from flask import Blueprint, render_template, request, redirect, jsonify, session, abort, flash
from flask.helpers import url_for
from datetime import datetime, timedelta
from uuid import uuid4
import os
from json import loads

from pymongo.collection import ReturnDocument

from main import app, db
from common.security import encrypt
from common.data_tools import generate_questions, evaluate_answers
from common.security.database import decrypt_find_one

views = Blueprint(
    'quiz_views',
    __name__,
    static_url_path='',
    template_folder='templates',
    static_folder='static'
)

@views.route('/')
@views.route('/home/')
def home():
    _id = session.get('_id')
    if _id and db.entries.find_one({'_id': _id}):
        return redirect(url_for('quiz_views.start_quiz'))
    return render_template('/quiz/index.html')

@views.route('/start/', methods = ['GET', 'POST'])
def start():
    from .forms import StartQuiz
    form = StartQuiz()
    if request.method == 'GET':
        _id = session.get('_id')
        if _id and db.entries.find_one({'_id': _id}):
            return redirect(url_for('quiz_views.start_quiz'))
        return render_template('/quiz/start-quiz.html', form=form)
    if request.method == 'POST':
        if form.validate_on_submit():
            name = {
                'first_name': request.form.get('first_name'),
                'surname': request.form.get('surname')
            }
            email = request.form.get('email')
            club = request.form.get('club')
            test_code = request.form.get('test_code').replace('—', '')
            user_code = request.form.get('user_code')
            user_code = None if user_code == '' else user_code
            test = db.tests.find_one({'test_code': test_code})
            if not test:
                return jsonify({'error': 'The exam code you entered is invalid.'}), 400
            if test['expiry_date'] < datetime.utcnow():
                return jsonify({'error': f'The exam code you entered expired on {test["expiry_date"].strftime("%d %b %Y")}.'}), 400
            if test['start_date'] > datetime.utcnow():
                return jsonify({'error': f'The exam has not yet opened. Your exam code will be valid from {test["start_date"].strftime("%d %b %Y %H:%M")}.'}), 400
            entry = {
                '_id': uuid4().hex,
                'name': encrypt(name),
                'email': encrypt(email),
                'club': encrypt(club),
                'test_code': test_code,
                'user_code': user_code
            }
            if db.entries.insert(entry):
                session['_id'] = entry['_id']
                return jsonify({
                    'success': 'Received and validated test and/or user code. Redirecting to test client.',
                    '_id': entry['_id']
                }), 200
        else:
            errors = [*form.errors]
            return jsonify({ 'error': errors}), 400

@views.route('/api/questions/', methods=['POST'])
def fetch_questions():
    _id = request.get_json()['_id']
    entry = db.entries.find_one({'_id': _id})
    if not entry:
        return abort(404)
    test_code = entry['test_code']
    # user_code = entry['user_code'] TODO Implement functionality for adjustments

    test = db.tests.find_one({'test_code' : test_code})
    time_limit = test['time_limit']
    if time_limit:
        _time_limit = int(time_limit)
        end_delta = timedelta(minutes=_time_limit)
        end_time = datetime.utcnow() + end_delta
    else:
        end_time = None
    update = {
        'start_time': datetime.utcnow(),
        'status': 'started',
        'end_time': end_time
    }
    entry = db.entries.find_one_and_update({'_id': _id}, {'$set': update}, upsert=False, return_document=ReturnDocument.AFTER)
    dataset = test['dataset']
    dataset_path = os.path.join(app.config['DATA_FILE_DIRECTORY'], dataset)
    with open(dataset_path, 'r') as data_file:
        data = loads(data_file.read())
    questions = generate_questions(data)
    return jsonify({
        'time_limit': end_time,
        'questions': questions,
        'start_time': entry['start_time']
    })

@views.route('/test/')
def start_quiz():
    _id = session.get('_id')
    if not _id or not db.entries.find_one({'_id': _id}):
        print('Foo')
        flash('Your log in was not recognised. Please sign in to the quiz again.', 'error')
        return redirect(url_for('quiz_views.start'))
    return render_template('quiz/client.html')

@views.route('/api/submit/', methods=['POST'])
def submit_quiz():
    _id = request.get_json()['_id']
    answers = request.get_json()['answers']
    entry = db.entries.find_one({'_id': _id})
    if not entry:
        return jsonify('Unrecognised ID', 'error'), 400
    status = 'submitted'
    if entry['end_time']:
        if datetime.utcnow() > entry['end_time'] + timedelta(minutes=2):
            status = 'late'
    test_code = entry['test_code']
    test = db.tests.find_one({'test_code' : test_code})
    dataset = test['dataset']
    dataset_path = os.path.join(app.config['DATA_FILE_DIRECTORY'], dataset)
    with open(dataset_path, 'r') as _dataset:
        data = loads(_dataset.read())
    results = evaluate_answers(data, answers)
    entry = db.entries.find_one_and_update({'_id': _id}, {'$set': {
        'status': status,
        'submission_time': datetime.utcnow(),
        'results': results,
        'answers': answers
    }})
    return jsonify({
        'success': 'Your submission has been processed. Redirecting you to receive your results.',
        '_id': _id
    }), 200

@views.route('/result/')
def result():
    _id = session.get('_id')
    entry = decrypt_find_one(db.entries, {'_id': _id})
    if not entry:
        return abort(404)
    score = round(100*entry['results']['score']/entry['results']['max'])
    tags_low = { tag: tag_result['max'] - tag_result['scored'] for tag, tag_result in entry['results']['tags'].items() }
    sorted_low = sorted(tags_low.items(), key=lambda x: x[1], reverse=True)
    show_low_tags = sorted_low[0:3]
    return render_template('/quiz/result.html', entry=entry, score=score, show_low_tags=show_low_tags)

@views.route('/privacy/')
def privacy():
    return render_template('/quiz/privacy.html')