import os
import pathlib
from json import dump, loads
from datetime import datetime, timedelta
from glob import glob

from flask.json import jsonify
from main import app
from random import shuffle

from werkzeug.utils import secure_filename

def check_data_folder_exists():
    if not os.path.exists(app.config['DATA_FILE_DIRECTORY']):
        pathlib.Path(app.config['DATA_FILE_DIRECTORY']).mkdir(parents='True', exist_ok='True')

def check_default_indicator():
    if not os.path.isfile(os.path.join(app.config['DATA_FILE_DIRECTORY'], '.default.txt')):
        open(os.path.join(app.config['DATA_FILE_DIRECTORY'], '.default.txt'),'w').close()

def get_default_dataset():
    check_default_indicator()
    default_file_path = os.path.join(app.config['DATA_FILE_DIRECTORY'], '.default.txt')
    with open(default_file_path, 'r') as default_file:
        default = default_file.read()
    return default

def available_datasets():
        files = glob(os.path.join(app.config["DATA_FILE_DIRECTORY"],'*.json'))
        default = get_default_dataset()
        output = []
        for file in files:
            filename = file.rsplit('/')[-1]
            label = f'{filename[:-5]} (Default)' if filename == default else filename[:-5]
            element = (filename, label)
            output.append(element)
        output.reverse()
        return output

def check_json_format(file):
    if not '.' in file.filename:
        return False
    if not file.filename.rsplit('.', 1)[-1] == 'json':
        return False
    return True

def validate_json_contents(file):
    file.stream.seek(0)
    data = loads(file.read())
    if not type(data) is dict:
        return False
    elif not all( key in data for key in ['meta', 'questions']):
        return False
    elif not type(data['meta']) is dict:
        return False
    elif not type(data['questions']) is list:
        return False
    return True

def store_data_file(file, default:bool=None):
    from admin.views import get_id_from_cookie
    check_default_indicator()
    timestamp = datetime.utcnow()
    filename = '.'.join([timestamp.strftime('%Y%m%d%H%M%S'),'json'])
    filename = secure_filename(filename)
    file_path = os.path.join(app.config['DATA_FILE_DIRECTORY'], filename)
    file.stream.seek(0)
    data = loads(file.read())
    data['meta']['timestamp'] = timestamp.strftime('%Y-%m-%d %H%M%S')
    data['meta']['author'] = get_id_from_cookie()
    data['meta']['tests'] = []
    with open(file_path, 'w') as _file:
        dump(data, _file, indent=2)
    if default:
        with open(os.path.join(app.config['DATA_FILE_DIRECTORY'], '.default.txt'), 'w') as _file:
            _file.write(filename)
    return filename

def randomise_list(list:list):
    _list = list.copy()
    shuffle(_list)
    return(_list)

def generate_questions(dataset:dict):
    questions_list = dataset['questions']
    output = []
    for block in randomise_list(questions_list):
        if block['type'] == 'question':
            question = {
                'type': 'question',
                'q_no': block['q_no'],
                'question_header': '',
                'text': block['text']
            }
            if block['q_type'] == 'Multiple Choice':
                question['options'] = randomise_list(block['options'])
            else:
                question['options'] = block['options'].copy()
            output.append(question)
        if block['type'] == 'block':
            for key, _question in enumerate(randomise_list(block['questions'])):
                question = {
                    'type': 'block',
                    'q_no': _question['q_no'],
                    'question_header': block['question_header'] if 'question_header' in block else '',
                    'block_length': len(block['questions']),
                    'block_q_no': key,
                    'text': _question['text']
                }
                if _question['q_type'] == 'Multiple Choice':
                    question['options'] = randomise_list(_question['options'])
                else:
                    question['options'] = _question['options'].copy()
                output.append(question)
    return output

def evaluate_answers(dataset: dict, answers: dict):
    score = 0
    max = 0
    tags = {}
    for block in dataset['questions']:
        if block['type'] == 'question':
            max += 1
            q_no = block['q_no']
            if str(q_no) in answers:
                correct = block['correct']
                correct_answer = block['options'][correct]
                if answers[str(q_no)] == correct_answer:
                    score += 1
                    for tag in block['tags']:
                        if tag not in tags:
                            tags[tag] = {
                                'scored': 1,
                                'max': 1
                            }
                        else:
                            tags[tag]['scored'] += 1
                            tags[tag]['max'] += 1
                else:
                    for tag in block['tags']:
                        if tag not in tags:
                            tags[tag] = {
                                'scored': 0,
                                'max': 1
                            }
                        else:
                            tags[tag]['max'] += 1
        if block['type'] == 'block':
            for question in block['questions']:
                max += 1
                q_no = question['q_no']
                if str(q_no) in answers:
                    correct = question['correct']
                    correct_answer = question['options'][correct]
                    if answers[str(q_no)] == correct_answer:
                        score += 1
                        for tag in question['tags']:
                            if tag not in tags:
                                tags[tag] = {
                                    'scored': 1,
                                    'max': 1
                                }
                            else:
                                tags[tag]['scored'] += 1
                                tags[tag]['max'] += 1
                else:
                    for tag in question['tags']:
                        if tag not in tags:
                            tags[tag] = {
                                'scored': 0,
                                'max': 1
                            }
                        else:
                            tags[tag]['max'] += 1

    grade = 'merit' if score/max >= .85 else 'pass' if score/max >= .70 else 'fail'
    return {
        'grade': grade,
        'tags': tags,
        'score': score,
        'max': max
    }

def get_tags_list(dataset:dict):
    output = []
    blocks = dataset['questions']
    for block in blocks:
        if block['type'] == 'question':
            output = list(set(output) | set(block['tags']))
        if block['type'] == 'block':
            for question in block['questions']:
                output = list(set(output) | set(question['tags']))
    return output           

def get_time_options():
    time_options = [
        ('none', 'None'),
        ('60', '1 hour'),
        ('90', '1 hour 30 minutes'),
        ('120', '2 hours')
    ]
    return time_options