#!/usr/bin/env python3
# Copyright 2022 The Pigweed 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
#
#     https://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.
"""Python client for pw_transfer integration test."""

import logging
import socket
import sys

from google.protobuf import text_format
from pw_hdlc.rpc import HdlcRpcClient, default_channels, SocketReader
from pw_status import Status
import pw_transfer
from pw_transfer import transfer_pb2
from pw_transfer.integration_test import config_pb2

_LOG = logging.getLogger('pw_transfer_integration_test_python_client')
_LOG.level = logging.DEBUG
_LOG.addHandler(logging.StreamHandler(sys.stdout))

HOSTNAME: str = "localhost"


def _perform_transfer_action(
    action: config_pb2.TransferAction, transfer_manager: pw_transfer.Manager
) -> bool:
    """Performs the transfer action and returns True on success."""
    protocol_version = pw_transfer.ProtocolVersion(int(action.protocol_version))

    # Default to the latest protocol version if none is specified.
    if protocol_version == pw_transfer.ProtocolVersion.UNKNOWN:
        protocol_version = pw_transfer.ProtocolVersion.LATEST

    if (
        action.transfer_type
        == config_pb2.TransferAction.TransferType.WRITE_TO_SERVER
    ):
        try:
            with open(action.file_path, 'rb') as f:
                data = f.read()
        except:
            _LOG.critical("Failed to read input file '%s'", action.file_path)
            return False

        try:
            transfer_manager.write(
                action.resource_id,
                data,
                protocol_version=protocol_version,
                initial_offset=action.initial_offset,
            )
        except pw_transfer.client.Error as e:
            if e.status != Status(action.expected_status):
                _LOG.exception(
                    "Unexpected error encountered during write transfer"
                )
                return False
            return True
        except:
            _LOG.exception("Transfer (write to server) failed")
            return False
    elif (
        action.transfer_type
        == config_pb2.TransferAction.TransferType.READ_FROM_SERVER
    ):
        try:
            data = transfer_manager.read(
                action.resource_id,
                protocol_version=protocol_version,
                initial_offset=action.initial_offset,
            )
        except pw_transfer.client.Error as e:
            if e.status != Status(action.expected_status):
                _LOG.exception(
                    "Unexpected error encountered during read transfer"
                )
                return False
            return True
        except:
            _LOG.exception("Transfer (read from server) failed")
            return False

        try:
            with open(action.file_path, 'wb') as f:
                f.write(data)
        except:
            _LOG.critical("Failed to write output file '%s'", action.file_path)
            return False
    else:
        _LOG.critical("Unknown transfer type: %d", action.transfer_type)
        return False
    if Status(action.expected_status) != Status.OK:
        _LOG.error("Transfer was not expected to succeed")
        return False
    return True


def _main() -> int:
    if len(sys.argv) != 2:
        _LOG.critical("Usage: PORT")
        return 1

    # The port is passed via the command line.
    try:
        port = int(sys.argv[1])
    except:
        _LOG.critical("Invalid port specified.")
        return 1

    # Load the config from stdin.
    try:
        text_config = sys.stdin.buffer.read()
        config = text_format.Parse(text_config, config_pb2.ClientConfig())
    except Exception as e:
        _LOG.critical("Failed to parse config file from stdin: %s", e)
        return 1

    # Open a connection to the server.
    try:
        rpc_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        rpc_socket.connect((HOSTNAME, port))
    except:
        _LOG.critical("Failed to connect to server at %s:%d", HOSTNAME, port)
        return 1

    # Initialize an RPC client using a socket reader and set up the
    # pw_transfer manager.
    reader = SocketReader(rpc_socket, 4096)
    with reader:
        rpc_client = HdlcRpcClient(
            reader,
            [transfer_pb2],
            default_channels(lambda data: rpc_socket.sendall(data)),
            lambda data: _LOG.info("%s", str(data)),
        )
        with rpc_client:
            transfer_service = rpc_client.rpcs().pw.transfer.Transfer
            transfer_manager = pw_transfer.Manager(
                transfer_service,
                default_response_timeout_s=config.chunk_timeout_ms / 1000,
                initial_response_timeout_s=config.initial_chunk_timeout_ms
                / 1000,
                max_retries=config.max_retries,
                max_lifetime_retries=config.max_lifetime_retries,
                default_protocol_version=pw_transfer.ProtocolVersion.LATEST,
            )

            transfer_logger = logging.getLogger('pw_transfer')
            transfer_logger.setLevel(logging.DEBUG)
            transfer_logger.addHandler(logging.StreamHandler(sys.stdout))

            # Perform the requested transfer actions.
            for action in config.transfer_actions:
                if not _perform_transfer_action(action, transfer_manager):
                    return 1

    _LOG.info("All transfers completed successfully")
    return 0


if __name__ == '__main__':
    sys.exit(_main())