import os, sys, argparse, subprocess, signal

# Project defaults
FLASK_APP = 'server/__init__.py'
DEFAULT_IP = '0.0.0.0:3000'

class Command:
	def __init__(self, name, descr, runcmd, env={}):
		self.name = name
		self.descr = descr
		self.runcmd = runcmd
		self.env = env

	def run(self, conf):
		cmd = self.runcmd(conf)
		env = os.environ
		env.update(conf)
		env.update(self.env)
		subprocess.call(cmd, env=env, shell=True)

class CommandManager:
	def __init__(self):
		self.commands = {}

	def add(self, command):
		self.commands[command.name] = command

	def configure(self, conf):
		self.conf = conf

	def run(self, command):
		if command in self.commands:
			self.commands[command].run(self.conf)
		else:
			print("invalid command specified\n")
			print(self.availableCommands())

	def availableCommands(self):
		commands = sorted(self.commands.values(), key=lambda c: c.name)
		space = max([len(c.name) for c in commands]) + 2
		description = 'available subcommands:\n'
		for c in commands:
			description += '  ' + c.name + ' ' * (space - len(c.name)) + c.descr + '\n'
		return description

cm = CommandManager()

cm.add(Command(
	"build",
	"compiles python files in project into .pyc binaries",
	lambda c: 'python -m compileall .'))

cm.add(Command(
	"start",
	"runs server with gunicorn in a production setting",
	lambda c: 'gunicorn -b {0}:{1} server:app'.format(c['host'], c['port']),
	{
		'FLASK_APP': FLASK_APP,
		'FLASK_DEBUG': 'false'
	}))

cm.add(Command(
	"run",
	"runs dev server using Flask's native debugger & backend reloader",
	lambda c: 'python -m flask run --host={0} --port={1} --debugger --reload'.format(c['host'], c['port']),
	{
		'FLASK_APP': FLASK_APP,
		'FLASK_DEBUG': 'true'
	}))

cm.add(Command(
	"livereload",
	"runs dev server using livereload for dynamic webpage reloading",
	lambda c: 'python -m flask run',
	{
		'FLASK_APP': FLASK_APP,
		'FLASK_LIVE_RELOAD': 'true',
	}))

cm.add(Command(
	"debug",
	"runs dev server in debug mode; use with an IDE's remote debugger",
	lambda c: 'python -m flask run --host={0} --port={1} --no-debugger --no-reload'.format(c['host'], c['port']),
	{
		'FLASK_APP': FLASK_APP,
		'FLASK_DEBUG': 'true'
	}))

cm.add(Command(
	"test",
	"runs all tests inside of `tests` directory",
	lambda c: 'python -m unittest discover -s tests -p "*.py"'))

# Create and format argument parser for CLI
parser = argparse.ArgumentParser(description=cm.availableCommands(),
								 formatter_class=argparse.RawDescriptionHelpFormatter)
parser.add_argument("subcommand", help="subcommand to run (see list above)")
parser.add_argument("ipaddress", nargs='?', default=DEFAULT_IP,
					help="address and port to run on (i.e. {0})".format(DEFAULT_IP))
def livereload_check():
	check = subprocess.call("lsof -n -i4TCP:3000", shell=True)
	if (check == 0):
		output = subprocess.check_output("pgrep Python", shell=True)
		pypid = int(output)
		os.kill(pypid, signal.SIGKILL)
		print("Discovered rogue Python process: {0}".format(pypid))
		print("Killing PID {0}...".format(pypid))
	else: 
		print(" No rogue Python process running")
		
# Take in command line input for configuration
try:
	args = parser.parse_args()
	cmd = args.subcommand
	addr = args.ipaddress.split(':')
	cm.configure({
		'host': addr[0],
		'port': addr[1],
	})
	cm.run(cmd)
except KeyboardInterrupt:
	if 'FLASK_LIVE_RELOAD' in os.environ and os.environ['FLASK_LIVE_RELOAD'] == 'true':
		livereload_check()
except:
	if len(sys.argv) == 1:
		print(cm.availableCommands())
	sys.exit(0)