<?php

/**
 * Part of the Joomla Framework Database Package
 *
 * @copyright  Copyright (C) 2005 - 2021 Open Source Matters, Inc. All rights reserved.
 * @license    GNU General Public License version 2 or later; see LICENSE
 */

namespace Joomla\Database\Sqlite;

use Joomla\Database\Pdo\PdoDriver;

/**
 * SQLite database driver supporting PDO based connections
 *
 * @link   https://www.php.net/manual/en/ref.pdo-sqlite.php
 * @since  1.0
 */
class SqliteDriver extends PdoDriver
{
    /**
     * The name of the database driver.
     *
     * @var    string
     * @since  1.0
     */
    public $name = 'sqlite';

    /**
     * The character(s) used to quote SQL statement names such as table names or field names, etc.
     *
     * If a single character string the same character is used for both sides of the quoted name, else the first character will be used for the
     * opening quote and the second for the closing quote.
     *
     * @var    string
     * @since  1.0
     */
    protected $nameQuote = '`';

    /**
     * Destructor.
     *
     * @since   1.0
     */
    public function __destruct()
    {
        $this->disconnect();
    }

    /**
     * Alter database's character set.
     *
     * @param   string  $dbName  The database name that will be altered
     *
     * @return  boolean|resource
     *
     * @since   2.0.0
     * @throws  \RuntimeException
     */
    public function alterDbCharacterSet($dbName)
    {
        return false;
    }

    /**
     * Connects to the database if needed.
     *
     * @return  void  Returns void if the database connected successfully.
     *
     * @since   2.0.0
     * @throws  \RuntimeException
     */
    public function connect()
    {
        if ($this->connection) {
            return;
        }

        parent::connect();

        $this->connection->sqliteCreateFunction(
            'ROW_NUMBER',
            function ($init = null) {
                static $rownum, $partition;

                if ($init !== null) {
                    $rownum    = $init;
                    $partition = null;

                    return $rownum;
                }

                $args = \func_get_args();
                array_shift($args);

                $partitionBy = $args ? implode(',', $args) : null;

                if ($partitionBy === null || $partitionBy === $partition) {
                    $rownum++;
                } else {
                    $rownum    = 1;
                    $partition = $partitionBy;
                }

                return $rownum;
            }
        );
    }

    /**
     * Create a new database using information from $options object.
     *
     * @param   \stdClass  $options  Object used to pass user and database name to database driver. This object must have "db_name" and "db_user" set.
     * @param   boolean    $utf      True if the database supports the UTF-8 character set.
     *
     * @return  boolean|resource
     *
     * @since   2.0.0
     * @throws  \RuntimeException
     */
    public function createDatabase($options, $utf = true)
    {
        // SQLite doesn't have a query for this
        return true;
    }

    /**
     * Method to escape a string for usage in an SQLite statement.
     *
     * Note: Using query objects with bound variables is preferable to the below.
     *
     * @param   string   $text   The string to be escaped.
     * @param   boolean  $extra  Unused optional parameter to provide extra escaping.
     *
     * @return  string  The escaped string.
     *
     * @since   1.0
     */
    public function escape($text, $extra = false)
    {
        if (\is_int($text)) {
            return $text;
        }

        if (\is_float($text)) {
            // Force the dot as a decimal point.
            return str_replace(',', '.', $text);
        }

        return \SQLite3::escapeString($text);
    }

    /**
     * Method to get the database collation in use by sampling a text field of a table in the database.
     *
     * @return  string|boolean  The collation in use by the database or boolean false if not supported.
     *
     * @since   1.0
     */
    public function getCollation()
    {
        return false;
    }

    /**
     * Method to get the database connection collation in use by sampling a text field of a table in the database.
     *
     * @return  string|boolean  The collation in use by the database connection (string) or boolean false if not supported.
     *
     * @since   1.6.0
     * @throws  \RuntimeException
     */
    public function getConnectionCollation()
    {
        return false;
    }

    /**
     * Method to get the database encryption details (cipher and protocol) in use.
     *
     * @return  string  The database encryption details.
     *
     * @since   2.0.0
     * @throws  \RuntimeException
     */
    public function getConnectionEncryption(): string
    {
        // TODO: Not fake this
        return '';
    }

    /**
     * Method to test if the database TLS connections encryption are supported.
     *
     * @return  boolean  Whether the database supports TLS connections encryption.
     *
     * @since   2.0.0
     */
    public function isConnectionEncryptionSupported(): bool
    {
        // TODO: Not fake this
        return false;
    }

    /**
     * Shows the table CREATE statement that creates the given tables.
     *
     * Note: Doesn't appear to have support in SQLite
     *
     * @param   mixed  $tables  A table name or a list of table names.
     *
     * @return  array  A list of the create SQL for the tables.
     *
     * @since   1.0
     * @throws  \RuntimeException
     */
    public function getTableCreate($tables)
    {
        $this->connect();

        // Sanitize input to an array and iterate over the list.
        $tables = (array) $tables;

        return $tables;
    }

    /**
     * Retrieves field information about a given table.
     *
     * @param   string   $table     The name of the database table.
     * @param   boolean  $typeOnly  True to only return field types.
     *
     * @return  array  An array of fields for the database table.
     *
     * @since   1.0
     * @throws  \RuntimeException
     */
    public function getTableColumns($table, $typeOnly = true)
    {
        $this->connect();

        $columns = [];

        $fieldCasing = $this->getOption(\PDO::ATTR_CASE);

        $this->setOption(\PDO::ATTR_CASE, \PDO::CASE_UPPER);

        $table = strtoupper($table);

        $fields = $this->setQuery('pragma table_info(' . $table . ')')->loadObjectList();

        if ($typeOnly) {
            foreach ($fields as $field) {
                $columns[$field->NAME] = $field->TYPE;
            }
        } else {
            foreach ($fields as $field) {
                // Do some dirty translation to MySQL output.
                // TODO: Come up with and implement a standard across databases.
                $columns[$field->NAME] = (object) [
                    'Field'   => $field->NAME,
                    'Type'    => $field->TYPE,
                    'Null'    => $field->NOTNULL == '1' ? 'NO' : 'YES',
                    'Default' => $field->DFLT_VALUE,
                    'Key'     => $field->PK != '0' ? 'PRI' : '',
                ];
            }
        }

        $this->setOption(\PDO::ATTR_CASE, $fieldCasing);

        return $columns;
    }

    /**
     * Get the details list of keys for a table.
     *
     * @param   string  $table  The name of the table.
     *
     * @return  array  An array of the column specification for the table.
     *
     * @since   1.0
     * @throws  \RuntimeException
     */
    public function getTableKeys($table)
    {
        $this->connect();

        $keys = [];

        $fieldCasing = $this->getOption(\PDO::ATTR_CASE);

        $this->setOption(\PDO::ATTR_CASE, \PDO::CASE_UPPER);

        $table = strtoupper($table);

        $rows = $this->setQuery('pragma table_info( ' . $table . ')')->loadObjectList();

        foreach ($rows as $column) {
            if ($column->PK == 1) {
                $keys[$column->NAME] = $column;
            }
        }

        $this->setOption(\PDO::ATTR_CASE, $fieldCasing);

        return $keys;
    }

    /**
     * Method to get an array of all tables in the database (schema).
     *
     * @return  array   An array of all the tables in the database.
     *
     * @since   1.0
     * @throws  \RuntimeException
     */
    public function getTableList()
    {
        $this->connect();

        $type = 'table';

        $query = $this->createQuery()
            ->select('name')
            ->from('sqlite_master')
            ->where('type = :type')
            ->bind(':type', $type)
            ->order('name');

        return $this->setQuery($query)->loadColumn();
    }

    /**
     * Get the version of the database connector.
     *
     * @return  string  The database connector version.
     *
     * @since   1.0
     */
    public function getVersion()
    {
        $this->connect();

        return $this->setQuery('SELECT sqlite_version()')->loadResult();
    }

    /**
     * Select a database for use.
     *
     * @param   string  $database  The name of the database to select for use.
     *
     * @return  boolean  True if the database was successfully selected.
     *
     * @since   1.0
     * @throws  \RuntimeException
     */
    public function select($database)
    {
        $this->connect();

        return true;
    }

    /**
     * Set the connection to use UTF-8 character encoding.
     *
     * Returns false automatically for the Oracle driver since
     * you can only set the character set when the connection
     * is created.
     *
     * @return  boolean  True on success.
     *
     * @since   1.0
     */
    public function setUtf()
    {
        $this->connect();

        return false;
    }

    /**
     * Locks a table in the database.
     *
     * @param   string  $table  The name of the table to unlock.
     *
     * @return  $this
     *
     * @since   1.0
     * @throws  \RuntimeException
     */
    public function lockTable($table)
    {
        return $this;
    }

    /**
     * Renames a table in the database.
     *
     * @param   string  $oldTable  The name of the table to be renamed
     * @param   string  $newTable  The new name for the table.
     * @param   string  $backup    Not used by Sqlite.
     * @param   string  $prefix    Not used by Sqlite.
     *
     * @return  $this
     *
     * @since   1.0
     * @throws  \RuntimeException
     */
    public function renameTable($oldTable, $newTable, $backup = null, $prefix = null)
    {
        $this->setQuery('ALTER TABLE ' . $oldTable . ' RENAME TO ' . $newTable)->execute();

        return $this;
    }

    /**
     * Method to truncate a table.
     *
     * @param   string  $table  The table to truncate
     *
     * @return  void
     *
     * @since   1.2.1
     * @throws  \RuntimeException
     */
    public function truncateTable($table)
    {
        $this->setQuery('DELETE FROM ' . $this->quoteName($table))
            ->execute();
    }

    /**
     * Unlocks tables in the database.
     *
     * @return  $this
     *
     * @since   1.0
     * @throws  \RuntimeException
     */
    public function unlockTables()
    {
        return $this;
    }

    /**
     * Test to see if the PDO ODBC connector is available.
     *
     * @return  boolean  True on success, false otherwise.
     *
     * @since   1.0
     */
    public static function isSupported()
    {
        return class_exists('\\PDO') && class_exists('\\SQLite3') && \in_array('sqlite', \PDO::getAvailableDrivers(), true);
    }

    /**
     * Method to commit a transaction.
     *
     * @param   boolean  $toSavepoint  If true, commit to the last savepoint.
     *
     * @return  void
     *
     * @since   1.0
     * @throws  \RuntimeException
     */
    public function transactionCommit($toSavepoint = false)
    {
        $this->connect();

        if (!$toSavepoint || $this->transactionDepth <= 1) {
            parent::transactionCommit($toSavepoint);
        } else {
            $this->transactionDepth--;
        }
    }

    /**
     * Method to roll back a transaction.
     *
     * @param   boolean  $toSavepoint  If true, rollback to the last savepoint.
     *
     * @return  void
     *
     * @since   1.0
     * @throws  \RuntimeException
     */
    public function transactionRollback($toSavepoint = false)
    {
        $this->connect();

        if (!$toSavepoint || $this->transactionDepth <= 1) {
            parent::transactionRollback($toSavepoint);
        } else {
            $savepoint = 'SP_' . ($this->transactionDepth - 1);
            $this->setQuery('ROLLBACK TO ' . $this->quoteName($savepoint))->execute();

            $this->transactionDepth--;
        }
    }

    /**
     * Method to initialize a transaction.
     *
     * @param   boolean  $asSavepoint  If true and a transaction is already active, a savepoint will be created.
     *
     * @return  void
     *
     * @since   1.0
     * @throws  \RuntimeException
     */
    public function transactionStart($asSavepoint = false)
    {
        $this->connect();

        if (!$asSavepoint || !$this->transactionDepth) {
            parent::transactionStart($asSavepoint);
        } else {
            $savepoint = 'SP_' . $this->transactionDepth;
            $this->setQuery('SAVEPOINT ' . $this->quoteName($savepoint))->execute();

            $this->transactionDepth++;
        }
    }
}
