#!/usr/bin/env python3

"""Main CHART-EPSSG launcher executable."""

import os
import sys
import warnings
with warnings.catch_warnings():
	warnings.filterwarnings('ignore', category=DeprecationWarning)

# bin directory containing this file
BIN_PATH = os.path.abspath(os.path.dirname(__file__))

# Project root
PROJ_DIR = os.path.dirname(BIN_PATH)

# Environment variable which can be set to enable launcher debug messages
ENV_CHART_DEBUG_LAUNCHER = 'CHART_DEBUG_LAUNCHER'

def print_debug(*mess):
	"""Show debug messages if $CHART_DEBUG_LAUNCHER is set."""
	# if os.environ.get('CHART_RELOADED') != '1':
	if os.environ.get('CHART_DEBUG_LAUNCHER') == '1':
		print(*mess)

print_debug('Starting launcher script')

def add_to_sys_path(new_dir):
	"""Insert `new_dir` as a standard import directory."""
	print_debug('Adding {c} to sys.path'.format(c=new_dir))
	# For this process...
	sys.path.insert(0, new_dir)
	# ... and for child processes
	os.environ['PYTHONPATH'] = ':'.join((new_dir, os.environ.get('PYTHONPATH', '')))

# Allow code to import from this project
add_to_sys_path(PROJ_DIR)

# Set us up as the active CHART project
import chartepssg.project  # (unused import) pylint: disable=W0611

# prerequisite check
try:
	import django

except ImportError:
	print('Could not import pre-requisites. Try running environment activate script')
	raise

def check_for_core(dirname):
	"""See if `dirname` appears to be a CHART core installation."""
	# Don't just import it! Python3 caches import failures so once you look for a module once and
	# fail to find it, you always fail to find it even if you later prepend the right directory to
	# sys.path
	print_debug('Checking if {c} is a CHART-core install'.format(c=dirname))
	return os.path.exists(os.path.join(dirname, 'chart', '__init__.py'))

def check_for_rest(dirname):
	"""See if `dirname` appears to be a CHART rest installation."""
	print_debug('Checking if {c} is a CDAT REST install'.format(c=dirname))
	return os.path.exists(os.path.join(dirname, 'chart_rest', '__init__.py'))

# Look for the CHART core in sys.path
core_dir = None
for testdir in sys.path:
	if check_for_core(testdir):
		core_dir = testdir
		print_debug('Found core in {c}'.format(c=testdir))
		break

else:
	# Look for core in a few well known places
	for testdir in (os.path.join(PROJ_DIR, 'chart'),
					os.path.join(os.path.dirname(PROJ_DIR), 'chart')):
		if check_for_core(testdir):
			core_dir = testdir
			print_debug('Adding core in {c}'.format(c=testdir))
			add_to_sys_path(testdir)
			break

	else:
		raise SystemExit('Cannot find CHART core')

# Look for CDAT REST API dir in sys.path
for testdir in sys.path:
	if check_for_rest(testdir):
		print_debug('Found REST in {c}'.format(c=testdir))
		break

else:
	for testdir in (os.path.join(PROJ_DIR, 'chart-rest'),
					os.path.join(core_dir, 'chart-rest')):
		if check_for_rest(testdir):
			print_debug('Adding REST in {c}'.format(c=testdir))
			add_to_sys_path(testdir)
			break

	else:
		print('Cannot find CHART-REST directory for CDAT support')

from chart.cmd import launcher
# import cProfile
# cProfile.run('launcher.launch()')
# print('launching')
launcher.launch()