# Copyright 2016 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.

# Generates the FeatureProviders files for extension features files.
# The following variables are required:
#   sources: The features.json files to use.
#   feature_type: The type of the features to generate, e.g. APIFeature.
#   provider_class: The name of the provider class to generate, e.g.
#                   APIFeatureProvider.
#   deps/public_deps/visibility: normal meaning
template("json_features") {
  assert(defined(invoker.sources),
         "\"sources\" must be defined for the $target_name template.")
  assert(defined(invoker.feature_type),
         "\"feature_type\" must be defined for the $target_name template.")
  assert(defined(invoker.provider_class),
         "\"provider_class\" must be defined for the $target_name template.")
  feature_type = invoker.feature_type
  provider_class = invoker.provider_class

  compiler_root = "//tools/json_schema_compiler"
  base_filename = target_name
  action_name = "${target_name}_json_features"
  source_set_name = target_name
  generated_files = [
    "$target_gen_dir/$base_filename.cc",
    "$target_gen_dir/$base_filename.h",
  ]

  action(action_name) {
    visibility = [ ":$source_set_name" ]
    sources = invoker.sources
    script = "$compiler_root/feature_compiler.py"
    inputs = [
      "$compiler_root/code.py",
      "$compiler_root/json_parse.py",
    ]
    outputs = generated_files
    rebased = rebase_path(sources, root_build_dir)
    args = [
             ".",
             "$feature_type",
             "$provider_class",
             rebase_path(target_gen_dir, root_build_dir),
             "$base_filename",
           ] + rebased

    # Add the deps in for the action as well, in case the deps generate the
    # inputs used by the action.
    forward_variables_from(invoker,
                           [
                             "deps",
                             "public_deps",
                           ])
  }

  source_set(target_name) {
    sources = generated_files
    forward_variables_from(invoker,
                           [
                             "deps",
                             "public_deps",
                             "visibility",
                           ])
    if (!defined(public_deps)) {
      public_deps = []
    }
    public_deps += [ ":$action_name" ]

    # Append a dependency on the extensions system. Headers in this target
    # are included by the feature compiler automatically.
    if (!defined(deps)) {
      deps = []
    }
    deps += [ "//extensions/common" ]
  }
}