feat: Implemen experimental bus stop usage display

1 files changed, 121 insertions, 0 deletions

diff --git a/src/Enmarcha.Backend/Services/Processors/VigoUsageProcessor.cs b/src/Enmarcha.Backend/Services/Processors/VigoUsageProcessor.cs
new file mode 100644
index 0000000..f5c7664
--- /dev/null
+++ b/src/Enmarcha.Backend/Services/Processors/VigoUsageProcessor.cs
@@ -0,0 +1,121 @@
+using System.Text.Json;
+using CsvHelper;
+using CsvHelper.Configuration;
+using Enmarcha.Backend.Types.Arrivals;
+using Microsoft.Extensions.Caching.Memory;
+using System.Globalization;
+
+namespace Enmarcha.Backend.Services.Processors;
+
+public class VigoUsageProcessor : IArrivalsProcessor
+{
+    private readonly HttpClient _httpClient;
+    private readonly IMemoryCache _cache;
+    private readonly ILogger<VigoUsageProcessor> _logger;
+    private readonly IHostEnvironment _environment;
+    private readonly FeedService _feedService;
+    private static readonly HashSet<string> _vigoStopsWhitelist = [];
+    private static bool _whitelistLoaded = false;
+    private static readonly object _lock = new();
+
+    public VigoUsageProcessor(
+        HttpClient httpClient,
+        IMemoryCache cache,
+        ILogger<VigoUsageProcessor> logger,
+        IHostEnvironment environment,
+        FeedService feedService)
+    {
+        _httpClient = httpClient;
+        _cache = cache;
+        _logger = logger;
+        _environment = environment;
+        _feedService = feedService;
+
+        LoadWhitelist();
+    }
+
+    private void LoadWhitelist()
+    {
+        if (_whitelistLoaded) return;
+
+        lock (_lock)
+        {
+            if (_whitelistLoaded) return;
+
+            try
+            {
+                var path = Path.Combine(_environment.ContentRootPath, "Data", "vitrasa_stops_p95.csv");
+                if (File.Exists(path))
+                {
+                    using var reader = new StreamReader(path);
+                    using var csv = new CsvReader(reader, CultureInfo.InvariantCulture);
+                    csv.Read();
+                    csv.ReadHeader();
+                    while (csv.Read())
+                    {
+                        var code = csv.GetField("codigo");
+                        if (!string.IsNullOrWhiteSpace(code))
+                        {
+                            _vigoStopsWhitelist.Add(code.Trim());
+                        }
+                    }
+                    _logger.LogInformation("Loaded {Count} Vigo stops for usage data whitelist", _vigoStopsWhitelist.Count);
+                }
+                else
+                {
+                    _logger.LogWarning("Vigo stops whitelist CSV not found at {Path}", path);
+                }
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Error loading Vigo stops whitelist");
+            }
+            finally
+            {
+                _whitelistLoaded = true;
+            }
+        }
+    }
+
+    public async Task ProcessAsync(ArrivalsContext context)
+    {
+        if (!context.StopId.StartsWith("vitrasa:")) return;
+
+        var normalizedCode = _feedService.NormalizeStopCode("vitrasa", context.StopCode);
+        if (!_vigoStopsWhitelist.Contains(normalizedCode)) return;
+
+        var cacheKey = $"vigo_usage_{normalizedCode}";
+        if (_cache.TryGetValue(cacheKey, out List<BusStopUsagePoint>? cachedUsage))
+        {
+            context.Usage = cachedUsage;
+            return;
+        }
+
+        try
+        {
+            using var activity = Telemetry.Source.StartActivity("FetchVigoUsage");
+            var url = $"https://datos.vigo.org/vci_api_app/api2.jsp?tipo=TRANSPORTE_PARADA_HORAS_USO&parada={normalizedCode}";
+            var response = await _httpClient.GetAsync(url);
+
+            if (response.IsSuccessStatusCode)
+            {
+                var json = await response.Content.ReadAsStringAsync();
+                var usage = JsonSerializer.Deserialize<List<BusStopUsagePoint>>(json);
+
+                if (usage != null)
+                {
+                    _cache.Set(cacheKey, usage, TimeSpan.FromDays(7));
+                    context.Usage = usage;
+                }
+            }
+            else
+            {
+                _logger.LogWarning("Failed to fetch usage data for stop {StopCode}, status: {Status}", normalizedCode, response.StatusCode);
+            }
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Error fetching usage data for Vigo stop {StopCode}", normalizedCode);
+        }
+    }
+}