import base64
import json
import logging
import os
import socket
import uuid
from typing import Dict, List, Optional
import aioredis
from aiohttp import web


logger = logging.getLogger(__name__)


async def setup_redis(app: web.Application) -> None:
    if not app.get("redis"):
        try:
            app["redis"] = await aioredis.create_redis_pool(app["config"].REDIS_URL)
        except Exception as e:
            # The application can continue to work if no connection to redis
            logger.exception(f"action=setup_redis, status=fail, {e}")
            app["redis"] = None

async def send_task(
    *,
    app: web.Application,
    queue: str,
    task_name: str,
    task_args: Optional[List] = None,
    task_kwargs: Optional[Dict] = None,
) -> None:
    """app is an instance of aiohttp application."""
    if not app["redis"]:
        await setup_redis(app)
    if not app["redis"]:
        return None
    if not task_args:
        task_args = []
    if not task_kwargs:
        task_kwargs = {}
    task_id = str(uuid.uuid4())
    delivery_tag = str(uuid.uuid4())
    body = base64.b64encode(json.dumps((task_args, task_kwargs, {})).encode("utf-8")).decode("utf-8")
    message = {
        "body": body,
        "content-encoding": "utf-8",
        "content-type": "application/json",
        "headers": {
            "lang": "py",
            "task": task_name,
            "id": task_id,
            "shadow": None,
            "eta": None,
            "expires": None,
            "group": None,
            "retries": 0,
            "timelimit": [None, None],
            "root_id": task_id,
            "parent_id": None,
            "argsrepr": repr(task_args),
            "kwargsrepr": repr(task_kwargs),
            "origin": f"{os.getpid()}@{socket.gethostname()}",
        },
        "properties": {
            "correlation_id": task_id,
            "delivery_mode": 2,  # persistent
            "delivery_info": {"exchange": "", "routing_key": queue},
            "priority": 0,
            "body_encoding": "base64",
            "delivery_tag": delivery_tag,
        },
    }
    try:
        await app["redis"].lpush(queue, json.dumps(message))
    except Exception as e:
        logger.exception(f"action=send_task, status=fail, {e}")