# Copyright 2013 The Flutter 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("//flutter/build/dart/rules.gni")
import("//flutter/common/config.gni")

is_aot_test =
    flutter_runtime_mode == "profile" || flutter_runtime_mode == "release"

# Build unit tests when any of the following are true:
# * host_toolchain: non-cross-compile, so we can run tests on the host.
# * is_mac: arm64 builds can run x64 binaries.
# * is_fuchsia: build unittests for testing on device.
declare_args() {
  enable_unittests = current_toolchain == host_toolchain || is_fuchsia || is_mac
}

# Creates a translation unit that defines the flutter::testing::GetFixturesPath
# method that tests can use to locate their fixtures.
#
# Arguments
#     assets_dir (required): The assets directory
template("fixtures_location") {
  testonly = true

  assert(defined(invoker.assets_dir), "The assets directory.")

  location_path = rebase_path(invoker.assets_dir)
  testing_assets_path = rebase_path("$root_out_dir/gen/flutter/testing/assets")
  source_path = rebase_path("//")

  # Array of source lines. We use a list to ensure a trailing newline is
  # emitted by write_file() to comply with -Wnewline-eof.
  location_source = [
    "namespace flutter { namespace testing { ",
    "const char* GetSourcePath() {return \"$source_path\";} ",
    "const char* GetFixturesPath() {return \"$location_path\";} ",
    "const char* GetTestingAssetsPath() {return \"$testing_assets_path\";} ",
    "}}",
  ]
  location_source_path = "$target_gen_dir/_fl_$target_name.cc"

  write_file(location_source_path, location_source)

  source_set(target_name) {
    public = []
    sources = [ location_source_path ]
  }
}

# Generates the Dart kernel snapshot.
#
# Arguments
#     dart_main (required): The Main Dart file.
#
#     dart_kernel (required): The path to the output kernel snapshot in the out
#                             directory.
template("dart_snapshot_kernel") {
  testonly = true

  assert(defined(invoker.dart_main), "The Dart Main file must be specified")
  assert(defined(invoker.dart_kernel),
         "The Dart Kernel file location must be specified")

  args = []
  if (flutter_runtime_mode == "release" ||
      flutter_runtime_mode == "jit_release") {
    args += [ "-Ddart.vm.product=true" ]
  }

  if (is_aot_test) {
    args += [
      "--aot",

      # type flow analysis
      "--tfa",
    ]
  }

  flutter_frontend_server(target_name) {
    testonly = true
    main_dart = invoker.dart_main
    kernel_output = invoker.dart_kernel
    extra_args = args
  }
}

# Generates an AOT snapshot from a kernel snapshot.
#
# Arguments:
#
#     dart_kernel (required): The path to the kernel snapshot.
#
#     dart_elf_filename (required): The filename of the AOT ELF snapshot.
template("dart_snapshot_aot") {
  testonly = true

  assert(defined(invoker.dart_kernel),
         "The Dart Kernel file location must be specified")

  assert(defined(invoker.dart_elf_filename),
         "The main Dart ELF filename must be specified.")

  compiled_action(target_name) {
    testonly = true

    tool = "$dart_src/runtime/bin:gen_snapshot"

    pool = "//flutter/build/dart:dart_pool"

    inputs = [ invoker.dart_kernel ]

    # Custom ELF loader is used for Mac and Windows.
    elf_object = "$target_gen_dir/assets/${invoker.dart_elf_filename}"

    loading_unit_manifest = "$target_gen_dir/assets/loading_unit_manifest.json"

    outputs = [ elf_object ]

    args = [
      "--deterministic",
      "--snapshot_kind=app-aot-elf",
      "--loading_unit_manifest=" + rebase_path(loading_unit_manifest),
      "--elf=" + rebase_path(elf_object),
      rebase_path(invoker.dart_kernel),
    ]

    forward_variables_from(invoker, [ "deps" ])
  }
}

# Generates a kernel or AOT snapshot as necessary from the main Dart file.
# Other Dart dependencies referenced by that main Dart file will be tracked.
#
# Arguments:
#
#     dart_main (required): The path to the main Dart file.
#
#     dart_kernel_filename (required): The filename of the kernel blob.
#
#     dart_elf_filename (required): The filename of the AOT ELF snapshot only if is_aot_test is true.
template("dart_snapshot") {
  assert(defined(invoker.dart_main), "The main Dart file must be specified.")
  assert(defined(invoker.dart_kernel_filename),
         "The main Dart kernel filename must be specified.")

  testonly = true

  dart_snapshot_kernel_target_name = "_dsk_$target_name"

  dart_snapshot_kernel_path =
      "$target_gen_dir/assets/${invoker.dart_kernel_filename}"

  dart_snapshot_kernel(dart_snapshot_kernel_target_name) {
    dart_main = invoker.dart_main
    dart_kernel = dart_snapshot_kernel_path
  }

  snapshot_deps = []
  snapshot_public_deps = [ ":$dart_snapshot_kernel_target_name" ]

  if (is_aot_test) {
    assert(defined(invoker.dart_elf_filename),
           "The main Dart ELF filename must be specified.")

    dart_snapshot_aot_target_name = "_dsa_$target_name"
    dart_snapshot_aot(dart_snapshot_aot_target_name) {
      dart_kernel = dart_snapshot_kernel_path
      dart_elf_filename = invoker.dart_elf_filename
      deps = [ ":$dart_snapshot_kernel_target_name" ]
    }
    snapshot_deps += [ ":$dart_snapshot_aot_target_name" ]
  }

  group(target_name) {
    testonly = true
    deps = snapshot_deps
    public_deps = snapshot_public_deps
  }
}

# Copies a (potentially empty) list of fixtures to the fixtures directory for
# the unit test.
#
# Arguments:
#
#     fixtures (required): The list of fixtures to copy.
#
#     dest (optional): When specified, the fixtures are placed under an
#                      'assets' subdirectory of this path rather than an
#                      'assets' subdirectory of target_gen_dir.
template("copy_fixtures") {
  testonly = true

  assert(defined(invoker.fixtures), "The test fixtures must be specified.")

  dest = target_gen_dir
  if (defined(invoker.dest)) {
    dest = invoker.dest
  }

  has_fixtures = false
  foreach(fixture, invoker.fixtures) {
    has_fixtures = true
  }

  if (has_fixtures) {
    copy(target_name) {
      sources = invoker.fixtures
      outputs = [ "$dest/assets/{{source_file_part}}" ]
      forward_variables_from(invoker, [ "deps" ])
    }
  } else {
    group(target_name) {
      # The copy target cannot accept an empty list.
    }
  }
}

# Specifies the fixtures to copy to a location known by the specific unit test.
# Test executable can only depend on one such target. You can use either one of
# both arguments to expand this template. If you have none, then you'll see the
# unused invoker scope error. In such cases specify the fixtures using an empty
# array.
#
# The targets which generate the outputs from these test fixtures (e.g. the
# Dart kernel snapshot) are exposed as public dependencies of the test fixture
# target. This is so that users can depend on the test fixture target directly
# and be able to access the generated outputs without needing to know about the
# internal dependency structure generated by this template.
#
# Arguments:
#
#     fixtures (optional): The list of test fixtures. An empty list may be
#                          specified.
#
#     dart_main (optional): The path to the main Dart file. If specified, it is
#                           snapshotted.
#
#     use_target_as_artifact_prefix(optional): If true, adds the target name as
#         prefix of the kernel and AOT ELF snapshot filename.
#
#     dest (optional): When specified, the fixtures are placed under an
#                      'assets' subdirectory of this path rather than an
#                      'assets' subdirectory of target_gen_dir.
template("test_fixtures") {
  dest = target_gen_dir
  if (defined(invoker.dest)) {
    dest = invoker.dest
  }

  # Not all paths use 'dest'
  not_needed([ "dest" ])

  # Even if no fixtures are present, the location of the fixtures directory
  # must always be known to tests.
  fixtures_location_target_name = "_fl_$target_name"
  fixtures_location(fixtures_location_target_name) {
    if (is_fuchsia) {
      assets_dir = "/pkg/data/assets"
    } else {
      assets_dir = "$dest/assets"
    }
  }
  test_deps = [ ":$fixtures_location_target_name" ]
  test_public_deps = []

  # If the fixtures are specified, copy them to the assets directory.
  if (defined(invoker.fixtures)) {
    copy_fixtures_target_name = "_cf_$target_name"
    copy_fixtures(copy_fixtures_target_name) {
      fixtures = invoker.fixtures
      dest = dest
      forward_variables_from(invoker, [ "deps" ])
    }
    test_public_deps += [ ":$copy_fixtures_target_name" ]
  }

  # If a Dart file is specified, snapshot it and place it in the generated
  # assets directory.
  if (defined(invoker.dart_main)) {
    if (defined(invoker.use_target_as_artifact_prefix) &&
        invoker.use_target_as_artifact_prefix) {
      artifact_prefix = "${target_name}_"
    } else {
      artifact_prefix = ""
    }
    dart_snapshot_target_name = "_ds_$target_name"
    dart_snapshot(dart_snapshot_target_name) {
      dart_main = invoker.dart_main
      dart_kernel_filename = "${artifact_prefix}kernel_blob.bin"
      if (is_aot_test) {
        dart_elf_filename = "${artifact_prefix}app_elf_snapshot.so"
      }
    }

    test_public_deps += [ ":$dart_snapshot_target_name" ]
  }

  group(target_name) {
    testonly = true
    deps = test_deps
    public_deps = test_public_deps
  }
}