# Copyright (C) 2009, 2010  Roman Zimbelmann <romanz@lavabit.com>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

"""Helper functions"""

import os.path
import sys
from ranger import *

LOGFILE = '/tmp/errorlog'

def parse_arguments():
	"""Parse the program arguments"""
	from optparse import OptionParser, SUPPRESS_HELP
	from ranger import __version__
	from ranger.ext.openstruct import OpenStruct
	from os.path import expanduser

	if 'XDG_CONFIG_HOME' in os.environ and os.environ['XDG_CONFIG_HOME']:
		default_confdir = os.environ['XDG_CONFIG_HOME'] + '/ranger'
	else:
		default_confdir = '~/.config/ranger'
	usage = '%prog [options] [path/filename]'

	minor_version = __version__[2:]  # assumes major version number is <10
	if '.' in minor_version:
		minor_version = minor_version[:minor_version.find('.')]
	version_tag = ' (stable)' if int(minor_version) % 2 == 0 else ' (testing)'
	if __version__.endswith('.0'):
		version_string = 'ranger ' + __version__[:-2] + version_tag
	else:
		version_string = 'ranger ' + __version__ + version_tag

	parser = OptionParser(usage=usage, version=version_string)

	parser.add_option('-d', '--debug', action='store_true',
			help="activate debug mode")
	parser.add_option('-c', '--clean', action='store_true',
			help="don't touch/require any config files. ")
	parser.add_option('--fail-if-run', action='store_true', # COMPAT
			help=SUPPRESS_HELP)
	parser.add_option('--copy-config', type='string', metavar='which',
			help="copy the default configs to the local config directory. "
			"Possible values: all, apps, commands, keys, options, scope")
	parser.add_option('--fail-unless-cd', action='store_true',
			help="experimental: return the exit code 1 if ranger is" \
					"used to run a file (with `ranger filename`)")
	parser.add_option('-r', '--confdir', type='string',
			metavar='dir', default=default_confdir,
			help="the configuration directory. (%default)")
	parser.add_option('-m', '--mode', type='int', default=0, metavar='n',
			help="if a filename is supplied, run it with this mode")
	parser.add_option('-f', '--flags', type='string', default='',
			metavar='string',
			help="if a filename is supplied, run it with these flags.")

	options, positional = parser.parse_args()
	arg = OpenStruct(options.__dict__, targets=positional)
	arg.confdir = expanduser(arg.confdir)
	if arg.fail_if_run:
		arg.fail_unless_cd = arg.fail_if_run
		del arg['fail_if_run']

	return arg


def load_settings(fm, clean):
	import ranger.core.shared
	import ranger.api.commands
	import ranger.api.keys
	if not clean:
		allow_access_to_confdir(ranger.arg.confdir, True)

		# Load commands
		comcont = ranger.api.commands.CommandContainer()
		ranger.api.commands.alias = comcont.alias
		try:
			import commands
			comcont.load_commands_from_module(commands)
		except ImportError:
			pass
		from ranger.defaults import commands
		comcont.load_commands_from_module(commands)
		commands = comcont

		# Load apps
		try:
			import apps
		except ImportError:
			from ranger.defaults import apps

		# Load keys
		keymanager = ranger.core.shared.EnvironmentAware.env.keymanager
		ranger.api.keys.keymanager = keymanager
		from ranger.defaults import keys
		try:
			import keys
		except ImportError:
			pass
		allow_access_to_confdir(ranger.arg.confdir, False)
	else:
		comcont = ranger.api.commands.CommandContainer()
		ranger.api.commands.alias = comcont.alias
		from ranger.api import keys
		keymanager = ranger.core.shared.EnvironmentAware.env.keymanager
		ranger.api.keys.keymanager = keymanager
		from ranger.defaults import commands, keys, apps
		comcont.load_commands_from_module(commands)
		commands = comcont
	fm.commands = commands
	fm.keys = keys
	fm.apps = apps.CustomApplications()


def load_apps(fm, clean):
	import ranger
	if not clean:
		allow_access_to_confdir(ranger.arg.confdir, True)
		try:
			import apps
		except ImportError:
			from ranger.defaults import apps
		allow_access_to_confdir(ranger.arg.confdir, False)
	else:
		from ranger.defaults import apps
	fm.apps = apps.CustomApplications()


def allow_access_to_confdir(confdir, allow):
	if allow:
		try:
			os.makedirs(confdir)
		except OSError as err:
			if err.errno != 17:  # 17 means it already exists
				print("This configuration directory could not be created:")
				print(confdir)
				print("To run ranger without the need for configuration")
				print("files, use the --clean option.")
				raise SystemExit()
		if not confdir in sys.path:
			sys.path[0:0] = [confdir]
	else:
		if sys.path[0] == confdir:
			del sys.path[0]


# Debugging functions.  These will be activated when run with --debug.
# Example usage in the code:
# import ranger; ranger.log("hello world")
def log(*objects, **keywords):
	"""
	Writes objects to a logfile (for the purpose of debugging only.)
	Has the same arguments as print() in python3.
	"""
	from ranger import arg
	if LOGFILE is None or not arg.debug or arg.clean: return
	start = 'start' in keywords and keywords['start'] or 'ranger:'
	sep   =   'sep' in keywords and keywords['sep']   or ' '
	_file =  'file' in keywords and keywords['file']  or open(LOGFILE, 'a')
	end   =   'end' in keywords and keywords['end']   or '\n'
	_file.write(sep.join(map(str, (start, ) + objects)) + end)


def log_traceback():
	from ranger import arg
	if LOGFILE is None or not arg.debug or arg.clean: return
	import traceback
	traceback.print_stack(file=open(LOGFILE, 'a'))