# Copyright 2026 Google LLC.
# Copyright (c) Microsoft Corporation.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Standalone GN Template for compiling TypeScript files, fully isolated inside the repository.

template("ts_library") {
  action(target_name) {
    script = "../tools/build/scripts/compile_ts.py"

    forward_variables_from(invoker, [
      "sources",
      "deps",
      "visibility",
      "inputs",
      "testonly",
    ])

    if (!defined(inputs)) {
      inputs = []
    }
    inputs += [
      "../tsconfig.base.json",
      "../node_modules/typescript/lib/tsc.js",
    ]

    if (defined(deps)) {
      foreach(dep, deps) {
        _dep_name = get_label_info(dep, "name")
        _dep_gen_dir = get_label_info(dep, "target_gen_dir")
        inputs += [
          "$_dep_gen_dir/$_dep_name-tsconfig.json",
          "$_dep_gen_dir/$_dep_name-tsconfig.json.tsbuildinfo",
        ]
      }
    }

    # Compute target generated tsconfig name and path
    _tsconfig_output = "$target_gen_dir/$target_name-tsconfig.json"

    args = [
      "--tsconfig_template", rebase_path("../tsconfig.base.json", root_build_dir),
      "--tsconfig_output", rebase_path(_tsconfig_output, root_build_dir),
      "--output_dir", rebase_path(target_gen_dir, root_build_dir),
      "--root_dir", rebase_path(".", root_build_dir),
    ]

    if (defined(invoker.es_target)) {
      args += [
        "--es-target",
        invoker.es_target,
      ]
    }

    if (defined(invoker.es_libs)) {
      args += [ "--es-libs" ] + invoker.es_libs
    }

    _no_emit = defined(invoker.no_emit) && invoker.no_emit
    if (_no_emit) {
      args += [ "--no-emit" ]
    }

    # Resolve dependency tsconfigs dynamically
    if (defined(deps)) {
      args += [ "--deps" ]
      foreach(dep, deps) {
        _dep_name = get_label_info(dep, "name")
        _dep_gen_dir = get_label_info(dep, "target_gen_dir")
        args += [ rebase_path("$_dep_gen_dir/$_dep_name-tsconfig.json", root_build_dir) ]
      }
    }

    # Append sources to compiler args
    if (defined(sources)) {
      args += [ "--sources" ] + rebase_path(sources, root_build_dir)
    }

    # Compute list of expected output files for Ninja tracking
    output_files = [
      _tsconfig_output,
      "${_tsconfig_output}.tsbuildinfo",
    ]
    if (!_no_emit && defined(sources)) {
      foreach(src, sources) {
        _fileName = get_path_info(src, "name")
        _dir = get_path_info(src, "dir")
        _rel_dir = rebase_path(_dir, ".")
        
        # Maps .ts files to compiled .js and map files in target gen directory
        output_files += [
          "$target_gen_dir/$_rel_dir/$_fileName.js",
          "$target_gen_dir/$_rel_dir/$_fileName.js.map",
          "$target_gen_dir/$_rel_dir/$_fileName.d.ts",
        ]
      }
    }

    outputs = output_files
    data = output_files

    if (defined(deps)) {
      # Expose deps to Ninja builder chain
      if (!defined(public_deps)) {
        public_deps = []
      }
      public_deps += deps
    }
  }
}