import socket


# s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# s.connect(('10.10.2.245', 554))

# s.send('OPTIONS rtsp://10.10.2.245:554/av0_1 RTSP/1.0\r\n'.encode('ascii'))
# s.send('CSeq: 1\r\n'.encode('ascii'))
# s.send('Require: implicit-play\r\n'.encode('ascii'))
# s.send('Prox-Require: gzipped-messages\r\n\r\n'.encode('ascii'))

# data = s.recv(1024)
# print(data.decode('ascii'))
# s.close()

from urllib.parse import urlparse

class Rtsp:
    def __init__(self, url, buffer_size=128*1024, chunk_size=1024, encoding='ascii'):
        self.raw_url = url
        self.parsed_url = urlparse(url)
        self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.cseq = 0
        self.crlf = b'\r\n'
        self.endmark = self.crlf + self.crlf
        self.endmark_size = len(self.endmark)
        self.buffer_size = buffer_size
        self.chunk_size = chunk_size
        self.buffer = bytearray(self.buffer_size)
        self.encoding = encoding
        self.buffer_appending_index = 0
        self.buffer_searching_index = 0
        self.buffer_previous_index = 0

    def connect(self):
        self.socket.connect((self.parsed_url.hostname, self.parsed_url.port))

    def send(self, data):
        print(data)
        self.socket.send(data)

    def sendline(self, *args):
        text = args[0]
        if len(args) > 1:
            text %= args[1:]
        self.send(text.encode(self.encoding) + self.crlf)

    def sendend(self):
        self.send(self.crlf)
        self.send(self.crlf)

    def sendcseq(self):
        self.cseq += 1
        self.sendline('CSeq: %d', self.cseq)
        return self.cseq

    def recv_resp(self):
        while True:
            chunk = self.socket.recv(self.chunk_size)
            if not chunk:
                return
            l = len(chunk)
            i = self.buffer_appending_index
            j = i + l
            if j > self.buffer_size:
                raise BufferError()
            self.buffer[i:j] = chunk
            start = i if i == 0 else i - self.endmark_size
            endmark_index = self.buffer.find(self.endmark, start, j)
            if ~endmark_index:
                frame = self.buffer[0:endmark_index]
                # cleanup buffer
                next_index = endmark_index + self.endmark_size
                rest_size = j - next_index
                self.buffer[0:rest_size] = self.buffer[next_index:j]
                self.buffer_appending_index = rest_size
                return frame
            else:
                self.buffer_appending_index = j


    def close(self):
        self.socket.close()

    def options(self):
        self.sendline('OPTIONS %s RTSP/1.0', self.raw_url)
        self.sendcseq()
        self.sendline('Require: implicit-play')
        self.sendend()
        resp = self.recv_resp()
        print(resp.decode(self.encoding))

    def describe(self):
        self.sendline('DESCRIBE %s RTSP/1.0', self.raw_url)
        self.sendcseq()
        self.sendend()
        resp = self.recv_resp()
        print(resp.decode(self.encoding))

rtsp = Rtsp('rtsp://10.10.2.245:554/av0_1',chunk_size=10)
rtsp.connect()
rtsp.options()
# rtsp.describe()
rtsp.close()
print(rtsp.buffer_appending_index)