import os
import socket
import sys
import requests
import random
import threading
import logging
import argparse

from concurrent.futures import ThreadPoolExecutor
from flask import Flask
from redis import Redis
from werkzeug.serving import WSGIRequestHandler

app = Flask(__name__)
redis = Redis(host='redis', port=6379)
pool = ThreadPoolExecutor(max_workers=10)
sessions = threading.local()
args = None

def do_redis():
  redis.incr('hits')
  return redis.get('hits')

def do_qotd():
  s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
  try:
    s.settimeout(args.timeout)
    s.connect((args.qotd, 4446))
    s.send("Hello")
    return s.recv(1024)
  finally:
    s.close()

def do_search():
  if getattr(sessions, 'session', None) == None:
    sessions.session = requests.Session()
  r = sessions.session.get(args.search, timeout=args.timeout)
  return r.text

def do_echo(text):
  if getattr(sessions, 'session', None) == None:
    sessions.session = requests.Session()
  r = sessions.session.get(args.echo, data=text, timeout=args.timeout)
  return r.text

def ignore_error(f):
  try:
    return str(f())
  except:
    logging.error("Error executing function", exc_info=sys.exc_info())
  return "Error"

# this root is for the tracing demo
@app.route('/hello')
def hello():
  qotd_msg = do_qotd()
  qotd_msg = do_echo(qotd_msg)
  return qotd_msg

# this is for normal demos
@app.route('/')
def root():
  counter_future = pool.submit(do_redis)
  search_future = pool.submit(do_search)
  qotd_future = pool.submit(do_qotd)
  echo_future = pool.submit(lambda: do_echo("foo"))
  result = 'Hello World! I have been seen %s times.' % ignore_error(counter_future.result)
  result += ignore_error(search_future.result)
  result += ignore_error(qotd_future.result)
  result += ignore_error(echo_future.result)
  return result

if __name__ == "__main__":
  parser = argparse.ArgumentParser()
  parser.add_argument('-redis', default="redis.weave.local")
  parser.add_argument('-search', default="http://search.weave.local:80/")
  parser.add_argument('-qotd', default="qotd.weave.local")
  parser.add_argument('-echo', default="http://echo.weave.local:80/")
  parser.add_argument('-timeout', default=0.5, type=float)
  args = parser.parse_args()

  logging.basicConfig(format='%(asctime)s %(levelname)s %(filename)s:%(lineno)d - %(message)s', level=logging.INFO)
  WSGIRequestHandler.protocol_version = "HTTP/1.1"
  app.run(host="0.0.0.0", port=80, debug=True)