# Copyright (c) 2018, ZIH,
# Technische Universitaet Dresden,
# Federal Republic of Germany
#
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without modification,
# are permitted provided that the following conditions are met:
#
#     * Redistributions of source code must retain the above copyright notice,
#       this list of conditions and the following disclaimer.
#     * Redistributions in binary form must reproduce the above copyright notice,
#       this list of conditions and the following disclaimer in the documentation
#       and/or other materials provided with the distribution.
#     * Neither the name of metricq nor the names of its contributors
#       may be used to endorse or promote products derived from this software
#       without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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import asyncio
from abc import abstractmethod

import aio_pika

from .data_client import DataClient
from .datachunk_pb2 import DataChunk
from .logging import get_logger
from .rpc import rpc_handler
from .source_metric import SourceMetric
from .types import Timestamp

logger = get_logger(__name__)


class Source(DataClient):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.metrics = dict()
        self.chunk_size = 1

    async def connect(self):
        await super().connect()
        response = await self.rpc("source.register")
        assert response is not None
        logger.info("register response: {}", response)
        await self.data_config(**response)

        self.data_exchange = await self.data_channel.declare_exchange(
            name=response["dataExchange"], passive=True
        )

        if "config" in response:
            await self.rpc_dispatch("config", **response["config"])

        self.event_loop.create_task(self.task())

    @abstractmethod
    def task(self):
        """
        override this with your main task for generating data, e.g.
        while True:
            await self.some_read_data_function()
            await self.send(...)
        """
        pass

    def __getitem__(self, id):
        if id not in self.metrics:
            self.metrics[id] = SourceMetric(id, self, chunk_size=self.chunk_size)
        return self.metrics[id]

    async def declare_metrics(self, metrics):
        logger.debug("declare_metrics({})", metrics)
        await self.rpc("source.declare_metrics", metrics=metrics)

    async def send(self, metric, time: Timestamp, value):
        """
        Logical send.
        Dispatches to the SourceMetric for chunking
        """
        logger.debug("send({},{},{})", metric, time, value)
        metric_object = self[metric]
        assert metric_object is not None
        await metric_object.send(time, value)

    async def flush(self):
        await asyncio.gather(*[m.flush() for m in self.metrics.values() if not m.empty])

    async def _send(self, metric, data_chunk: DataChunk):
        """
        Actual send of a chunk,
        don't call from anywhere other than SourceMetric
        """
        msg = aio_pika.Message(data_chunk.SerializeToString())
        await self.data_exchange.publish(msg, routing_key=metric, mandatory=False)

    @rpc_handler("config")
    async def _source_config(self, **kwargs):
        logger.info("received config {}", kwargs)
