# Copyright 2018 The ChromiumOS Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""The Build API entry point."""

import logging
import os
import sys

from chromite.api import api_config as api_config_lib
from chromite.api import controller
from chromite.api import message_util
from chromite.api import router as router_lib
from chromite.api.gen.chromite.api import build_api_config_pb2
from chromite.lib import commandline
from chromite.lib import cros_build_lib
from chromite.lib import namespaces
from chromite.utils import matching


def GetParser():
    """Build the argument parser."""
    parser = commandline.ArgumentParser(description=__doc__)

    parser.add_argument(
        "service_method",
        help='The "chromite.api.Service/Method" that is being called.',
    )
    # Input arguments.
    input_args = parser.add_mutually_exclusive_group(required=True)
    input_args.add_argument(
        "--input-binary",
        type="str_path",
        help="Path to the protobuf binary serialization of the input message.",
    )
    input_args.add_argument(
        "--input-json",
        type="str_path",
        help="Path to the JSON serialized input argument protobuf message.",
    )
    # Output options.
    parser.add_argument(
        "--output-binary",
        type="str_path",
        help="The path to which the protobuf binary serialization of the "
        "response message should be written.",
    )
    parser.add_argument(
        "--output-json",
        type="str_path",
        help="The path to which the JSON serialization of the response message "
        "should be written.",
    )
    # Config options.
    config_args = parser.add_mutually_exclusive_group()
    config_args.add_argument(
        "--config-binary",
        type="str_path",
        help="The path to the protobuf binary serialization of the Build API "
        "call configs.",
    )
    config_args.add_argument(
        "--config-json",
        type="str_path",
        help="The path to the JSON encoded Build API call configs.",
    )

    return parser


def _ParseArgs(argv, router):
    """Parse and validate arguments."""
    parser = GetParser()
    opts, unknown = parser.parse_known_args(
        argv, namespace=commandline.ArgumentNamespace()
    )
    parser.DoPostParseSetup(opts, unknown)

    if unknown:
        logging.warning("Unknown args ignored: %s", " ".join(unknown))

    methods = router.ListMethods()

    # Positional service_method argument validation.
    parts = opts.service_method.split("/")
    if len(parts) != 2:
        parser.error(
            "Invalid service/method specification format. It should be "
            "something like chromite.api.SdkService/Create."
        )

    if opts.service_method not in methods:
        # Unknown method, try to match against known methods and make a
        # suggestion. This is just for developer assistance, e.g. misspellings
        # when testing.
        matched = matching.GetMostLikelyMatchedObject(
            methods, opts.service_method, matched_score_threshold=0.6
        )
        error = "Unrecognized service name."
        if matched:
            error += "\nDid you mean: \n%s" % "\n".join(matched)
        parser.error(error)

    opts.service = parts[0]
    opts.method = parts[1]

    # Input and output validation.
    if not opts.output_binary and not opts.output_json:
        parser.error("At least one output file must be specified.")

    if not os.path.exists(opts.input_binary or opts.input_json):
        parser.error("Input file does not exist.")

    config_msg = build_api_config_pb2.BuildApiConfig()
    if opts.config_json:
        handler = message_util.get_message_handler(
            opts.config_json, message_util.FORMAT_JSON
        )
    else:
        handler = message_util.get_message_handler(
            opts.config_binary, message_util.FORMAT_BINARY
        )

    if opts.config_json or opts.config_binary:
        # We have been given a config, so read it.
        try:
            handler.read_into(config_msg)
        except message_util.Error as e:
            parser.error(str(e))

    opts.config = api_config_lib.build_config_from_proto(config_msg)
    opts.config_handler = handler

    opts.Freeze()
    return opts


def _get_io_handlers(opts):
    """Build the input and output handlers."""
    if opts.input_binary:
        input_handler = message_util.get_message_handler(
            opts.input_binary, message_util.FORMAT_BINARY
        )
    else:
        input_handler = message_util.get_message_handler(
            opts.input_json, message_util.FORMAT_JSON
        )

    output_handlers = []
    if opts.output_binary:
        handler = message_util.get_message_handler(
            opts.output_binary, message_util.FORMAT_BINARY
        )
        output_handlers.append(handler)
    if opts.output_json:
        handler = message_util.get_message_handler(
            opts.output_json, message_util.FORMAT_JSON
        )
        output_handlers.append(handler)

    return input_handler, output_handlers


def main(argv):
    router = router_lib.GetRouter()
    opts = _ParseArgs(argv, router)

    # For `cros build-image`, make sure we run with network disabled to prevent
    # leakage.
    if (
        cros_build_lib.IsInsideChroot()
        and opts.service_method == "chromite.api.ImageService/Create"
    ):
        logging.debug("Reexecuting without network access.")
        namespaces.ReExecuteWithNamespace(
            [sys.executable, *sys.argv], preserve_env=True
        )

    # We currently don't have any APIs that want to access stdin, so rebind.
    # pylint: disable=consider-using-with
    sys.stdin = open(os.devnull, "r", encoding="utf-8")
    # pylint: enable=consider-using-with
    os.dup2(sys.stdin.fileno(), 0)

    if opts.config.log_path:
        logging.warning("Ignoring log_path config option")
    if "BUILD_API_TEE_LOG_FILE" in os.environ:
        logging.warning("Ignoring $BUILD_API_TEE_LOG_FILE env var")

    if opts.config.mock_invalid:
        # --mock-invalid handling. We print error messages, but no output is
        # ever set for validation errors, so we can handle it by just giving
        # back the correct return code here.
        return controller.RETURN_CODE_INVALID_INPUT

    input_handler, output_handlers = _get_io_handlers(opts)

    try:
        return router.Route(
            opts.service,
            opts.method,
            opts.config,
            input_handler,
            output_handlers,
            opts.config_handler,
        )
    except router_lib.Error as e:
        # Handle router_lib.Error derivatives nicely, but let anything else
        # bubble up.
        cros_build_lib.Die(e)