# Copyright 2020 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/components.gni")
import("//build/dart/dart_component.gni")
import("//build/dart/dart_library.gni")

# Defines a Dart application that can be run in the Dart content handler
#
# Parameters
#
#   meta (required)
#     A list of exactly one scope with the path to the cmx file associated with
#     the dart app.
#
#   fuchsia_package_name (optional)
#     Name of the Fuchsia package.
#
#   resources (optional)
#     Resources for the package (see //build/package.gni)
#
#   pubspec (optional)
#     Path to the pubspec file. Must be "pubspec.yaml".
#
#   analysis_options (optional)
#     Path to the analysis options file. Must be "analysis_options.yaml".
#
#   components (required)
#     [list of one scope] Defines the component in the package. Either main_dart
#     or components must be defined, but not both.
#
#     The entry in a scope in the resources list:
#
#       main_dart (required)
#         File containing the main function of the component.
#
#       component_name (required)
#         Name of the component.
#
#       component_type (optional)
#         Always "dart".
#
#       sources (optional)
#         Relative path of source files to be included in the dart package for
#         the component at $package_root/lib.
#
#       deps (optional)
#         List of Dart packages the application depends on.
#
#   main_dart (required)
#     Name of the Dart file containing the main function. Either main_dart or
#     components must be defined, but not both.
#
#   package_name (optional)
#     Name of the Dart package. Can only be defined if main_dart is defined.
#
#   sources (optional)
#     Can only be defined if main_dart is defined.
#
#   deps (optional)
#     List of Dart packages the application depends on. Can only be defined if
#     main_dart is defined.
template("dart_app") {
  assert(defined(invoker.meta), "Must define meta")
  _invoker_meta = invoker.meta
  assert(_invoker_meta != [] && _invoker_meta == [ _invoker_meta[0] ],
         "meta must have exactly 1 element!")
  _meta = _invoker_meta[0]
  assert(defined(_meta.path), "Must define meta[0].path")
  assert(!defined(invoker.pubspec) || invoker.pubspec == "pubspec.yaml",
         "pubspec must be 'pubspec.yaml'")
  _package_name = target_name
  if (defined(invoker.package_name)) {
    _package_name = invoker.package_name
  }
  _sources = []
  _deps = []
  _fuchsia_package_name = target_name
  if (defined(invoker.fuchsia_package_name)) {
    _fuchsia_package_name = invoker.fuchsia_package_name
  }
  if (defined(invoker.main_dart)) {
    assert(!defined(invoker.components),
           "either components or main_dart should be defined, but not both")
    _main_dart = invoker.main_dart
    if (defined(invoker.sources)) {
      _sources = invoker.sources
    }
    if (defined(invoker.deps)) {
      _deps = invoker.deps
    }
  } else {
    assert(defined(invoker.components),
           "either components or main_dart should be defined, but not both")
    assert(!defined(invoker.package_name),
           "package_name cannot be defined if components is defined")
    assert(!defined(invoker.sources),
           "sources cannot be defined if components is defined")
    assert(!defined(invoker.deps),
           "deps cannot be defined if components is defined")
    _components = invoker.components
    assert(_components == [ _components[0] ],
           "components should contain exactly one scope")
    _component = _components[0]
    assert(defined(_component.main_dart) && defined(_component.component_name),
           "components[0] should define main_dart and component_name")
    assert(!defined(_component.component_type) ||
               _component.component_type == "dart",
           "components[0].component_type must be 'dart'")
    _main_dart = _component.main_dart
    if (defined(_component.component_name)) {
      _package_name = _component.component_name
    }
    if (defined(_component.sources)) {
      _sources = _component.sources
    }
    if (defined(_component.deps)) {
      _deps = _component.deps
    }
  }
  if (defined(invoker.source_dir)) {
    _source_dir = invoker.source_dir
  } else {
    _split_main_dart = string_split(_main_dart, "lib/")
    if (_split_main_dart[0] == "") {
      _main_dart = string_replace(_main_dart, "lib/", "", 1)
      _source_dir = "lib"
    } else {
      _source_dir = "."
    }
  }

  resource_gn_labels = []
  if (defined(invoker.resources)) {
    i = 0
    foreach(res, invoker.resources) {
      current_gn_label = target_name + "_resource_" + i
      resource(current_gn_label) {
        sources = [ res.path ]
        outputs = [ "data/" + res.dest ]
      }
      resource_gn_labels += [ ":$current_gn_label" ]
      i += 1
    }
  }

  dart_library_gn_label = target_name + "_dart_library"
  dart_library(dart_library_gn_label) {
    forward_variables_from(invoker, [ "null_safe" ])
    package_name = _package_name
    sources = _sources
    source_dir = _source_dir
    deps = _deps + resource_gn_labels
  }

  dart_component_gn_label = target_name + "_dart_component"
  dart_component(dart_component_gn_label) {
    main_package = _package_name
    component_name = string_replace(_fuchsia_package_name, "_", "-")
    main_dart = _main_dart
    manifest = _meta.path
    deps = [ ":$dart_library_gn_label" ]
  }

  fuchsia_package_gn_label = string_replace(target_name, "_", "-")
  fuchsia_package(fuchsia_package_gn_label) {
    package_name = string_replace(_fuchsia_package_name, "_", "-")
    deps = [
      ":$dart_component_gn_label",
      "//build/dart:deprecated_dart_app_allowlist",
    ]
  }

  # @TODO(fxb/62741): For purposes of soft transition.
  if (target_name != fuchsia_package_gn_label) {
    group(target_name) {
      deps = [ ":$fuchsia_package_gn_label" ]
    }
  }
}