/*
 * Copyright (C) 2017  Kevin Whitaker <eyecreate@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 */

#include "LoginInterface.h"
#include "../db/UserAction.h"
#include <Wt/WApplication>
#include <Wt/WEnvironment>
#include <Wt/Dbo/ptr>
#include <Wt/Auth/HashFunction>
#include <Wt/WRandom>

LoginInterface::LoginInterface(WebInterface* app) 
{
    this->app = app;
    loginContainer = new Wt::WContainerWidget();
    loginLayout = new Wt::WVBoxLayout();
    loginMessage = new Wt::WText("Please Login to access.");
    loginContainer->setLayout(loginLayout);
    usernameArea = new Wt::WHBoxLayout();
    passwordArea = new Wt::WHBoxLayout();
    usernameContainer = new Wt::WContainerWidget();
    passwordContainer = new Wt::WContainerWidget();
    usernameContainer->setLayout(usernameArea);
    passwordContainer->setLayout(passwordArea);
    usernameField = new Wt::WLineEdit();
    passwordField = new Wt::WLineEdit();
    passwordField->setEchoMode(Wt::WLineEdit::EchoMode::Password);
    usernameArea->addWidget(new Wt::WText("Username:"));
    usernameArea->addWidget(usernameField);
    passwordArea->addWidget(new Wt::WText("Password:"));
    passwordArea->addWidget(passwordField);
    loginLayout->addWidget(loginMessage);
    loginLayout->addWidget(usernameContainer);
    loginLayout->addWidget(passwordContainer);
    loginButton = new Wt::WPushButton("Login");
    loginButton->clicked().connect(this, &LoginInterface::loginCheck);
    setContentAlignment(Wt::AlignmentFlag::AlignCenter);
    loginLayout->addWidget(loginButton);
    addChild(loginContainer);
    loginContainer->setWidth(Wt::WLength(50, Wt::WLength::Percentage));
}

void LoginInterface::checkSessionValidity()
{
    Wt::Dbo::Session sqlSession;
    sqlSession.setConnectionPool(*GroovePlayerMgr::getInstance()->connectionPool);
    sqlSession.mapClass<User>("user");
    sqlSession.mapClass<AudioTrack>("tracks");
    sqlSession.mapClass<UserAction>("actions");
    //First check if cookie is set and if is a valid user. Skip login if valid.
    try{
        if(Wt::WApplication::instance()->environment().getCookieValue("arbitrateor_user") != nullptr && getUserForLoginCookie(&sqlSession, *Wt::WApplication::instance()->environment().getCookieValue("arbitrateor_user")).username != User().username)
        {
            app->currentUser = getUserForLoginCookie(&sqlSession, *Wt::WApplication::instance()->environment().getCookieValue("arbitrateor_user"));
            app->loginCompleted();
        }
    }
    catch(std::runtime_error e){}
}

void LoginInterface::loginCheck()
{
    //Reset message in case of success.
    loginMessage->setText("Please Login to access.");
    loginMessage->decorationStyle().setForegroundColor(Wt::WColor("black"));
    
    //First, check if username and password are filled.
    if(usernameField->text().empty() || passwordField->text().empty())
    {
        loginMessage->setText("Please fill out username and password.");
        loginMessage->decorationStyle().setForegroundColor(Wt::WColor("red"));
        return;
    }
    
    Wt::Dbo::Session sqlSession;
    sqlSession.setConnectionPool(*GroovePlayerMgr::getInstance()->connectionPool);
    sqlSession.mapClass<User>("user");
    sqlSession.mapClass<AudioTrack>("tracks");
    sqlSession.mapClass<UserAction>("actions");
    
    //Check if there are any users. If not, use the username/password as new admin user.
    if(getUserCount(&sqlSession) < 1)
    {
        createUser(&sqlSession, usernameField->text().toUTF8(),passwordField->text().toUTF8(), true);
    }
    //Check if the credentials match anything in the DB. If so, store cookie to skip login.
    if(getUserForLoginAuth(&sqlSession, usernameField->text().toUTF8(),passwordField->text().toUTF8()).username != User().username && !getUserForLoginAuth(&sqlSession, usernameField->text().toUTF8(),passwordField->text().toUTF8()).isDisabled)
    {
        app->currentUser = getUserForLoginAuth(&sqlSession, usernameField->text().toUTF8(),passwordField->text().toUTF8());
        Wt::log("info") << "login by "<< app->currentUser.username << " happened.";
        setLocalCookieForUser(app->currentUser);
        app->loginCompleted();
        //Now mark this as a successful login.
        Wt::Dbo::Transaction loginTransaction(sqlSession);
        UserAction* action = new UserAction();
        action->action = UserAction::UAction::Login;
        action->user = sqlSession.find<User>().where("username = ?").bind(app->currentUser.username);
        action->datetime = Wt::WDateTime::currentDateTime();
        sqlSession.add(action);
        loginTransaction.commit();
    }
    //If credentials don't match, reject user with message saying crednetials are wrong and they can ask an admin to make them an account.
    else
    {
        loginMessage->setText("Username or password is incorrect. Do you have an account?");
        loginMessage->decorationStyle().setForegroundColor(Wt::WColor("red"));
    }
}

void LoginInterface::createUser(Wt::Dbo::Session* session, std::string username, std::string rawPassword, bool isAdmin)
{
    Wt::Dbo::Transaction transaction(*session);
    Wt::Auth::BCryptHashFunction hasher;
    User* user = new User();
    user->isAdmin = isAdmin;
    user->username = username;
    user->isDisabled = false;
    user->passwordSalt = Wt::WRandom::generateId();
    user->passwordHash = hasher.compute(rawPassword, user->passwordSalt);
    user->loginCookieToken = Wt::WRandom::generateId();
    session->add(user);
    transaction.commit();
}

int LoginInterface::getUserCount(Wt::Dbo::Session* session)
{
    Wt::Dbo::Transaction transaction(*session);
    int userCount = session->query<int>("select count(username) from user");
    transaction.commit();
    return userCount;
}

User LoginInterface::getUserForLoginCookie(Wt::Dbo::Session* session, std::string cookie)
{
    Wt::Dbo::Transaction transaction(*session);
    Wt::Dbo::ptr<User> user = session->find<User>().where("cookie = ?").bind(cookie);
    transaction.commit();
    if(user.get() != nullptr)
    {
        return (*user);
    }
    return User();
}

User LoginInterface::getUserForLoginAuth(Wt::Dbo::Session* session, std::string username, std::string rawPassword)
{
    Wt::Dbo::Transaction transaction(*session);
    Wt::Auth::BCryptHashFunction hasher;
    Wt::Dbo::ptr<User> user = session->find<User>().where("username = ?").bind(username);
    if(user.get() != nullptr && hasher.compute(rawPassword,(*user).passwordSalt) == (*user).passwordHash)
    {
        transaction.commit();
        return (*user);
    }
    transaction.commit();
    return User();
}

void LoginInterface::setLocalCookieForUser(User user)
{
    this->app->setCookie("arbitrateor_user", user.loginCookieToken,2628000);
}