#!/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.

import ast
import os
import re
import subprocess
import sys

os.chdir(os.path.join(os.path.dirname(sys.argv[0]), '../../..'))

git_hash_pattern = re.compile('[0-9a-f]{40}')

# Parse git hashes from submodules
git_submodules = subprocess.check_output(
    'git submodule', shell=True).decode().strip().split('\n')
git_submodule_hashes = {
    re.search(git_hash_pattern, s).group() for s in git_submodules
}

_BAZEL_SKYLIB_DEP_NAME = 'bazel_skylib'
_BAZEL_TOOLCHAINS_DEP_NAME = 'bazel_toolchains'
_BAZEL_COMPDB_DEP_NAME = 'bazel_compdb'
_TWISTED_TWISTED_DEP_NAME = 'com_github_twisted_twisted'
_YAML_PYYAML_DEP_NAME = 'com_github_yaml_pyyaml'
_TWISTED_INCREMENTAL_DEP_NAME = 'com_github_twisted_incremental'
_ZOPEFOUNDATION_ZOPE_INTERFACE_DEP_NAME = 'com_github_zopefoundation_zope_interface'
_TWISTED_CONSTANTLY_DEP_NAME = 'com_github_twisted_constantly'

_GRPC_DEP_NAMES = [
    'upb', 'boringssl', 'zlib', 'com_google_protobuf', 'com_google_googletest',
    'rules_cc', 'com_github_google_benchmark', 'com_github_cares_cares',
    'com_google_absl', 'io_opencensus_cpp', 'envoy_api', _BAZEL_SKYLIB_DEP_NAME,
    _BAZEL_TOOLCHAINS_DEP_NAME, _BAZEL_COMPDB_DEP_NAME,
    _TWISTED_TWISTED_DEP_NAME, _YAML_PYYAML_DEP_NAME,
    _TWISTED_INCREMENTAL_DEP_NAME, _ZOPEFOUNDATION_ZOPE_INTERFACE_DEP_NAME,
    _TWISTED_CONSTANTLY_DEP_NAME, 'io_bazel_rules_go',
    'build_bazel_rules_apple', 'build_bazel_apple_support', 'libuv',
    'com_googlesource_code_re2', 'bazel_gazelle', 'opencensus_proto',
    'com_envoyproxy_protoc_gen_validate', 'com_google_googleapis',
    'com_google_libprotobuf_mutator'
]

_GRPC_BAZEL_ONLY_DEPS = [
    'upb',  # third_party/upb is checked in locally
    'rules_cc',
    'com_google_absl',
    'io_opencensus_cpp',
    _BAZEL_SKYLIB_DEP_NAME,
    _BAZEL_TOOLCHAINS_DEP_NAME,
    _BAZEL_COMPDB_DEP_NAME,
    _TWISTED_TWISTED_DEP_NAME,
    _YAML_PYYAML_DEP_NAME,
    _TWISTED_INCREMENTAL_DEP_NAME,
    _ZOPEFOUNDATION_ZOPE_INTERFACE_DEP_NAME,
    _TWISTED_CONSTANTLY_DEP_NAME,
    'io_bazel_rules_go',
    'build_bazel_rules_apple',
    'build_bazel_apple_support',
    'com_googlesource_code_re2',
    'bazel_gazelle',
    'opencensus_proto',
    'com_envoyproxy_protoc_gen_validate',
    'com_google_googleapis',
    'com_google_libprotobuf_mutator'
]


class BazelEvalState(object):

    def __init__(self, names_and_urls, overridden_name=None):
        self.names_and_urls = names_and_urls
        self.overridden_name = overridden_name

    def http_archive(self, **args):
        self.archive(**args)

    def new_http_archive(self, **args):
        self.archive(**args)

    def bind(self, **args):
        pass

    def existing_rules(self):
        if self.overridden_name:
            return [self.overridden_name]
        return []

    def archive(self, **args):
        assert self.names_and_urls.get(args['name']) is None
        if args['name'] in _GRPC_BAZEL_ONLY_DEPS:
            self.names_and_urls[args['name']] = 'dont care'
            return
        url = args.get('url', None)
        if not url:
            # we will only be looking for git commit hashes, so concatenating
            # the urls is fine.
            url = ' '.join(args['urls'])
        self.names_and_urls[args['name']] = url

    def git_repository(self, **args):
        assert self.names_and_urls.get(args['name']) is None
        if args['name'] in _GRPC_BAZEL_ONLY_DEPS:
            self.names_and_urls[args['name']] = 'dont care'
            return
        self.names_and_urls[args['name']] = args['remote']

    def grpc_python_deps(self):
        pass


# Parse git hashes from bazel/grpc_deps.bzl {new_}http_archive rules
with open(os.path.join('bazel', 'grpc_deps.bzl'), 'r') as f:
    names_and_urls = {}
    eval_state = BazelEvalState(names_and_urls)
    bazel_file = f.read()

# grpc_deps.bzl only defines 'grpc_deps' and 'grpc_test_only_deps', add these
# lines to call them.
bazel_file += '\ngrpc_deps()\n'
bazel_file += '\ngrpc_test_only_deps()\n'
build_rules = {
    'native': eval_state,
    'http_archive': lambda **args: eval_state.http_archive(**args),
    'load': lambda a, b: None,
    'git_repository': lambda **args: eval_state.git_repository(**args),
    'grpc_python_deps': lambda: None,
}
exec((bazel_file), build_rules)
for name in _GRPC_DEP_NAMES:
    assert name in list(names_and_urls.keys())
assert len(_GRPC_DEP_NAMES) == len(list(names_and_urls.keys()))

# There are some "bazel-only" deps that are exceptions to this sanity check,
# we don't require that there is a corresponding git module for these.
names_without_bazel_only_deps = list(names_and_urls.keys())
for dep_name in _GRPC_BAZEL_ONLY_DEPS:
    names_without_bazel_only_deps.remove(dep_name)
archive_urls = [names_and_urls[name] for name in names_without_bazel_only_deps]
workspace_git_hashes = {
    re.search(git_hash_pattern, url).group() for url in archive_urls
}
if len(workspace_git_hashes) == 0:
    print("(Likely) parse error, did not find any bazel git dependencies.")
    sys.exit(1)

# Validate the equivalence of the git submodules and Bazel git dependencies. The
# condition we impose is that there is a git submodule for every dependency in
# the workspace, but not necessarily conversely. E.g. Bloaty is a dependency
# not used by any of the targets built by Bazel.
if len(workspace_git_hashes - git_submodule_hashes) > 0:
    print(
        "Found discrepancies between git submodules and Bazel WORKSPACE dependencies"
    )
    print(("workspace_git_hashes: %s" % workspace_git_hashes))
    print(("git_submodule_hashes: %s" % git_submodule_hashes))
    print(("workspace_git_hashes - git_submodule_hashes: %s" %
           (workspace_git_hashes - git_submodule_hashes)))
    sys.exit(1)

# Also check that we can override each dependency
for name in _GRPC_DEP_NAMES:
    names_and_urls_with_overridden_name = {}
    state = BazelEvalState(names_and_urls_with_overridden_name,
                           overridden_name=name)
    rules = {
        'native': state,
        'http_archive': lambda **args: state.http_archive(**args),
        'load': lambda a, b: None,
        'git_repository': lambda **args: state.git_repository(**args),
        'grpc_python_deps': lambda *args, **kwargs: None,
    }
    exec((bazel_file), rules)
    assert name not in list(names_and_urls_with_overridden_name.keys())

sys.exit(0)