# Copyright 2020 The Pigweed Authors
#
# 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
#
#     https://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.

import("//build_overrides/pigweed.gni")

import("$dir_pw_build/python_action.gni")

# Updates a tokenized string database in the source tree with artifacts from one
# or more targets. Other database files may also be used.
#
# The database file must exist. A CSV or binary database can be created with the
# pw/pw_tokenizer/database.py tool. An empty CSV database file can be also
# created as a starting point.
#
# Args:
#   database: if updating a database, path to an existing database in the source
#       tree; optional if creating a database, but may provide an output
#       directory path to override the default of
#       "$target_gen_dir/$target_name.[csv/binary]"
#   create: if specified, create a database instead of updating one; 'create'
#       must be set to one of the supported database types: "csv" or "binary"
#   targets: GN targets (executables or libraries) from which to add tokens;
#       these targets are added to deps
#   optional_targets: GN targets from which to add tokens, if the output files
#       already exist; these targets are NOT added to deps
#   input_databases: paths to other database files from which to add tokens
#   deps: GN targets to build prior to generating the database; artifacts from
#       these targets are NOT implicitly used for database generation
#   domain: if provided, extract strings from tokenization domains matching this
#       regular expression
#
template("pw_tokenizer_database") {
  assert(defined(invoker.database) || defined(invoker.create),
         "pw_tokenizer_database requires a 'database' variable, unless " +
             "'create' is specified")

  if (defined(invoker.create)) {
    assert(invoker.create == "csv" || invoker.create == "binary",
           "If provided, 'create' must be \"csv\" or \"binary\"")
    _create = invoker.create
  } else {
    _create = ""
  }

  if (defined(invoker.database)) {
    _database = invoker.database
  } else {
    _database = "$target_gen_dir/$target_name.${invoker.create}"
  }
  if (defined(invoker.targets)) {
    _targets = invoker.targets
  } else {
    _targets = []
  }

  if (defined(invoker.optional_targets)) {
    _optional_targets = invoker.optional_targets
  } else {
    _optional_targets = []
  }

  if (defined(invoker.input_databases)) {
    _input_databases = invoker.input_databases
  } else {
    _input_databases = []
  }

  if (defined(invoker.domain)) {
    _domain = "#" + invoker.domain
  } else {
    _domain = ""
  }

  if (_targets == [] && _optional_targets == []) {
    # If no targets were specified, the domain will not be used, which is OK.
    not_needed([ "_domain" ])
  }

  # Restrict parallelism for updating this database file to one thread. This
  # makes it safe to update it from multiple toolchains.
  pool("$target_name._pool") {
    depth = 1
  }

  pw_python_action(target_name) {
    script = "$dir_pw_tokenizer/py/pw_tokenizer/database.py"
    pool = ":$target_name._pool"

    inputs = _input_databases

    if (_create == "") {
      args = [ "add" ]
      inputs += [ _database ]
      stamp = true
    } else {
      args = [
        "create",
        "--force",
        "--type",
        _create,
      ]
      outputs = [ _database ]
    }

    args += [
      "--database",
      rebase_path(_database),
    ]
    args += rebase_path(_input_databases)

    foreach(target, _targets) {
      args += [ "<TARGET_FILE($target)>$_domain" ]
    }

    # For optional targets, the build outputs may not exist, since they aren't
    # added to deps. Use TARGET_FILE_IF_EXISTS to handle this.
    foreach(target, _optional_targets) {
      args += [ "<TARGET_FILE_IF_EXISTS($target)>$_domain" ]
    }

    deps = _targets

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