# Copyright 2019 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("cmc.gni")

# Define a Fuchsia component() target.
#
# The target generates a json file defining the component contents. This
# component is used to assemble components into distributions, such as packages.
#
# Parameters
#
#   deps
#     Optional: Dependencies for this component. These dependencies are external
#       to the component, such as other components that are used via FIDL.
#
#   data_deps
#     Required: Dependencies examined for metadata. These dependencies define
#     the contents of the component. These are executables and libraries.
#
#   manifest
#     Required: The source manifest file for this component. This can be
#     either a v1 (.cmx) or v2 (.cml) manifest. v2 manifests must have
#     the file extension ".cml".
#
#   manifest_output_name
#     Optional: The name of the manifest file contained in the distribution
#     that this component is included in.
#
#     By default, for v1 (.cmx) manifests, the output name is the same as
#     `manifest` with the extension ".cmx", and for v2 (.cml) manifests,
#     with the extension ".cm".
#
#     The output name should have no extension or prefixes. The resulting
#     filename will have an extension that is determined by `manifest_version`.
#
#     For example, if `manifest` is "foo.cmx" and `manifest_output_name` is
#     "bar", the filename will be "bar.cmx". If `manifest` is "foo.cml"
#     (a v2 manifest), the filename will be "bar.cm".
#
#   manifest_version
#     Optional: The version of the source `manifest` file. This can be either
#     "v1" for .cmx manifests, or "v2" for .cml manifests.
#
#     By default, the version is guessed from the `manifest` file extension.
#
#   resources
#     Optional: Non-executable resources to include in the component.
#
template("fuchsia_component") {
  forward_variables_from(invoker,
                         [
                           "manifest",
                           "manifest_output_name",
                           "manifest_version",
                         ])
  assert(defined(manifest), "manifest file required for this component")

  if (!defined(manifest_output_name)) {
    manifest_output_name = get_path_info(manifest, "name")
  }

  # Guess `manifest_version` from the `manifest` file extension.
  if (!defined(manifest_version)) {
    manifest_extension = get_path_info(manifest, "extension")
    if (manifest_extension == "cmx") {
      manifest_version = "v1"
    } else if (manifest_extension == "cml") {
      manifest_version = "v2"
    }
  }

  assert(
      defined(manifest_version),
      "manifest_version required and could not be determined from manifest file extension")
  assert(manifest_version == "v1" || manifest_version == "v2",
         "manifest_version must be one of: \"v1\", \"v2\"")

  if (manifest_version == "v1") {
    manifest_source = rebase_path(manifest)
  } else if (manifest_version == "v2") {
    compiled_manifest =
        "compiled_" + target_name + "_" + get_path_info(manifest, "file")

    cmc_compile(compiled_manifest) {
      manifest = rebase_path(manifest)
    }

    compiled_manifest_outputs = get_target_outputs(":$compiled_manifest")
    manifest_source = rebase_path(compiled_manifest_outputs[0])
  }

  group(target_name) {
    forward_variables_from(invoker,
                           [
                             "deps",
                             "data_deps",
                             "friend",
                             "resources",
                             "testonly",
                             "visibility",
                           ])
    assert(defined(data_deps),
           "data_deps required to define contents of this component")

    if (!defined(resources)) {
      resources = []
    }

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

    if (manifest_version == "v2") {
      deps += [ ":$compiled_manifest" ]
    }

    component_contents = []

    foreach(dep, data_deps) {
      component_contents += [
        {
          type = "dep"
          source = rebase_path(dep)
        },
      ]
    }

    foreach(resource, resources) {
      component_contents += [
        {
          type = "resource"
          source = rebase_path(resource.path)
        },
      ]
    }

    # TODO(fxb/42370): add cmx validation

    component_contents += [
      {
        type = "manifest"
        source = manifest_source
        output_name = manifest_output_name
        manifest_version = manifest_version
      },
    ]

    # The contents of the component are enumerated in the
    # metadata. The metadata is processed by the package
    # template, or the distribution rule.
    metadata = {
      contents = [ component_contents ]
    }
  }
}