Add CORS configuration and tile handling improvements

SatelliteProvider.Api/Program.cs

@@ -1,5 +1,6 @@
 using System.ComponentModel.DataAnnotations;
 using Microsoft.AspNetCore.Mvc;
+using Microsoft.Extensions.Caching.Memory;
 using Microsoft.OpenApi.Models;
 using Swashbuckle.AspNetCore.SwaggerGen;
 using SatelliteProvider.DataAccess;
@@ -8,6 +9,7 @@ using SatelliteProvider.DataAccess.Repositories;
 using SatelliteProvider.Common.Configs;
 using SatelliteProvider.Common.DTO;
 using SatelliteProvider.Common.Interfaces;
+using SatelliteProvider.Common.Utils;
 using SatelliteProvider.Services;
 using Serilog;
 
@@ -28,9 +30,22 @@ builder.Services.AddSingleton<IRegionRepository>(sp => new RegionRepository(conn
 builder.Services.AddSingleton<IRouteRepository>(sp => new RouteRepository(connectionString, sp.GetRequiredService<ILogger<RouteRepository>>()));
 
 builder.Services.AddHttpClient();
+builder.Services.AddMemoryCache();
 builder.Services.AddSingleton<GoogleMapsDownloaderV2>();
 builder.Services.AddSingleton<ITileService, TileService>();
 
+var allowedOrigins = builder.Configuration.GetSection("CorsConfig:AllowedOrigins").Get<string[]>() ?? Array.Empty<string>();
+builder.Services.AddCors(options =>
+{
+    options.AddPolicy("TilesCors", policy =>
+    {
+        if (allowedOrigins.Length > 0)
+            policy.WithOrigins(allowedOrigins).AllowAnyHeader().AllowAnyMethod();
+        else
+            policy.AllowAnyOrigin().AllowAnyHeader().AllowAnyMethod();
+    });
+});
+
 var processingConfig = builder.Configuration.GetSection("ProcessingConfig").Get<ProcessingConfig>() ?? new ProcessingConfig();
 builder.Services.AddSingleton<IRegionRequestQueue>(sp => 
 {
@@ -93,6 +108,10 @@ if (app.Environment.IsDevelopment())
 }
 
 app.UseHttpsRedirection();
+app.UseCors("TilesCors");
+
+app.MapGet("/tiles/{z:int}/{x:int}/{y:int}", ServeTile)
+    .WithOpenApi(op => new(op) { Summary = "Get satellite tile image by z/x/y coordinates (Slippy Map tile server)" });
 
 app.MapGet("/api/satellite/tiles/latlon", GetTileByLatLon)
     .WithOpenApi(op => new(op) { Summary = "Get satellite tile by latitude and longitude coordinates" });
@@ -119,6 +138,71 @@ app.MapGet("/api/satellite/route/{id:guid}", GetRoute)
 
 app.Run();
 
+async Task<IResult> ServeTile(int z, int x, int y, HttpContext httpContext, ITileRepository tileRepository, GoogleMapsDownloaderV2 downloader, IMemoryCache cache, ILogger<Program> logger)
+{
+    var cacheKey = $"tile_{z}_{x}_{y}";
+    try
+    {
+        if (cache.TryGetValue(cacheKey, out byte[]? cachedBytes) && cachedBytes != null)
+        {
+            httpContext.Response.Headers.CacheControl = "public, max-age=86400";
+            httpContext.Response.Headers.ETag = $"\"{z}_{x}_{y}\"";
+            return Results.Bytes(cachedBytes, "image/jpeg");
+        }
+
+        string? filePath = null;
+
+        var tile = await tileRepository.GetByTileCoordinatesAsync(z, x, y);
+        if (tile != null && File.Exists(tile.FilePath))
+        {
+            filePath = tile.FilePath;
+        }
+        else
+        {
+            var tileCenter = GeoUtils.TileToWorldPos(x, y, z);
+            var downloadedTile = await downloader.DownloadSingleTileAsync(tileCenter.Lat, tileCenter.Lon, z);
+
+            var now = DateTime.UtcNow;
+            var tileEntity = new TileEntity
+            {
+                Id = Guid.NewGuid(),
+                TileZoom = z,
+                TileX = downloadedTile.X,
+                TileY = downloadedTile.Y,
+                Latitude = downloadedTile.CenterLatitude,
+                Longitude = downloadedTile.CenterLongitude,
+                TileSizeMeters = downloadedTile.TileSizeMeters,
+                TileSizePixels = 256,
+                ImageType = "jpg",
+                MapsVersion = $"downloaded_{now:yyyy-MM-dd}",
+                Version = now.Year,
+                FilePath = downloadedTile.FilePath,
+                CreatedAt = now,
+                UpdatedAt = now
+            };
+
+            await tileRepository.InsertAsync(tileEntity);
+            filePath = tileEntity.FilePath;
+        }
+
+        var bytes = await File.ReadAllBytesAsync(filePath);
+        cache.Set(cacheKey, bytes, new MemoryCacheEntryOptions
+        {
+            AbsoluteExpirationRelativeToNow = TimeSpan.FromHours(1),
+            SlidingExpiration = TimeSpan.FromMinutes(30)
+        });
+
+        httpContext.Response.Headers.CacheControl = "public, max-age=86400";
+        httpContext.Response.Headers.ETag = $"\"{z}_{x}_{y}\"";
+        return Results.Bytes(bytes, "image/jpeg");
+    }
+    catch (Exception ex)
+    {
+        logger.LogError(ex, "Failed to serve tile {Z}/{X}/{Y}", z, x, y);
+        return Results.Problem(detail: ex.Message, statusCode: 500);
+    }
+}
+
 async Task<IResult> GetTileByLatLon([FromQuery] double Latitude, [FromQuery] double Longitude, [FromQuery] int ZoomLevel, GoogleMapsDownloaderV2 downloader, ITileRepository tileRepository, ILogger<Program> logger)
 {
     try
@@ -133,7 +217,9 @@ async Task<IResult> GetTileByLatLon([FromQuery] double Latitude, [FromQuery] dou
         var tileEntity = new TileEntity
         {
             Id = Guid.NewGuid(),
-            ZoomLevel = downloadedTile.ZoomLevel,
+            TileZoom = downloadedTile.ZoomLevel,
+            TileX = downloadedTile.X,
+            TileY = downloadedTile.Y,
             Latitude = downloadedTile.CenterLatitude,
             Longitude = downloadedTile.CenterLongitude,
             TileSizeMeters = downloadedTile.TileSizeMeters,
@@ -151,7 +237,7 @@ async Task<IResult> GetTileByLatLon([FromQuery] double Latitude, [FromQuery] dou
         var response = new DownloadTileResponse
         {
             Id = tileEntity.Id,
-            ZoomLevel = tileEntity.ZoomLevel,
+            ZoomLevel = tileEntity.TileZoom,
             Latitude = tileEntity.Latitude,
             Longitude = tileEntity.Longitude,
             TileSizeMeters = tileEntity.TileSizeMeters,