# 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.

import("//build/host.gni")
import("//build/rust/rustc_binary.gni")
import("//build/sdk/sdk_atom.gni")
import("//src/developer/ffx/build/ffx_action.gni")
import("//src/developer/ffx/config.gni")
import("//src/developer/ffx/lib/version/build/ffx_apply_version.gni")

# Defines an ffx-compatible subtool in the form of a rust binary target
#
# All parameters to `rustc_binary` are available, along with the additional
# parameters below.
#
# Additional Parameters
#
#    sdk_target_name (optional)
#      The target name to generate for an sdk atom definition. If not
#      set, no sdk target will be generated.
#
#    sdk_category (required if `sdk_target_name` is set)
#      The sdk category this will be installed to.
#      See `sdk_atom`'s `category` argument for more information.
#
#   sdk_area (optional)
#     [string] The API area responsible for maintaining this tool.
#     See //build/sdk/sdk_atom.gni.
#
#    sdk_deps (optional, ignored if `sdk_target_name` not set)
#      Dependencies for inclusion in the sdk. See `sdk_atom` for more
#      information on this.
#
# The following targets will be produced, in addition to any from `rustc_binary`:
#
#   `<target_name>`
#     The rust binary before applying build version information to it.
#     Output: `<output_name>_unversioned`
#
#   `<target_name>_versioned`
#     The rust binary after applying build version information to it.
#     Output: `<output_name>`
#
#   `<target_name>_metadata`
#     The json metadata for this tool that allows ffx to discover it
#     and determine compatibility information.
#     Output: `<output_name>.json`
#
#   `<target_name>_host_tool`
#     Installation of the versioned binary and metadata as a host tool.
#     Output: `host-tools/<output_name>`, `host-tools/<output_name>.json`
#
#   `<target_name>_test_data`
#     A `host_test_data` target that includes the files necessary to make sure
#     this tool is available to tests.
#
# The following target will be produced only if `sdk_target_name` is set:
#
#   `<sdk_target_name>`
#     Include the tool in the sdk as a host tool with metadata attached.
#     Output: (see `sdk_atom` for more information)
#
template("ffx_tool") {
  if (!defined(invoker.output_name)) {
    output_name = target_name
  } else {
    output_name = invoker.output_name
  }

  # targets that are part of the 'public interface' of ffx_tool
  target_versioned = "${target_name}_versioned"
  target_unversioned = target_name
  target_metadata = "${target_name}_metadata"
  target_host_tool = "${target_name}_host_tool"
  target_test_data = "${target_name}_test_data"

  # targets that are part of the private interface of ffx_tool
  # (prefixed with _ to differentiate).
  target_versioned_bin = "_${target_name}_versioned_bin"

  output_versioned = output_name
  output_unversioned = "${output_name}_unversioned"
  output_metadata = "${output_name}.json"

  assert_no_deps = []
  if (defined(invoker.assert_no_deps)) {
    assert_no_deps += invoker.assert_no_deps
  }

  # TODO(b/314822328): improve this logic to cascade properly
  if (defined(invoker.sdk_category) && invoker.sdk_category != "internal") {
    assert_no_deps += [
      "//sdk:marker-cts",
      "//sdk:marker-excluded",
      "//sdk:marker-experimental",
      "//sdk:marker-internal",
      "//sdk:marker-unknown",
    ]
  }

  # Make the rust binary
  rustc_binary(target_unversioned) {
    output_name = output_unversioned
    forward_variables_from(invoker,
                           "*",
                           [
                             "output_name",
                             "sdk_target_name",
                             "sdk_category",
                             "sdk_area",
                             "sdk_deps",
                             "assert_no_deps",
                           ])
  }

  # Replace the special linker sections containing the version information with the real values
  ffx_apply_version(target_versioned_bin) {
    output_name = output_versioned
    ffx_unversioned_binary_path = "${root_out_dir}/${output_unversioned}"
    runtime_files = [ "$root_out_dir/$output_metadata" ]
    deps = [
      ":$target_metadata",
      ":$target_unversioned",
    ]
  }

  # Create the metadata file for in-tree discovery
  ffx_action(target_metadata) {
    # Use the unversion-stamped binary to generate the metadata file.  The
    # ffx_action() template will convert these names to the correct ones by
    # adding the '_unversioned' suffix to the 'output_name'.
    #
    # This is the default, but it's set here for extra clarity.
    use_versioned_binary = false
    ffx_tool = ":$target_unversioned"
    ffx_tool_output_name = output_versioned  # without _unversioned suffix

    needs_sdk = false
    inputs = []
    outputs = [ "$root_out_dir/$output_metadata" ]
    args = [
      "metadata",
      rebase_path("$root_out_dir/$output_metadata", root_build_dir),
    ]
  }

  # Combine those into a target that represents both the versioned binary
  # and the metadata.
  group(target_versioned) {
    public_deps = [
      ":$target_metadata",
      ":$target_versioned_bin",
    ]
  }

  # Install host tool
  install_host_tools(target_host_tool) {
    deps = [ ":$target_versioned" ]
    outputs = [
      output_name,
      output_metadata,
    ]
  }

  # Install host tool and metadata as test data
  host_test_data(target_test_data) {
    forward_variables_from(invoker, [ "testonly" ])

    data_deps = [ ":$target_host_tool" ]
    sources = [
      "${host_tools_dir}/${output_metadata}",
      "${host_tools_dir}/${output_name}",
    ]
  }

  if (defined(invoker.sdk_target_name)) {
    # Add to the sdk
    file_base_root = "tools/ffx_tools"
    if (host_os == "linux" || host_os == "mac") {
      file_base_root = "tools/$current_cpu/ffx_tools"
    }

    file_base = "$file_base_root/$output_name"
    file_base_metadata = "$file_base_root/$output_metadata"

    assert(
        defined(invoker.sdk_category),
        "Must specify an sdk category if generating an sdk target for ffx tool")

    # for the moment this goes directly to sdk_atom because this is a 'weird'
    # host tool that includes a json metadata file.
    sdk_atom(invoker.sdk_target_name) {
      forward_variables_from(invoker, [ "sdk_area" ])

      id = "sdk://$file_base"

      category = invoker.sdk_category

      _target_files = {
        executable = file_base
        executable_metadata = file_base_metadata
      }

      meta = {
        dest = "$file_base-meta.json"
        schema = "ffx_tool"
        sources = [ "//build/sdk/meta/host_tool.json" ]
        value = {
          type = "ffx_tool"
          name = output_name
          root = "tools"
          files = {
          }
          target_files = {
          }
          if (current_cpu == "arm64") {
            target_files.arm64 = _target_files
          } else if (current_cpu == "x64") {
            target_files.x64 = _target_files
          } else if (current_cpu == "riscv64") {
            target_files.riscv64 = _target_files
          } else {
            assert(false, "Unknown CPU type: $current_cpu")
          }
        }
      }

      files = [
        {
          source = "$root_out_dir/$output_versioned"
          dest = file_base
        },
        {
          source = "$root_out_dir/$output_metadata"
          dest = file_base_metadata
        },
      ]

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

      non_sdk_deps = [
        ":$target_metadata",
        ":$target_versioned",
      ]
    }
  }
}