# Copyright (c) 2015, Frappe Technologies Pvt. Ltd. and Contributors
# MIT License. See license.txt

from __future__ import unicode_literals

try:
	from zxcvbn import zxcvbn
except Exception as e:
	import zxcvbn

import frappe
from frappe import _


def test_password_strength(password, user_inputs=None):
	'''Wrapper around zxcvbn.password_strength'''
	result = zxcvbn(password, user_inputs)
	result.update({
		"feedback": get_feedback(result.get('score'), result.get('sequence'))
	})
	return result

# NOTE: code modified for frappe translations
# -------------------------------------------
# feedback functionality code from https://github.com/sans-serif/python-zxcvbn/blob/master/zxcvbn/feedback.py
# see license for feedback code at https://github.com/sans-serif/python-zxcvbn/blob/master/LICENSE.txt

# Used for regex matching capitalization
import re
# Used to get the regex patterns for capitalization
# (Used the same way in the original zxcvbn)
from zxcvbn import scoring

# Default feedback value
default_feedback = {
	"warning": "",
	"suggestions":[
		_("Use a few words, avoid common phrases."),
		_("No need for symbols, digits, or uppercase letters."),
	],
}


def get_feedback(score, sequence):
	"""
	Returns the feedback dictionary consisting of ("warning","suggestions") for the given sequences.
	"""
	global default_feedback
	minimum_password_score = int(frappe.db.get_single_value("System Settings", "minimum_password_score") or 2)

	# Starting feedback
	if len(sequence) == 0:
		return default_feedback

	# No feedback if score is good or great
	if score >= minimum_password_score:
		return dict({"warning": "", "suggestions": []})

	# Tie feedback to the longest match for longer sequences
	longest_match = max(sequence, key=lambda seq: len(seq.get('token', '')))

	# Get feedback for this match
	feedback = get_match_feedback(longest_match, len(sequence) == 1)

	# If no concrete feedback returned, give more general feedback
	if not feedback:
		feedback = {
			"warning": "",
			"suggestions":[
				_("Better add a few more letters or another word")
			],
		}
	return feedback


def get_match_feedback(match, is_sole_match):
	"""
	Returns feedback as a dictionary for a certain match
	"""
	def fun_bruteforce():
		# Define a number of functions that are used in a look up dictionary
		return None

	def fun_dictionary():
		# If the match is of type dictionary, call specific function
		return get_dictionary_match_feedback(match, is_sole_match)

	def fun_spatial():
		feedback = {
			"warning": _('Short keyboard patterns are easy to guess'),
			"suggestions": [
				_("Make use of longer keyboard patterns")
			],
		}

		if match.get("turns") == 1:
			feedback = {
				"warning": _('Straight rows of keys are easy to guess'),
				"suggestions": [
					_("Try to use a longer keyboard pattern with more turns")
				],
			}

		return feedback

	def fun_repeat():
		feedback = {
			"warning": _('Repeats like "abcabcabc" are only slightly harder to guess than "abc"'),
			"suggestions": [
				_("Try to avoid repeated words and characters")
			],
		}
		if len(match.get("repeated_char")) == 1:
			feedback = {
				"warning": _('Repeats like "aaa" are easy to guess'),
				"suggestions": [
					_("Let's avoid repeated words and characters")
				],
			}
		return feedback

	def fun_sequence():
		return {
			"suggestions": [
				_("Avoid sequences like abc or 6543 as they are easy to guess")
			],
		}

	def fun_regex():
		if match["regex_name"] == "recent_year":
			return {
				"warning": _("Recent years are easy to guess."),
				"suggestions": [
					_("Avoid recent years."),
					_("Avoid years that are associated with you.")
				],
			}

	def fun_date():
		return {
			"warning": _("Dates are often easy to guess."),
			"suggestions": [
				_("Avoid dates and years that are associated with you.")
			],
		}

	# Dictionary that maps pattern names to funtions that return feedback
	patterns = {
		"bruteforce": fun_bruteforce,
		"dictionary": fun_dictionary,
		"spatial": fun_spatial,
		"repeat": fun_repeat,
		"sequence": fun_sequence,
		"regex": fun_regex,
		"date": fun_date,
		"year": fun_date
	}
	pattern_fn = patterns.get(match['pattern'])
	if pattern_fn:
		return (pattern_fn())

def get_dictionary_match_feedback(match, is_sole_match):
	"""
	Returns feedback for a match that is found in a dictionary
	"""
	warning = ""
	suggestions = []

	# If the match is a common password
	if match.get("dictionary_name") == "passwords":
		if is_sole_match and not match.get("l33t_entropy"):
			if match.get("rank") <= 10:
				warning = _("This is a top-10 common password.")
			elif match.get("rank") <= 100:
				warning = _("This is a top-100 common password.")
			else:
				warning = _("This is a very common password.")
		else:
			warning = _("This is similar to a commonly used password.")

	# If the match is a common english word
	elif match.get("dictionary_name") == "english":
		if is_sole_match:
			warning = _("A word by itself is easy to guess.")

	# If the match is a common surname/name
	elif match.get("dictionary_name") in ["surnames", "male_names", "female_names"]:
		if is_sole_match:
			warning = _("Names and surnames by themselves are easy to guess.")
		else:
			warning = _("Common names and surnames are easy to guess.")

	word = match.get("token")
	# Variations of the match like UPPERCASES
	if re.match(scoring.START_UPPER, word):
		suggestions.append(_("Capitalization doesn't help very much."))
	elif re.match(scoring.ALL_UPPER, word):
		suggestions.append(_("All-uppercase is almost as easy to guess as all-lowercase."))

	# Match contains l33t speak substitutions
	if match.get("l33t_entropy"):
		suggestions.append(_("Predictable substitutions like '@' instead of 'a' don't help very much."))

	return {
		"warning": warning,
		"suggestions": suggestions
	}