#!/usr/bin/env python3
# -*-coding:UTF-8 -*

'''
    Flask functions and routes for the rest api
'''

import os
import re
import sys
import uuid
import json
import redis
import datetime

from flask import Flask, render_template, jsonify, request, Blueprint, redirect, url_for, Response
from flask_login import login_required

from functools import wraps

# ============ BLUEPRINT ============

restApi = Blueprint('restApi', __name__, template_folder='templates')

# ============ VARIABLES ============

host_redis_metadata = os.getenv('D4_REDIS_METADATA_HOST', "localhost")
port_redis_metadata = int(os.getenv('D4_REDIS_METADATA_PORT', 6380))

r_serv_db = redis.StrictRedis(
                host=host_redis_metadata,
                port=port_redis_metadata,
                db=1,
                decode_responses=True)

# ============ AUTH FUNCTIONS ============

def check_token_format(strg, search=re.compile(r'[^a-zA-Z0-9_-]').search):
    return not bool(search(strg))

def verify_token(token):
    if len(token) != 41:
        return False

    if not check_token_format(token):
        return False

    if r_serv_db.hexists('user:tokens', token):
        return True
    else:
        return False

def get_user_from_token(token):
    return r_serv_db.hget('user:tokens', token)

def verify_user_role(role, token):
    user_id = get_user_from_token(token)
    if user_id:
        if is_in_role(user_id, role):
            return True
        else:
            return False
    else:
        return False

def is_in_role(user_id, role):
    if r_serv_db.sismember('user_role:{}'.format(role), user_id):
        return True
    else:
        return False

# ============ DECORATOR ============

def token_required(user_role):
    def actual_decorator(funct):
        @wraps(funct)
        def api_token(*args, **kwargs):
            data = authErrors(user_role)
            if data:
                return Response(json.dumps(data[0], indent=2, sort_keys=True), mimetype='application/json'), data[1]
            else:
                return funct(*args, **kwargs)
        return api_token
    return actual_decorator

def get_auth_from_header():
    token = request.headers.get('Authorization').replace(' ', '') # remove space
    return token

def authErrors(user_role):
    # Check auth
    if not request.headers.get('Authorization'):
        return ({'status': 'error', 'reason': 'Authentication needed'}, 401)
    token = get_auth_from_header()
    data = None
    # verify token format

    '''
    # brute force protection
    current_ip = request.remote_addr
    login_failed_ip = r_cache.get('failed_login_ip_api:{}'.format(current_ip))
    # brute force by ip
    if login_failed_ip:
        login_failed_ip = int(login_failed_ip)
        if login_failed_ip >= 5:
            return ({'status': 'error', 'reason': 'Max Connection Attempts reached, Please wait {}s'.format(r_cache.ttl('failed_login_ip_api:{}'.format(current_ip)))}, 401)
    '''

    try:
        authenticated = False
        if verify_token(token):
            authenticated = True

            # check user role
            if not verify_user_role(user_role, token):
                data = ({'status': 'error', 'reason': 'Access Forbidden'}, 403)

        if not authenticated:
            #r_cache.incr('failed_login_ip_api:{}'.format(current_ip))
            #r_cache.expire('failed_login_ip_api:{}'.format(current_ip), 300)
            data = ({'status': 'error', 'reason': 'Authentication failed'}, 401)
    except Exception as e:
        print(e)
        data = ({'status': 'error', 'reason': 'Malformed Authentication String'}, 400)
    if data:
        return data
    else:
        return None

# ============ FUNCTIONS ============

def is_valid_uuid_v4(header_uuid):
    try:
        header_uuid=header_uuid.replace('-', '')
        uuid_test = uuid.UUID(hex=header_uuid, version=4)
        return uuid_test.hex == header_uuid
    except:
        return False

def one():
    return 1

# ============= ROUTES ==============


@restApi.route("/api/v1/get/item", methods=['GET'])
@token_required('user')
def get_item_id():
    data = request.get_json()
    res = ({'test': 2}, 200)
    return Response(json.dumps(res[0], indent=2, sort_keys=True), mimetype='application/json'), res[1]