# Copyright 2018 The Fuchsia 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("//build/compiled_action.gni")
import("//build/dart/dart_library.gni")
import("//build/dart/toolchain.gni")
import("//build/fidl/toolchain.gni")
import("//build/sdk/sdk_atom_alias.gni")

# Generates Dart bindings for a FIDL library.
#
# Parameters (see //build/fidl/fidl.gni for descriptions):
#
#   dart_analysis
#   name
#   public_deps
#   sdk_category
#   testonly
#   visibility
#
template("fidl_dart") {
  assert(
      current_toolchain == dart_toolchain,
      "This template can only be used in the Dart toolchain $dart_toolchain.")

  generation_target_name = "${target_name}_dart_generate"

  library_name = target_name
  if (defined(invoker.name)) {
    library_name = invoker.name
  }

  json_representation_target = ":${target_name}($fidl_toolchain)"
  fidl_target_gen_dir =
      get_label_info(json_representation_target, "target_gen_dir")
  json_representation = "$fidl_target_gen_dir/$target_name.fidl.json"

  root_dir = "$fidl_target_gen_dir/${library_name}_package"
  if (library_name != target_name) {
    root_dir = "$fidl_target_gen_dir/${target_name}_${library_name}_package"
  }
  bindings_dir = "$root_dir/lib"
  async_bindings_file = "$bindings_dir/fidl_async.dart"
  test_bindings_file = "$bindings_dir/fidl_test.dart"

  compiled_action(generation_target_name) {
    forward_variables_from(invoker, [ "testonly" ])

    visibility = [
      ":*",
      "//tools/fidl/fidlgen_dart:*",
    ]

    tool = "//tools/fidl/fidlgen_dart"

    inputs = [ json_representation ]

    outputs = [
      async_bindings_file,
      test_bindings_file,
    ]

    args = [
      "--json",
      rebase_path(json_representation, root_build_dir),
      "--output-async",
      rebase_path(async_bindings_file, root_build_dir),
      "--output-test",
      rebase_path(test_bindings_file, root_build_dir),
    ]

    deps = [ json_representation_target ]

    # Don't run the formatter if we are using a custom-built Dart SDK in a
    # cross-build.
    if (host_cpu == target_cpu) {
      args += [
        "--dart",
        rebase_path(prebuilt_dart, root_build_dir),
      ]
      deps += dart_sdk_deps
    }

    metadata = {
      generated_sources = rebase_path(outputs, root_build_dir)
    }
  }

  copy_pubspec_target_name = "${target_name}_dart_pubspec"

  copy(copy_pubspec_target_name) {
    sources = [ "//build/dart/empty_pubspec.yaml" ]

    outputs = [ "$root_dir/pubspec.yaml" ]
  }

  dart_library(target_name) {
    forward_variables_from(invoker,
                           [
                             "testonly",
                             "visibility",
                           ])

    # Dart analysis can take tens of second, so skip by default to save build
    # time.
    disable_analysis = !defined(invoker.dart_analysis) || !invoker.dart_analysis

    package_root = root_dir

    package_name = "fidl_" + string_replace(library_name, ".", "_")

    null_safe = true

    sources = [
      rebase_path(async_bindings_file, bindings_dir),
      rebase_path(test_bindings_file, bindings_dir),
    ]

    deps = [
      ":$copy_pubspec_target_name",
      ":$generation_target_name",
      "//sdk/dart/fidl",
      "//sdk/dart/zircon",
      "//third_party/dart-pkg/pub/meta",
    ]

    if (defined(invoker.public_deps)) {
      deps += invoker.public_deps
    }
  }

  if (defined(invoker.sdk_category) && invoker.sdk_category != "excluded") {
    # Instead of depending on the generated bindings, set up a dependency on the
    # original library.
    sdk_target_name = "${target_name}_sdk"
    sdk_atom_alias(sdk_target_name) {
      atom = ":$sdk_target_name($fidl_toolchain)"
    }
  }
}