<?php

require_once "common_func.php";

class User
{
    private int $id; // User's ID
    private string $nickname; // User's nickname
    private string $password; // User's password in it's encoded form or left empty
    private string $realname; // User's real name displayed in their profile
    private array $groups; // User's assigned groups
    private string $privilege; // User's privilege
    private UserMgr $userMgr; // UserManager object governing this object.

    // -------------------------------------------

    // Store modifications to the database.
    private function storeMods(): void
    {
        $this->userMgr->updateUser($this);
    }

    // -------------------------------------------

    function __construct(UserMgr &$usrmgr, int $id, string $nickname = null, string $password = null, string $realname = null, array $groups = null, string $privilege = null)
    {
        $this->id = $id;
        $this->nickname = $nickname;
        $this->password = $password;
        $this->realname = $realname;
        $this->groups = $groups;
        $this->privilege = $privilege;

        // save reference to user manager
        $this->userMgr = &$usrmgr;
    }

    // Create user from an array
    static function fromArray(UserMgr &$usrmgr, array $a): User
    {
        $id = $a["id"] ?? -1;
        return new User($usrmgr, $id, $a["nickname"], $a["password"], $a["realname"], $a["groups"], $a["privilege"]);
    }

    // Convert user to array
    function toArray(array $omit = []): array
    {
        $a = [
            "_id" => $this->id,
            "nickname" => $this->nickname,
            "password" => $this->password,
            "realname" => $this->realname,
            "groups" => $this->groups,
            "privilege" => $this->privilege
        ];

        // omit specific fields
        foreach ($omit as $field) {
            unset($a[$field]);
        }

        return $a;
    }

    // Change user password. If $safe, then $old is checked.
    function changePassword(string $new, string $old, bool $safe = true): bool
    {
        if (!$safe || password_verify($old, $this->password)) {
            $this->password = password_hash($new, PASSWORD_DEFAULT);
            $this->storeMods(); // store modifications
            return true;
        } else {
            return false;
        }
    }

    // Change user groups
    function changeGroups(array $add, array $remove): void
    {
        alter_array_contents($this->groups, $add, $remove);
        $this->storeMods(); // store modifications
    }

    // Get user's groups
    function getGroups(): array
    {
        return $this->groups;
    }

    // Set user privilege level
    function setPrivilege(string $privilege): void
    {
        $this->privilege = ($this->nickname === QUIZMASTER_NICKNAME) ? PRIVILEGE_QUIZMASTER : $privilege; // quizmaster's privilege mustn't be tampered with
        $this->storeMods(); // store modifications
    }

    // Get user privilege level
    function getPrivilege(): string
    {
        return $this->privilege;
    }

    // Get user's nickname.
    function getNickname(): string
    {
        return $this->nickname;
    }

    // Set user's real name.
    function setRealname(string $realname): void
    {
        $this->realname = $realname;
    }

    // Get user's real name.
    function getRealname(): string
    {
        return $this->realname;
    }

    // Check against user credentials.
    function checkPassword(string $password): bool
    {
        return password_verify($password, $this->password);
    }

    // Has the user quizmaster privileges?
    function hasQuizmasterPrivilege(): bool
    {
        return $this->privilege == PRIVILEGE_QUIZMASTER;
    }
}

class UserMgr
{
    public \SleekDB\Store $db;

    function __construct()
    {
        // create database
        $this->db = new \SleekDB\Store(USERDB, DATADIR, ["timeout" => false]);
    }

    // Get user by nickname. Returns with a User object if found, null else.
    function getUser(string $nickname): User|null
    {
        $user_data_array = $this->db->findBy(["nickname", "=", $nickname]);
        return count($user_data_array) != 0 ? User::fromArray($this, $user_data_array[0]) : null;
    }

    // Update user.
    function updateUser(User $user): void
    {
        $a = $user->toArray(); // convert to array
        $this->db->update($a); // update using the extracted array
    }

    // checks if a nickname is taken
    function isNicknameTaken(string $nickname): bool
    {
        return !($this->db->findOneBy(["nickname", "=", $nickname]) == null);
    }

    // Add new user.
    function addUser(string $nickname, string $password, string $realname, array $groupids = [], string $privilege = PRIVILEGE_PLAYER): bool
    {
        if ($this->isNicknameTaken($nickname)) { // user exists
            return false;
        }

        $a = [
            "nickname" => $nickname,
            "password" => password_hash($password, PASSWORD_DEFAULT),
            "realname" => $realname,
            "groups" => $groupids,
            "privilege" => $privilege
        ];

        // create user object
        $user = User::fromArray($this, $a);

        // add user to specific groups FIXME!!!!
        foreach ($groupids as $groupid) {
            change_group_user_assignments($groupid, $nickname, null);
        }

        $this->db->insert($user->toArray(["_id"]));

        return true; // user registration successful
    }

    // Delete user from the storage
    function deleteUser(string $nickname): void
    {
        // cannot delete quizmaster
        if ($nickname == QUIZMASTER_NICKNAME) {
            return;
        }

//        $user = $this->getUser($nickname);
//        if ($user !== null) {
//            foreach ($user->getGroups() as $groupid) {
//                change_group_user_assignments($groupid, null, $nickname);
//            }
        $this->db->deleteBy(["nickname", "=", $nickname]);
        //}
    }

    // Dump all users. Users come wrapped in User objects.
    function getAllUsers(): array
    {
        return array_map(fn($a): User => User::fromArray($this, $a), $this->db->findAll());
    }

    // Get all nicknames.
    function getAllNicknames(): array
    {
        $qb = $this->db->createQueryBuilder();
        return array_map(fn($c): string => $c["nickname"], $qb->select(["nickname"])->getQuery()->fetch());
    }
}