# 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/dart/config.gni")
import("//build/dart/dart.gni")
import("//build/dart/dart_package_config.gni")
import("//build/dart/kernel/dart_kernel.gni")
import("//src/sys/build/components.gni")
import("//tools/cmc/build/cmc.gni")

# Creates a flutter asset manifest from the pubspec.yaml file.
#
# Parameters
#
#   pubsec (required)
#     The path to the pubsec.yaml file which contains the assets
#     Type: path
#
#   component_name (required)
#     The name of the component
#     Type: string
#
#   package_config (required)
#     The path to the package_config.json file which contains the source map
#     Type: path
#
template("_flutter_asset_manifest") {
  action(target_name) {
    forward_variables_from(invoker,
                           [
                             "deps",
                             "testonly",
                             "visibility",
                           ])
    assert(defined(invoker.component_name), "component_name is required")
    assert(defined(invoker.package_config), "package_config is required")
    assert(defined(invoker.pubspec), "pubspec is required")

    _flutter_base = "//third_party/dart-pkg/git/flutter"
    _flutter_asset_tools_label = "$_flutter_base/packages/flutter_tools:fuchsia_asset_builder($host_toolchain)"
    _flutter_asset_tools_out_dir =
        get_label_info(_flutter_asset_tools_label, "root_out_dir")
    _flutter_asset_tools_bin =
        "$_flutter_asset_tools_out_dir/dart-tools/fuchsia_asset_builder"

    _asset_manifest =
        "$target_gen_dir/build/${invoker.component_name}_pkgassets"

    script = "//build/flutter/internal/gen_asset_manifest.py"

    args = [
      "--flutter-root",
      rebase_path(_flutter_base),
      "--flutter-tools",
      rebase_path(_flutter_asset_tools_bin),
      "--asset-dir",
      rebase_path("$target_gen_dir/build"),
      "--app-dir",
      rebase_path("."),
      "--packages",
      rebase_path(invoker.package_config),
      "--output",
      rebase_path(_asset_manifest),
      "--component-name",
      invoker.component_name,
      "--manifest",
      rebase_path(invoker.pubspec),
    ]

    if (!defined(deps)) {
      deps = []
    }
    deps += [ _flutter_asset_tools_label ]

    outputs = [ _asset_manifest ]

    metadata = {
      distribution_entries = [
        {
          file = rebase_path(_asset_manifest, root_build_dir)
          label = get_label_info(target_name, "label_with_toolchain")
        },
      ]
    }
  }
}

# Defines a component which will run in a flutter_runner or dart_runner
#
# This template is not intended to be used directly. Users should use the
# flutter_component and dart_component actions instead.
#
# Parameters
#
#   manifest (required)
#     The component manifest
#     Type: path
#
#   main_package (required)
#     The name of the package containing the main_dart
#     Type: string
#
#   component_name (optional)
#     The name of the component.
#     Type: string
#     Default: target_name
#
#   build_cfg (required)
#    A description of how to build this component. This object needs
#    to contain the following variables:
#      runtime_meta: a path to the partial cmx file containing the runner
#      platform_name: either 'dart_runner' or 'flutter_runner'
#      is_aot: a boolean indicating if this is an AOT build
#      is_product: a boolean indicating if this is a product build
#      enable_asserts: whether we should enable asserts when compiling
#
#   main_dart (required)
#     File containing the main function of the component.
#     Type: string
#
#   generate_asset_manifest (optional)
#     If true, will generate an asset manifest for this component
#     Type: boolean
#     Default: false
#
#  deps
#  testonly
#  visibility
template("flutter_dart_component") {
  assert(defined(invoker.manifest), "must specify a manifest file")
  assert(defined(invoker.build_cfg), "must specify build_cfg")
  assert(defined(invoker.main_dart), "Must specify main_dart")
  assert(defined(invoker.main_package), "Must specify main_package")

  build_cfg = invoker.build_cfg

  _component_deps = []
  if (defined(invoker.deps)) {
    _component_deps += invoker.deps
  }

  if (defined(invoker.component_name)) {
    _component_name = invoker.component_name
  } else {
    _component_name = target_name
  }

  # merge the runner cmx into this one which allows us to switch runners based
  # on compilation modes
  _merged_target_name = "${target_name}_merged.cmx"

  cmc_merge(_merged_target_name) {
    forward_variables_from(invoker,
                           [
                             "testonly",
                             "visibility",
                           ])
    sources = [
      invoker.manifest,
      rebase_path(build_cfg.runtime_meta, "."),
    ]
  }

  _merged_outputs = []
  _merged_outputs += get_target_outputs(":$_merged_target_name")
  _merged_manifest = _merged_outputs[0]

  _component_deps += [ ":$_merged_target_name" ]

  _dart_package_config_target_name = "${target_name}_dart_package"
  dart_package_config(_dart_package_config_target_name) {
    forward_variables_from(invoker,
                           [
                             "testonly",
                             "visibility",
                           ])

    deps = _component_deps
  }

  _package_config_output = []
  _package_config_output =
      get_target_outputs(":$_dart_package_config_target_name")
  _packages_path = _package_config_output[0]

  _kernel_target_name = _component_name + "_kernel"
  _kernel_target_dep_name = _kernel_target_name + "_gen_file"
  _kernel_path = "$target_gen_dir/${target_name}.dil"

  dart_kernel2(_kernel_target_name) {
    kernel_path = _kernel_path

    # establishes a dependency chain for the snapshot since
    # the kernel is wrapped in a group
    kernel_target_name = _kernel_target_dep_name

    forward_variables_from(invoker,
                           [
                             "testonly",
                             "visibility",
                             "main_dart",
                             "main_package",
                           ])

    deps = [ ":$_dart_package_config_target_name" ]

    packages_path = _packages_path
    args = [
      "--component-name",
      _component_name,
    ]

    # always generate a manifest for fuchsia builds. If this is an aot build
    # the kernel will ignore this variable.
    generate_manifest = true

    platform_name = build_cfg.platform_name
    product = build_cfg.is_product
    is_aot = build_cfg.is_aot
  }

  _component_deps += [ ":$_kernel_target_name" ]

  if (defined(invoker.generate_asset_manifest) &&
      invoker.generate_asset_manifest) {
    _asset_manifest_target_name = "${target_name}_asset_manifest"
    _flutter_asset_manifest(_asset_manifest_target_name) {
      forward_variables_from(invoker,
                             [
                               "testonly",
                               "visibility",
                             ])
      component_name = _component_name
      package_config = _packages_path
      pubspec = "pubspec.yaml"
      deps = [ ":$_dart_package_config_target_name" ]
    }

    _component_deps += [ ":$_asset_manifest_target_name" ]
  }

  if (build_cfg.is_aot) {
    _snapshot_path = "$target_gen_dir/${_component_name}_snapshot.so"
    _snapshot_target_name = target_name + "_snapshot"

    _stats_json_path =
        "$target_gen_dir/${_component_name}/stats/symbol_sizes.json"

    action(_snapshot_target_name) {
      forward_variables_from(invoker,
                             [
                               "testonly",
                               "visibility",
                             ])

      deps = [ ":$_kernel_target_dep_name" ]
      inputs = [ _kernel_path ]
      outputs = [
        _snapshot_path,
        _stats_json_path,
      ]

      if (build_cfg.is_product) {
        script = gen_snapshot_product
      } else {
        script = gen_snapshot
      }

      args = [
        "--no_causal_async_stacks",
        "--deterministic",
        "--snapshot_kind=app-aot-elf",
        "--elf=" + rebase_path(_snapshot_path, root_build_dir),
        "--print-instructions-sizes-to=" +
            rebase_path(_stats_json_path, root_build_dir),
      ]

      # No asserts in debug or release product.
      # No asserts in non-product release
      # Yes asserts in non-product debug.
      # if (is_debug && !dart_force_product) {
      if (build_cfg.enable_asserts) {
        args += [ "--enable_asserts" ]
      }
      args += [ rebase_path(_kernel_path, root_build_dir) ]

      pool = "//build/dart:dart_pool($dart_toolchain)"
    }

    # copy the snapshot as a resource
    _snapshot_resource_target_name = "${target_name}_snapshot_resource"
    resource(_snapshot_resource_target_name) {
      sources = [ _snapshot_path ]
      outputs = [ "data/${_component_name}/app_aot_snapshot.so" ]
    }

    _component_deps += [
      ":$_snapshot_resource_target_name",
      ":$_snapshot_target_name",
    ]
  }

  fuchsia_component(target_name) {
    forward_variables_from(invoker,
                           [
                             "testonly",
                             "visibility",
                             "component_name",
                           ])
    deps = _component_deps
    manifest = _merged_manifest
  }
}