// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
// https://developers.google.com/protocol-buffers/
//
// 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.

// Author: kenton@google.com (Kenton Varda)
//  Based on original Protocol Buffers design by
//  Sanjay Ghemawat, Jeff Dean, and others.

#include <google/protobuf/compiler/java/java_message.h>

#include <algorithm>
#include <google/protobuf/stubs/hash.h>
#include <map>
#include <memory>
#ifndef _SHARED_PTR_H
#include <google/protobuf/stubs/shared_ptr.h>
#endif
#include <vector>

#include <google/protobuf/compiler/java/java_context.h>
#include <google/protobuf/compiler/java/java_doc_comment.h>
#include <google/protobuf/compiler/java/java_enum.h>
#include <google/protobuf/compiler/java/java_extension.h>
#include <google/protobuf/compiler/java/java_generator_factory.h>
#include <google/protobuf/compiler/java/java_helpers.h>
#include <google/protobuf/compiler/java/java_message_builder.h>
#include <google/protobuf/compiler/java/java_message_builder_lite.h>
#include <google/protobuf/compiler/java/java_name_resolver.h>
#include <google/protobuf/io/coded_stream.h>
#include <google/protobuf/io/printer.h>
#include <google/protobuf/descriptor.pb.h>
#include <google/protobuf/wire_format.h>
#include <google/protobuf/stubs/strutil.h>
#include <google/protobuf/stubs/substitute.h>

namespace google {
namespace protobuf {
namespace compiler {
namespace java {

using internal::WireFormat;
using internal::WireFormatLite;

namespace {
bool GenerateHasBits(const Descriptor* descriptor) {
  return SupportFieldPresence(descriptor->file()) ||
      HasRepeatedFields(descriptor);
}

string MapValueImmutableClassdName(const Descriptor* descriptor,
                                   ClassNameResolver* name_resolver) {
  const FieldDescriptor* value_field = descriptor->FindFieldByName("value");
  GOOGLE_CHECK_EQ(FieldDescriptor::TYPE_MESSAGE, value_field->type());
  return name_resolver->GetImmutableClassName(value_field->message_type());
}
}  // namespace

// ===================================================================

MessageGenerator::MessageGenerator(const Descriptor* descriptor)
  : descriptor_(descriptor) {}

MessageGenerator::~MessageGenerator() {}

// ===================================================================
// TODO(api): Move this class to a separate immutable_message.cc file.
ImmutableMessageGenerator::ImmutableMessageGenerator(
    const Descriptor* descriptor, Context* context)
  : MessageGenerator(descriptor), context_(context),
    name_resolver_(context->GetNameResolver()),
    field_generators_(descriptor, context_) {
  GOOGLE_CHECK_NE(
      FileOptions::LITE_RUNTIME, descriptor->file()->options().optimize_for());
}

ImmutableMessageGenerator::~ImmutableMessageGenerator() {}

void ImmutableMessageGenerator::GenerateStaticVariables(io::Printer* printer) {
  // Because descriptor.proto (com.google.protobuf.DescriptorProtos) is
  // used in the construction of descriptors, we have a tricky bootstrapping
  // problem.  To help control static initialization order, we make sure all
  // descriptors and other static data that depends on them are members of
  // the outermost class in the file.  This way, they will be initialized in
  // a deterministic order.

  map<string, string> vars;
  vars["identifier"] = UniqueFileScopeIdentifier(descriptor_);
  vars["index"] = SimpleItoa(descriptor_->index());
  vars["classname"] = name_resolver_->GetImmutableClassName(descriptor_);
  if (descriptor_->containing_type() != NULL) {
    vars["parent"] = UniqueFileScopeIdentifier(
        descriptor_->containing_type());
  }
  if (MultipleJavaFiles(descriptor_->file(), /* immutable = */ true)) {
    // We can only make these package-private since the classes that use them
    // are in separate files.
    vars["private"] = "";
  } else {
    vars["private"] = "private ";
  }

  // The descriptor for this type.
  printer->Print(vars,
    // TODO(teboring): final needs to be added back. The way to fix it is to
    // generate methods that can construct the types, and then still declare the
    // types, and then init them in clinit with the new method calls.
    "$private$static com.google.protobuf.Descriptors.Descriptor\n"
    "  internal_$identifier$_descriptor;\n");

  // And the FieldAccessorTable.
  GenerateFieldAccessorTable(printer);

  // Generate static members for all nested types.
  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
    // TODO(kenton):  Reuse MessageGenerator objects?
    ImmutableMessageGenerator(descriptor_->nested_type(i), context_)
      .GenerateStaticVariables(printer);
  }
}

int ImmutableMessageGenerator::GenerateStaticVariableInitializers(
    io::Printer* printer) {
  int bytecode_estimate = 0;
  map<string, string> vars;
  vars["identifier"] = UniqueFileScopeIdentifier(descriptor_);
  vars["index"] = SimpleItoa(descriptor_->index());
  vars["classname"] = name_resolver_->GetImmutableClassName(descriptor_);
  if (descriptor_->containing_type() != NULL) {
    vars["parent"] = UniqueFileScopeIdentifier(
        descriptor_->containing_type());
  }

  // The descriptor for this type.
  if (descriptor_->containing_type() == NULL) {
    printer->Print(vars,
      "internal_$identifier$_descriptor =\n"
      "  getDescriptor().getMessageTypes().get($index$);\n");
    bytecode_estimate += 30;
  } else {
    printer->Print(vars,
      "internal_$identifier$_descriptor =\n"
      "  internal_$parent$_descriptor.getNestedTypes().get($index$);\n");
    bytecode_estimate += 30;
  }

  // And the FieldAccessorTable.
  bytecode_estimate += GenerateFieldAccessorTableInitializer(printer);

  // Generate static member initializers for all nested types.
  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
    // TODO(kenton):  Reuse MessageGenerator objects?
    bytecode_estimate +=
        ImmutableMessageGenerator(descriptor_->nested_type(i), context_)
            .GenerateStaticVariableInitializers(printer);
  }
  return bytecode_estimate;
}

void ImmutableMessageGenerator::
GenerateFieldAccessorTable(io::Printer* printer) {
  map<string, string> vars;
  vars["identifier"] = UniqueFileScopeIdentifier(descriptor_);
  if (MultipleJavaFiles(descriptor_->file(), /* immutable = */ true)) {
    // We can only make these package-private since the classes that use them
    // are in separate files.
    vars["private"] = "";
  } else {
    vars["private"] = "private ";
  }
  printer->Print(vars,
    "$private$static\n"
    "  com.google.protobuf.GeneratedMessage.FieldAccessorTable\n"
    "    internal_$identifier$_fieldAccessorTable;\n");
}

int ImmutableMessageGenerator::
GenerateFieldAccessorTableInitializer(io::Printer* printer) {
  int bytecode_estimate = 10;
  printer->Print(
    "internal_$identifier$_fieldAccessorTable = new\n"
    "  com.google.protobuf.GeneratedMessage.FieldAccessorTable(\n"
    "    internal_$identifier$_descriptor,\n"
    "    new java.lang.String[] { ",
    "identifier",
    UniqueFileScopeIdentifier(descriptor_));
  for (int i = 0; i < descriptor_->field_count(); i++) {
    const FieldDescriptor* field = descriptor_->field(i);
    const FieldGeneratorInfo* info = context_->GetFieldGeneratorInfo(field);
    bytecode_estimate += 6;
    printer->Print(
      "\"$field_name$\", ",
      "field_name", info->capitalized_name);
  }
  for (int i = 0; i < descriptor_->oneof_decl_count(); i++) {
    const OneofDescriptor* oneof = descriptor_->oneof_decl(i);
    const OneofGeneratorInfo* info = context_->GetOneofGeneratorInfo(oneof);
    bytecode_estimate += 6;
    printer->Print(
      "\"$oneof_name$\", ",
      "oneof_name", info->capitalized_name);
  }
  printer->Print("});\n");
  return bytecode_estimate;
}

// ===================================================================

void ImmutableMessageGenerator::GenerateInterface(io::Printer* printer) {
  if (descriptor_->extension_range_count() > 0) {
    printer->Print(
      "public interface $classname$OrBuilder extends\n"
      "    $extra_interfaces$\n"
      "    com.google.protobuf.GeneratedMessage.\n"
      "        ExtendableMessageOrBuilder<$classname$> {\n",
      "extra_interfaces", ExtraMessageOrBuilderInterfaces(descriptor_),
      "classname", descriptor_->name());
  } else {
    printer->Print(
      "public interface $classname$OrBuilder extends\n"
      "    $extra_interfaces$\n"
      "    com.google.protobuf.MessageOrBuilder {\n",
      "extra_interfaces", ExtraMessageOrBuilderInterfaces(descriptor_),
      "classname", descriptor_->name());
  }

  printer->Indent();
    for (int i = 0; i < descriptor_->field_count(); i++) {
      printer->Print("\n");
      field_generators_.get(descriptor_->field(i))
                       .GenerateInterfaceMembers(printer);
    }
  printer->Outdent();

  printer->Print("}\n");
}

// ===================================================================

void ImmutableMessageGenerator::Generate(io::Printer* printer) {
  bool is_own_file =
    descriptor_->containing_type() == NULL &&
    MultipleJavaFiles(descriptor_->file(), /* immutable = */ true);

  map<string, string> variables;
  variables["static"] = is_own_file ? " " : " static ";
  variables["classname"] = descriptor_->name();
  variables["extra_interfaces"] = ExtraMessageInterfaces(descriptor_);

  WriteMessageDocComment(printer, descriptor_);

  // The builder_type stores the super type name of the nested Builder class.
  string builder_type;
  if (descriptor_->extension_range_count() > 0) {
    printer->Print(variables,
      "public $static$final class $classname$ extends\n"
      "    com.google.protobuf.GeneratedMessage.ExtendableMessage<\n"
      "      $classname$> implements\n"
      "    $extra_interfaces$\n"
      "    $classname$OrBuilder {\n");
    builder_type = strings::Substitute(
             "com.google.protobuf.GeneratedMessage.ExtendableBuilder<$0, ?>",
             name_resolver_->GetImmutableClassName(descriptor_));
  } else {
    printer->Print(variables,
      "public $static$final class $classname$ extends\n"
      "    com.google.protobuf.GeneratedMessage implements\n"
      "    $extra_interfaces$\n"
      "    $classname$OrBuilder {\n");

    builder_type = "com.google.protobuf.GeneratedMessage.Builder";
  }
  printer->Indent();
  // Using builder_type, instead of Builder, prevents the Builder class from
  // being loaded into PermGen space when the default instance is created.
  // This optimizes the PermGen space usage for clients that do not modify
  // messages.
  printer->Print(
    "// Use $classname$.newBuilder() to construct.\n"
    "private $classname$($buildertype$ builder) {\n"
    "  super(builder);\n"
    "}\n",
    "classname", descriptor_->name(),
    "buildertype", builder_type);
  printer->Print(
    "private $classname$() {\n",
    "classname", descriptor_->name());
  printer->Indent();
  GenerateInitializers(printer);
  printer->Outdent();
  printer->Print(
    "}\n"
    "\n");

  printer->Print(
    "@java.lang.Override\n"
    "public final com.google.protobuf.UnknownFieldSet\n"
    "getUnknownFields() {\n");
  if (PreserveUnknownFields(descriptor_)) {
    printer->Print(
      "  return this.unknownFields;\n");
  } else {
    printer->Print(
      "  return com.google.protobuf.UnknownFieldSet.getDefaultInstance();\n");
  }
  printer->Print(
    "}\n");

  if (HasGeneratedMethods(descriptor_)) {
    GenerateParsingConstructor(printer);
  }

  GenerateDescriptorMethods(printer);

  // Nested types
  for (int i = 0; i < descriptor_->enum_type_count(); i++) {
    EnumGenerator(descriptor_->enum_type(i), true, context_)
        .Generate(printer);
  }

  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
    // Don't generate Java classes for map entry messages.
    if (IsMapEntry(descriptor_->nested_type(i))) continue;
    ImmutableMessageGenerator messageGenerator(
        descriptor_->nested_type(i), context_);
    messageGenerator.GenerateInterface(printer);
    messageGenerator.Generate(printer);
  }

  if (GenerateHasBits(descriptor_)) {
    // Integers for bit fields.
    int totalBits = 0;
    for (int i = 0; i < descriptor_->field_count(); i++) {
      totalBits += field_generators_.get(descriptor_->field(i))
          .GetNumBitsForMessage();
    }
    int totalInts = (totalBits + 31) / 32;
    for (int i = 0; i < totalInts; i++) {
      printer->Print("private int $bit_field_name$;\n",
        "bit_field_name", GetBitFieldName(i));
    }
  }

  // oneof
  map<string, string> vars;
  for (int i = 0; i < descriptor_->oneof_decl_count(); i++) {
    vars["oneof_name"] = context_->GetOneofGeneratorInfo(
        descriptor_->oneof_decl(i))->name;
    vars["oneof_capitalized_name"] = context_->GetOneofGeneratorInfo(
        descriptor_->oneof_decl(i))->capitalized_name;
    vars["oneof_index"] = SimpleItoa(descriptor_->oneof_decl(i)->index());
    // oneofCase_ and oneof_
    printer->Print(vars,
      "private int $oneof_name$Case_ = 0;\n"
      "private java.lang.Object $oneof_name$_;\n");
    // OneofCase enum
    printer->Print(vars,
      "public enum $oneof_capitalized_name$Case\n"
      "    implements com.google.protobuf.Internal.EnumLite {\n");
    printer->Indent();
    for (int j = 0; j < descriptor_->oneof_decl(i)->field_count(); j++) {
      const FieldDescriptor* field = descriptor_->oneof_decl(i)->field(j);
      printer->Print(
        "$field_name$($field_number$),\n",
        "field_name",
        ToUpper(field->name()),
        "field_number",
        SimpleItoa(field->number()));
    }
    printer->Print(
      "$cap_oneof_name$_NOT_SET(0);\n",
      "cap_oneof_name",
      ToUpper(vars["oneof_name"]));
    printer->Print(vars,
      "private int value = 0;\n"
      "private $oneof_capitalized_name$Case(int value) {\n"
      "  this.value = value;\n"
      "}\n");
    printer->Print(vars,
      "public static $oneof_capitalized_name$Case valueOf(int value) {\n"
      "  switch (value) {\n");
    for (int j = 0; j < descriptor_->oneof_decl(i)->field_count(); j++) {
      const FieldDescriptor* field = descriptor_->oneof_decl(i)->field(j);
      printer->Print(
        "    case $field_number$: return $field_name$;\n",
        "field_number",
        SimpleItoa(field->number()),
        "field_name",
        ToUpper(field->name()));
    }
    printer->Print(
      "    case 0: return $cap_oneof_name$_NOT_SET;\n"
      "    default: throw new java.lang.IllegalArgumentException(\n"
      "      \"Value is undefined for this oneof enum.\");\n"
      "  }\n"
      "}\n"
      "public int getNumber() {\n"
      "  return this.value;\n"
      "}\n",
      "cap_oneof_name", ToUpper(vars["oneof_name"]));
    printer->Outdent();
    printer->Print("};\n\n");
    // oneofCase()
    printer->Print(vars,
      "public $oneof_capitalized_name$Case\n"
      "get$oneof_capitalized_name$Case() {\n"
      "  return $oneof_capitalized_name$Case.valueOf(\n"
      "      $oneof_name$Case_);\n"
      "}\n"
      "\n");
  }

  // Fields
  for (int i = 0; i < descriptor_->field_count(); i++) {
    printer->Print("public static final int $constant_name$ = $number$;\n",
      "constant_name", FieldConstantName(descriptor_->field(i)),
      "number", SimpleItoa(descriptor_->field(i)->number()));
    field_generators_.get(descriptor_->field(i)).GenerateMembers(printer);
    printer->Print("\n");
  }

  if (HasGeneratedMethods(descriptor_)) {
    GenerateIsInitialized(printer);
    GenerateMessageSerializationMethods(printer);
  }

  if (HasEqualsAndHashCode(descriptor_)) {
    GenerateEqualsAndHashCode(printer);
  }


  GenerateParseFromMethods(printer);
  GenerateBuilder(printer);

  printer->Print(
    "\n"
    "// @@protoc_insertion_point(class_scope:$full_name$)\n",
    "full_name", descriptor_->full_name());


  // Carefully initialize the default instance in such a way that it doesn't
  // conflict with other initialization.
  printer->Print(
    "private static final $classname$ DEFAULT_INSTANCE;\n",
    "classname", name_resolver_->GetImmutableClassName(descriptor_));
  printer->Print(
    "static {\n"
    "  DEFAULT_INSTANCE = new $classname$();\n"
    "}\n"
    "\n",
    "classname", name_resolver_->GetImmutableClassName(descriptor_));

  printer->Print(
      "public static $classname$ getDefaultInstance() {\n"
      "  return DEFAULT_INSTANCE;\n"
      "}\n"
      "\n",
      "classname", name_resolver_->GetImmutableClassName(descriptor_));

  GenerateParser(printer);

  printer->Print(
    "public $classname$ getDefaultInstanceForType() {\n"
    "  return DEFAULT_INSTANCE;\n"
    "}\n"
    "\n",
    "classname", name_resolver_->GetImmutableClassName(descriptor_));

  // Extensions must be declared after the DEFAULT_INSTANCE is initialized
  // because the DEFAULT_INSTANCE is used by the extension to lazily retrieve
  // the outer class's FileDescriptor.
  for (int i = 0; i < descriptor_->extension_count(); i++) {
    ImmutableExtensionGenerator(descriptor_->extension(i), context_)
        .Generate(printer);
  }

  printer->Outdent();
  printer->Print("}\n\n");
}


// ===================================================================

void ImmutableMessageGenerator::
GenerateMessageSerializationMethods(io::Printer* printer) {
  google::protobuf::scoped_array<const FieldDescriptor * > sorted_fields(
      SortFieldsByNumber(descriptor_));

  vector<const Descriptor::ExtensionRange*> sorted_extensions;
  for (int i = 0; i < descriptor_->extension_range_count(); ++i) {
    sorted_extensions.push_back(descriptor_->extension_range(i));
  }
  std::sort(sorted_extensions.begin(), sorted_extensions.end(),
            ExtensionRangeOrdering());

  printer->Print(
    "public void writeTo(com.google.protobuf.CodedOutputStream output)\n"
    "                    throws java.io.IOException {\n");
  printer->Indent();
  if (HasPackedFields(descriptor_)) {
    // writeTo(CodedOutputStream output) might be invoked without
    // getSerializedSize() ever being called, but we need the memoized
    // sizes in case this message has packed fields. Rather than emit checks for
    // each packed field, just call getSerializedSize() up front.
    // In most cases, getSerializedSize() will have already been called anyway
    // by one of the wrapper writeTo() methods, making this call cheap.
    printer->Print(
      "getSerializedSize();\n");
  }

  if (descriptor_->extension_range_count() > 0) {
    if (descriptor_->options().message_set_wire_format()) {
      printer->Print(
        "com.google.protobuf.GeneratedMessage\n"
        "  .ExtendableMessage<$classname$>.ExtensionWriter\n"
        "    extensionWriter = newMessageSetExtensionWriter();\n",
        "classname", name_resolver_->GetImmutableClassName(descriptor_));
    } else {
      printer->Print(
        "com.google.protobuf.GeneratedMessage\n"
        "  .ExtendableMessage<$classname$>.ExtensionWriter\n"
        "    extensionWriter = newExtensionWriter();\n",
        "classname", name_resolver_->GetImmutableClassName(descriptor_));
    }
  }

  // Merge the fields and the extension ranges, both sorted by field number.
  for (int i = 0, j = 0;
       i < descriptor_->field_count() || j < sorted_extensions.size();
       ) {
    if (i == descriptor_->field_count()) {
      GenerateSerializeOneExtensionRange(printer, sorted_extensions[j++]);
    } else if (j == sorted_extensions.size()) {
      GenerateSerializeOneField(printer, sorted_fields[i++]);
    } else if (sorted_fields[i]->number() < sorted_extensions[j]->start) {
      GenerateSerializeOneField(printer, sorted_fields[i++]);
    } else {
      GenerateSerializeOneExtensionRange(printer, sorted_extensions[j++]);
    }
  }

  if (PreserveUnknownFields(descriptor_)) {
    if (descriptor_->options().message_set_wire_format()) {
      printer->Print(
        "unknownFields.writeAsMessageSetTo(output);\n");
    } else {
      printer->Print(
        "unknownFields.writeTo(output);\n");
    }
  }

  printer->Outdent();
  printer->Print(
    "}\n"
    "\n"
    "private int memoizedSerializedSize = -1;\n"
    "public int getSerializedSize() {\n"
    "  int size = memoizedSerializedSize;\n"
    "  if (size != -1) return size;\n"
    "\n"
    "  size = 0;\n");
  printer->Indent();

  for (int i = 0; i < descriptor_->field_count(); i++) {
    field_generators_.get(sorted_fields[i]).GenerateSerializedSizeCode(printer);
  }

  if (descriptor_->extension_range_count() > 0) {
    if (descriptor_->options().message_set_wire_format()) {
      printer->Print(
        "size += extensionsSerializedSizeAsMessageSet();\n");
    } else {
      printer->Print(
        "size += extensionsSerializedSize();\n");
    }
  }

  if (PreserveUnknownFields(descriptor_)) {
    if (descriptor_->options().message_set_wire_format()) {
      printer->Print(
        "size += unknownFields.getSerializedSizeAsMessageSet();\n");
    } else {
      printer->Print(
        "size += unknownFields.getSerializedSize();\n");
    }
  }

  printer->Outdent();
  printer->Print(
    "  memoizedSerializedSize = size;\n"
    "  return size;\n"
    "}\n"
    "\n");

  printer->Print(
    "private static final long serialVersionUID = 0L;\n");
}

void ImmutableMessageGenerator::
GenerateParseFromMethods(io::Printer* printer) {
  // Note:  These are separate from GenerateMessageSerializationMethods()
  //   because they need to be generated even for messages that are optimized
  //   for code size.
  printer->Print(
    "public static $classname$ parseFrom(\n"
    "    com.google.protobuf.ByteString data)\n"
    "    throws com.google.protobuf.InvalidProtocolBufferException {\n"
    "  return PARSER.parseFrom(data);\n"
    "}\n"
    "public static $classname$ parseFrom(\n"
    "    com.google.protobuf.ByteString data,\n"
    "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
    "    throws com.google.protobuf.InvalidProtocolBufferException {\n"
    "  return PARSER.parseFrom(data, extensionRegistry);\n"
    "}\n"
    "public static $classname$ parseFrom(byte[] data)\n"
    "    throws com.google.protobuf.InvalidProtocolBufferException {\n"
    "  return PARSER.parseFrom(data);\n"
    "}\n"
    "public static $classname$ parseFrom(\n"
    "    byte[] data,\n"
    "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
    "    throws com.google.protobuf.InvalidProtocolBufferException {\n"
    "  return PARSER.parseFrom(data, extensionRegistry);\n"
    "}\n"
    "public static $classname$ parseFrom(java.io.InputStream input)\n"
    "    throws java.io.IOException {\n"
    "  return PARSER.parseFrom(input);\n"
    "}\n"
    "public static $classname$ parseFrom(\n"
    "    java.io.InputStream input,\n"
    "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
    "    throws java.io.IOException {\n"
    "  return PARSER.parseFrom(input, extensionRegistry);\n"
    "}\n"
    "public static $classname$ parseDelimitedFrom(java.io.InputStream input)\n"
    "    throws java.io.IOException {\n"
    "  return PARSER.parseDelimitedFrom(input);\n"
    "}\n"
    "public static $classname$ parseDelimitedFrom(\n"
    "    java.io.InputStream input,\n"
    "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
    "    throws java.io.IOException {\n"
    "  return PARSER.parseDelimitedFrom(input, extensionRegistry);\n"
    "}\n"
    "public static $classname$ parseFrom(\n"
    "    com.google.protobuf.CodedInputStream input)\n"
    "    throws java.io.IOException {\n"
    "  return PARSER.parseFrom(input);\n"
    "}\n"
    "public static $classname$ parseFrom(\n"
    "    com.google.protobuf.CodedInputStream input,\n"
    "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
    "    throws java.io.IOException {\n"
    "  return PARSER.parseFrom(input, extensionRegistry);\n"
    "}\n"
    "\n",
    "classname", name_resolver_->GetImmutableClassName(descriptor_));
}

void ImmutableMessageGenerator::GenerateSerializeOneField(
    io::Printer* printer, const FieldDescriptor* field) {
  field_generators_.get(field).GenerateSerializationCode(printer);
}

void ImmutableMessageGenerator::GenerateSerializeOneExtensionRange(
    io::Printer* printer, const Descriptor::ExtensionRange* range) {
  printer->Print(
    "extensionWriter.writeUntil($end$, output);\n",
    "end", SimpleItoa(range->end));
}

// ===================================================================

void ImmutableMessageGenerator::GenerateBuilder(io::Printer* printer) {
  // LITE_RUNTIME implements this at the GeneratedMessageLite level.
  printer->Print(
    "public Builder newBuilderForType() { return newBuilder(); }\n");

  printer->Print(
    "public static Builder newBuilder() {\n"
    "  return DEFAULT_INSTANCE.toBuilder();\n"
    "}\n"
    "public static Builder newBuilder($classname$ prototype) {\n"
    "  return DEFAULT_INSTANCE.toBuilder().mergeFrom(prototype);\n"
    "}\n"
    "public Builder toBuilder() {\n"
    "  return this == DEFAULT_INSTANCE\n"
    "      ? new Builder() : new Builder().mergeFrom(this);\n"
    "}\n"
    "\n",
    "classname", name_resolver_->GetImmutableClassName(descriptor_));

  printer->Print(
    "@java.lang.Override\n"
    "protected Builder newBuilderForType(\n"
    "    com.google.protobuf.GeneratedMessage.BuilderParent parent) {\n"
    "  Builder builder = new Builder(parent);\n"
    "  return builder;\n"
    "}\n");

  MessageBuilderGenerator builderGenerator(descriptor_, context_);
  builderGenerator.Generate(printer);
}

void ImmutableMessageGenerator::
GenerateDescriptorMethods(io::Printer* printer) {
  if (!descriptor_->options().no_standard_descriptor_accessor()) {
    printer->Print(
      "public static final com.google.protobuf.Descriptors.Descriptor\n"
      "    getDescriptor() {\n"
      "  return $fileclass$.internal_$identifier$_descriptor;\n"
      "}\n"
      "\n",
      "fileclass", name_resolver_->GetImmutableClassName(descriptor_->file()),
      "identifier", UniqueFileScopeIdentifier(descriptor_));
  }
  vector<const FieldDescriptor*> map_fields;
  for (int i = 0; i < descriptor_->field_count(); i++) {
    const FieldDescriptor* field = descriptor_->field(i);
    if (GetJavaType(field) == JAVATYPE_MESSAGE &&
        IsMapEntry(field->message_type())) {
      map_fields.push_back(field);
    }
  }
  if (!map_fields.empty()) {
    printer->Print(
      "@SuppressWarnings({\"rawtypes\"})\n"
      "protected com.google.protobuf.MapField internalGetMapField(\n"
      "    int number) {\n"
      "  switch (number) {\n");
    printer->Indent();
    printer->Indent();
    for (int i = 0; i < map_fields.size(); ++i) {
      const FieldDescriptor* field = map_fields[i];
      const FieldGeneratorInfo* info = context_->GetFieldGeneratorInfo(field);
      printer->Print(
        "case $number$:\n"
        "  return internalGet$capitalized_name$();\n",
        "number", SimpleItoa(field->number()),
        "capitalized_name", info->capitalized_name);
    }
    printer->Print(
        "default:\n"
        "  throw new RuntimeException(\n"
        "      \"Invalid map field number: \" + number);\n");
    printer->Outdent();
    printer->Outdent();
    printer->Print(
        "  }\n"
        "}\n");
  }
  printer->Print(
    "protected com.google.protobuf.GeneratedMessage.FieldAccessorTable\n"
    "    internalGetFieldAccessorTable() {\n"
    "  return $fileclass$.internal_$identifier$_fieldAccessorTable\n"
    "      .ensureFieldAccessorsInitialized(\n"
    "          $classname$.class, $classname$.Builder.class);\n"
    "}\n"
    "\n",
    "classname", name_resolver_->GetImmutableClassName(descriptor_),
    "fileclass", name_resolver_->GetImmutableClassName(descriptor_->file()),
    "identifier", UniqueFileScopeIdentifier(descriptor_));
}

// ===================================================================

void ImmutableMessageGenerator::GenerateIsInitialized(
    io::Printer* printer) {
  // Memoizes whether the protocol buffer is fully initialized (has all
  // required fields). -1 means not yet computed. 0 means false and 1 means
  // true.
  printer->Print(
    "private byte memoizedIsInitialized = -1;\n");
  printer->Print(
    "public final boolean isInitialized() {\n");
  printer->Indent();

  // Don't directly compare to -1 to avoid an Android x86 JIT bug.
  printer->Print(
    "byte isInitialized = memoizedIsInitialized;\n"
    "if (isInitialized == 1) return true;\n"
    "if (isInitialized == 0) return false;\n"
    "\n");

  // Check that all required fields in this message are set.
  // TODO(kenton):  We can optimize this when we switch to putting all the
  //   "has" fields into a single bitfield.
  for (int i = 0; i < descriptor_->field_count(); i++) {
    const FieldDescriptor* field = descriptor_->field(i);
    const FieldGeneratorInfo* info = context_->GetFieldGeneratorInfo(field);

    if (field->is_required()) {
      printer->Print(
        "if (!has$name$()) {\n"
        "  memoizedIsInitialized = 0;\n"
        "  return false;\n"
        "}\n",
        "name", info->capitalized_name);
    }
  }

  // Now check that all embedded messages are initialized.
  for (int i = 0; i < descriptor_->field_count(); i++) {
    const FieldDescriptor* field = descriptor_->field(i);
    const FieldGeneratorInfo* info = context_->GetFieldGeneratorInfo(field);
    if (GetJavaType(field) == JAVATYPE_MESSAGE &&
        HasRequiredFields(field->message_type())) {
      switch (field->label()) {
        case FieldDescriptor::LABEL_REQUIRED:
          printer->Print(
            "if (!get$name$().isInitialized()) {\n"
             "  memoizedIsInitialized = 0;\n"
             "  return false;\n"
             "}\n",
            "type", name_resolver_->GetImmutableClassName(
                field->message_type()),
            "name", info->capitalized_name);
          break;
        case FieldDescriptor::LABEL_OPTIONAL:
          if (!SupportFieldPresence(descriptor_->file()) &&
              field->containing_oneof() != NULL) {
            const OneofDescriptor* oneof = field->containing_oneof();
            const OneofGeneratorInfo* oneof_info =
                context_->GetOneofGeneratorInfo(oneof);
            printer->Print(
              "if ($oneof_name$Case_ == $field_number$) {\n",
              "oneof_name", oneof_info->name,
              "field_number", SimpleItoa(field->number()));
          } else {
            printer->Print(
              "if (has$name$()) {\n",
              "name", info->capitalized_name);
          }
          printer->Print(
            "  if (!get$name$().isInitialized()) {\n"
            "    memoizedIsInitialized = 0;\n"
            "    return false;\n"
            "  }\n"
            "}\n",
            "name", info->capitalized_name);
          break;
        case FieldDescriptor::LABEL_REPEATED:
          if (IsMapEntry(field->message_type())) {
            printer->Print(
              "for ($type$ item : get$name$().values()) {\n"
              "  if (!item.isInitialized()) {\n"
              "    memoizedIsInitialized = 0;\n"
              "    return false;\n"
              "  }\n"
              "}\n",
              "type", MapValueImmutableClassdName(field->message_type(),
                                                  name_resolver_),
              "name", info->capitalized_name);
          } else {
            printer->Print(
              "for (int i = 0; i < get$name$Count(); i++) {\n"
              "  if (!get$name$(i).isInitialized()) {\n"
              "    memoizedIsInitialized = 0;\n"
              "    return false;\n"
              "  }\n"
              "}\n",
              "type", name_resolver_->GetImmutableClassName(
                  field->message_type()),
              "name", info->capitalized_name);
          }
          break;
      }
    }
  }

  if (descriptor_->extension_range_count() > 0) {
    printer->Print(
      "if (!extensionsAreInitialized()) {\n"
      "  memoizedIsInitialized = 0;\n"
      "  return false;\n"
      "}\n");
  }

  printer->Outdent();

  printer->Print(
    "  memoizedIsInitialized = 1;\n");

  printer->Print(
    "  return true;\n"
    "}\n"
    "\n");
}

// ===================================================================

namespace {
bool CheckHasBitsForEqualsAndHashCode(const FieldDescriptor* field) {
  if (field->is_repeated()) {
    return false;
  }
  if (SupportFieldPresence(field->file())) {
    return true;
  }
  return GetJavaType(field) == JAVATYPE_MESSAGE &&
      field->containing_oneof() == NULL;
}
}  // namespace

void ImmutableMessageGenerator::
GenerateEqualsAndHashCode(io::Printer* printer) {
  printer->Print(
    "@java.lang.Override\n"
    "public boolean equals(final java.lang.Object obj) {\n");
  printer->Indent();
  printer->Print(
    "if (obj == this) {\n"
    " return true;\n"
    "}\n"
    "if (!(obj instanceof $classname$)) {\n"
    "  return super.equals(obj);\n"
    "}\n"
    "$classname$ other = ($classname$) obj;\n"
    "\n",
    "classname", name_resolver_->GetImmutableClassName(descriptor_));

  printer->Print("boolean result = true;\n");
  for (int i = 0; i < descriptor_->field_count(); i++) {
    const FieldDescriptor* field = descriptor_->field(i);
    const FieldGeneratorInfo* info = context_->GetFieldGeneratorInfo(field);
    bool check_has_bits = CheckHasBitsForEqualsAndHashCode(field);
    if (check_has_bits) {
      printer->Print(
        "result = result && (has$name$() == other.has$name$());\n"
        "if (has$name$()) {\n",
        "name", info->capitalized_name);
      printer->Indent();
    }
    field_generators_.get(field).GenerateEqualsCode(printer);
    if (check_has_bits) {
      printer->Outdent();
      printer->Print(
        "}\n");
    }
  }
  if (PreserveUnknownFields(descriptor_)) {
    // Always consider unknown fields for equality. This will sometimes return
    // false for non-canonical ordering when running in LITE_RUNTIME but it's
    // the best we can do.
    printer->Print(
      "result = result && unknownFields.equals(other.unknownFields);\n");
  }
  if (descriptor_->extension_range_count() > 0) {
    printer->Print(
      "result = result &&\n"
      "    getExtensionFields().equals(other.getExtensionFields());\n");
  }
  printer->Print(
    "return result;\n");
  printer->Outdent();
  printer->Print(
    "}\n"
    "\n");

  printer->Print(
    "@java.lang.Override\n"
    "public int hashCode() {\n");
  printer->Indent();
  printer->Print(
    "if (memoizedHashCode != 0) {\n");
  printer->Indent();
  printer->Print(
    "return memoizedHashCode;\n");
  printer->Outdent();
  printer->Print(
    "}\n"
    "int hash = 41;\n");

  printer->Print("hash = (19 * hash) + getDescriptorForType().hashCode();\n");

  for (int i = 0; i < descriptor_->field_count(); i++) {
    const FieldDescriptor* field = descriptor_->field(i);
    const FieldGeneratorInfo* info = context_->GetFieldGeneratorInfo(field);
    bool check_has_bits = CheckHasBitsForEqualsAndHashCode(field);
    if (check_has_bits) {
      printer->Print(
        "if (has$name$()) {\n",
        "name", info->capitalized_name);
      printer->Indent();
    }
    field_generators_.get(field).GenerateHashCode(printer);
    if (check_has_bits) {
      printer->Outdent();
      printer->Print("}\n");
    }
  }
  if (descriptor_->extension_range_count() > 0) {
    printer->Print(
      "hash = hashFields(hash, getExtensionFields());\n");
  }

  printer->Print(
    "hash = (29 * hash) + unknownFields.hashCode();\n");
  printer->Print(
    "memoizedHashCode = hash;\n"
    "return hash;\n");
  printer->Outdent();
  printer->Print(
    "}\n"
    "\n");
}

// ===================================================================

void ImmutableMessageGenerator::
GenerateExtensionRegistrationCode(io::Printer* printer) {
  for (int i = 0; i < descriptor_->extension_count(); i++) {
    ImmutableExtensionGenerator(descriptor_->extension(i), context_)
      .GenerateRegistrationCode(printer);
  }

  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
    ImmutableMessageGenerator(descriptor_->nested_type(i), context_)
      .GenerateExtensionRegistrationCode(printer);
  }
}

// ===================================================================
void ImmutableMessageGenerator::
GenerateParsingConstructor(io::Printer* printer) {
  google::protobuf::scoped_array<const FieldDescriptor * > sorted_fields(
      SortFieldsByNumber(descriptor_));

  printer->Print(
      "private $classname$(\n"
      "    com.google.protobuf.CodedInputStream input,\n"
      "    com.google.protobuf.ExtensionRegistryLite extensionRegistry) {\n",
      "classname", descriptor_->name());
  printer->Indent();

  // Initialize all fields to default.
  printer->Print(
      "this();\n");

  // Use builder bits to track mutable repeated fields.
  int totalBuilderBits = 0;
  for (int i = 0; i < descriptor_->field_count(); i++) {
    const ImmutableFieldGenerator& field =
        field_generators_.get(descriptor_->field(i));
    totalBuilderBits += field.GetNumBitsForBuilder();
  }
  int totalBuilderInts = (totalBuilderBits + 31) / 32;
  for (int i = 0; i < totalBuilderInts; i++) {
    printer->Print("int mutable_$bit_field_name$ = 0;\n",
      "bit_field_name", GetBitFieldName(i));
  }

  if (PreserveUnknownFields(descriptor_)) {
    printer->Print(
      "com.google.protobuf.UnknownFieldSet.Builder unknownFields =\n"
      "    com.google.protobuf.UnknownFieldSet.newBuilder();\n");
  }

  printer->Print(
      "try {\n");
  printer->Indent();

  printer->Print(
    "boolean done = false;\n"
    "while (!done) {\n");
  printer->Indent();

  printer->Print(
    "int tag = input.readTag();\n"
    "switch (tag) {\n");
  printer->Indent();

  printer->Print(
    "case 0:\n"          // zero signals EOF / limit reached
    "  done = true;\n"
    "  break;\n");

  if (PreserveUnknownFields(descriptor_)) {
    printer->Print(
      "default: {\n"
      "  if (!parseUnknownField(input, unknownFields,\n"
      "                         extensionRegistry, tag)) {\n"
      "    done = true;\n"  // it's an endgroup tag
      "  }\n"
      "  break;\n"
      "}\n");
  } else {
    printer->Print(
      "default: {\n"
      "  if (!input.skipField(tag)) {\n"
      "    done = true;\n"  // it's an endgroup tag
      "  }\n"
      "  break;\n"
      "}\n");
  }

  for (int i = 0; i < descriptor_->field_count(); i++) {
    const FieldDescriptor* field = sorted_fields[i];
    uint32 tag = WireFormatLite::MakeTag(field->number(),
      WireFormat::WireTypeForFieldType(field->type()));

    printer->Print(
      "case $tag$: {\n",
      "tag", SimpleItoa(tag));
    printer->Indent();

    field_generators_.get(field).GenerateParsingCode(printer);

    printer->Outdent();
    printer->Print(
      "  break;\n"
      "}\n");

    if (field->is_packable()) {
      // To make packed = true wire compatible, we generate parsing code from a
      // packed version of this field regardless of field->options().packed().
      uint32 packed_tag = WireFormatLite::MakeTag(field->number(),
        WireFormatLite::WIRETYPE_LENGTH_DELIMITED);
      printer->Print(
        "case $tag$: {\n",
        "tag", SimpleItoa(packed_tag));
      printer->Indent();

      field_generators_.get(field).GenerateParsingCodeFromPacked(printer);

      printer->Outdent();
      printer->Print(
        "  break;\n"
        "}\n");
    }
  }

  printer->Outdent();
  printer->Outdent();
  printer->Print(
      "  }\n"     // switch (tag)
      "}\n");     // while (!done)

  printer->Outdent();
  printer->Print(
      "} catch (com.google.protobuf.InvalidProtocolBufferException e) {\n"
      "  throw new RuntimeException(e.setUnfinishedMessage(this));\n"
      "} catch (java.io.IOException e) {\n"
      "  throw new RuntimeException(\n"
      "      new com.google.protobuf.InvalidProtocolBufferException(\n"
      "          e.getMessage()).setUnfinishedMessage(this));\n"
      "} finally {\n");
  printer->Indent();

  // Make repeated field list immutable.
  for (int i = 0; i < descriptor_->field_count(); i++) {
    const FieldDescriptor* field = sorted_fields[i];
    field_generators_.get(field).GenerateParsingDoneCode(printer);
  }

  if (PreserveUnknownFields(descriptor_)) {
    // Make unknown fields immutable.
    printer->Print("this.unknownFields = unknownFields.build();\n");
  }

  // Make extensions immutable.
  printer->Print(
      "makeExtensionsImmutable();\n");

  printer->Outdent();
  printer->Outdent();
  printer->Print(
      "  }\n"     // finally
      "}\n");
}

// ===================================================================
void ImmutableMessageGenerator::GenerateParser(io::Printer* printer) {
  printer->Print(
      "public static final com.google.protobuf.Parser<$classname$> PARSER =\n"
      "    new com.google.protobuf.AbstractParser<$classname$>() {\n",
      "classname", descriptor_->name());
  printer->Indent();
  printer->Print(
      "public $classname$ parsePartialFrom(\n"
      "    com.google.protobuf.CodedInputStream input,\n"
      "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
      "    throws com.google.protobuf.InvalidProtocolBufferException {\n",
      "classname", descriptor_->name());
  if (HasGeneratedMethods(descriptor_)) {
    // The parsing constructor throws an InvalidProtocolBufferException via a
    // RuntimeException to aid in method pruning. We unwrap it here.
    printer->Print(
        "  try {\n"
        "    return new $classname$(input, extensionRegistry);\n"
        "  } catch (RuntimeException e) {\n"
        "    if (e.getCause() instanceof\n"
        "        com.google.protobuf.InvalidProtocolBufferException) {\n"
        "      throw (com.google.protobuf.InvalidProtocolBufferException)\n"
        "          e.getCause();\n"
        "    }\n"
        "    throw e;\n"
        "  }\n",
        "classname", descriptor_->name());
  } else {
    // When parsing constructor isn't generated, use builder to parse
    // messages. Note, will fallback to use reflection based mergeFieldFrom()
    // in AbstractMessage.Builder.
    printer->Indent();
    printer->Print(
        "Builder builder = newBuilder();\n"
        "try {\n"
        "  builder.mergeFrom(input, extensionRegistry);\n"
        "} catch (com.google.protobuf.InvalidProtocolBufferException e) {\n"
        "  throw e.setUnfinishedMessage(builder.buildPartial());\n"
        "} catch (java.io.IOException e) {\n"
        "  throw new com.google.protobuf.InvalidProtocolBufferException(\n"
        "      e.getMessage()).setUnfinishedMessage(\n"
        "          builder.buildPartial());\n"
        "}\n"
        "return builder.buildPartial();\n");
    printer->Outdent();
  }
  printer->Print(
        "}\n");
  printer->Outdent();
  printer->Print(
      "};\n"
      "\n");

  printer->Print(
      "@java.lang.Override\n"
      "public com.google.protobuf.Parser<$classname$> getParserForType() {\n"
      "  return PARSER;\n"
      "}\n"
      "\n",
      "classname", descriptor_->name());
}

// ===================================================================
void ImmutableMessageGenerator::GenerateInitializers(io::Printer* printer) {
  for (int i = 0; i < descriptor_->field_count(); i++) {
    if (!descriptor_->field(i)->containing_oneof()) {
      field_generators_.get(descriptor_->field(i))
          .GenerateInitializationCode(printer);
    }
  }
}


}  // namespace java
}  // namespace compiler
}  // namespace protobuf
}  // namespace google
