import requests
import subprocess
import os
import sys
from selenium import webdriver
from bs4 import BeautifulSoup as bs

def getLocalFileName(url):
    last_path = url.split('/')[-1]
    return last_path[0:last_path.find("?")]

def download_file(url):
    local_filename = getLocalFileName(url)
    # NOTE the stream=True parameter
    r = requests.get(url, stream=True)
    with open(local_filename, 'wb') as f:
        for chunk in r.iter_content(chunk_size=1024):
            if chunk: # filter out keep-alive new chunks
                f.write(chunk)
                #f.flush() commented by recommendation from J.F.Sebastian
    return local_filename,r

def isDownloaded(url):
     local_filename = getLocalFileName(url)
     return local_filename in os.listdir("./")

def downloadVideos(root):
    filenames = []
    i = 1;
    is_ok = True;
    print("Downloading Videos...")
    while(is_ok):
        if not isDownloaded(root%i):
            local_filename,request = download_file(root%i)
            is_ok =request.ok
            if not is_ok:
                os.remove(local_filename)
            else:
                #print("downloaded %s" % local_filename)
                filenames.append(local_filename)
        else:
            local_filename = getLocalFileName(root%i)
            print("downloaded already %s" % local_filename)
            filenames.append(local_filename)

        i=i+1
    print("")
    return filenames


def mergeVideos(filenames,filename):
    print ""
    print "Download process finished merging videos.. It may take a long time."
    ##merge files
    if "videos.txt" in os.listdir("./"):
        os.remove("videos.txt")
    videos_file= open("videos.txt","w")
    for video in filenames:
        videos_file.write("file '"+video+"'\n")
    videos_file.close()

    command = "ffmpeg -f concat -i videos.txt -c copy %s.mp4" % filename
    subprocess.check_output(command, shell=True)

    for video in filenames:
        os.remove(video)

    os.remove("videos.txt")

def getRootUrl(url):
    driver = webdriver.Chrome()
    driver.set_window_size(0,0)
    driver.get(url)
    source = driver.page_source
    soup = bs(source,"html5lib")
    video = soup.find("video").find("source").get("src")
    video = video.replace("index.m3u8","1000/prog_index%d.ts")
    title = driver.title
    driver.close()
    return video,title

def main():
    url = sys.argv[1]
    root_url,title = getRootUrl(url)
    title = title.replace(" ","_")
    filenames = downloadVideos(root_url)
    mergeVideos(filenames,title)
    print("Video downloaded and merged successfully as name:%s"%title)


if __name__ == "__main__":
    main()