import aioredis
import argparse
import asyncio
import binascii
from collections import defaultdict
import json
import websockets

parser = argparse.ArgumentParser(description="parse information for the web ui")
parser.add_argument("--port", type=int, help="port to use for the web ui")
parser.add_argument("--redis-address", required=True, type=str, help="the address to use for redis")

loop = asyncio.get_event_loop()

IDENTIFIER_LENGTH = 20

def hex_identifier(identifier):
  return binascii.hexlify(identifier).decode()

def identifier(hex_identifier):
  return binascii.unhexlify(hex_identifier)

def key_to_hex_identifier(key):
  return hex_identifier(key[(key.index(b":") + 1):(key.index(b":") + IDENTIFIER_LENGTH + 1)])

def key_to_hex_identifiers(key):
  # Extract worker_id and task_id from key of the form prefix:worker_id:task_id.
  offset = key.index(b":") + 1
  worker_id = hex_identifier(key[offset:(offset + IDENTIFIER_LENGTH)])
  offset += IDENTIFIER_LENGTH + 1
  task_id = hex_identifier(key[offset:(offset + IDENTIFIER_LENGTH)])
  return worker_id, task_id


async def hello(websocket, path):
  conn = await aioredis.create_connection((redis_host, redis_port), loop=loop)

  while True:
    command = json.loads(await websocket.recv())
    print("received command {}".format(command))

    if command["command"] == "get-workers":
      result = []
      workers = await conn.execute("keys", "WorkerInfo:*")
      for key in workers:
        content = await conn.execute("hgetall", key)
        worker_id = key_to_hex_identifier(key)
        result.append({"worker": worker_id, "export_counter": int(content[1])})
      await websocket.send(json.dumps(result))
    elif command["command"] == "get-clients":
      result = []
      clients = await conn.execute("keys", "CL:*")
      for key in clients:
        content = await conn.execute("hgetall", key)
        result.append({"client": hex_identifier(content[1]),
                       "node_ip_address": content[3].decode(),
                       "client_type": content[5].decode()})
      await websocket.send(json.dumps(result))
    elif command["command"] == "get-objects":
      result = []
      objects = await conn.execute("keys", "OI:*")
      for key in objects:
        content = await conn.execute("hgetall", key)
        result.append({"object_id": hex_identifier(content[1]),
                       "hash": hex_identifier(content[3]),
                       "data_size": content[5].decode()})
      await websocket.send(json.dumps(result))
    elif command["command"] == "get-object-info":
      # TODO(pcm): Get the object here (have to connect to ray) and ship content
      # and type back to webclient. One challenge here is that the naive
      # implementation will block the web ui backend, which is not ok if it is
      # serving multiple users.
      await websocket.send(json.dumps({"object_id": "none"}))
    elif command["command"] == "get-tasks":
      result = []
      tasks = await conn.execute("keys", "TT:*")
      for key in tasks:
        content = await conn.execute("hgetall", key)
        result.append({"task_id": key_to_hex_identifier(key),
                       "state": int(content[1]),
                       "node_id": hex_identifier(content[3])})
      await websocket.send(json.dumps(result))
    elif command["command"] == "get-timeline":
      tasks = defaultdict(list)
      for key in await conn.execute("keys", "event_log:*"):
        worker_id, task_id = key_to_hex_identifiers(key)
        content = await conn.execute("lrange", key, "0", "-1")
        data = json.loads(content[0].decode())
        begin_and_end_time = [timestamp for (timestamp, task, kind, info) in data if task == "ray:task"]
        tasks[worker_id].append({"task_id": task_id,
                                 "start_task": min(begin_and_end_time),
                                 "end_task": max(begin_and_end_time)})
      await websocket.send(json.dumps(tasks))
    elif command["command"] == "get-events":
      result = []
      for key in await conn.execute("keys", "event_log:*"):
        worker_id, task_id = key_to_hex_identifiers(key)
        answer = await conn.execute("lrange", key, "0", "-1")
        assert len(answer) == 1
        events = json.loads(answer[0].decode())
        result.extend([{"worker_id": worker_id,
                        "task_id": task_id,
                        "time": event[0],
                        "type": event[1]} for event in events])
      await websocket.send(json.dumps(result))

if __name__ == "__main__":
  args = parser.parse_args()
  redis_address = args.redis_address.split(":")
  redis_host, redis_port = redis_address[0], int(redis_address[1])

  start_server = websockets.serve(hello, "localhost", args.port)

  loop.run_until_complete(start_server)
  loop.run_forever()