# Copyright 2022 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")

# Runs the FIDL compiler.
#
# Parameters (see //build/fidl/fidl_ir.gni for descriptions):
#
#   available (required)
#   fidl_library_name (required)
#   fidl_target_name (required)
#   gen_dir (required)
#   json_representation (required)
#   sources (required)
#   experimental_flags
#   non_fidl_deps
#   public_deps
#   testonly
#   versioned
#   visibility
#
template("fidlc") {
  assert(defined(invoker.fidl_library_name), "fidl_library_name is required")
  assert(defined(invoker.fidl_target_name), "fidl_target_name is required")
  assert(defined(invoker.gen_dir), "gen_dir is required")
  assert(defined(invoker.json_representation),
         "json_representation is required")
  assert(defined(invoker.sources), "sources is required")

  experimental_flags = []

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

  main_target_name = target_name
  fidl_target_name = invoker.fidl_target_name

  # These paths are expected by the templates in //build/c/fidlc.gni.
  generated_binding_dir = "${invoker.gen_dir}/$fidl_target_name/c"
  fidlc_depfile_path = "$generated_binding_dir/${invoker.fidl_library_name}.d"

  libraries_file = "${invoker.gen_dir}/$fidl_target_name.libraries"
  response_file = "${invoker.gen_dir}/$target_name.args"
  response_file_target_name = "${main_target_name}_response_file"
  action(response_file_target_name) {
    forward_variables_from(invoker,
                           [
                             "applicable_licenses",
                             "testonly",
                             "public_deps",
                           ])
    visibility = [ ":*" ]

    script = "//build/fidl/gen_response_file.py"

    outputs = [
      response_file,
      libraries_file,
    ]

    args = [
             "--out-response-file",
             rebase_path(response_file, root_build_dir),
             "--out-libraries",
             rebase_path(libraries_file, root_build_dir),
             "--json",
             rebase_path(invoker.json_representation, root_build_dir),
             "--name",
             invoker.fidl_library_name,
             "--depfile",
             rebase_path(fidlc_depfile_path, root_build_dir),
             "--sources",
           ] + rebase_path(invoker.sources, root_build_dir)

    if (defined(invoker.public_deps)) {
      inputs = []
      foreach(dep, invoker.public_deps) {
        # Note: We are using the .libraries file from the dependency's
        # target_gen_dir, even though this template invocation may have received
        # a custom gen_dir for API compatibility testing. This is OK since the
        # .libraries file will be identical for all target API levels (imports
        # are not versioned, i.e. @available is not allowed on `using`).
        _dep_gen_dir = get_label_info(dep, "target_gen_dir")
        _dep_name = get_label_info(dep, "name")
        inputs += [ "$_dep_gen_dir/$_dep_name.libraries" ]
      }
      args += [ "--dep-libraries" ] + rebase_path(inputs, root_build_dir)
    }

    if (defined(invoker.versioned)) {
      args += [
        "--versioned",
        invoker.versioned,
      ]
    }
    foreach(available, invoker.available) {
      args += [
        "--available",
        available,
      ]
    }
    foreach(flag, experimental_flags) {
      args += [
        "--experimental",
        flag,
      ]
    }
  }

  compiled_action(main_target_name) {
    forward_variables_from(invoker,
                           [
                             "applicable_licenses",
                             "sources",
                             "testonly",
                             "visibility",
                           ])
    tool = "//tools/fidl/fidlc:fidlc"
    inputs = [ response_file ]
    depfile = fidlc_depfile_path
    outputs = [ invoker.json_representation ]
    mnemonic = "FIDLC"
    args = [ "@" + rebase_path(response_file, root_build_dir) ]
    if (defined(invoker.non_fidl_deps)) {
      deps = invoker.non_fidl_deps
    }
    public_deps = [ ":$response_file_target_name" ]
    if (defined(invoker.public_deps)) {
      public_deps += invoker.public_deps
    }
  }
}