#!/usr/bin/python3
# Used to check cameras before commiting to install
# Executed before primary apt install of files

def col(id):
	"""Add color escape sequences"""
	if id == 1: return "\033[32m"
	if id == 2: return "\033[33m"
	if id == 3: return "\033[31m"
	return "\033[0m"

import subprocess
import time
import sys
import os
import re
import signal

# Backup the config file if we're upgrading
if "upgrade" in sys.argv:
	# Try to copy the config file as a backup
	try:
		subprocess.call(["cp /lib/security/howdy/config.ini /tmp/howdy_config_backup_v" + sys.argv[2] + ".ini"], shell=True)

		# Let the user know so he knows where to look on a failed install
		print("Backup of Howdy config file created in /tmp/howdy_config_backup_v" + sys.argv[2] + ".ini")
	except e:
		print("Could not make an backup of old Howdy config file")

	# Don't continue setup when we're just upgrading
	sys.exit(0)

# Don't run if we're not trying to install fresh
if "install" not in sys.argv:
	sys.exit(0)

# The default picked video device id
picked = "none"

print(col(1) + "Starting IR camera check...\n" + col(0))

# If prompting has been disabled, skip camera check
if "HOWDY_NO_PROMPT" in os.environ:
	print(col(2) + "AUTOMATED INSTALL, YOU WILL NOT BE ASKED FOR INPUT AND CHECKS WILL BE SKIPPED" + col(0))

	# Write the default device to disk and exit
	with open("/tmp/howdy_picked_device", "w") as out_file:
		out_file.write("none")

	sys.exit(0)

# Get all devices
devices = os.listdir("/dev/v4l/by-path")

# Loop though all devices
for dev in devices:
	time.sleep(.5)

	# The full path to the device is the default name
	device_name = "/dev/v4l/by-path/" + dev
	# Get the udevadm details to try to get a better name
	udevadm = subprocess.check_output(["udevadm info -r --query=all -n " + device_name], shell=True).decode("utf-8")

	# Loop though udevadm to search for a better name
	for line in udevadm.split("\n"):
		# Match it and encase it in quotes
		re_name = re.search('product.*=(.*)$', line, re.IGNORECASE)
		if re_name:
			device_name = '"' + re_name.group(1) + '"'

	# Show what device we're using
	print("Trying " + device_name)

	# Let fswebcam keep the camera open in the background
	sub = subprocess.Popen(["streamer -t 1:0:0 -c /dev/v4l/by-path/" + dev + " -b 16 -f rgb24 -o /dev/null 1>/dev/null 2>/dev/null"], shell=True, preexec_fn=os.setsid)

	try:
		# Ask the user if this is the right one
		print(col(2) + "One of your cameras should now be on." + col(0))
		ans = input("Did your IR emitters turn on? [y/N]: ")
	except KeyboardInterrupt:
		# Kill fswebcam if the user aborts
		os.killpg(os.getpgid(sub.pid), signal.SIGTERM)
		raise

	# The user has answered, kill fswebcam
	os.killpg(os.getpgid(sub.pid), signal.SIGTERM)

	# Set this camera as picked if the answer was yes, go to the next one if no
	if ans.lower().strip() == "y" or ans.lower().strip() == "yes":
		picked = dev
		break
	else:
		print("Interpreting as a " + col(3) + "\"NO\"\n" + col(0))

# Abort if no camera was picked
if picked == "none":
	print(col(3) + "No suitable IR camera found, aborting install." + col(0))
	sys.exit(23)

# Write the result to disk so postinst can have a look at it
with open("/tmp/howdy_picked_device", "w") as out_file:
	out_file.write("/dev/v4l/by-path/" + picked)

# Add a line break
print("")