<?php
/**
 * Initial setup
 *
 * PHP version 7
 *
 * Copyright (C) Ere Maijala 2018-2021
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2,
 * as published by the Free Software Foundation.
 *
 * 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
 *
 * @category MLInvoice
 * @package  MLInvoice\Base
 * @author   Ere Maijala <ere@labs.fi>
 * @license  http://opensource.org/licenses/gpl-2.0.php GNU General Public License
 * @link     http://labs.fi/mlinvoice.eng.php
 */

use phpseclib\Crypt\Random;

/**
 * Initial setup
 *
 * @category MLInvoice
 * @package  MLInvoice\Base
 * @author   Ere Maijala <ere@labs.fi>
 * @license  https://opensource.org/licenses/GPL-2.0 GNU Public License 2.0
 * @link     http://github.com/emaijala/MLInvoice
 */
class Setup
{
    /**
     * Any error encountered
     *
     * @var string
     */
    protected $errorMsg = '';

    /**
     * Initialize database and settings
     *
     * @return void
     */
    public function initialSetup()
    {
        $formMessage = '';
        $setupComplete = false;
        list($host, $database, $username, $password, $prefix, $lang, $defaultlang, $encryptionKey, $encryptionKeyGenerated)
            = $this->getConfigDefaults();
        $adminPassword = '';
        if (isset($_POST['host']) && isset($_POST['database'])
            && isset($_POST['username']) && isset($_POST['password'])
            && isset($_POST['prefix']) && isset($_POST['adminpass'])
            && isset($_POST['lang']) && isset($_POST['defaultlang'])
            && isset($_POST['encryptionkey'])
        ) {
            $host = $_POST['host'];
            $database = $_POST['database'];
            $username = $_POST['username'];
            $password = $_POST['password'];
            $prefix = $_POST['prefix'];
            $adminPassword = $_POST['adminpass'];
            $adminPassword2 = $_POST['adminpass2'];
            $lang = $_POST['lang'];
            $defaultlang = $_POST['defaultlang'];
            $encryptionKey = $_POST['encryptionkey'];
            $encryptionKeyGenerated = false;

            if (empty($lang)) {
                $formMessage = 'At least one language must be selected';
            }
            if (strlen($encryptionKey) < 32) {
                $formMessage = 'Encryption key must be at least 32 characters';
            }
            if ($adminPassword !== $adminPassword2) {
                $formMessage = 'Password for the admin user does not match the verification';
            }
            if ('' === $formMessage) {
                $initParams = compact(
                    'host', 'database', 'username', 'password', 'prefix', 'lang',
                    'defaultlang', 'encryptionKey'
                );
                $db = $this->initDatabaseConnection($initParams);
                if ($db === false) {
                    $formMessage = $this->errorMsg;
                    $this->errorMsg = '';
                } else {
                    $tablesExist = $this->checkDatabaseTables($db, $prefix);
                    if (!$tablesExist && empty($adminPassword)) {
                        $formMessage = 'Password for the admin user is required';
                    } else {
                        $result = copy(
                            __DIR__ . DIRECTORY_SEPARATOR . 'config.php.sample',
                            __DIR__ . DIRECTORY_SEPARATOR . 'config.php'
                        );
                        if (false === $result) {
                            $error = error_get_last();
                            $this->errorMsg = 'Failed to copy config.php.sample to config.php: '
                                . $error['message'];
                        } else {
                            if (!$this->updateConfig($initParams)) {
                                $this->errorMsg = 'Could not write to config.php';
                            } else {
                                if (!$tablesExist) {
                                    $setupComplete = $this->createDatabaseTables($adminPassword);
                                } else {
                                    $setupComplete = empty($adminPassword) || $this->updateAdminPassword($adminPassword);
                                }
                            }
                        }
                    }
                }
            }
        }

        header('Cache-Control: no-store, no-cache, must-revalidate');
        header('Cache-Control: post-check=0, pre-check=0', false);
        // Date in the past
        header('Expires: Mon, 26 Jul 1997 05:00:00 GMT');
        // always modified
        header('Last-Modified: ' . gmdate('D, d M Y H:i:s') . ' GMT');

        $css = [
            'css/style.css'
        ];

        foreach ($css as &$style) {
            $style = '  <link rel="stylesheet" type="text/css" href="'
                . $style . '">';
        }
        $cssLinks = implode("\n", $css);

        ?>
<!DOCTYPE html>
<html lang="en-US">
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>Setup</title>
    <link rel="shortcut icon" href="favicon.ico" type="image/x-icon">
        <?php echo $cssLinks?>
</head>
<body>
    <div class="pagewrapper login mb-4">
        <nav class="navbar navbar-expand-md navbar-light border-bottom mb-2">
            <div class="container-fluid">
                <a class="navbar-brand" href="#">MLInvoice</a>
            </div>
        </nav>

        <?php
        if ($setupComplete) {
            ?>
            <div class="alert alert-success">
                Setup complete. <a href="login.php">Continue to login</a>.
            </div>
            <br />
            <?php
        } elseif ($this->errorMsg) {
            ?>
            <div class="setup-form">
                Please correct the following issues before trying to continue:
            </div>
            <div class="alert alert-danger message">
                <?php echo $this->errorMsg?>
            </div>
            <br />
            <?php
        } else {
            ?>
            <?php if ($formMessage) { ?>
                <div class="alert alert-danger message">
                    <?php echo $formMessage?>
                </div>
            <?php } ?>
            <div class="form setup-form">
                <h1>Welcome</h1>
                <p>
                    Some initial settings are needed before continuing.
                </p>
                <form method="POST" autocomplete="off">
                    <div class="setup-group">
                        <h2>Database Connection</h2>
                        <p>
                            Please enter the following database connection settings.
                        </p>
                        <p>
                            <label>Database server host:<br>
                                <input type="text" name="host" class="form-control medium" value="<?php echo htmlentities($host)?>">
                            </label>
                        </p>
                        <p>
                            <label>Database name:<br>
                                <input type="text" name="database" class="form-control medium" value="<?php echo htmlentities($database)?>">
                            </label>
                        </p>
                        <p>
                            <label>Database username:<br>
                                <input type="text" name="username" class="form-control medium" value="<?php echo htmlentities($username)?>">
                            </label>
                        </p>
                        <p>
                            <label>Database password:<br>
                                <input type="password" name="password" class="form-control medium" value="<?php echo htmlentities($password)?>">
                            </label>
                        </p>
                        <p>
                            <label>Database table name prefix (note that an underscore will be appended to the prefix automatically):<br>
                                <input type="text" name="prefix" class="form-control medium" value="<?php echo htmlentities($prefix)?>">
                            </label>
                        </p>
                    </div>
                    <div class="setup-group">
                        <h2>Admin User</h2>
                        <p>
                            A user called 'admin' will be automatically created and can be used as the login user.
                            Please enter a password for 'admin' that you can use to log in after setup is complete.
                        </p>
                        <p>
                            <label>Password for the 'admin' user for logging in to MLInvoice (optional if the database already exists):<br>
                                <input type="password" name="adminpass" class="form-control medium" value="<?php echo htmlentities($adminPassword)?>">
                            </label>
                        </p>
                        <p>
                            <label>Verify the password for the 'admin' user:<br>
                                <input type="password" name="adminpass2" class="form-control medium" value="<?php echo htmlentities($adminPassword2)?>">
                            </label>
                        </p>
                    </div>
                    <div class="setup-group">
                        <h2>Encryption Key</h2>
                        <p>
                            Please enter an encryption key that is used to encrypt e.g. passwords for mail sending services.
                            The key must be something secret and at least 32 characters long.
                        </p>
                        <?php if ($encryptionKeyGenerated) { ?>
                            <p>
                                A key has been automatically generated. Usually there is no need to modify the key.
                            </p>
                        <?php } ?>
                        <p>
                            <label>Encryption key:<br>
                                <input type="text" name="encryptionkey" class="form-control long" value="<?php echo htmlentities($encryptionKey)?>">
                            </label>
                        </p>
                    </div>
                    <div class="setup-group">
                        <h2>Languages</h2>
                        <p>
                            Finally, please choose the user interface languages that can be selected on login.
                        </p>
                        <p>
                            <label>
                                <input type="checkbox" name="lang[fi-FI]"<?php echo isset($lang['fi-FI']) ? ' checked="checked"' : ''?>>
                                Suomi (Finnish)
                            </label>
                            <br>
                            <label>
                                <input type="checkbox" name="lang[en-US]"<?php echo isset($lang['en-US']) ? ' checked="checked"' : ''?>>
                                English
                            </label>
                            <br>
                            <label>
                                <input type="checkbox" name="lang[sv-FI]"<?php echo isset($lang['sv-FI']) ? ' checked="checked"' : ''?>>
                                Svenska (Swedish)
                            </label>
                        </p>
                        <p>
                            <label>Default Language:<br>
                                <select name="defaultlang">
                                    <option value="fi-FI"<?php echo $defaultlang === 'fi-FI' ? ' selected="selected"' : ''?>>Suomi (Finnish)</option>
                                    <option value="en-US"<?php echo $defaultlang === 'en-US' ? ' selected="selected"' : ''?>>English</option>
                                    <option value="sv-FI"<?php echo $defaultlang === 'sv-FI' ? ' selected="selected"' : ''?>>Svenska (Swedish)</option>
                                </select>
                            </label>
                        </p>
                    </div>
                    <p>
                        <button type="submit" class="btn btn-primary">Continue</button>
                    </p>
                </form>
            </div>
            <?php
        }
        ?>
        </div>
    </div>
</body>
        <?php
    }

    /**
     * Get defaults from config.php.sample
     *
     * @return array host, database, username, password, prefix, languages, default
     * language, encryption key
     */
    protected function getConfigDefaults()
    {
        $host = 'localhost';
        $database = 'mlinvoice';
        $username = 'mlinvoice';
        $password = '';
        $prefix = 'mlinvoice';
        $lang = [];
        $defaultlang = 'fi-FI';
        $encryptionKey = '';
        $encryptionKeyGenerated = false;

        $config = file_get_contents(__DIR__ . DIRECTORY_SEPARATOR . 'config.php.sample');
        if (false === $config) {
            die('Could not read config.php.sample');
        }
        if (preg_match("/define\('_DB_SERVER_', '(.*?)'\)/", $config, $matches)) {
            $host = $matches[1];
        }
        if (preg_match("/define\('_DB_NAME_', '(.*?)'\)/", $config, $matches)) {
            $database = $matches[1];
        }
        if (preg_match("/define\('_DB_USERNAME_', '(.*?)'\)/", $config, $matches)) {
            $username = $matches[1];
        }
        if (preg_match("/define\('_DB_PASSWORD_', '(.*?)'\)/", $config, $matches)) {
            $password = $matches[1];
        }
        if (preg_match("/define\('_DB_PREFIX_', '(.*?)'\)/", $config, $matches)) {
            $prefix = $matches[1];
        }
        if (preg_match("/define\('_UI_LANGUAGE_SELECTION_', '(.*?)'\)/", $config, $matches)) {
            foreach (explode('|', $matches[1]) as $choice) {
                list($code) = explode('=', $choice);
                $lang[$code] = 'on';
            }
        }
        if (preg_match("/define\('_UI_LANGUAGE_', '(.*?)'\)/", $config, $matches)) {
            $defaultlang = $matches[1];
        }
        if (preg_match("/define\('_ENCRYPTION_KEY_', '(.*?)'\)/", $config, $matches)) {
            $encryptionKey = $matches[1];
        }

        if (!$encryptionKey || 'replacewithsomethingsecure' === $encryptionKey) {
            $encryptionKey = trim(base64_encode(Random::string(32)), '=');
            $encryptionKeyGenerated = true;
        }

        return [
            $host,
            $database,
            $username,
            $password,
            $prefix,
            $lang,
            $defaultlang,
            $encryptionKey,
            $encryptionKeyGenerated
        ];
    }

    /**
     * Check if basic config exists
     *
     * @return bool
     */
    protected function configExists()
    {
        return file_exists(__DIR__ . DIRECTORY_SEPARATOR . 'config.php');
    }

    /**
     * Update config file with the given parameters
     *
     * @param array $params Parameters to update
     *
     * @return bool
     */
    protected function updateConfig($params)
    {
        $filename = __DIR__ . DIRECTORY_SEPARATOR . 'config.php';
        $config = file_get_contents($filename);
        if (false === $config) {
            return false;
        }
        $fields = [
            '_DB_SERVER_' => 'host',
            '_DB_NAME_' => 'database',
            '_DB_USERNAME_' => 'username',
            '_DB_PASSWORD_' => 'password',
            '_DB_PREFIX_' => 'prefix',
            '_UI_LANGUAGE_' => 'defaultlang',
            '_ENCRYPTION_KEY_' => 'encryptionKey'
        ];
        foreach ($fields as $key => $value) {
            if (isset($params[$value])) {
                $newVal = str_replace('\'', '\\\'', $params[$value]);
                $config = preg_replace("/\/*define\('$key'\s*,\s*'.*?'\);/", "define('$key', '$newVal');", $config);
            }
        }
        if (!empty($params['lang'])) {
            $langStrings = [
                'en-US' => 'In English',
                'fi-FI' => 'Suomeksi',
                'sv-FI' => 'På svenska'
            ];
            $choices = [];
            foreach ($params['lang'] as $lang => $set) {
                $choices[] = "$lang=" . (isset($langStrings[$lang]) ? $langStrings[$lang] : $lang);
            }
            $newVal = implode('|', $choices);
            $config = preg_replace(
                "/\/*define\('_UI_LANGUAGE_SELECTION_'\s*,\s*'.*?'\);/",
                "define('_UI_LANGUAGE_SELECTION_', '$newVal');",
                $config
            );
        }
        return file_put_contents($filename, $config) !== false;
    }

    /**
     * Initialize database connection
     *
     * @param array $settings Settings to use (overrides config.php if defined)
     *
     * @return object|false
     */
    protected function initDatabaseConnection($settings = [])
    {
        if (isset($settings['host']) && isset($settings['database'])
            && isset($settings['username']) && isset($settings['password'])
        ) {
            $host = $settings['host'];
            $database = $settings['database'];
            $username = $settings['username'];
            $password = $settings['password'];
        } else {
            include_once 'config.php';
            $host = _DB_SERVER_;
            $database = _DB_NAME_;
            $username = _DB_USERNAME_;
            $password = _DB_PASSWORD_;
        }

        $db = @mysqli_connect($host, $username, $password);

        if (mysqli_connect_errno()) {
            $this->errorMsg = 'Database connection failed: ' . mysqli_connect_error();
            return false;
        }
        if (!mysqli_select_db($db, $database)) {
            $this->errorMsg = 'Database selection failed: ' . mysqli_error($db);
            return false;
        }
        if (false === mysqli_query($db, 'SET NAMES \'utf8\'')) {
            $this->errorMsg = 'Database UTF-8 selection failed: ' . mysqli_error($db);
            return false;
        }
        if (false === mysqli_query($db, 'SET AUTOCOMMIT=1')) {
            $this->errorMsg = 'Database autocommit setup failed: ' . mysqli_error($db);
            return false;
        }
        return $db;
    }

    /**
     * Check if database tables exist
     *
     * @param object $db     Database connection
     * @param string $prefix Table name prefix
     *
     * @return bool
     */
    protected function checkDatabaseTables($db, $prefix)
    {
        $res = mysqli_query($db, "SHOW TABLES LIKE '" . $prefix . "_invoice'");
        if (false === $res) {
            $this->errorMsg = 'Could not fetch table list: ' . mysqli_error($db);
            return false;
        }
        if ($row = mysqli_fetch_row($res)) {
            return true;
        }
        return false;
    }

    /**
     * Create database tables
     *
     * @param string $adminPassword Password for the admin user
     *
     * @return bool
     */
    protected function createDatabaseTables($adminPassword = '')
    {
        include_once 'config.php';
        $db = $this->initDatabaseConnection();

        $createCommands = file_get_contents(__DIR__ . DIRECTORY_SEPARATOR . 'create_database.sql');
        $createCommands = str_replace('mlinvoice_', _DB_PREFIX_ . '_', $createCommands);

        $res = mysqli_multi_query($db, $createCommands);
        if (false === $res) {
            $this->errorMsg = 'Could not create database tables: ' . mysqli_error($db);
            return false;
        }
        while (mysqli_more_results($db)) {
            mysqli_next_result($db);
        }

        if ('' !== $adminPassword) {
            $this->updateAdminPassword($adminPassword);
        }

        return true;
    }

    /**
     * Update password for the admin user
     *
     * @param string $adminPassword New password
     *
     * @return bool
     */
    protected function updateAdminPassword($adminPassword = '')
    {
        include_once 'config.php';
        $db = $this->initDatabaseConnection();
        $res = mysqli_query(
            $db,
            'UPDATE '  . _DB_PREFIX_ . "_users SET passwd = '"
            . password_hash($adminPassword, PASSWORD_DEFAULT) . "' WHERE "
            . "login = 'admin'"
        );
        if (false === $res) {
            die('Updating admin password failed: ' . mysqli_error($db));
        }

        return true;
    }
}