#!/usr/bin/env python2.7
# Copyright 2015 gRPC 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
#
#     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.


"""Generates the appropriate build.json data for all the proto files."""
from __future__ import print_function
import yaml
import collections
import os
import re
import sys

def update_deps(key, proto_filename, deps, deps_external, is_trans, visited):
  if not proto_filename in visited:
    visited.append(proto_filename)
    with open(proto_filename) as inp:
      for line in inp:
        imp = re.search(r'import "([^"]*)"', line)
        if not imp: continue
        imp_proto = imp.group(1)
        # This indicates an external dependency, which we should handle
        # differently and not traverse recursively
        if imp_proto.startswith('google/'):
          if key not in deps_external:
            deps_external[key] = []
          deps_external[key].append(imp_proto[:-6])
          continue
        # In case that the path is changed by copybara,
        # revert the change to avoid file error.
        if imp_proto.startswith('third_party/grpc'):
          imp_proto = imp_proto[17:]          
        if key not in deps: deps[key] = []
        deps[key].append(imp_proto[:-6])
        if is_trans:
          update_deps(key, imp_proto, deps, deps_external, is_trans, visited)

def main():
  proto_dir = os.path.abspath(os.path.dirname(sys.argv[0]))
  os.chdir(os.path.join(proto_dir, '../..'))

  deps = {}
  deps_trans = {}
  deps_external = {}
  deps_external_trans = {}
  for root, dirs, files in os.walk('src/proto'):
    for f in files:
      if f[-6:] != '.proto': continue
      look_at = os.path.join(root, f)
      deps_for = look_at[:-6]
      # First level deps
      update_deps(deps_for, look_at, deps, deps_external, False, [])
      # Transitive deps
      update_deps(deps_for, look_at, deps_trans, deps_external_trans, True, [])

  json = {
    'proto_deps': deps,
    'proto_transitive_deps': deps_trans,
    'proto_external_deps': deps_external,
    'proto_transitive_external_deps': deps_external_trans
  }

  print(yaml.dump(json))

if __name__ == '__main__':
  main()
