Initial commit

src/PowderCoating.Application/Services/CompanyLogoService.cs

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+using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.Options;
+using PowderCoating.Application.Configuration;
+using PowderCoating.Application.Interfaces;
+
+namespace PowderCoating.Application.Services;
+
+/// <summary>
+/// Manages company logo files stored in Azure Blob Storage.
+/// Logos are stored in the <c>companylogos</c> container using the path
+/// <c>{companyId}/company-logo{ext}</c> (e.g. <c>7/company-logo.png</c>).
+/// The service enforces a 10 MB size limit and restricts uploads to common
+/// web-safe image formats.  It also handles the "replace" case by deleting
+/// blobs of every other allowed extension before writing the new one, so a
+/// company can never end up with multiple active logos at different paths.
+/// </summary>
+public class CompanyLogoService : ICompanyLogoService
+{
+    private readonly IAzureBlobStorageService _blobService;
+    private readonly StorageSettings _settings;
+
+    /// <summary>Maximum logo file size accepted on upload (10 MB).</summary>
+    private const long MaxFileSize = 10 * 1024 * 1024; // 10 MB
+
+    /// <summary>
+    /// Exhaustive list of image extensions permitted for company logos.
+    /// SVG is included because some companies upload vector-format brand assets.
+    /// </summary>
+    private static readonly string[] AllowedExtensions = [".jpg", ".jpeg", ".png", ".gif", ".webp", ".svg"];
+
+    /// <summary>
+    /// Initialises the service with the blob storage provider and storage
+    /// configuration (container names, etc.).
+    /// </summary>
+    public CompanyLogoService(
+        IAzureBlobStorageService blobService,
+        IOptions<StorageSettings> settings)
+    {
+        _blobService = blobService;
+        _settings = settings.Value;
+    }
+
+    /// <summary>
+    /// Returns the deterministic blob path for a company logo given its file
+    /// extension.  Using a fixed name (rather than a GUID) allows the path to
+    /// be derived from <c>companyId</c> alone — useful for PDF embedding and
+    /// sidebar rendering without an extra DB lookup.
+    /// </summary>
+    /// <param name="companyId">The tenant company's database ID.</param>
+    /// <param name="extension">File extension including the leading dot (e.g. <c>.png</c>).</param>
+    /// <returns>Blob-relative path such as <c>7/company-logo.png</c>.</returns>
+    public string GetCompanyLogoPath(int companyId, string extension)
+    {
+        return $"{companyId}/company-logo{extension}";
+    }
+
+    /// <summary>
+    /// Validates and uploads a new company logo, replacing any existing logo
+    /// regardless of its extension.  Old blobs at alternative extensions are
+    /// deleted first so the container never holds stale copies.
+    /// </summary>
+    /// <param name="file">The uploaded file from the HTTP request.</param>
+    /// <param name="companyId">The tenant company's database ID.</param>
+    /// <returns>
+    /// A tuple indicating success, the stored blob path (on success), and a
+    /// human-readable error message (on failure).
+    /// </returns>
+    public async Task<(bool Success, string FilePath, string ErrorMessage)> SaveCompanyLogoAsync(IFormFile file, int companyId)
+    {
+        if (file == null || file.Length == 0)
+            return (false, string.Empty, "No file provided");
+
+        if (file.Length > MaxFileSize)
+            return (false, string.Empty, $"File size exceeds maximum allowed size of {MaxFileSize / 1024 / 1024} MB");
+
+        var extension = Path.GetExtension(file.FileName).ToLowerInvariant();
+        if (!AllowedExtensions.Contains(extension))
+            return (false, string.Empty, $"File type not allowed. Allowed types: {string.Join(", ", AllowedExtensions)}");
+
+        // Delete old logo (any extension) before saving new one
+        await DeleteOldLogosAsync(companyId, extension);
+
+        var blobName = GetCompanyLogoPath(companyId, extension);
+        var contentType = GetContentType(extension);
+
+        using var stream = file.OpenReadStream();
+        var result = await _blobService.UploadAsync(_settings.Containers.CompanyLogos, blobName, stream, contentType);
+
+        if (!result.Success)
+            return (false, string.Empty, result.ErrorMessage);
+
+        return (true, blobName, string.Empty);
+    }
+
+    /// <summary>
+    /// Deletes the company logo blob at the given path from Azure Blob Storage.
+    /// </summary>
+    /// <param name="filePath">Blob-relative path previously returned by <see cref="SaveCompanyLogoAsync"/>.</param>
+    /// <returns>Success flag and an error message on failure.</returns>
+    public async Task<(bool Success, string ErrorMessage)> DeleteCompanyLogoAsync(string filePath)
+    {
+        if (string.IsNullOrEmpty(filePath))
+            return (false, "File path is empty");
+
+        return await _blobService.DeleteAsync(_settings.Containers.CompanyLogos, filePath);
+    }
+
+    /// <summary>
+    /// Downloads the raw bytes of the company logo for embedding in PDFs or
+    /// serving through the <c>/CompanyLogo</c> controller endpoint.
+    /// </summary>
+    /// <param name="filePath">Blob-relative path of the logo.</param>
+    /// <returns>
+    /// A tuple with a success flag, the raw file bytes, the MIME content type,
+    /// and an error message on failure.
+    /// </returns>
+    public async Task<(bool Success, byte[] FileContent, string ContentType, string ErrorMessage)> GetCompanyLogoAsync(string filePath)
+    {
+        if (string.IsNullOrEmpty(filePath))
+            return (false, Array.Empty<byte>(), string.Empty, "File path is empty");
+
+        return await _blobService.DownloadAsync(_settings.Containers.CompanyLogos, filePath);
+    }
+
+    /// <summary>
+    /// Checks whether a logo blob exists at the given path without downloading it.
+    /// Used by the sidebar to decide whether to show the tenant logo or fall back
+    /// to the default PCL logo.
+    /// </summary>
+    /// <param name="filePath">Blob-relative path to check.</param>
+    /// <returns><c>true</c> if the blob exists; otherwise <c>false</c>.</returns>
+    public async Task<bool> CompanyLogoExistsAsync(string filePath)
+    {
+        if (string.IsNullOrEmpty(filePath))
+            return false;
+
+        return await _blobService.ExistsAsync(_settings.Containers.CompanyLogos, filePath);
+    }
+
+    /// <summary>
+    /// Deletes any pre-existing logo blobs at extensions other than
+    /// <paramref name="currentExtension"/> so that uploading a PNG logo
+    /// automatically removes a previously stored JPG logo (and vice versa).
+    /// Errors are intentionally swallowed — a missing old blob is not a failure.
+    /// </summary>
+    /// <param name="companyId">The tenant company's database ID.</param>
+    /// <param name="currentExtension">
+    /// The extension of the incoming upload; blobs with this extension are
+    /// skipped because they will be overwritten by the caller.
+    /// </param>
+    private async Task DeleteOldLogosAsync(int companyId, string currentExtension)
+    {
+        foreach (var ext in AllowedExtensions)
+        {
+            if (ext == currentExtension) continue;
+            var oldBlobName = GetCompanyLogoPath(companyId, ext);
+            await _blobService.DeleteAsync(_settings.Containers.CompanyLogos, oldBlobName);
+        }
+    }
+
+    /// <summary>
+    /// Maps a lowercase file extension to its canonical MIME content type.
+    /// The correct content type is required so that browsers render the image
+    /// inline rather than triggering a download.
+    /// </summary>
+    /// <param name="extension">Lowercase file extension including the leading dot.</param>
+    /// <returns>MIME type string, or <c>application/octet-stream</c> as a safe fallback.</returns>
+    private static string GetContentType(string extension) => extension switch
+    {
+        ".jpg" or ".jpeg" => "image/jpeg",
+        ".png" => "image/png",
+        ".gif" => "image/gif",
+        ".webp" => "image/webp",
+        ".svg" => "image/svg+xml",
+        _ => "application/octet-stream"
+    };
+}