1 files changed, 101 insertions, 0 deletions
diff --git a/src/Costasdev.Busurbano.Backend/Services/NominatimGeocodingService.cs b/src/Costasdev.Busurbano.Backend/Services/NominatimGeocodingService.cs
new file mode 100644
index 0000000..01e57f1
--- /dev/null
+++ b/src/Costasdev.Busurbano.Backend/Services/NominatimGeocodingService.cs
@@ -0,0 +1,101 @@
+using System.Globalization;
+using Costasdev.Busurbano.Backend.Configuration;
+using Costasdev.Busurbano.Backend.Types.Nominatim;
+using Costasdev.Busurbano.Backend.Types.Planner;
+using Microsoft.Extensions.Caching.Memory;
+using Microsoft.Extensions.Options;
+
+namespace Costasdev.Busurbano.Backend.Services;
+
+public class NominatimGeocodingService : IGeocodingService
+{
+    private readonly HttpClient _httpClient;
+    private readonly IMemoryCache _cache;
+    private readonly ILogger<NominatimGeocodingService> _logger;
+    private readonly AppConfiguration _config;
+
+    private const string GaliciaBounds = "-9.3,43.8,-6.7,41.7";
+
+    public NominatimGeocodingService(HttpClient httpClient, IMemoryCache cache, ILogger<NominatimGeocodingService> logger, IOptions<AppConfiguration> config)
+    {
+        _httpClient = httpClient;
+        _cache = cache;
+        _logger = logger;
+        _config = config.Value;
+
+        // Nominatim requires a User-Agent
+        if (!_httpClient.DefaultRequestHeaders.Contains("User-Agent"))
+        {
+            _httpClient.DefaultRequestHeaders.Add("User-Agent", "Busurbano/1.0 (https://github.com/arielcostas/Busurbano)");
+        }
+    }
+
+    public async Task<List<PlannerSearchResult>> GetAutocompleteAsync(string query)
+    {
+        if (string.IsNullOrWhiteSpace(query)) return new List<PlannerSearchResult>();
+
+        var cacheKey = $"nominatim_autocomplete_{query.ToLowerInvariant()}";
+        if (_cache.TryGetValue(cacheKey, out List<PlannerSearchResult>? cachedResults) && cachedResults != null)
+        {
+            return cachedResults;
+        }
+
+        try
+        {
+            var url = $"{_config.NominatimBaseUrl}/search?q={Uri.EscapeDataString(query)}&format=jsonv2&viewbox={GaliciaBounds}&bounded=1&countrycodes=es&addressdetails=1";
+            var response = await _httpClient.GetFromJsonAsync<List<NominatimSearchResult>>(url);
+
+            var results = response?.Select(MapToPlannerSearchResult).ToList() ?? new List<PlannerSearchResult>();
+
+            _cache.Set(cacheKey, results, TimeSpan.FromMinutes(30));
+            return results;
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Error fetching Nominatim autocomplete results from {Url}", _config.NominatimBaseUrl);
+            return new List<PlannerSearchResult>();
+        }
+    }
+
+    public async Task<PlannerSearchResult?> GetReverseGeocodeAsync(double lat, double lon)
+    {
+        var cacheKey = $"nominatim_reverse_{lat:F5}_{lon:F5}";
+        if (_cache.TryGetValue(cacheKey, out PlannerSearchResult? cachedResult) && cachedResult != null)
+        {
+            return cachedResult;
+        }
+
+        try
+        {
+            var url = $"{_config.NominatimBaseUrl}/reverse?lat={lat.ToString(CultureInfo.InvariantCulture)}&lon={lon.ToString(CultureInfo.InvariantCulture)}&format=jsonv2&addressdetails=1";
+            var response = await _httpClient.GetFromJsonAsync<NominatimSearchResult>(url);
+
+            if (response == null) return null;
+
+            var result = MapToPlannerSearchResult(response);
+
+            _cache.Set(cacheKey, result, TimeSpan.FromMinutes(60));
+            return result;
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Error fetching Nominatim reverse geocode results from {Url}", _config.NominatimBaseUrl);
+            return null;
+        }
+    }
+
+    private PlannerSearchResult MapToPlannerSearchResult(NominatimSearchResult result)
+    {
+        var name = result.Address?.Road ?? result.DisplayName?.Split(',').FirstOrDefault();
+        var label = result.DisplayName;
+
+        return new PlannerSearchResult
+        {
+            Name = name,
+            Label = label,
+            Lat = double.TryParse(result.Lat, CultureInfo.InvariantCulture, out var lat) ? lat : 0,
+            Lon = double.TryParse(result.Lon, CultureInfo.InvariantCulture, out var lon) ? lon : 0,
+            Layer = result.Type
+        };
+    }
+}