first commit

Services/ImageService.cs

@@ -0,0 +1,61 @@
+using StitcherApi.Models;
+using StitcherApi.Services.Utilities;
+
+namespace StitcherApi.Services;
+
+public class ImageService : IImageService
+{
+    private readonly ImageProcessor _processor;
+    private const int TILE_SIZE = 720;
+
+    public ImageService(IConfiguration configuration)
+    {
+        string assetPath =
+            configuration["AssetPath"]
+            ?? throw new InvalidOperationException("AssetPath is not configured.");
+        _processor = new ImageProcessor(assetPath);
+    }
+
+    public async Task<byte[]> GenerateImageAsync(GenerateImageRequest request)
+    {
+        // 1. Delegate parsing to the CoordinateParser
+        var (minRow, minCol, maxRow, maxCol) = CoordinateParser.ParseCanvasRect(request.CanvasRect);
+
+        // 2. Perform high-level calculations
+        var stitchedCanvasWidth = (maxCol - minCol + 1) * TILE_SIZE;
+        var stitchedCanvasHeight = (maxRow - minRow + 1) * TILE_SIZE;
+
+        int cropX = (int)(request.CropOffset[0] * stitchedCanvasWidth);
+        int cropY = (int)(request.CropOffset[1] * stitchedCanvasHeight);
+        int cropW = (int)(request.CropSize[0] * stitchedCanvasWidth);
+        int cropH = (int)(request.CropSize[1] * stitchedCanvasHeight);
+
+        if (cropW <= 0 || cropH <= 0)
+        {
+            throw new ArgumentException("Calculated crop dimensions are invalid.");
+        }
+
+        var startTileCol = minCol + (cropX / TILE_SIZE);
+        var endTileCol = minCol + ((cropX + cropW - 1) / TILE_SIZE);
+        var startTileRow = minRow + (cropY / TILE_SIZE);
+        var endTileRow = minRow + ((cropY + cropH - 1) / TILE_SIZE);
+
+        // 3. Create a parameter object for the processor
+        var stitchRequest = new StitchRequest(
+            minRow,
+            minCol,
+            startTileRow,
+            startTileCol,
+            endTileRow,
+            endTileCol,
+            cropX,
+            cropY,
+            cropW,
+            cropH,
+            request.OutputScale
+        );
+
+        // 4. Delegate image processing work
+        return await _processor.StitchAndCropAsync(stitchRequest);
+    }
+}