#!/usr/bin/env python
## -*- coding: utf-8 -*-
from __future__ import unicode_literals, print_function
from io import open


class Question:
    """
    Represents one MoxQuizz question.
    """

    category = None
    question = None
    answer = None
    regexp = None
    author = None
    level = None
    comment = None
    score = 0
    tip = list()
    tipcycle = 0

    TRIVIAL = 1
    EASY = 2
    NORMAL = 3
    HARD = 4
    EXTREME = 5

    LEVELS = (TRIVIAL, EASY, NORMAL, HARD, EXTREME)

    def __init__(self, attributes_dict):
        self.parse(attributes_dict)

    def parse(self, attributes_dict):
        """
        Populate fields from a dictionary of attributes (from a question bank).
        """

        ## Valid keys:
        #  ----------
        #  Category?                              (should always be on top!)
        #  Question                               (should always stand after Category)
        #  Answer                                 (will be matched if no regexp is provided)
        #  Regexp?                                (use UNIX-style expressions)
        #  Author?                                (the brain behind this question)
        #  Level? [baby|easy|normal|hard|extreme] (difficulty)
        #  Comment?                               (comment line)
        #  Score? [#]                             (credits for answering this question)
        #  Tip*                                   (provide one or more hints)
        #  TipCycle? [#]                          (Specify number of generated tips)

        if 'Question' in attributes_dict.keys():
            self.question = attributes_dict['Question']
        else:
            raise Exception("Cannot instantiate Question: 'Question' attribute required.")

        if 'Category' in attributes_dict.keys():
            self.category = attributes_dict['Category']

        if 'Answer' in attributes_dict.keys():
            self.answer = attributes_dict['Answer']
        else:
            raise Exception("Cannot instantiate Question: 'Answer' attribute required.")

        if 'Regexp' in attributes_dict.keys():
            self.regexp = attributes_dict['Regexp']

        if 'Author' in attributes_dict.keys():
            self.category = attributes_dict['Author']

        if 'Level' in attributes_dict.keys() and attributes_dict['Level'] in self.LEVELS:
            self.level = attributes_dict['level']

        if 'Comment' in attributes_dict.keys():
            self.comment = attributes_dict['Comment']

        if 'Score' in attributes_dict.keys():
            self.score = attributes_dict['Score']

        if 'Tip' in attributes_dict.keys():
            self.tip = attributes_dict['Tip']

        if 'Tipcycle' in attributes_dict.keys():
            self.tipcycle = attributes_dict['Tipcycle']


class QuestionBank:
    """
    Represents a MoxQuizz question bank.
    """

    filename = ''
    questions = list()

    # Case sensitive, to remain backwards-compatible with MoxQuizz.
    KEYS = ('Answer',
            'Author',
            'Category',
            'Comment',
            'Level',
            'Question',
            'Regexp',
            'Score',
            'Tip',
            'Tipcycle',
            )

    def __init__(self, filename):
        """
        Construct a question bank from a file.
        """
        self.filename = filename
        self.questions = self.parse(filename)

    def parse(self, filename):
        """
        Read a Moxquizz question bank file into a list.
        """
        questions = list()

        with open(filename) as f:
            key = ''
            i = 0

            # new question
            q = dict()
            q['Tip'] = list()

            for line in f:
                line = line.strip()
                i += 1

                # Ignore comments.
                if line.startswith('#'):
                    continue

                # A blank line starts a new question.
                if line == '':
                    # Store the previous question, if valid.
                    if 'Question' in q.keys() and 'Answer' in q.keys():
                        question = Question(q)
                        questions.append(question)

                    # Start a new question.
                    q = dict()
                    q['Tip'] = list()
                    continue

                # Fetch the next parameter.
                try:
                    (key, value) = line.split(':', 1)
                except ValueError:
                    print("Unexpected weirdness in MoxQuizz questionbank '%s', line %s." % (self.filename, i))
                    continue
                    # break  # TODO: is it appropriate to bail on broken bank files?

                # Ignore bad parameters.
                if key not in self.KEYS:
                    print("Unexpected key '%s' in MoxQuizz questionbank '%s', line %s." % (key, self.filename, i))
                    continue

                # Enumerate the Tips.
                if key == 'Tip':
                    q['Tip'].append(value.strip())
                else:
                    q[key] = value.strip()

        return questions


# A crappy test.
if __name__ == '__main__':
    qb = QuestionBank('questions.doctorlard.en')
    for q in qb.questions:
        print(q.question)
        a = unicode(raw_input('A: '), 'utf8')
        #a = input('A: ')  # Python 3
        if a.lower() == q.answer.lower():
            print("Correct!")
        else:
            print("Incorrect - the answer is '%s'" % q.answer)