# Copyright 2023 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/bazel/bazel_build_action.gni")
import("//build/bazel/bazel_workspace.gni")
import("//build/components.gni")

# Compares a GN built driver with a Bazel built driver.
#
# Example:
# ```
# verify_driver_package("verify_example_libc_driver") {
#   gn_driver_package = "//examples/drivers/v2/demo-libc:component"
#   bazel_driver_package_target =
#       "//examples/drivers/v2/demo-libc:pkg_fuchsia_package"
#   bazel_package_name = "demo_libc"
#   blobs_to_ignore = [
#     "lib/ld.so.1",
#   ]
# }
# ```
# Parameters
#
# gn_driver_package (required)
#   The GN target for the driver package
#   Type: string (GN label)
#
# bazel_driver_package_target (required)
#   The bazel target for the package containing the driver
#   Type: string (Bazel label)
#
# bazel_package_name (required)
#   The name of the bazel package being built. This is needed so that we can create
#     a gn package with the same name
#   Type: string
#
# blobs_to_ignore (optional)
#   A list of blobs to ignore during validation. The values should be the install
#     path of the blob
#
# testonly
# visibility
#
template("verify_driver_package") {
  assert(defined(invoker.gn_driver_package), "gn_driver_package is required")
  assert(defined(invoker.bazel_driver_package_target),
         "bazel_driver_package_target is required")

  labels = {
    # The gn package provided by the user
    gn_package_target_name = invoker.gn_driver_package

    # The target inside fuchsia_package which builds the manifest
    gn_package_manifest_target_name = invoker.gn_driver_package + ".pkg"

    # The bazel driver package provided by the user
    bazel_driver_package_target_name = invoker.bazel_driver_package_target

    # The bazel_build_action to build the bazel package
    bazel_action_target_name = "${target_name}.bazel_package"

    # The main target
    main_target_name = target_name
  }

  _gn_package_out_dir =
      get_label_info(labels.gn_package_manifest_target_name, "target_out_dir")
  _gn_package_name = get_label_info(labels.gn_package_target_name, "name")

  files = {
    # The built gn package manifest
    gn_package_manifest =
        "${_gn_package_out_dir}/${_gn_package_name}/package_manifest.json"

    # The bazel built package manifest in the bazel sandbox
    bazel_built_package_manifest = "{{BAZEL_TARGET_OUT_DIR}}/{{BAZEL_TARGET_NAME}}_pkg/package_manifest.json"

    # The bazel built package manifest after copying back to ninja
    bazel_ninja_package_manifest = "${target_name}/bazel_package_manifest.json"

    # The diff output file
    diff = "${target_out_dir}/${target_name}/diff"
  }

  # Build out driver package with bazel
  bazel_build_action(labels.bazel_action_target_name) {
    forward_variables_from(invoker,
                           [
                             "deps",
                             "testonly",
                           ])
    visibility = [ ":${labels.main_target_name}" ]
    bazel_target = labels.bazel_driver_package_target_name
    copy_outputs = [
      {
        bazel = files.bazel_built_package_manifest
        ninja = files.bazel_ninja_package_manifest
      },
    ]
  }

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

    # Keep inputs in sync with args below.
    inputs = [
      files.gn_package_manifest,
      "${target_out_dir}/${files.bazel_ninja_package_manifest}",
    ]
    outputs = [ files.diff ]

    deps = [
      ":${labels.bazel_action_target_name}",
      labels.gn_package_manifest_target_name,
    ]

    script = "//build/bazel/drivers/verify_driver_package.py"

    args = [
      "--gn-package-manifest",
      rebase_path(inputs[0], root_build_dir),
      "--bazel-package-manifest",
      rebase_path(inputs[1], root_build_dir),
      "--output",
      rebase_path(outputs[0], root_build_dir),
    ]

    if (defined(invoker.blobs_to_ignore)) {
      args += [ "--blobs-to-ignore" ]
      args += invoker.blobs_to_ignore
    }

    if (defined(invoker.size_check_blobs)) {
      # This is needed to soft-transition
      not_needed(invoker.size_check_blobs)
    }

    if (!is_debug) {
      # In debug mode the gn drivers are larger, we just want to check that
      # bazel doesn't grow larger than gn in this case
      args += [ "--require-exact-sizes" ]
    }
  }
}