# 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/json/validate_json.gni")
import("//build/python/python_action.gni")
import("config.gni")
import("meta/version.gni")
import("sdk_molecule.gni")

# Prepare a collection of elements to be published in an IDK.
#
# This creates the $BUILD_DIR/sdk/exported/{sdk_name}/ directory, which will
# follow the standard IDK layout, including a top-level meta/manifest.json
# file describing all atoms in the collection using the standard IDK schema.
#
# It also writes the $BUILD_DIR/sdk/manifest/{sdk_name} file, as an internal
# SDK manifest describing all atoms as well. Note that this format is internal
# to the build system, and should not be used outside of it (though it is
# ok for `ffx` to use that from a Fuchsia checkout).
#
# If `generate_archive` is true, this will also create a compressed tarball
# under $BUILD_DIR/sdk/archive/{sdk_name}.tar.gz, which will store the same
# files as the exported directory described above.
#
# This last feature is only provided for legacy reasons and will be removed
# soon. IDK archives should be generated with idk_archive() instead.
#
# Parameters
#
#   id (optional)
#     An opaque identifier for the SDK.
#     Defaults to the empty string.
#
#   category (required)
#     Describes the minimum category that atoms in this SDK must have.
#     See //build/sdk/sdk_atom.gni for possible values.
#
#   generate_archive (optional)
#     Boolean. Set to true to generate a compressed archive for this collection.
#     This feature is deprecated and will be removed when all clients
#     will rely on IDK archives instead. Defaults to false.
#
#   deps
#     A list of sdk_atom() and sdk_molecule() targets that will be walked to
#     collect all SDK atom dependencies for this collection.
#
#   testonly
#     Usual GN meaning.
#
template("sdk_collection") {
  assert(defined(invoker.category), "Must define an SDK category")

  # Compute target and host triples, which will be written to the
  # top-level meta/manifest.json file for this collection.
  target_triple = target_cpu
  if (host_cpu == "x64") {
    host_triple_cpu = "x86_64"
  } else if (host_cpu == "arm64") {
    host_triple_cpu = "aarch64"
  } else {
    assert(false, "Unrecognized host CPU: $host_cpu")
  }
  if (host_os == "linux") {
    host_triple_os = "linux-gnu"
  } else if (host_os == "mac") {
    host_triple_os = "apple-darwin"
  } else if (host_os == "fuchsia") {
    host_triple_os = "fuchsia"
  } else {
    assert(false, "Unrecognized host OS: $host_os")
  }
  host_triple = "$host_triple_cpu-$host_triple_os"

  # The name used for this collection's output directory and archives.
  sdk_name = target_name

  # Labels and file paths for all targets generated by this template.
  labels = {
    export = "${target_name}_export"
    final_archive = "${target_name}_archive"
    final_manifest = "${target_name}_final_manifest"
    local_archive = "${target_name}_local_archive"
    local_manifest = "${target_name}_molecule"
    main = target_name
    sdk_meta = "${target_name}_sdk_meta"
    tarmaker_manifest = "${target_name}_tarmaker_manifest"
    verify_manifest = "${target_name}_verify_manifest"
    verify_sdk_meta = "${target_name}_verify_sdk_meta"
  }

  files = {
    final_archive = "${root_out_dir}/sdk/archive/${sdk_name}.tar.gz"
    final_manifest = "$root_out_dir/sdk/manifest/$sdk_name"
    local_archive = "$target_gen_dir/$target_name.tar.gz"
    local_manifest = "$target_gen_dir/${labels.main}.sdk"
    sdk_meta = "$target_gen_dir/$sdk_name.sdk_meta.json"
    tarmaker_manifest = "$target_gen_dir/${sdk_name}.tarmaker_manifest"
  }

  # Generates an internal molecule target, which creates an internal SDK
  # manifest file describing all atoms in it.
  sdk_molecule(labels.local_manifest) {
    # Do not expose this molecule to other labels. Depending directly on the
    # contents of an SDK foregoes API verification, which is not desirable.
    visibility = [ ":*" ]

    # Ensure the internal manifest is named foo.sdk instead of foo_molecule.sdk
    output_name = labels.main

    forward_variables_from(invoker,
                           [
                             "assert_no_deps",
                             "category",
                             "deps",
                             "testonly",
                           ])

    if (!defined(deps)) {
      deps = []
    }
    deps += [ "//build/sdk/meta" ]
  }

  # Copies the manifest to a central location + verify the collection API if
  # needed.
  copy(labels.final_manifest) {
    forward_variables_from(invoker, [ "testonly" ])

    sources = [ files.local_manifest ]

    outputs = [ files.final_manifest ]

    deps = [ ":${labels.local_manifest}" ]

    metadata = {
      # Used by distribution_manifest() template. Ensure that dependencies are not
      # installed into Fuchsia packages that depend on the current target.
      distribution_entries_barrier = []
    }
  }

  # Verifies that the manifest is valid.
  validate_json(labels.verify_manifest) {
    forward_variables_from(invoker, [ "testonly" ])

    data = files.final_manifest

    schema = "//build/sdk/manifest_schema.json"

    deps = [ ":${labels.final_manifest}" ]
  }

  # Generates a metadata file (meta/manifest.json) describing the various
  # parts of the SDK collection.
  python_action(labels.sdk_meta) {
    forward_variables_from(invoker, [ "testonly" ])

    binary_label = "//build/sdk:generate_meta"

    inputs = [ files.local_manifest ]

    outputs = [ files.sdk_meta ]

    args = [
      "--manifest",
      rebase_path(files.local_manifest, root_build_dir),
      "--meta",
      rebase_path(files.sdk_meta, root_build_dir),
      "--target-arch",
      target_triple,
      "--host-arch",
      host_triple,
      "--schema-version",
      sdk_metadata_schema_version,
    ]

    if (defined(invoker.id) && invoker.id != "") {
      args += [
        "--id",
        invoker.id,
      ]
    }

    public_deps = [ ":${labels.local_manifest}" ]
  }

  # Verifies that the metadata manifest is valid.
  validate_json(labels.verify_sdk_meta) {
    forward_variables_from(invoker, [ "testonly" ])

    data = files.sdk_meta

    schema = "//build/sdk/meta/manifest.json"
    sources = [
      # This file is imported by all schemas.
      "//build/sdk/meta/common.json",
    ]

    public_deps = [ ":${labels.sdk_meta}" ]
  }

  additional_archive_files = [
    {
      source = files.sdk_meta
      dest = "meta/manifest.json"
      deps = [ ":${labels.sdk_meta}" ]
    },
  ]

  # Generate an input tarmaker manifest that will be used to create
  # a tarball archive from the content listed in final_manifest.
  python_action(labels.tarmaker_manifest) {
    forward_variables_from(invoker, [ "testonly" ])

    binary_label = "//build/sdk:generate_archive_manifest"

    inputs = [ files.final_manifest ]

    outputs = [ files.tarmaker_manifest ]

    args = [
      "--manifest",
      rebase_path(inputs[0], root_build_dir),
      "--output",
      rebase_path(outputs[0], root_build_dir),
    ]

    deps = [ ":${labels.final_manifest}" ]

    foreach(file, additional_archive_files) {
      inputs += [ file.source ]
      args += [
        "--mapping",
        file.dest,
        rebase_path(file.source, root_build_dir),
      ]
      deps += file.deps
    }
  }

  # Populate the content of the $BUILD_DIR/sdk/exported/{name}/
  # directory from the content of the archive manifest.
  action(labels.export) {
    forward_variables_from(invoker, [ "testonly" ])

    script = "//build/sdk/export_sdk.py"

    inputs = [ files.tarmaker_manifest ]

    _out_dir = "$root_out_dir/sdk/exported/$sdk_name"
    _stamp_file = "$target_gen_dir/$target_name.exported"

    outputs = [
      _stamp_file,
      "$_out_dir/meta/manifest.json",
    ]

    depfile = "${_stamp_file}.d"

    args = [
      "--out-dir",
      rebase_path(_out_dir, root_build_dir),
      "--stamp-file",
      rebase_path(_stamp_file, root_build_dir),
      "--manifest",
      rebase_path(files.tarmaker_manifest, root_build_dir),
      "--depfile",
      rebase_path(depfile, root_build_dir),
    ]

    deps = [ ":${labels.tarmaker_manifest}" ]
  }

  _generate_archive =
      defined(invoker.generate_archive) && invoker.generate_archive

  # Generates the local archive, then copy it to its final location.
  compiled_action(labels.local_archive) {
    forward_variables_from(invoker, [ "testonly" ])

    tool = "//build/tools/tarmaker"

    inputs = [ files.tarmaker_manifest ]

    outputs = [ files.local_archive ]

    args = [
      "-manifest",
      rebase_path(inputs[0], root_build_dir),
      "-output",
      rebase_path(outputs[0], root_build_dir),
    ]

    deps = [ ":${labels.tarmaker_manifest}" ]
  }

  copy(labels.final_archive) {
    forward_variables_from(invoker, [ "testonly" ])

    sources = [ files.local_archive ]

    outputs = [ files.final_archive ]

    public_deps = [ ":${labels.local_archive}" ]

    metadata = {
      sdk_archives = [
        {
          name = sdk_name
          os = current_os
          cpu = current_cpu
          label = get_label_info(":$target_name", "label_with_toolchain")
          path = rebase_path(files.final_archive, root_build_dir)
        },
      ]
    }
  }

  group(labels.main) {
    forward_variables_from(invoker,
                           [
                             "testonly",
                             "visibility",
                           ])

    deps = [
      ":${labels.verify_manifest}",
      ":${labels.verify_sdk_meta}",
    ]

    public_deps = [
      ":${labels.export}",
      ":${labels.final_manifest}",
    ]
    if (_generate_archive) {
      public_deps += [ ":${labels.final_archive}" ]
    }

    # TODO(https://fxbug.dev/42174965): Block all metadata traversals such as the following:
    # metadata = {
    #   expect_includes_barrier = []
    # }
  }
}