# 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.

# Looks just like a generated_file() target but $outputs is like resource().
#
# A generated_resource() target is like a resource() target whose $sources
# matches the $outputs of a generated_file() target, but rolled into one.
# Using $data_deps to this generated_resource() target in each target whose
# code uses $outputs at runtime ensures that the files will be present on
# the system.  The files can have fixed contents given directly in the
# target or be generated from metadata collection, as in generated_file().
#
# Parameters
#
#   outputs
#     Required: See resource.gni.
#
# See generated_file() for other parameters.
#
template("generated_resource") {
  generated_file(target_name) {
    original_target_name = target_name
    forward_variables_from(invoker, "*", [ "metadata" ])
    assert(outputs != [] && outputs == [ outputs[0] ],
           "generated_resource() requires a single element in `outputs")

    # Select a place to generate the contents at `gn gen` time.
    file = "$target_gen_dir/$target_name"
    if (defined(output_conversion) && output_conversion == "json") {
      file += ".json"
    } else {
      file += ".txt"
    }

    # Add metadata to add that file to a filesystem image.
    metadata = {
      # Used by the distribution_manifest() template.
      distribution_entries_barrier = []
      distribution_entries = []

      # Used by zbi() template.
      zbi_input_barrier = []

      if (defined(invoker.metadata)) {
        forward_variables_from(invoker.metadata, "*")
      }

      # Stop *_manifest() and zbi_test() from picking up files or
      # zbi_input() items from the deps, but let them reach the data_deps.
      if (defined(data_deps)) {
        distribution_entries_barrier += data_deps
        zbi_input_barrier += data_deps
      }

      distribution_entries += [
        {
          source = rebase_path(file, root_build_dir)
          destination = outputs[0]
          label =
              get_label_info(":$original_target_name", "label_with_toolchain")
        },
      ]
    }

    # That static file is the actual output of this target.
    outputs = []
    outputs = [ file ]
  }
}