#!/usr/bin/env python3

# Copyright 2016 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.

from __future__ import print_function

import errno
import filecmp
import glob
import os
import os.path
import shutil
import subprocess
import sys
import traceback
import uuid

DEPS_FILE_CONTENT = """
# Copyright 2017 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.

# AUTO-GENERATED BY make_grpcio_tools.py!
CC_FILES={cc_files}
PROTO_FILES={proto_files}

CC_INCLUDE={cc_include}
PROTO_INCLUDE={proto_include}

{commit_hash}
"""

COMMIT_HASH_PREFIX = 'PROTOBUF_SUBMODULE_VERSION="'
COMMIT_HASH_SUFFIX = '"'

# Bazel query result prefix for expected source files in protobuf.
PROTOBUF_CC_PREFIX = '//:src/'
PROTOBUF_PROTO_PREFIX = '//:src/'

GRPC_ROOT = os.path.abspath(
    os.path.join(os.path.dirname(os.path.abspath(__file__)), '..', '..', '..'))

GRPC_PYTHON_ROOT = os.path.join(GRPC_ROOT, 'tools', 'distrib', 'python',
                                'grpcio_tools')

GRPC_PYTHON_PROTOBUF_RELATIVE_ROOT = os.path.join('third_party', 'protobuf',
                                                  'src')
GRPC_PROTOBUF = os.path.join(GRPC_ROOT, GRPC_PYTHON_PROTOBUF_RELATIVE_ROOT)
GRPC_PROTOBUF_SUBMODULE_ROOT = os.path.join(GRPC_ROOT, 'third_party',
                                            'protobuf')
GRPC_PROTOC_PLUGINS = os.path.join(GRPC_ROOT, 'src', 'compiler')
GRPC_PYTHON_PROTOBUF = os.path.join(GRPC_PYTHON_ROOT, 'third_party', 'protobuf',
                                    'src')
GRPC_PYTHON_PROTOC_PLUGINS = os.path.join(GRPC_PYTHON_ROOT, 'grpc_root', 'src',
                                          'compiler')
GRPC_PYTHON_PROTOC_LIB_DEPS = os.path.join(GRPC_PYTHON_ROOT,
                                           'protoc_lib_deps.py')

GRPC_INCLUDE = os.path.join(GRPC_ROOT, 'include')
GRPC_PYTHON_INCLUDE = os.path.join(GRPC_PYTHON_ROOT, 'grpc_root', 'include')

BAZEL_DEPS = os.path.join(GRPC_ROOT, 'tools', 'distrib', 'python',
                          'bazel_deps.sh')
BAZEL_DEPS_PROTOC_LIB_QUERY = '//:protoc_lib'
BAZEL_DEPS_COMMON_PROTOS_QUERY = '//:well_known_protos'


def protobuf_submodule_commit_hash():
    """Gets the commit hash for the HEAD of the protobuf submodule currently
     checked out."""
    cwd = os.getcwd()
    os.chdir(GRPC_PROTOBUF_SUBMODULE_ROOT)
    output = subprocess.check_output(['git', 'rev-parse', 'HEAD'])
    os.chdir(cwd)
    return output.decode("ascii").splitlines()[0].strip()


def bazel_query(query):
    print('Running "bazel query %s"' % query)
    output = subprocess.check_output([BAZEL_DEPS, query])
    return output.decode("ascii").splitlines()


def get_deps():
    """Write the result of the bazel query `query` against protobuf to
     `out_file`."""
    cc_files_output = bazel_query(BAZEL_DEPS_PROTOC_LIB_QUERY)
    cc_files = [
        name[len(PROTOBUF_CC_PREFIX):]
        for name in cc_files_output
        if name.endswith('.cc') and name.startswith(PROTOBUF_CC_PREFIX)
    ]
    proto_files_output = bazel_query(BAZEL_DEPS_COMMON_PROTOS_QUERY)
    proto_files = [
        name[len(PROTOBUF_PROTO_PREFIX):]
        for name in proto_files_output
        if name.endswith('.proto') and name.startswith(PROTOBUF_PROTO_PREFIX)
    ]
    commit_hash = protobuf_submodule_commit_hash()
    deps_file_content = DEPS_FILE_CONTENT.format(
        cc_files=cc_files,
        proto_files=proto_files,
        cc_include=repr(GRPC_PYTHON_PROTOBUF_RELATIVE_ROOT),
        proto_include=repr(GRPC_PYTHON_PROTOBUF_RELATIVE_ROOT),
        commit_hash=COMMIT_HASH_PREFIX + commit_hash + COMMIT_HASH_SUFFIX)
    return deps_file_content


def long_path(path):
    if os.name == 'nt':
        return '\\\\?\\' + path
    else:
        return path


def main():
    os.chdir(GRPC_ROOT)

    for source, target in [(GRPC_PROTOBUF, GRPC_PYTHON_PROTOBUF),
                           (GRPC_PROTOC_PLUGINS, GRPC_PYTHON_PROTOC_PLUGINS),
                           (GRPC_INCLUDE, GRPC_PYTHON_INCLUDE)]:
        for source_dir, _, files in os.walk(source):
            target_dir = os.path.abspath(
                os.path.join(target, os.path.relpath(source_dir, source)))
            try:
                os.makedirs(target_dir)
            except OSError as error:
                if error.errno != errno.EEXIST:
                    raise
            for relative_file in files:
                source_file = os.path.abspath(
                    os.path.join(source_dir, relative_file))
                target_file = os.path.abspath(
                    os.path.join(target_dir, relative_file))
                shutil.copyfile(source_file, target_file)

    try:
        print('Invoking "bazel query" to gather the protobuf dependencies.')
        protoc_lib_deps_content = get_deps()
    except Exception as error:
        # We allow this script to succeed even if we couldn't get the dependencies,
        # as then we can assume that even without a successful bazel run the
        # dependencies currently in source control are 'good enough'.
        sys.stderr.write("Got non-fatal error:\n")
        traceback.print_exc(file=sys.stderr)
        return
    # If we successfully got the dependencies, truncate and rewrite the deps file.
    with open(GRPC_PYTHON_PROTOC_LIB_DEPS, 'w') as deps_file:
        deps_file.write(protoc_lib_deps_content)
    print('File "%s" updated.' % GRPC_PYTHON_PROTOC_LIB_DEPS)
    print('Done.')


if __name__ == '__main__':
    main()