#region Copyright notice and license
// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
// http://github.com/jskeet/dotnet-protobufs/
// Original C++/Java/Python code:
// http://code.google.com/p/protobuf/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#endregion

using Google.ProtocolBuffers.Descriptors;

namespace Google.ProtocolBuffers.ProtoGen {
  internal class ExtensionGenerator : SourceGeneratorBase<FieldDescriptor>, ISourceGenerator {

    private readonly string scope;
    private readonly string type;
    private readonly string name;

    internal ExtensionGenerator(FieldDescriptor descriptor) : base(descriptor) {
      if (Descriptor.ExtensionScope != null) {
        scope = GetClassName(Descriptor.ExtensionScope);
      } else {
        scope = DescriptorUtil.GetFullUmbrellaClassName(Descriptor.File);
      }
      switch (Descriptor.MappedType) {
        case MappedType.Message:
          type = GetClassName(Descriptor.MessageType);
          break;
        case MappedType.Enum:
          type = GetClassName(Descriptor.EnumType);
          break;
        default:
          type = DescriptorUtil.GetMappedTypeName(Descriptor.MappedType);
          break;
      }
      name = Descriptor.CSharpOptions.PropertyName;
    }

    public void Generate(TextGenerator writer) {
      writer.WriteLine ("public const int {0} = {1};", GetFieldConstantName(Descriptor), Descriptor.FieldNumber);
      if (Descriptor.IsRepeated) {
        if (!Descriptor.IsCLSCompliant) {
          writer.WriteLine("[global::System.CLSCompliant(false)]");
        }
        writer.WriteLine("{0} static pb::GeneratedExtensionBase<scg::IList<{1}>> {2};", ClassAccessLevel, type, name);
      } else {
        if (!Descriptor.IsCLSCompliant) {
          writer.WriteLine("[global::System.CLSCompliant(false)]");
        }
        writer.WriteLine("{0} static pb::GeneratedExtensionBase<{1}> {2};", ClassAccessLevel, type, name);
      }
    }

    internal void GenerateStaticVariableInitializers(TextGenerator writer) {
      if (Descriptor.IsRepeated) {
        writer.WriteLine("{0}.{1} = pb::GeneratedRepeatExtension<{2}>.CreateInstance({0}.Descriptor.Extensions[{3}]);", scope, name, type, Descriptor.Index);
      } else {
        writer.WriteLine("{0}.{1} = pb::GeneratedSingleExtension<{2}>.CreateInstance({0}.Descriptor.Extensions[{3}]);", scope, name, type, Descriptor.Index);
      }
    }

    internal void GenerateExtensionRegistrationCode(TextGenerator writer) {
      writer.WriteLine("registry.Add({0}.{1});", scope, name);
    }
  }
}