#!/usr/bin/python
"""
StreamProxy daemon (based on Livestream daemon)
Ensures persistent cookies, User-Agents and others tricks to play protected HLS/DASH streams
"""
import os
import sys
import time
import atexit
import re
import binascii

from signal import SIGTERM

from BaseHTTPServer import HTTPServer, BaseHTTPRequestHandler
from SocketServer import ThreadingMixIn
from urllib import unquote, quote
import urllib,urlparse
#import cookielib,urllib2
import requests
try:
    from requests.packages.urllib3.exceptions import InsecureRequestWarning
    requests.packages.urllib3.disable_warnings(InsecureRequestWarning)
except:
    pass

HOST_NAME = ""
PORT_NUMBER = 88
DEBUG = False

headers2dict = lambda  h: dict([l.strip().split(": ") for l in h.strip().splitlines()])
sessions = {}

class StreamHandler(BaseHTTPRequestHandler):

    def do_HEAD(self):
        self.send_response(200)
        self.send_header("Server", "StreamProxy")
        self.send_header("Content-type", "text/html")
        self.end_headers()

    def do_GET(self):
        """Respond to a GET request."""
        SPLIT_CHAR = "~"
        SPLIT_CODE = "%7E"
        EQ_CODE = "%3D"
        COL_CODE = "%3A"
        self.log_message("get_url: \n%s", self.path)
        p = self.path.split("~")
        url = urllib.unquote(p[0][1:])
        url = url.replace(COL_CODE, ":")
        headers = headers2dict("""
        User-Agent: Mozilla/5.0 (iPhone; CPU iPhone OS 8_0_2 like Mac OS X) AppleWebKit/600.1.4 (KHTML, like Gecko) Version/8.0 Mobile/12A366 Safari/600.1.4
        """)
        if len(p)>1:
            for h in p[1:]:
                headers[h.split("=")[0]]=urllib.unquote(h.split("=")[1])
        #self.fetch_offline(self.wfile)
        try:
            self.fetch_url2(self.wfile, url, headers)
        except Exception as e:
            print "Got Exception: ", str(e)

    def fetch_offline(self,wfile):
        self.send_response(200)
        self.send_header("Server", "StreamProxy")
        self.send_header("Content-type", "video/mp4")
        self.end_headers()
        self.wfile.write(open("offline.mp4", "rb").read())
        self.wfile.close()


    def fetch_url2(self, wfile, url, headers):
        if DEBUG: print "\n***********************************************************"
        self.log_message("fetch_url: \n%s", url)
        #self.log_message("headers: %s", headers)

        base_url = "/".join(url.split("/")[0:-1])
        if base_url not in sessions:
            sessions[base_url]={}
            sessions[base_url]["session"] = requests.Session()
            sessions[base_url]["key"] = binascii.a2b_hex(headers["key"]) if "key" in headers and headers["key"] else None
            #cj = cookielib.CookieJar()
            #sessions[base_url] = urllib2.build_opener(urllib2.HTTPCookieProcessor(cj))
        else:
            if "key" in headers and headers["key"]: sessions[base_url]["key"] = binascii.a2b_hex(headers["key"])
        ses = sessions[base_url]["session"]
        key = sessions[base_url]["key"]

        if DEBUG: print "**Request headers: "
        ses.headers.update(headers)
        #ses.addheaders=[]
        for h in ses.headers:
            #ses.addheaders.append((h,headers[h]))
            if DEBUG: print h,"=",ses.headers[h]
        r = ses.get(url, stream=True,verify=False)
        #r = ses.open(url)
        code = r.status_code #r.status_code
        if DEBUG: print "**Response:", code #r.status_code
        if DEBUG: print "**Response headers: "
        for h in r.headers:
            if DEBUG: print h,"=",r.headers[h]
        self.send_response(code)

        print code
        if code <> 200:
            self.fetch_offline(wfile)
            return

        if DEBUG: print "**Return headers:"
        headers2 = {}
        for h in r.headers:
            if h.lower() in ("user-agent","server","transfer-encoding","content-encoding","connection"):
                if DEBUG: print h," - skipped"
                continue
            else:
                headers2[h] = r.headers[h]
                if DEBUG:print h,"=",r.headers[h]

        # Content-Type: application/vnd.apple.mpegurl
        if r.headers["Content-Type"] == "application/vnd.apple.mpegurl" and key:
            content = r.content
            content = r.content.replace(base_url+"/","")
            content = re.sub("#EXT-X-KEY:METHOD=AES-128.+\n", "", content, 0, re.IGNORECASE | re.MULTILINE)
            headers2["Content-Length"] = "%s"%len(content)
            self.send_headers(headers2)
            wfile.write(content)

        # Content-Type: video/MP2T
        elif r.headers["Content-Type"] == "video/MP2T" and key:
            content = r.content
            from Crypto.Cipher import AES
            iv = content[:16]
            d = AES.new(key, AES.MODE_CBC, iv)
            content = d.decrypt(content[16:])
            headers2["Content-Length"] = "%s"%len(content)
            self.send_headers(headers2)
            wfile.write(content)

        else:
            self.send_headers(headers2)
            CHUNK_SIZE = 4 * 1024
            if code == 200:
                #while True:
                    #chunk = r.read(CHUNK_SIZE)
                    #if not chunk:
                        #break
                    #wfile.write(chunk)
                #pass
                #wfile.close()
                for chunk in r.iter_content(1024):
                    try:
                        #print "#",
                        wfile.write(chunk)
                    except Exception as e:
                        print "Exception: ", str(e)
                        return
                if DEBUG: print "  = file downloaded = "
                time.sleep(1)
        self.wfile.close()

    def send_headers(self,headers):
        for h in headers:
            self.send_header(h, headers[h])
        self.end_headers()


class ThreadedHTTPServer(ThreadingMixIn, HTTPServer):
    """Handle requests in a separate thread."""

def start():
    httpd = ThreadedHTTPServer((HOST_NAME, PORT_NUMBER), StreamHandler)
    print time.asctime(), "Server Starts - %s:%s" % (HOST_NAME, PORT_NUMBER)
    try:
        httpd.serve_forever()
    except KeyboardInterrupt:
        pass
    httpd.server_close()
    print time.asctime(), "Server Stops - %s:%s" % (HOST_NAME, PORT_NUMBER)


class Daemon:
    """
    A generic daemon class.
    Usage: subclass the Daemon class and override the run() method
    """
    def __init__(self, pidfile, stdin="/dev/null", stdout="/dev/null", stderr="/dev/null"):
        self.stdin = stdin
        self.stdout = stdout
        self.stderr = stderr
        self.pidfile = pidfile

    def daemonize(self):
        """
        do the UNIX double-fork magic, see Stevens' "Advanced
        Programming in the UNIX Environment" for details (ISBN 0201563177)
        http://www.erlenstar.demon.co.uk/unix/faq_2.html#SEC16
        """
        try:
            pid = os.fork()
            if pid > 0:
                # exit first parent
                sys.exit(0)
        except OSError, e:
            sys.stderr.write("fork #1 failed: %d (%s)\n" % (e.errno, e.strerror))
            sys.exit(1)

        # decouple from parent environment
        os.chdir("/")
        os.setsid()
        os.umask(0)

        # do second fork
        try:
            pid = os.fork()
            if pid > 0:
                # exit from second parent
                sys.exit(0)
        except OSError, e:
            sys.stderr.write("fork #2 failed: %d (%s)\n" % (e.errno, e.strerror))
            sys.exit(1)

        # redirect standard file descriptors
        sys.stdout.flush()
        sys.stderr.flush()
        si = file(self.stdin, "r")
        so = file(self.stdout, "a+")
        se = file(self.stderr, "a+", 0)
        os.dup2(si.fileno(), sys.stdin.fileno())
        os.dup2(so.fileno(), sys.stdout.fileno())
        os.dup2(se.fileno(), sys.stderr.fileno())

        # write pidfile
        atexit.register(self.delpid)
        pid = str(os.getpid())
        file(self.pidfile,"w+").write("%s\n" % pid)

    def delpid(self):
        os.remove(self.pidfile)

    def start(self):
        """
        Start the daemon
        """
        # Check for a pidfile to see if the daemon already runs
        try:
            pf = file(self.pidfile,"r")
            pid = int(pf.read().strip())
            pf.close()
        except IOError:
            pid = None

        if pid:
            message = "pidfile %s already exist. Daemon already running?\n"
            sys.stderr.write(message % self.pidfile)
            sys.exit(1)

        # Start the daemon
        self.daemonize()
        self.run()

    def stop(self):
        """
        Stop the daemon
        """
        # Get the pid from the pidfile
        try:
            pf = file(self.pidfile,"r")
            pid = int(pf.read().strip())
            pf.close()
        except IOError:
            pid = None

        if not pid:
            message = "pidfile %s does not exist. Daemon not running?\n"
            sys.stderr.write(message % self.pidfile)
            return # not an error in a restart

        # Try killing the daemon process
        try:
            while 1:
                os.kill(pid, SIGTERM)
                time.sleep(0.1)
        except OSError, err:
            err = str(err)
            if err.find("No such process") > 0:
                if os.path.exists(self.pidfile):
                    os.remove(self.pidfile)
            else:
                print str(err)
                sys.exit(1)

    def restart(self):
        """
        Restart the daemon
        """
        self.stop()
        self.start()

    def run(self):
        """
        You should override this method when you subclass Daemon. It will be called after the process has been
        daemonized by start() or restart().
        """

class ProxyDaemon(Daemon):
    def run(self):
        start()

if __name__ == "__main__":
    daemon = ProxyDaemon("/var/run/playstreamproxy.pid")
    if len(sys.argv) == 2:
        if "start" == sys.argv[1]:
            daemon.start()
        elif "stop" == sys.argv[1]:
            daemon.stop()
        elif "restart" == sys.argv[1]:
            daemon.restart()
        elif "manualstart" == sys.argv[1]:
            start()
        else:
            print "Unknown command"
            sys.exit(2)
        sys.exit(0)
    else:
        print "usage: %s start|stop|restart|manualstart" % sys.argv[0]
        sys.exit(2)