#!/usr/bin/env python3
import os, sys, subprocess, pathlib, logging, pprint

# Static config
DEBUG      = False
lang_undef = 'und'
ffprobe_exec = 'ffprobe'

# Env config
if 'DEBUG' in os.environ:
  DEBUG = bool(os.environ['DEBUG'])
if 'EXEC' in os.environ:
  ffprobe_exec = pathlib.Path(os.environ['EXEC'])

# CLI config
if len(sys.argv) < 2:
  print(f"Usage: {sys.argv[0]} input_file", file=sys.stderr)
  sys.exit(-1)

# Logging
if DEBUG:
  logging.basicConfig(stream=sys.stderr, level=logging.DEBUG)
else:
  logging.basicConfig(stream=sys.stderr, level=logging.WARN)
logger = logging.getLogger(__name__)

# Parse to array of dicts of stream data
def ffprobe(path):
  streams = {}

  # ffprobe
  args = [ ffprobe_exec, '-hide_banner', '-show_streams', path ]
  logger.debug(f"ffprobe command: {args}")
  probe = subprocess.run(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
  logger.debug(f"ffprobe result: {probe}")
  data = probe.stdout.decode('utf-8')
  if probe.returncode != 0:
    logger.error(f"ffprobe error ({probe.returncode}): {probe.stderr.decode('utf-8')}")
    logger.debug(f"ffprobe stdout: {data}")
    sys.exit(probe.returncode)

  # Process streams
  stream = None
  for line in data.splitlines():
    if line == "[STREAM]":
      logger.debug('Stream start')
      stream = {}
    elif line == "[/STREAM]":
      logger.debug('Stream end')
      i = len(streams)
      try:
        i = int(stream['index'])
      except ValueError:
        pass
      if i in streams:
        logger.error(f"Inconsistent stream index: {i}")
        logger.debug(f"Streams: {steams}\nNext stream: {stream}")
        continue
      streams[i] = stream
      steam = None
    elif stream is not None:
      logger.debug(f"\tStream data: {line}")
      try:
        (key, val) = line.split('=', 1)
      except ValueError:
        logger.error(f"Skipping unexpected stream data: {line}")
        continue
      stream[key] = val

  # Return the set of all parsed streams
  return streams

# Execute
streams = ffprobe(sys.argv[1])
if len(sys.argv) == 2:
  pprint.pp(streams)
else:
  for (i, stream) in streams.items():
    for key in sys.argv[2:]:
      if key in stream:
        print(f"{i}: {key}={stream[key]}")
      else:
        print(f"{i}: {key}=")