/*Canopy - The next generation of stoner streaming software
Copyright (C) 2024  Rainbownapkin and the TTN Community

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as
published by the Free Software Foundation, either version 3 of the
License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License
along with this program.  If not, see <https://www.gnu.org/licenses/>.*/

//local imports
const {userModel} = require('../schemas/user/userSchema');
const userBanModel = require('../schemas/user/userBanSchema')
const altchaUtils = require('../utils/altchaUtils');

//Create failed sign-in cache since it's easier and more preformant to implement it this way than adding extra burdon to the database
//Server restarts are far and few between. It would take multiple during a single bruteforce attempt for this to become an issue.
const failedAttempts = new Map();
const throttleAttempts = 5;
const maxAttempts = 200;

//this module is good for keeping wrappers for userModel and other shit in that does more session handling than database access/modification.
module.exports.authenticateSession = async function(user, pass, req){
    //Fuck you yoda
    try{
        //Grab previous attempts
        const attempt = failedAttempts.get(user);

        //If we have failed attempts
        if(attempt != null){
            //If we have more failed attempts than allowed
            if(attempt.count > maxAttempts){
                throw new Error("This account has been locked for at 24 hours due to a large amount of failed log-in attempts");
            }

            //If we're throttling logins
            if(attempt.count > throttleAttempts){
                //Verification doesnt get sanatized or checked since that would most likely break the cryptography
                //Since we've already got access to the request and dont need to import anything, why bother getting it from a parameter?
                if(req.body.verification == null){
                    throw new Error("Verification failed!");
                }else if(!altchaUtils.verify(req.body.verification, user)){
                    throw new Error("Verification failed!");
                }
            }
        }

        //Authenticate the session
        const userDB = await userModel.authenticate(user, pass);
        const banDB = await userBanModel.checkBanByUserDoc(userDB);

        //If the user is banned
        if(banDB){
            //Make the number a little prettier despite the lack of precision since we're not doing calculations here :P
            const expiration = banDB.getDaysUntilExpiration() < 1 ? 0 : banDB.getDaysUntilExpiration();
            if(banDB.permanent){
                throw new Error(`Your account has been permanently banned, and will be nuked from the database in: ${expiration} day(s)`);
            }else{
                throw new Error(`Your account has been temporarily banned, and will be reinstated in: ${expiration} day(s)`);
            }
        }

        //Tattoo the session with user and metadata
        //unfortunately store.all() does not return sessions w/ their ID so we had to improvise...
        //Not sure if this is just how connect-mongo is implemented or if it's an express issue, but connect-mongodb-session seems to not implement the all() function what so ever...
        req.session.seshid = req.session.id;
        req.session.authdate = new Date();
        req.session.authip = req.ip;
        req.session.user = {
            user: userDB.user,
            id: userDB.id,
            rank: userDB.rank
        }

        //Tattoo hashed IP address to user account for seven days
        userDB.tattooIPRecord(req.ip);

        //If we got to here then the log-in was successful. We should clear-out any failed attempts.
        failedAttempts.delete(user);

        //return user
        return userDB.user;
    }catch(err){
        //Look for previous failed attempts
        var attempt = failedAttempts.get(user);

        //If this is the first attempt
        if(attempt == null){
            //Create new attempt object
            attempt = {
                count: 1,
                lastAttempt: new Date()
            }
        }else{
            //Create updated attempt object
            attempt = {
                count: attempt.count + 1,
                lastAttempt: new Date()
            }
        }

        //Commit the failed attempt to the failed sign-in cache
        failedAttempts.set(user, attempt);

        //y33t
        throw err;
    }
}

module.exports.killSession = async function(session){
    session.destroy();
}

module.exports.getLoginAttempts = function(user){
    //Read the code, i'm not explaining this
    return failedAttempts.get(user);
}

module.exports.processExpiredAttempts = function(){
    for(user of failedAttempts.keys()){
        //Get attempt by user
        const attempt = failedAttempts.get(user);
        //Check how long its been
        const daysSinceLastAttempt = ((new Date() - attempt.lastAttempt) / (1000 * 60 * 60 * 24)).toFixed(1);

        //If it's been more than a day since anyones tried to log in as this user
        if(daysSinceLastAttempt >= 1){
            //Clear out the attempts so that they don't need to fuck with a captcha anymore
            failedAttempts.delete(user);
        }
    }
}

module.exports.throttleAttempts = throttleAttempts;
module.exports.maxAttempts = maxAttempts;