# 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/fidl/toolchain.gni")
import("//build/rust/toolchain.gni")

fidl_rust_tools_dir = "//prebuilt/third_party/rust_tools/$host_platform"

# Generates some Rust bindings for a FIDL library.
#
# The parameters for this template are defined in //build/fidl/fidl.gni. The
# relevant parameters in this template are:
#   - name.

template("fidl_rust") {
  assert(current_toolchain == rust_toolchain,
         "This template can only be used in $rust_toolchain.")

  not_needed(invoker, [ "sources" ])

  main_target_name = target_name
  generation_target_name = "${target_name}_rust_generate"

  library_name = target_name
  if (defined(invoker.name)) {
    library_name = invoker.name
  }

  underscore_name = "fidl_" + string_replace(library_name, ".", "_")

  fidl_target_gen_dir =
      get_label_info(":bogus($fidl_toolchain)", "target_gen_dir")
  filename = "$fidl_target_gen_dir/$main_target_name/$underscore_name.rs"
  json_representation = "$fidl_target_gen_dir/$target_name.fidl.json"

  compiled_action(generation_target_name) {
    forward_variables_from(invoker, [ "testonly" ])

    visibility = [
      ":*",
      "//tools/fidl/fidlgen_rust:*",
    ]

    tool = "//tools/fidl/fidlgen_rust"

    # This action depends on rustfmt and rustfmt.toml, but instead of listing
    # them here we do so in //tools/fidl/fidlgen_rust/BUILD.gn.
    inputs = [ json_representation ]

    outputs = [ filename ]

    args = [
      "--json",
      rebase_path(json_representation, root_build_dir),
      "--output-filename",
      rebase_path(filename, root_build_dir),
      "--rustfmt",
      rebase_path("$fidl_rust_tools_dir/bin/rustfmt", root_build_dir),
      "--rustfmt-config",
      rebase_path("//rustfmt.toml", root_build_dir),
    ]

    deps = [ ":$main_target_name($fidl_toolchain)" ]

    metadata = {
      generated_sources = rebase_path(outputs, root_build_dir)
    }
  }

  group(main_target_name) {
    forward_variables_from(invoker,
                           [
                             "public_deps",
                             "testonly",
                             "visibility",
                           ])

    deps = [ ":$generation_target_name" ]

    if (defined(invoker.deps)) {
      deps += invoker.deps
    }
  }
}