Add Azure Maps road and satellite layers

Services/AzureMapsService.cs

@@ -0,0 +1,53 @@
+using System.Text.Json;
+
+namespace LMEMappeCatastaliApp.Services;
+
+public sealed class AzureMapsService
+{
+    private const string TilesetEndpoint = "https://atlas.microsoft.com/map/tileset";
+    private readonly HttpClient _httpClient = new()
+    {
+        Timeout = TimeSpan.FromSeconds(20)
+    };
+    private string? _validatedKey;
+
+    public AzureMapsService()
+    {
+        _httpClient.DefaultRequestHeaders.UserAgent.ParseAdd("LMEMappeCatastali/0.2.3");
+        _httpClient.DefaultRequestHeaders.Accept.ParseAdd("application/json");
+    }
+
+    public async Task ValidateKeyAsync(string subscriptionKey, CancellationToken cancellationToken = default)
+    {
+        var key = subscriptionKey.Trim();
+        if (string.IsNullOrWhiteSpace(key))
+        {
+            throw new ArgumentException("Chiave Azure Maps mancante.", nameof(subscriptionKey));
+        }
+
+        if (string.Equals(_validatedKey, key, StringComparison.Ordinal))
+        {
+            return;
+        }
+
+        var url = $"{TilesetEndpoint}?api-version=2024-04-01&tilesetId=microsoft.base.road";
+        using var request = new HttpRequestMessage(HttpMethod.Get, url);
+        request.Headers.Add("subscription-key", key);
+        using var response = await _httpClient.SendAsync(request, cancellationToken);
+        if (!response.IsSuccessStatusCode)
+        {
+            throw new InvalidOperationException(response.StatusCode is System.Net.HttpStatusCode.Unauthorized or System.Net.HttpStatusCode.Forbidden
+                ? "Chiave Azure Maps non valida o priva dei permessi Render."
+                : $"Azure Maps ha risposto {((int)response.StatusCode)}.");
+        }
+
+        await using var content = await response.Content.ReadAsStreamAsync(cancellationToken);
+        using var payload = await JsonDocument.ParseAsync(content, cancellationToken: cancellationToken);
+        if (!payload.RootElement.TryGetProperty("tiles", out _))
+        {
+            throw new InvalidDataException("Azure Maps ha restituito una configurazione non valida.");
+        }
+
+        _validatedKey = key;
+    }
+}