from werkzeug.security import generate_password_hash
from flask import Flask
from flask_restful import Api, Resource, request
from flask_sqlalchemy import SQLAlchemy
from marshmallow import Schema, fields, ValidationError, validate, validates
from flask_migrate import Migrate
from decouple import config
from password_strength import PasswordPolicy

app = Flask(__name__)
db_user = config('DB_USER')
db_pw = config('DB_PASSWORD')
db_name = config('DB_NAME')
db_port = config('DB_PORT')
app.config['SQLALCHEMY_DATABASE_URI'] = f'postgresql://{db_user}:{db_pw}@localhost:{db_port}/{db_name}'

db = SQLAlchemy(app)
api = Api(app)
migrate = Migrate(app, db)
policy = PasswordPolicy.from_names(uppercase=1, numbers=1, special=1, nonletters=1)


class Client(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String, nullable=False)
    password = db.Column(db.String, nullable=False)
    role = db.Column(db.String, nullable=True, server_default="user")


def validate_password(value):
    errors = policy.test(value)
    if errors:
        raise ValidationError(f"Not a valid password")


def user_name_not_exist(value):
    if value not in [name.username for name in Client.query.all()]:
        raise ValidationError(f"User doesnt exists")


def password_not_match(value):
    user = Client.query.filter_by(username=request.json["username"]).first()
    if user and user.password != generate_password_hash(value, method='sha256'):
        raise ValidationError(f"Wrong password! Try again.")


class ClientValidation(Schema):
    username = fields.String(required=True)
    password = fields.String(required=True, validate=validate.And(validate.Length(min=8, max=20), validate_password))


class LogInValidation(Schema):
    username = fields.String(required=True, validate=user_name_not_exist)
    password = fields.String(required=True, validate=password_not_match)


class SignUp(Resource):
    def post(self):
        data = request.get_json()
        schema = ClientValidation()
        errors = schema.validate(data)

        if not errors:
            data["password"] = generate_password_hash(data["password"], method='sha256')
            client = Client(**data)
            db.session.add(client)
            db.session.commit()
            return 201

        return errors


class LogIn(Resource):
    def post(self):
        data = request.get_json()
        schema = LogInValidation()
        errors = schema.validate(data)

        if not errors:
            return 201
        return errors


api.add_resource(SignUp, "/sign_up")
api.add_resource(LogIn, "/login")

if __name__ == "__main__":
    app.run(debug=True)