<?php

interface IPassword
{
    /**
     * @abstract
     * @param $salt string
     * @return bool
     */
    public function Validate($salt);

    /**
     * @abstract
     * @param $userid int
     * @return void
     */
    public function Migrate($userid);
}

class PasswordMigration
{
    /**
     * @param $plaintext
     * @param $oldpassword
     * @param $newpassword
     * @return IPassword
     */
    public function Create($plaintext, $oldpassword, $newpassword)
    {
        if (!empty($newpassword)) {
            return new Password($plaintext, $newpassword);
        }
        return new OldPassword($plaintext, $oldpassword, new RetiredPasswordEncryption());
    }
}

class Password implements IPassword
{
    /**
     * @internal
     * @var null|string
     */
    public static $_Random = null;

    /**
     * @var \PasswordEncryption
     */
    public $Encryption;

    /**
     * @var string
     */
    protected $plaintext;

    /**
     * @var string
     */
    protected $encrypted;

    /**
     * @param $plaintext string
     * @param $encrypted string
     */
    public function __construct($plaintext, $encrypted)
    {
        $this->plaintext = $plaintext;
        $this->encrypted = $encrypted;

        $this->Encryption = new PasswordEncryption();
    }

    /**
     * @return string
     */
    public function PlainText()
    {
        return $this->plaintext;
    }

    /**
     * @return string
     */
    public function Encrypted()
    {
        return $this->encrypted;
    }

    public function Validate($salt)
    {
        $encrypted = $this->Encryption->Encrypt($this->plaintext, $salt);

        return $this->encrypted == $encrypted;
    }

    public function Migrate($userid)
    {
        // noop
    }

    /**
     * @static
     * @return string
     */
    public static function GenerateRandom()
    {
        if (self::$_Random != null) {
            return self::$_Random;
        }

        $length = 10;
        $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ@#$%';
        $password ='';
        $max = strlen($characters) - 1;

        for ($i = 0; $i < $length; $i++) {
            $password .= $characters[mt_rand(0, $max)];
        }

        return $password;
    }
}

class OldPassword extends Password
{
    public $RetiredPasswordEncryption;

    public function __construct($plaintext, $encrypted)
    {
        $this->RetiredPasswordEncryption = new RetiredPasswordEncryption();
        parent::__construct($plaintext, $encrypted);
    }

    public function Validate($salt)
    {
        return $this->encrypted == $this->RetiredPasswordEncryption->Encrypt($this->plaintext);
    }

    public function Migrate($userid)
    {
        $salt = $this->Encryption->Salt();
        $encrypted = $this->Encryption->Encrypt($this->plaintext, $salt);
        ServiceLocator::GetDatabase()->Execute(new MigratePasswordCommand($userid, $encrypted, $salt));
        ServiceLocator::GetDatabase()->Execute(new RemoveLegacyPasswordCommand($userid));
    }
}
