# -*- coding:utf-8 -*-
"""asyncio 异步IO"""

__author__ = 'Eddie Chow'


import asyncio
import threading


@asyncio.coroutine
def hello():
    print('Hello World! (%s)' % threading.currentThread())
    # 后续代码不会阻塞主线程，都是同一个线程
    r = yield from asyncio.sleep(1)
    print('Hello again! (%s)' % threading.currentThread())


async def hello_async():
    """
    从Python 3.5 开始引入的新语法，async 替换 @asyncio.coroutine，await 替换 yield from
    :return:
    """
    print('Hello world (%s)' % threading.currentThread())
    r = await asyncio.sleep(1)
    print('Hello again (%s)' % threading.currentThread())


async def wget(host):
    print('wget %s...' % host)
    connect = asyncio.open_connection(host, 80)
    reader, writer = await connect
    header = 'GET / HTTP/1.0\r\nHost: %s\r\n\r\n' % host
    writer.write(header.encode('utf-8'))
    await writer.drain()
    while True:
        line = await reader.readline()
        if line == b'\r\n':
            break
        print('%s header > %s' % (host, line.decode('utf-8').strip()))
    writer.close()


if __name__ == '__main__':
    # loop = asyncio.get_event_loop()
    # tasks = [hello(), hello()]
    # loop.run_until_complete(asyncio.wait(tasks))
    # loop.close()

    # 异步网络连接获取sina sohu 163 首页
    loop = asyncio.get_event_loop()
    tasks = [wget(host) for host in ['www.sina.com.cn', 'www.sohu.com', 'www.163.com']]
    loop.run_until_complete(asyncio.wait(tasks))
    loop.close()

    # loop = asyncio.get_event_loop()
    # tasks = [hello_async(), hello_async()]
    # loop.run_until_complete(asyncio.wait(tasks))
    # loop.close()