# Copyright 2021 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/rustc_library.gni")
import("//build/sdk/sdk_atom_alias.gni")

template("_fidl_banjo_c") {
  c_target_name = "${target_name}_banjo_c"
  c_fidlgen_target_name = "$c_target_name.gen"
  c_config_target_name = "$c_target_name.config"

  ir_target_name = get_label_info(invoker.fidl_library, "name")
  ir_gen_dir = get_label_info(invoker.fidl_library, "target_gen_dir")
  ir_file = "$ir_gen_dir/$ir_target_name.fidl.json"

  c_header_path = string_replace(invoker.library_name, ".", "/")
  c_header_path = string_replace(c_header_path, "_", "-")
  c_header_include_base = "$target_gen_dir/$c_target_name"
  c_header_file = "$c_header_include_base/$c_header_path/c/banjo.h"

  # Run fidlgen_banjo on the IR and generate C code.
  compiled_action(c_fidlgen_target_name) {
    forward_variables_from(invoker, [ "testonly" ])

    tool = "//src/devices/tools/fidlgen_banjo:bin"
    tool_output_name = "fidlgen_banjo"

    inputs = [ ir_file ]

    outputs = [ c_header_file ]

    deps = [ invoker.fidl_library ]

    args = [
      "--ir",
      rebase_path(ir_file, root_build_dir),
      "--output",
      rebase_path(c_header_file, root_build_dir),
      "--backend",
      "c",
    ]
  }

  # This config ensures dependents can find the generated header within the
  # output directory.
  config(c_config_target_name) {
    include_dirs = [ c_header_include_base ]
  }

  # Exposes the bindings as C sources to the rest of the build.
  # Eventually this target will be surfaced via the `fidl` template.
  source_set(c_target_name) {
    forward_variables_from(invoker, [ "testonly" ])

    public = [ c_header_file ]

    public_configs = [ ":$c_config_target_name" ]

    deps = [ ":$c_fidlgen_target_name" ]

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

    public_deps = []
    if (defined(invoker.public_deps)) {
      foreach(dep, invoker.public_deps) {
        _name = get_label_info(dep, "name")
        _dir = get_label_info(dep, "dir")
        public_deps += [ "$_dir:${_name}_banjo_c" ]
      }
    }
  }
}

template("_fidl_banjo_cpp") {
  c_target_name = "${target_name}_banjo_c"
  cpp_target_name = "${target_name}_banjo_cpp"
  cpp_mock_target_name = "${target_name}_banjo_cpp_mock"
  cpp_public_fidlgen_target_name = "$cpp_target_name.public.gen"
  cpp_private_fidlgen_target_name = "$cpp_target_name.private.gen"
  cpp_mock_fidlgen_target_name = "$cpp_target_name.mock.gen"

  ir_target_name = get_label_info(invoker.fidl_library, "name")
  ir_gen_dir = get_label_info(invoker.fidl_library, "target_gen_dir")
  ir_file = "$ir_gen_dir/$ir_target_name.fidl.json"

  cpp_header_path = string_replace(invoker.library_name, ".", "/")
  cpp_header_path = string_replace(cpp_header_path, "_", "-")

  # Note: C++ headers are explicitly installed in the same location as their C
  # counterparts as they expect to be colocated.
  cpp_header_include_base = "$target_gen_dir/$c_target_name"
  cpp_public_file = "$cpp_header_include_base/$cpp_header_path/cpp/banjo.h"
  cpp_private_file =
      "$cpp_header_include_base/$cpp_header_path/cpp/banjo-internal.h"
  cpp_mock_file = "$cpp_header_include_base/$cpp_header_path/cpp/banjo-mock.h"

  # Run fidlgen_banjo on the IR and generate C++ code.

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

    tool = "//src/devices/tools/fidlgen_banjo:bin"
    tool_output_name = "fidlgen_banjo"

    inputs = [ ir_file ]

    outputs = [ cpp_public_file ]

    deps = [ invoker.fidl_library ]

    args = [
      "--ir",
      rebase_path(ir_file, root_build_dir),
      "--output",
      rebase_path(cpp_public_file, root_build_dir),
      "--backend",
      "cpp",
    ]
  }

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

    tool = "//src/devices/tools/fidlgen_banjo:bin"
    tool_output_name = "fidlgen_banjo"

    inputs = [ ir_file ]

    outputs = [ cpp_private_file ]

    deps = [ invoker.fidl_library ]

    args = [
      "--ir",
      rebase_path(ir_file, root_build_dir),
      "--output",
      rebase_path(cpp_private_file, root_build_dir),
      "--backend",
      "cpp_internal",
    ]
  }

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

    tool = "//src/devices/tools/fidlgen_banjo:bin"
    tool_output_name = "fidlgen_banjo"

    inputs = [ ir_file ]

    outputs = [ cpp_mock_file ]

    deps = [ invoker.fidl_library ]

    args = [
      "--ir",
      rebase_path(ir_file, root_build_dir),
      "--output",
      rebase_path(cpp_mock_file, root_build_dir),
      "--backend",
      "cpp_mock",
    ]
  }

  source_set(cpp_target_name) {
    forward_variables_from(invoker, [ "testonly" ])

    public = [ cpp_public_file ]

    sources = [ cpp_private_file ]

    # Let dependencies use `#include "$file_stem.h"`.
    public_configs = [ "//build/c:banjo_gen_config" ]

    deps = [
      ":$cpp_private_fidlgen_target_name",
      ":$cpp_public_fidlgen_target_name",
      "//src/zircon/lib/zircon",
    ]

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

    public_deps = [
      ":$c_target_name",

      # The generated headers #include <ddk/*.h> and #include <ddktl/*.h>
      # files from the libraries (that aren't generated).
      "//src/lib/ddk",
      "//src/lib/ddktl",
      "//zircon/system/ulib/zx",
    ]

    if (defined(invoker.public_deps)) {
      foreach(dep, invoker.public_deps) {
        _name = get_label_info(dep, "name")
        _dir = get_label_info(dep, "dir")
        deps += [ "$_dir:${_name}_banjo_cpp" ]
      }
    }
  }

  source_set(cpp_mock_target_name) {
    testonly = true

    public = [ cpp_mock_file ]

    deps = [ ":$cpp_mock_fidlgen_target_name" ]

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

    public_deps = [
      ":$cpp_target_name",
      "//zircon/system/ulib/fbl",
      "//zircon/system/ulib/mock-function",
      "//zircon/system/ulib/zxtest",
    ]

    if (defined(invoker.public_deps)) {
      foreach(dep, invoker.public_deps) {
        _name = get_label_info(dep, "name")
        _dir = get_label_info(dep, "dir")
        deps += [ "$_dir:${_name}_banjo_cpp_mock" ]
      }
    }
  }

  if (current_toolchain != fidl_toolchain) {
    # Set up an SDK item for this library
    if (defined(invoker.sdk_category) && invoker.sdk_category != "excluded") {
      # Instead of depending on the generated bindings, set up a dependency on
      # the original library.
      sdk_target_name = "${cpp_target_name}_sdk"
      original_library_name = "${target_name}_sdk"
      sdk_atom_alias(sdk_target_name) {
        atom = ":$original_library_name($fidl_toolchain)"
      }
    }
  }
}

template("_fidl_banjo_rust") {
  rust_target_name = "${target_name}_banjo_rust"
  rust_fidlgen_target_name = "$rust_target_name.gen"

  ir_target_name = get_label_info(invoker.fidl_library, "name")
  ir_gen_dir = get_label_info(invoker.fidl_library, "target_gen_dir")
  ir_file = "$ir_gen_dir/$ir_target_name.fidl.json"

  rust_library_name = "banjo_" + string_replace(invoker.library_name, ".", "_")
  rust_file_name = "$rust_library_name.rs"
  rust_source_file = "$target_gen_dir/$rust_target_name/$rust_file_name"

  # Run fidlgen_banjo on the IR and generate Rust code.
  compiled_action(rust_fidlgen_target_name) {
    forward_variables_from(invoker, [ "testonly" ])

    tool = "//src/devices/tools/fidlgen_banjo:bin"
    tool_output_name = "fidlgen_banjo"

    inputs = [ ir_file ]

    outputs = [ rust_source_file ]

    deps = [ invoker.fidl_library ]

    args = [
      "--ir",
      rebase_path(ir_file, root_build_dir),
      "--output",
      rebase_path(rust_source_file, root_build_dir),
      "--backend",
      "rust",
    ]
  }

  rustc_library(rust_target_name) {
    forward_variables_from(invoker, [ "testonly" ])

    name = rust_library_name
    version = "0.1.0"
    edition = "2018"

    source_root = rebase_path(rust_source_file)
    sources = [ rust_source_file ]

    output_dir = "$target_out_dir/banjo/$rust_target_name"

    non_rust_deps = [ ":$rust_fidlgen_target_name" ]

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

    deps = [
      "//src/lib/fuchsia-async",
      "//src/lib/zircon/rust:fuchsia-zircon",
      "//third_party/rust_crates:futures",
    ]

    configs -= [ "//build/config/rust:allow_unused_results" ]

    if (defined(invoker.public_deps)) {
      foreach(dep, invoker.public_deps) {
        _name = get_label_info(dep, "name")
        _dir = get_label_info(dep, "dir")
        deps += [ "$_dir:${_name}_banjo_rust" ]
      }
    }
  }
}

template("fidl_banjo") {
  not_needed(invoker, "*")
  params = {
    forward_variables_from(invoker,
                           [
                             "deps",
                             "public_deps",
                             "sdk_category",
                             "testonly",
                           ])
  }
  params.fidl_library = ":$target_name($fidl_toolchain)"
  params.library_name = target_name
  if (defined(invoker.name)) {
    params.library_name = invoker.name
  }
  if (defined(invoker.sdk_category)) {
    params.sdk_category = invoker.sdk_category
  }
  _fidl_banjo_c(target_name) {
    forward_variables_from(params, "*")
  }

  _fidl_banjo_cpp(target_name) {
    forward_variables_from(params, "*")
  }

  _fidl_banjo_rust(target_name) {
    forward_variables_from(params, "*")
  }
}