import sys
import re

def printArray(a):
  s = a[0]
  for i in range(1, len(a)):
    if i == len(a) - 1:
      s += " and " + a[i]
    else:
      s += ", " + a[i]
  print(s)

def printHelp():
  print("How to use:")
  print("First argument is the m3u")
  print("Second argument is your channel list")
  print("Ex: 'python3 m3ufilter.py ./full.m3u ./mychannels.txt'")
  print("If all the files are in the same folder")

def safeOpen(path, mode):
  
  try:
    openFile = open(path, mode)
  except:
    sys.exit("ERROR: Could not open " + path)
  
  return openFile

#Main
m3uFile = None;
filterFile = None;

if len(sys.argv) < 3:
  printHelp()
  sys.exit("ERROR: Too few arguments")
else:
  m3uPath = sys.argv[1]
  filterPath = sys.argv[2]

  if m3uPath.endswith("m3u"):
    #load m3uFile
    m3uFile = safeOpen(m3uPath, "r")

  else:
    sys.exit("ERROR: The first file is not .m3u")
  
  filterFile = safeOpen(filterPath, "r")

#Load channels
allChannels = []
currentChannel = ""

for line in m3uFile:
  #skip to the first channel
  if len(allChannels) == 0 and currentChannel == "" and not line.startswith("#EXTINF"):
    continue

  if line.startswith("#EXTINF") and currentChannel != "":
    allChannels.append(currentChannel)
    currentChannel = ""
  
  currentChannel += line
allChannels.append(currentChannel)
m3uFile.close()

filterChannels = []

for filterChName in filterFile:
  filterChannels.append(filterChName.rstrip().lower())
filterFile.close()

m3uoutFile = safeOpen('out.m3u', 'w')
matchedChannels = []
m3uoutFile.write("#EXTM3U")
for ch in allChannels:
  name = re.search(r',(.*)(?=\nhttp)',ch)[1]

  if name.lower() in filterChannels:
    m3uoutFile.write("\n"+ch.rstrip())
    matchedChannels.append(name)
m3uoutFile.close()

print("Channels found (saved in out.m3u):")
printArray(matchedChannels)