#!/usr/bin/env python3

# Copyright 2022 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 argparse
import collections
from doctest import SKIP
import multiprocessing
import os
import re
import sys

import run_buildozer

# find our home
ROOT = os.path.abspath(os.path.join(os.path.dirname(sys.argv[0]), "../.."))
os.chdir(ROOT)

vendors = collections.defaultdict(list)
scores = collections.defaultdict(int)
avoidness = collections.defaultdict(int)
consumes = {}
no_update = set()
buildozer_commands = []
original_deps = {}
original_external_deps = {}
skip_headers = collections.defaultdict(set)

# TODO(ctiller): ideally we wouldn't hardcode a bunch of paths here.
# We can likely parse out BUILD files from dependencies to generate this index.
EXTERNAL_DEPS = {
    "absl/algorithm/container.h": "absl/algorithm:container",
    "absl/base/attributes.h": "absl/base:core_headers",
    "absl/base/call_once.h": "absl/base",
    # TODO(ctiller) remove this
    "absl/base/internal/endian.h": "absl/base",
    "absl/base/thread_annotations.h": "absl/base:core_headers",
    "absl/container/flat_hash_map.h": "absl/container:flat_hash_map",
    "absl/container/flat_hash_set.h": "absl/container:flat_hash_set",
    "absl/container/inlined_vector.h": "absl/container:inlined_vector",
    "absl/cleanup/cleanup.h": "absl/cleanup",
    "absl/debugging/failure_signal_handler.h": (
        "absl/debugging:failure_signal_handler"
    ),
    "absl/debugging/stacktrace.h": "absl/debugging:stacktrace",
    "absl/debugging/symbolize.h": "absl/debugging:symbolize",
    "absl/flags/flag.h": "absl/flags:flag",
    "absl/flags/marshalling.h": "absl/flags:marshalling",
    "absl/flags/parse.h": "absl/flags:parse",
    "absl/functional/any_invocable.h": "absl/functional:any_invocable",
    "absl/functional/bind_front.h": "absl/functional:bind_front",
    "absl/functional/function_ref.h": "absl/functional:function_ref",
    "absl/hash/hash.h": "absl/hash",
    "absl/memory/memory.h": "absl/memory",
    "absl/meta/type_traits.h": "absl/meta:type_traits",
    "absl/numeric/int128.h": "absl/numeric:int128",
    "absl/random/random.h": "absl/random",
    "absl/random/bit_gen_ref.h": "absl/random:bit_gen_ref",
    "absl/random/mocking_bit_gen.h": "absl/random:mocking_bit_gen",
    "absl/random/distributions.h": "absl/random:distributions",
    "absl/random/uniform_int_distribution.h": "absl/random:distributions",
    "absl/status/status.h": "absl/status",
    "absl/status/statusor.h": "absl/status:statusor",
    "absl/strings/ascii.h": "absl/strings",
    "absl/strings/cord.h": "absl/strings:cord",
    "absl/strings/escaping.h": "absl/strings",
    "absl/strings/match.h": "absl/strings",
    "absl/strings/numbers.h": "absl/strings",
    "absl/strings/str_cat.h": "absl/strings",
    "absl/strings/str_format.h": "absl/strings:str_format",
    "absl/strings/str_join.h": "absl/strings",
    "absl/strings/str_replace.h": "absl/strings",
    "absl/strings/str_split.h": "absl/strings",
    "absl/strings/string_view.h": "absl/strings",
    "absl/strings/strip.h": "absl/strings",
    "absl/strings/substitute.h": "absl/strings",
    "absl/synchronization/mutex.h": "absl/synchronization",
    "absl/synchronization/notification.h": "absl/synchronization",
    "absl/time/clock.h": "absl/time",
    "absl/time/time.h": "absl/time",
    "absl/types/optional.h": "absl/types:optional",
    "absl/types/span.h": "absl/types:span",
    "absl/types/variant.h": "absl/types:variant",
    "absl/utility/utility.h": "absl/utility",
    "address_sorting/address_sorting.h": "address_sorting",
    "google/cloud/opentelemetry/resource_detector.h": "google_cloud_cpp:experimental-opentelemetry",
    "opentelemetry/common/attribute_value.h": "otel/api",
    "opentelemetry/common/key_value_iterable.h": "otel/api",
    "opentelemetry/nostd/function_ref.h": "otel/api",
    "opentelemetry/nostd/string_view.h": "otel/api",
    "opentelemetry/context/context.h": "otel/api",
    "opentelemetry/metrics/meter.h": "otel/api",
    "opentelemetry/metrics/meter_provider.h": "otel/api",
    "opentelemetry/metrics/provider.h": "otel/api",
    "opentelemetry/metrics/sync_instruments.h": "otel/api",
    "opentelemetry/nostd/shared_ptr.h": "otel/api",
    "opentelemetry/nostd/unique_ptr.h": "otel/api",
    "opentelemetry/sdk/metrics/meter_provider.h": "otel/sdk/src/metrics",
    "opentelemetry/sdk/common/attribute_utils.h": "otel/sdk:headers",
    "opentelemetry/sdk/resource/resource.h": "otel/sdk:headers",
    "opentelemetry/sdk/resource/resource_detector.h": "otel/sdk:headers",
    "opentelemetry/sdk/resource/semantic_conventions.h": "otel/sdk:headers",
    "ares.h": "cares",
    "fuzztest/fuzztest.h": ["fuzztest", "fuzztest_main"],
    "google/api/monitored_resource.pb.h": (
        "google/api:monitored_resource_cc_proto"
    ),
    "google/devtools/cloudtrace/v2/tracing.grpc.pb.h": (
        "googleapis_trace_grpc_service"
    ),
    "google/logging/v2/logging.grpc.pb.h": "googleapis_logging_grpc_service",
    "google/logging/v2/logging.pb.h": "googleapis_logging_cc_proto",
    "google/logging/v2/log_entry.pb.h": "googleapis_logging_cc_proto",
    "google/monitoring/v3/metric_service.grpc.pb.h": (
        "googleapis_monitoring_grpc_service"
    ),
    "gmock/gmock.h": "gtest",
    "gtest/gtest.h": "gtest",
    "opencensus/exporters/stats/stackdriver/stackdriver_exporter.h": (
        "opencensus-stats-stackdriver_exporter"
    ),
    "opencensus/exporters/trace/stackdriver/stackdriver_exporter.h": (
        "opencensus-trace-stackdriver_exporter"
    ),
    "opencensus/trace/context_util.h": "opencensus-trace-context_util",
    "opencensus/trace/propagation/grpc_trace_bin.h": (
        "opencensus-trace-propagation"
    ),
    "opencensus/tags/context_util.h": "opencensus-tags-context_util",
    "opencensus/trace/span_context.h": "opencensus-trace-span_context",
    "openssl/base.h": "libssl",
    "openssl/bio.h": "libssl",
    "openssl/bn.h": "libcrypto",
    "openssl/buffer.h": "libcrypto",
    "openssl/crypto.h": "libcrypto",
    "openssl/digest.h": "libssl",
    "openssl/engine.h": "libcrypto",
    "openssl/err.h": "libcrypto",
    "openssl/evp.h": "libcrypto",
    "openssl/hmac.h": "libcrypto",
    "openssl/mem.h": "libcrypto",
    "openssl/param_build.h": "libcrypto",
    "openssl/pem.h": "libcrypto",
    "openssl/rsa.h": "libcrypto",
    "openssl/sha.h": "libcrypto",
    "openssl/ssl.h": "libssl",
    "openssl/tls1.h": "libssl",
    "openssl/x509.h": "libcrypto",
    "openssl/x509v3.h": "libcrypto",
    "re2/re2.h": "re2",
    "upb/arena.h": "upb_lib",
    "upb/base/string_view.h": "upb_lib",
    "upb/collections/map.h": "upb_collections_lib",
    "upb/def.h": "upb_lib",
    "upb/json_encode.h": "upb_json_lib",
    "upb/mem/arena.h": "upb_lib",
    "upb/text_encode.h": "upb_textformat_lib",
    "upb/def.hpp": "upb_reflection",
    "upb/upb.h": "upb_lib",
    "upb/upb.hpp": "upb_lib",
    "xxhash.h": "xxhash",
    "zlib.h": "madler_zlib",
}

INTERNAL_DEPS = {
    "test/core/event_engine/fuzzing_event_engine/fuzzing_event_engine.h": (
        "//test/core/event_engine/fuzzing_event_engine"
    ),
    "test/core/event_engine/fuzzing_event_engine/fuzzing_event_engine.pb.h": "//test/core/event_engine/fuzzing_event_engine:fuzzing_event_engine_proto",
    "test/core/experiments/test_experiments.h": "//test/core/experiments:test_experiments_lib",
    "google/api/expr/v1alpha1/syntax.upb.h": "google_api_expr_v1alpha1_syntax_upb",
    "google/rpc/status.upb.h": "google_rpc_status_upb",
    "google/protobuf/any.upb.h": "protobuf_any_upb",
    "google/protobuf/duration.upb.h": "protobuf_duration_upb",
    "google/protobuf/struct.upb.h": "protobuf_struct_upb",
    "google/protobuf/timestamp.upb.h": "protobuf_timestamp_upb",
    "google/protobuf/wrappers.upb.h": "protobuf_wrappers_upb",
    "grpc/status.h": "grpc_public_hdrs",
    "src/proto/grpc/channelz/channelz.grpc.pb.h": (
        "//src/proto/grpc/channelz:channelz_proto"
    ),
    "src/proto/grpc/core/stats.pb.h": "//src/proto/grpc/core:stats_proto",
    "src/proto/grpc/health/v1/health.upb.h": "grpc_health_upb",
    "src/proto/grpc/lb/v1/load_reporter.grpc.pb.h": (
        "//src/proto/grpc/lb/v1:load_reporter_proto"
    ),
    "src/proto/grpc/lb/v1/load_balancer.upb.h": "grpc_lb_upb",
    "src/proto/grpc/reflection/v1alpha/reflection.grpc.pb.h": (
        "//src/proto/grpc/reflection/v1alpha:reflection_proto"
    ),
    "src/proto/grpc/gcp/transport_security_common.upb.h": "alts_upb",
    "src/proto/grpc/gcp/handshaker.upb.h": "alts_upb",
    "src/proto/grpc/gcp/altscontext.upb.h": "alts_upb",
    "src/proto/grpc/lookup/v1/rls.upb.h": "rls_upb",
    "src/proto/grpc/lookup/v1/rls_config.upb.h": "rls_config_upb",
    "src/proto/grpc/lookup/v1/rls_config.upbdefs.h": "rls_config_upbdefs",
    "src/proto/grpc/testing/xds/v3/csds.grpc.pb.h": (
        "//src/proto/grpc/testing/xds/v3:csds_proto"
    ),
    "xds/data/orca/v3/orca_load_report.upb.h": "xds_orca_upb",
    "xds/service/orca/v3/orca.upb.h": "xds_orca_service_upb",
    "xds/type/v3/typed_struct.upb.h": "xds_type_upb",
}


class FakeSelects:
    def config_setting_group(self, **kwargs):
        pass


num_cc_libraries = 0
num_opted_out_cc_libraries = 0
parsing_path = None


# Convert the source or header target to a relative path.
def _get_filename(name, parsing_path):
    filename = "%s%s" % (
        (
            parsing_path + "/"
            if (parsing_path and not name.startswith("//"))
            else ""
        ),
        name,
    )
    filename = filename.replace("//:", "")
    filename = filename.replace("//src/core:", "src/core/")
    filename = filename.replace(
        "//src/cpp/ext/filters/census:", "src/cpp/ext/filters/census/"
    )
    return filename


def grpc_cc_library(
    name,
    hdrs=[],
    public_hdrs=[],
    srcs=[],
    select_deps=None,
    tags=[],
    deps=[],
    external_deps=[],
    proto=None,
    **kwargs,
):
    global args
    global num_cc_libraries
    global num_opted_out_cc_libraries
    global parsing_path
    assert parsing_path is not None
    name = "//%s:%s" % (parsing_path, name)
    num_cc_libraries += 1
    if select_deps or "nofixdeps" in tags:
        if args.whats_left and not select_deps and "nofixdeps" not in tags:
            num_opted_out_cc_libraries += 1
            print("Not opted in: {}".format(name))
        no_update.add(name)
    scores[name] = len(public_hdrs + hdrs)
    # avoid_dep is the internal way of saying prefer something else
    # we add grpc_avoid_dep to allow internal grpc-only stuff to avoid each
    # other, whilst not biasing dependent projects
    if "avoid_dep" in tags or "grpc_avoid_dep" in tags:
        avoidness[name] += 10
    if proto:
        proto_hdr = "%s%s" % (
            (parsing_path + "/" if parsing_path else ""),
            proto.replace(".proto", ".pb.h"),
        )
        skip_headers[name].add(proto_hdr)

    for hdr in hdrs + public_hdrs:
        vendors[_get_filename(hdr, parsing_path)].append(name)
    inc = set()
    original_deps[name] = frozenset(deps)
    original_external_deps[name] = frozenset(external_deps)
    for src in hdrs + public_hdrs + srcs:
        for line in open(_get_filename(src, parsing_path)):
            m = re.search(r"^#include <(.*)>", line)
            if m:
                inc.add(m.group(1))
            m = re.search(r'^#include "(.*)"', line)
            if m:
                inc.add(m.group(1))
    consumes[name] = list(inc)


def grpc_proto_library(name, srcs, **kwargs):
    global parsing_path
    assert parsing_path is not None
    name = "//%s:%s" % (parsing_path, name)
    for src in srcs:
        proto_hdr = src.replace(".proto", ".pb.h")
        vendors[_get_filename(proto_hdr, parsing_path)].append(name)


def buildozer(cmd, target):
    buildozer_commands.append("%s|%s" % (cmd, target))


def buildozer_set_list(name, values, target, via=""):
    if not values:
        buildozer("remove %s" % name, target)
        return
    adjust = via if via else name
    buildozer(
        "set %s %s" % (adjust, " ".join('"%s"' % s for s in values)), target
    )
    if via:
        buildozer("remove %s" % name, target)
        buildozer("rename %s %s" % (via, name), target)


def score_edit_distance(proposed, existing):
    """Score a proposed change primarily by edit distance"""
    sum = 0
    for p in proposed:
        if p not in existing:
            sum += 1
    for e in existing:
        if e not in proposed:
            sum += 1
    return sum


def total_score(proposal):
    return sum(scores[dep] for dep in proposal)


def total_avoidness(proposal):
    return sum(avoidness[dep] for dep in proposal)


def score_list_size(proposed, existing):
    """Score a proposed change primarily by number of dependencies"""
    return len(proposed)


def score_best(proposed, existing):
    """Score a proposed change primarily by dependency score"""
    return 0


SCORERS = {
    "edit_distance": score_edit_distance,
    "list_size": score_list_size,
    "best": score_best,
}

parser = argparse.ArgumentParser(description="Fix build dependencies")
parser.add_argument(
    "targets", nargs="*", default=[], help="targets to fix (empty => all)"
)
parser.add_argument(
    "--score",
    type=str,
    default="edit_distance",
    help="scoring function to use: one of " + ", ".join(SCORERS.keys()),
)
parser.add_argument(
    "--whats_left",
    action="store_true",
    default=False,
    help="show what is left to opt in",
)
parser.add_argument(
    "--explain",
    action="store_true",
    default=False,
    help="try to explain some decisions",
)
parser.add_argument(
    "--why",
    type=str,
    default=None,
    help="with --explain, target why a given dependency is needed",
)
args = parser.parse_args()

for dirname in [
    "",
    "src/core",
    "src/cpp/ext/gcp",
    "src/cpp/ext/csm",
    "src/cpp/ext/otel",
    "test/core/backoff",
    "test/core/experiments",
    "test/core/uri",
    "test/core/util",
    "test/core/end2end",
    "test/core/event_engine",
    "test/core/filters",
    "test/core/promise",
    "test/core/resource_quota",
    "test/core/transport/chaotic_good",
    "fuzztest",
    "fuzztest/core/channel",
]:
    parsing_path = dirname
    exec(
        open("%sBUILD" % (dirname + "/" if dirname else ""), "r").read(),
        {
            "load": lambda filename, *args: None,
            "licenses": lambda licenses: None,
            "package": lambda **kwargs: None,
            "exports_files": lambda files, visibility=None: None,
            "bool_flag": lambda **kwargs: None,
            "config_setting": lambda **kwargs: None,
            "selects": FakeSelects(),
            "python_config_settings": lambda **kwargs: None,
            "grpc_cc_binary": grpc_cc_library,
            "grpc_cc_library": grpc_cc_library,
            "grpc_cc_test": grpc_cc_library,
            "grpc_core_end2end_test": lambda **kwargs: None,
            "grpc_fuzzer": grpc_cc_library,
            "grpc_fuzz_test": grpc_cc_library,
            "grpc_proto_fuzzer": grpc_cc_library,
            "grpc_proto_library": grpc_proto_library,
            "select": lambda d: d["//conditions:default"],
            "glob": lambda files: None,
            "grpc_end2end_tests": lambda: None,
            "grpc_upb_proto_library": lambda name, **kwargs: None,
            "grpc_upb_proto_reflection_library": lambda name, **kwargs: None,
            "grpc_generate_one_off_targets": lambda: None,
            "grpc_generate_one_off_internal_targets": lambda: None,
            "grpc_package": lambda **kwargs: None,
            "filegroup": lambda name, **kwargs: None,
            "sh_library": lambda name, **kwargs: None,
        },
        {},
    )
    parsing_path = None

if args.whats_left:
    print(
        "{}/{} libraries are opted in".format(
            num_cc_libraries - num_opted_out_cc_libraries, num_cc_libraries
        )
    )


def make_relative_path(dep, lib):
    if lib is None:
        return dep
    lib_path = lib[: lib.rfind(":") + 1]
    if dep.startswith(lib_path):
        return dep[len(lib_path) :]
    return dep


if args.whats_left:
    print(
        "{}/{} libraries are opted in".format(
            num_cc_libraries - num_opted_out_cc_libraries, num_cc_libraries
        )
    )


# Keeps track of all possible sets of dependencies that could satify the
# problem. (models the list monad in Haskell!)
class Choices:
    def __init__(self, library, substitutions):
        self.library = library
        self.to_add = []
        self.to_remove = []
        self.substitutions = substitutions

    def add_one_of(self, choices, trigger):
        if not choices:
            return
        choices = sum(
            [self.apply_substitutions(choice) for choice in choices], []
        )
        if args.explain and (args.why is None or args.why in choices):
            print(
                "{}: Adding one of {} for {}".format(
                    self.library, choices, trigger
                )
            )
        self.to_add.append(
            tuple(
                make_relative_path(choice, self.library) for choice in choices
            )
        )

    def add(self, choice, trigger):
        self.add_one_of([choice], trigger)

    def remove(self, remove):
        for remove in self.apply_substitutions(remove):
            self.to_remove.append(make_relative_path(remove, self.library))

    def apply_substitutions(self, dep):
        if dep in self.substitutions:
            return self.substitutions[dep]
        return [dep]

    def best(self, scorer):
        choices = set()
        choices.add(frozenset())

        for add in sorted(set(self.to_add), key=lambda x: (len(x), x)):
            new_choices = set()
            for append_choice in add:
                for choice in choices:
                    new_choices.add(choice.union([append_choice]))
            choices = new_choices
        for remove in sorted(set(self.to_remove)):
            new_choices = set()
            for choice in choices:
                new_choices.add(choice.difference([remove]))
            choices = new_choices

        best = None

        def final_scorer(x):
            return (total_avoidness(x), scorer(x), total_score(x))

        for choice in choices:
            if best is None or final_scorer(choice) < final_scorer(best):
                best = choice
        return best


def make_library(library):
    error = False
    hdrs = sorted(consumes[library])
    # we need a little trickery here since grpc_base has channel.cc, which calls grpc_init
    # which is in grpc, which is illegal but hard to change
    # once EventEngine lands we can clean this up
    deps = Choices(
        library,
        {"//:grpc_base": ["//:grpc", "//:grpc_unsecure"]}
        if library.startswith("//test/")
        else {},
    )
    external_deps = Choices(None, {})
    for hdr in hdrs:
        if hdr in skip_headers[library]:
            continue

        if hdr == "systemd/sd-daemon.h":
            continue

        if hdr == "src/core/lib/profiling/stap_probes.h":
            continue

        if hdr.startswith("src/libfuzzer/"):
            continue

        if hdr == "grpc/grpc.h" and library.startswith("//test:"):
            # not the root build including grpc.h ==> //:grpc
            deps.add_one_of(["//:grpc", "//:grpc_unsecure"], hdr)
            continue

        if hdr in INTERNAL_DEPS:
            dep = INTERNAL_DEPS[hdr]
            if isinstance(dep, list):
                for d in dep:
                    deps.add(d, hdr)
            else:
                if not ("//" in dep):
                    dep = "//:" + dep
                deps.add(dep, hdr)
            continue

        if hdr in vendors:
            deps.add_one_of(vendors[hdr], hdr)
            continue

        if "include/" + hdr in vendors:
            deps.add_one_of(vendors["include/" + hdr], hdr)
            continue

        if "." not in hdr:
            # assume a c++ system include
            continue

        if hdr in EXTERNAL_DEPS:
            if isinstance(EXTERNAL_DEPS[hdr], list):
                for dep in EXTERNAL_DEPS[hdr]:
                    external_deps.add(dep, hdr)
            else:
                external_deps.add(EXTERNAL_DEPS[hdr], hdr)
            continue

        if hdr.startswith("opencensus/"):
            trail = hdr[len("opencensus/") :]
            trail = trail[: trail.find("/")]
            external_deps.add("opencensus-" + trail, hdr)
            continue

        if hdr.startswith("envoy/"):
            path, file = os.path.split(hdr)
            file = file.split(".")
            path = path.split("/")
            dep = "_".join(path[:-1] + [file[1]])
            deps.add(dep, hdr)
            continue

        if hdr.startswith("google/protobuf/") and not hdr.endswith(".upb.h"):
            external_deps.add("protobuf_headers", hdr)
            continue

        if "/" not in hdr:
            # assume a system include
            continue

        is_sys_include = False
        for sys_path in [
            "sys",
            "arpa",
            "gperftools",
            "netinet",
            "linux",
            "android",
            "mach",
            "net",
            "CoreFoundation",
        ]:
            if hdr.startswith(sys_path + "/"):
                is_sys_include = True
                break
        if is_sys_include:
            # assume a system include
            continue

        print(
            "# ERROR: can't categorize header: %s used by %s" % (hdr, library)
        )
        error = True

    deps.remove(library)

    deps = sorted(
        deps.best(lambda x: SCORERS[args.score](x, original_deps[library]))
    )
    external_deps = sorted(
        external_deps.best(
            lambda x: SCORERS[args.score](x, original_external_deps[library])
        )
    )

    return (library, error, deps, external_deps)


def main() -> None:
    update_libraries = []
    for library in sorted(consumes.keys()):
        if library in no_update:
            continue
        if args.targets and library not in args.targets:
            continue
        update_libraries.append(library)
    with multiprocessing.Pool(processes=multiprocessing.cpu_count()) as p:
        updated_libraries = p.map(make_library, update_libraries, 1)

    error = False
    for library, lib_error, deps, external_deps in updated_libraries:
        if lib_error:
            error = True
            continue
        buildozer_set_list("external_deps", external_deps, library, via="deps")
        buildozer_set_list("deps", deps, library)

    run_buildozer.run_buildozer(buildozer_commands)

    if error:
        sys.exit(1)


if __name__ == "__main__":
    main()
