# Copyright 2013 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import os.path

from code import Code
import cpp_util


class CCGenerator(object):
  def Generate(self, feature_defs, source_file, namespace):
    return _Generator(feature_defs, source_file, namespace).Generate()


class _Generator(object):
  """A .cc generator for features.
  """
  def __init__(self, feature_defs, source_file, namespace):
    self._feature_defs = feature_defs
    self._source_file = source_file
    self._source_file_filename, _ = os.path.splitext(source_file)
    self._class_name = cpp_util.ClassName(self._source_file_filename)
    self._namespace = namespace

  def Generate(self):
    """Generates a Code object for features.
    """
    c = Code()
    (c.Append(cpp_util.CHROMIUM_LICENSE)
      .Append()
      .Append(cpp_util.GENERATED_FEATURE_MESSAGE % self._source_file)
      .Append()
      .Append('#include <string>')
      .Append()
      .Append('#include "%s.h"' % self._source_file_filename)
      .Append()
      .Append('#include "base/logging.h"')
      .Append()
      .Concat(cpp_util.OpenNamespace(self._namespace))
      .Append()
    )

    # Generate the constructor.
    (c.Append('%s::%s() {' % (self._class_name, self._class_name))
      .Sblock()
    )
    for feature in self._feature_defs:
      c.Append('features_["%s"] = %s;'
                       % (feature.name, cpp_util.ConstantName(feature.name)))
    (c.Eblock()
      .Append('}')
      .Append()
    )

    # Generate the ToString function.
    (c.Append('const char* %s::ToString('
                  '%s::ID id) const {' % (self._class_name, self._class_name))
      .Sblock()
      .Append('switch (id) {')
      .Sblock()
    )
    for feature in self._feature_defs:
      c.Append('case %s: return "%s";' %
          (cpp_util.ConstantName(feature.name), feature.name))
    (c.Append('case kUnknown: break;')
      .Append('case kEnumBoundary: break;')
      .Eblock()
      .Append('}')
      .Append('NOTREACHED();')
      .Append('return "";')
    )
    (c.Eblock()
      .Append('}')
      .Append()
    )

    # Generate the FromString function.

    (c.Append('%s::ID %s::FromString('
                  'const std::string& id) const {'
                  % (self._class_name, self._class_name))
      .Sblock()
      .Append('const auto& it = features_.find(id);' % self._class_name)
      .Append('return (it == features_.end()) ? kUnknown : it->second;')
      .Eblock()
      .Append('}')
      .Append()
      .Cblock(cpp_util.CloseNamespace(self._namespace))
    )

    return c