Add Pro fiducial monograph lookup

Services/FiducialPointService.cs

@@ -0,0 +1,148 @@
+using System.Net;
+using System.Net.Http.Headers;
+using System.Text.RegularExpressions;
+
+namespace LMEMappeCatastaliApp.Services;
+
+public sealed partial class FiducialPointService
+{
+    private const string ServiceBaseUrl = "https://www1.agenziaentrate.gov.it/servizi/Monografie/";
+    private readonly HttpClient _httpClient = new() { Timeout = TimeSpan.FromSeconds(30) };
+
+    public FiducialPointService()
+    {
+        _httpClient.DefaultRequestHeaders.UserAgent.ParseAdd("LMEMappeCatastali/1.0 (Android)");
+        _httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("text/html"));
+    }
+
+    public async Task<IReadOnlyList<FiducialAreaOption>> GetProvincesAsync(
+        CancellationToken cancellationToken = default)
+    {
+        var html = await GetHtmlAsync("ricerca.php", cancellationToken);
+        return ParseOptions(html, "provincia");
+    }
+
+    public async Task<IReadOnlyList<FiducialAreaOption>> GetMunicipalitiesAsync(
+        string provinceCode,
+        CancellationToken cancellationToken = default)
+    {
+        var code = NormalizeCode(provinceCode);
+        var html = await GetHtmlAsync($"ricerca.php?level=1&prov={Uri.EscapeDataString(code)}", cancellationToken);
+        return ParseOptions(html, "co");
+    }
+
+    public async Task<IReadOnlyList<FiducialAreaOption>> GetSheetsAsync(
+        string provinceCode,
+        string municipalityCode,
+        CancellationToken cancellationToken = default)
+    {
+        var province = NormalizeCode(provinceCode);
+        var municipality = NormalizeCode(municipalityCode);
+        var path = $"ricerca.php?level=2&prov={Uri.EscapeDataString(province)}";
+        var html = await PostFormAsync(path, new Dictionary<string, string> { ["co"] = municipality }, cancellationToken);
+        return ParseOptions(html, "foglio");
+    }
+
+    public async Task<IReadOnlyList<FiducialPointEntry>> GetFiducialsAsync(
+        string provinceName,
+        string municipalityName,
+        string municipalityCode,
+        string sheet,
+        CancellationToken cancellationToken = default)
+    {
+        var code = NormalizeCode(municipalityCode);
+        var normalizedSheet = sheet.Trim();
+        var query = string.Join("&",
+        [
+            $"provincia={Uri.EscapeDataString(provinceName.Trim())}",
+            $"comune={Uri.EscapeDataString(municipalityName.Trim())}",
+            $"co={Uri.EscapeDataString(code)}"
+        ]);
+        var html = await PostFormAsync(
+            $"risultato.php?{query}",
+            new Dictionary<string, string> { ["foglio"] = normalizedSheet },
+            cancellationToken);
+
+        return DownloadLinkRegex().Matches(html)
+            .Select(match =>
+            {
+                var relativeUrl = WebUtility.HtmlDecode(match.Groups["url"].Value);
+                var fileName = WebUtility.HtmlDecode(match.Groups["name"].Value);
+                return new FiducialPointEntry(
+                    FormatIdentifier(fileName),
+                    new Uri(new Uri(ServiceBaseUrl), relativeUrl).AbsoluteUri);
+            })
+            .DistinctBy(item => item.Identifier, StringComparer.OrdinalIgnoreCase)
+            .OrderBy(item => item.Identifier, StringComparer.OrdinalIgnoreCase)
+            .ToArray();
+    }
+
+    private async Task<string> GetHtmlAsync(string relativeUrl, CancellationToken cancellationToken)
+    {
+        using var response = await _httpClient.GetAsync(ServiceBaseUrl + relativeUrl, cancellationToken);
+        response.EnsureSuccessStatusCode();
+        return await response.Content.ReadAsStringAsync(cancellationToken);
+    }
+
+    private async Task<string> PostFormAsync(
+        string relativeUrl,
+        IReadOnlyDictionary<string, string> values,
+        CancellationToken cancellationToken)
+    {
+        using var content = new FormUrlEncodedContent(values);
+        using var response = await _httpClient.PostAsync(ServiceBaseUrl + relativeUrl, content, cancellationToken);
+        response.EnsureSuccessStatusCode();
+        return await response.Content.ReadAsStringAsync(cancellationToken);
+    }
+
+    private static IReadOnlyList<FiducialAreaOption> ParseOptions(string html, string selectId)
+    {
+        var select = SelectRegex().Matches(html)
+            .LastOrDefault(match => string.Equals(match.Groups["id"].Value, selectId, StringComparison.OrdinalIgnoreCase));
+        if (select is null)
+        {
+            return [];
+        }
+
+        return OptionRegex().Matches(select.Groups["body"].Value)
+            .Select(match => new FiducialAreaOption(
+                WebUtility.HtmlDecode(match.Groups["value"].Value).Trim(),
+                WebUtility.HtmlDecode(StripTagsRegex().Replace(match.Groups["label"].Value, string.Empty)).Trim()))
+            .Where(item => !string.IsNullOrWhiteSpace(item.Code) && !string.IsNullOrWhiteSpace(item.Name))
+            .DistinctBy(item => item.Code, StringComparer.OrdinalIgnoreCase)
+            .ToArray();
+    }
+
+    private static string NormalizeCode(string value)
+    {
+        var normalized = value.Trim().ToUpperInvariant();
+        if (normalized.Length is < 2 or > 4 || normalized.Any(character => !char.IsLetterOrDigit(character)))
+        {
+            throw new ArgumentException("Codice territoriale non valido.", nameof(value));
+        }
+
+        return normalized;
+    }
+
+    private static string FormatIdentifier(string fileName)
+    {
+        var parts = fileName.Split('-', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+        return parts.Length == 3 ? $"PF{parts[2]}/{parts[1]}/{parts[0]}" : fileName;
+    }
+
+    [GeneratedRegex("<select\\b[^>]*(?:id|name)=[\\\"'](?<id>[^\\\"']+)[\\\"'][^>]*>(?<body>[\\s\\S]*?)</select>", RegexOptions.IgnoreCase, matchTimeoutMilliseconds: 2000)]
+    private static partial Regex SelectRegex();
+
+    [GeneratedRegex("<option\\b[^>]*value=[\\\"'](?<value>[^\\\"']*)[\\\"'][^>]*>(?<label>[\\s\\S]*?)</option>", RegexOptions.IgnoreCase, matchTimeoutMilliseconds: 2000)]
+    private static partial Regex OptionRegex();
+
+    [GeneratedRegex("href=[\\\"'](?<url>download\\.php\\?[^\\\"']*namefile=(?<name>[A-Z0-9-]+))[^\\\"']*[\\\"']", RegexOptions.IgnoreCase, matchTimeoutMilliseconds: 2000)]
+    private static partial Regex DownloadLinkRegex();
+
+    [GeneratedRegex("<[^>]+>", RegexOptions.None, 2000)]
+    private static partial Regex StripTagsRegex();
+}
+
+public sealed record FiducialAreaOption(string Code, string Name);
+
+public sealed record FiducialPointEntry(string Identifier, string MonographUrl);