Add MappingBuilder to build mappings in code and export to Models or JSON (#869)

* MappingBuilder

* .

* ...

* sc

* t

* .

src/WireMock.Net/MappingBuilder.cs

@@ -0,0 +1,116 @@
+using System;
+using System.Linq;
+using Newtonsoft.Json;
+using Stef.Validation;
+using WireMock.Admin.Mappings;
+using WireMock.Matchers.Request;
+using WireMock.Owin;
+using WireMock.Serialization;
+using WireMock.Server;
+using WireMock.Settings;
+
+namespace WireMock;
+
+/// <summary>
+/// MappingBuilder
+/// </summary>
+public class MappingBuilder : IMappingBuilder
+{
+    private readonly WireMockServerSettings _settings;
+    private readonly IWireMockMiddlewareOptions _options;
+
+    private readonly MappingConverter _mappingConverter;
+    private readonly MappingToFileSaver _mappingToFileSaver;
+
+    /// <summary>
+    /// Create a MappingBuilder
+    /// </summary>
+    /// <param name="settings">The optional <see cref="WireMockServerSettings"/>.</param>
+    public MappingBuilder(WireMockServerSettings? settings = null)
+    {
+        _settings = settings ?? new WireMockServerSettings();
+        _options = WireMockMiddlewareOptionsHelper.InitFromSettings(_settings);
+
+        var matcherMapper = new MatcherMapper(_settings);
+        _mappingConverter = new MappingConverter(matcherMapper);
+        _mappingToFileSaver = new MappingToFileSaver(_settings, _mappingConverter);
+    }
+
+    internal MappingBuilder(
+        WireMockServerSettings settings,
+        IWireMockMiddlewareOptions options,
+        MappingConverter mappingConverter,
+        MappingToFileSaver mappingToFileSaver
+    )
+    {
+        _settings = Guard.NotNull(settings);
+        _options = Guard.NotNull(options);
+        _mappingConverter = Guard.NotNull(mappingConverter);
+        _mappingToFileSaver = Guard.NotNull(mappingToFileSaver);
+    }
+
+    /// <inheritdoc />
+    public IRespondWithAProvider Given(IRequestMatcher requestMatcher, bool saveToFile = false)
+    {
+        return new RespondWithAProvider(RegisterMapping, Guard.NotNull(requestMatcher), _settings, saveToFile);
+    }
+
+    /// <inheritdoc />
+    public MappingModel[] GetMappings()
+    {
+        return _options.Mappings.Values.ToArray()
+            .Where(m => !m.IsAdminInterface)
+            .Select(_mappingConverter.ToMappingModel)
+            .ToArray();
+    }
+
+    /// <inheritdoc />
+    public string ToJson()
+    {
+        return ToJson(GetMappings());
+    }
+
+    /// <inheritdoc />
+    public void SaveMappingsToFile(string path)
+    {
+        _mappingToFileSaver.SaveMappingsToFile(GetNonAdminMappings(), path);
+    }
+
+    /// <inheritdoc />
+    public void SaveMappingsToFolder(string? folder)
+    {
+        foreach (var mapping in GetNonAdminMappings().Where(m => !m.IsAdminInterface))
+        {
+            _mappingToFileSaver.SaveMappingToFile(mapping, folder);
+        }
+    }
+
+    private IMapping[] GetNonAdminMappings()
+    {
+        return _options.Mappings.Values.ToArray();
+    }
+
+    private void RegisterMapping(IMapping mapping, bool saveToFile)
+    {
+        // Check a mapping exists with the same Guid. If so, update the datetime and replace it.
+        if (_options.Mappings.ContainsKey(mapping.Guid))
+        {
+            mapping.UpdatedAt = DateTime.UtcNow;
+            _options.Mappings[mapping.Guid] = mapping;
+        }
+        else
+        {
+            _options.Mappings.TryAdd(mapping.Guid, mapping);
+        }
+
+        if (saveToFile)
+        {
+            _mappingToFileSaver.SaveMappingToFile(mapping);
+        }
+    }
+
+    private static string ToJson(object value)
+    {
+        return JsonConvert.SerializeObject(value, JsonSerializationConstants.JsonSerializerSettingsDefault);
+    }
+}