellationToken cancellationToken)
    {
        // Direct pass-through to MediatR
        var result = await Mediator.Send(query, cancellationToken);
        
        return Ok(result);
    }
}