<?php

namespace Doctrine\DBAL\Schema;

use Doctrine\DBAL\Platforms\MariaDb1027Platform;
use Doctrine\DBAL\Platforms\MySqlPlatform;
use Doctrine\DBAL\Types\Type;

use function array_change_key_case;
use function array_shift;
use function array_values;
use function assert;
use function explode;
use function is_string;
use function preg_match;
use function strpos;
use function strtok;
use function strtolower;
use function strtr;

use const CASE_LOWER;

/**
 * Schema manager for the MySql RDBMS.
 */
class MySqlSchemaManager extends AbstractSchemaManager
{
    /**
     * @see https://mariadb.com/kb/en/library/string-literals/#escape-sequences
     */
    private const MARIADB_ESCAPE_SEQUENCES = [
        '\\0' => "\0",
        "\\'" => "'",
        '\\"' => '"',
        '\\b' => "\b",
        '\\n' => "\n",
        '\\r' => "\r",
        '\\t' => "\t",
        '\\Z' => "\x1a",
        '\\\\' => '\\',
        '\\%' => '%',
        '\\_' => '_',

        // Internally, MariaDB escapes single quotes using the standard syntax
        "''" => "'",
    ];

    /**
     * {@inheritdoc}
     */
    protected function _getPortableViewDefinition($view)
    {
        return new View($view['TABLE_NAME'], $view['VIEW_DEFINITION']);
    }

    /**
     * {@inheritdoc}
     */
    protected function _getPortableTableDefinition($table)
    {
        return array_shift($table);
    }

    /**
     * {@inheritdoc}
     */
    protected function _getPortableUserDefinition($user)
    {
        return [
            'user' => $user['User'],
            'password' => $user['Password'],
        ];
    }

    /**
     * {@inheritdoc}
     */
    protected function _getPortableTableIndexesList($tableIndexes, $tableName = null)
    {
        foreach ($tableIndexes as $k => $v) {
            $v = array_change_key_case($v, CASE_LOWER);
            if ($v['key_name'] === 'PRIMARY') {
                $v['primary'] = true;
            } else {
                $v['primary'] = false;
            }

            if (strpos($v['index_type'], 'FULLTEXT') !== false) {
                $v['flags'] = ['FULLTEXT'];
            } elseif (strpos($v['index_type'], 'SPATIAL') !== false) {
                $v['flags'] = ['SPATIAL'];
            }

            $v['length'] = isset($v['sub_part']) ? (int) $v['sub_part'] : null;

            $tableIndexes[$k] = $v;
        }

        return parent::_getPortableTableIndexesList($tableIndexes, $tableName);
    }

    /**
     * {@inheritdoc}
     */
    protected function _getPortableDatabaseDefinition($database)
    {
        return $database['Database'];
    }

    /**
     * {@inheritdoc}
     */
    protected function _getPortableTableColumnDefinition($tableColumn)
    {
        $tableColumn = array_change_key_case($tableColumn, CASE_LOWER);

        $dbType = strtolower($tableColumn['type']);
        $dbType = strtok($dbType, '(), ');
        assert(is_string($dbType));

        $length = $tableColumn['length'] ?? strtok('(), ');

        $fixed = null;

        if (! isset($tableColumn['name'])) {
            $tableColumn['name'] = '';
        }

        $scale     = null;
        $precision = null;

        $type = $this->_platform->getDoctrineTypeMapping($dbType);

        // In cases where not connected to a database DESCRIBE $table does not return 'Comment'
        if (isset($tableColumn['comment'])) {
            $type                   = $this->extractDoctrineTypeFromComment($tableColumn['comment'], $type);
            $tableColumn['comment'] = $this->removeDoctrineTypeFromComment($tableColumn['comment'], $type);
        }

        switch ($dbType) {
            case 'char':
            case 'binary':
                $fixed = true;
                break;

            case 'float':
            case 'double':
            case 'real':
            case 'numeric':
            case 'decimal':
                if (preg_match('([A-Za-z]+\(([0-9]+)\,([0-9]+)\))', $tableColumn['type'], $match)) {
                    $precision = $match[1];
                    $scale     = $match[2];
                    $length    = null;
                }

                break;

            case 'tinytext':
                $length = MySqlPlatform::LENGTH_LIMIT_TINYTEXT;
                break;

            case 'text':
                $length = MySqlPlatform::LENGTH_LIMIT_TEXT;
                break;

            case 'mediumtext':
                $length = MySqlPlatform::LENGTH_LIMIT_MEDIUMTEXT;
                break;

            case 'tinyblob':
                $length = MySqlPlatform::LENGTH_LIMIT_TINYBLOB;
                break;

            case 'blob':
                $length = MySqlPlatform::LENGTH_LIMIT_BLOB;
                break;

            case 'mediumblob':
                $length = MySqlPlatform::LENGTH_LIMIT_MEDIUMBLOB;
                break;

            case 'tinyint':
            case 'smallint':
            case 'mediumint':
            case 'int':
            case 'integer':
            case 'bigint':
            case 'year':
                $length = null;
                break;
        }

        if ($this->_platform instanceof MariaDb1027Platform) {
            $columnDefault = $this->getMariaDb1027ColumnDefault($this->_platform, $tableColumn['default']);
        } else {
            $columnDefault = $tableColumn['default'];
        }

        $options = [
            'length'        => $length !== null ? (int) $length : null,
            'unsigned'      => strpos($tableColumn['type'], 'unsigned') !== false,
            'fixed'         => (bool) $fixed,
            'default'       => $columnDefault,
            'notnull'       => $tableColumn['null'] !== 'YES',
            'scale'         => null,
            'precision'     => null,
            'autoincrement' => strpos($tableColumn['extra'], 'auto_increment') !== false,
            'comment'       => isset($tableColumn['comment']) && $tableColumn['comment'] !== ''
                ? $tableColumn['comment']
                : null,
        ];

        if ($scale !== null && $precision !== null) {
            $options['scale']     = (int) $scale;
            $options['precision'] = (int) $precision;
        }

        $column = new Column($tableColumn['field'], Type::getType($type), $options);

        if (isset($tableColumn['characterset'])) {
            $column->setPlatformOption('charset', $tableColumn['characterset']);
        }

        if (isset($tableColumn['collation'])) {
            $column->setPlatformOption('collation', $tableColumn['collation']);
        }

        return $column;
    }

    /**
     * Return Doctrine/Mysql-compatible column default values for MariaDB 10.2.7+ servers.
     *
     * - Since MariaDb 10.2.7 column defaults stored in information_schema are now quoted
     *   to distinguish them from expressions (see MDEV-10134).
     * - CURRENT_TIMESTAMP, CURRENT_TIME, CURRENT_DATE are stored in information_schema
     *   as current_timestamp(), currdate(), currtime()
     * - Quoted 'NULL' is not enforced by Maria, it is technically possible to have
     *   null in some circumstances (see https://jira.mariadb.org/browse/MDEV-14053)
     * - \' is always stored as '' in information_schema (normalized)
     *
     * @link https://mariadb.com/kb/en/library/information-schema-columns-table/
     * @link https://jira.mariadb.org/browse/MDEV-13132
     *
     * @param string|null $columnDefault default value as stored in information_schema for MariaDB >= 10.2.7
     */
    private function getMariaDb1027ColumnDefault(MariaDb1027Platform $platform, ?string $columnDefault): ?string
    {
        if ($columnDefault === 'NULL' || $columnDefault === null) {
            return null;
        }

        if (preg_match('/^\'(.*)\'$/', $columnDefault, $matches)) {
            return strtr($matches[1], self::MARIADB_ESCAPE_SEQUENCES);
        }

        switch ($columnDefault) {
            case 'current_timestamp()':
                return $platform->getCurrentTimestampSQL();

            case 'curdate()':
                return $platform->getCurrentDateSQL();

            case 'curtime()':
                return $platform->getCurrentTimeSQL();
        }

        return $columnDefault;
    }

    /**
     * {@inheritdoc}
     */
    protected function _getPortableTableForeignKeysList($tableForeignKeys)
    {
        $list = [];
        foreach ($tableForeignKeys as $value) {
            $value = array_change_key_case($value, CASE_LOWER);
            if (! isset($list[$value['constraint_name']])) {
                if (! isset($value['delete_rule']) || $value['delete_rule'] === 'RESTRICT') {
                    $value['delete_rule'] = null;
                }

                if (! isset($value['update_rule']) || $value['update_rule'] === 'RESTRICT') {
                    $value['update_rule'] = null;
                }

                $list[$value['constraint_name']] = [
                    'name' => $value['constraint_name'],
                    'local' => [],
                    'foreign' => [],
                    'foreignTable' => $value['referenced_table_name'],
                    'onDelete' => $value['delete_rule'],
                    'onUpdate' => $value['update_rule'],
                ];
            }

            $list[$value['constraint_name']]['local'][]   = $value['column_name'];
            $list[$value['constraint_name']]['foreign'][] = $value['referenced_column_name'];
        }

        $result = [];
        foreach ($list as $constraint) {
            $result[] = new ForeignKeyConstraint(
                array_values($constraint['local']),
                $constraint['foreignTable'],
                array_values($constraint['foreign']),
                $constraint['name'],
                [
                    'onDelete' => $constraint['onDelete'],
                    'onUpdate' => $constraint['onUpdate'],
                ]
            );
        }

        return $result;
    }

    /**
     * {@inheritdoc}
     */
    public function listTableDetails($name)
    {
        $table = parent::listTableDetails($name);

        $platform = $this->_platform;
        assert($platform instanceof MySqlPlatform);
        $sql = $platform->getListTableMetadataSQL($name);

        $tableOptions = $this->_conn->fetchAssoc($sql);

        if ($tableOptions === false) {
            return $table;
        }

        $table->addOption('engine', $tableOptions['ENGINE']);

        if ($tableOptions['TABLE_COLLATION'] !== null) {
            $table->addOption('collation', $tableOptions['TABLE_COLLATION']);
        }

        if ($tableOptions['AUTO_INCREMENT'] !== null) {
            $table->addOption('autoincrement', $tableOptions['AUTO_INCREMENT']);
        }

        $table->addOption('comment', $tableOptions['TABLE_COMMENT']);
        $table->addOption('create_options', $this->parseCreateOptions($tableOptions['CREATE_OPTIONS']));

        return $table;
    }

    /**
     * @return string[]|true[]
     */
    private function parseCreateOptions(?string $string): array
    {
        $options = [];

        if ($string === null || $string === '') {
            return $options;
        }

        foreach (explode(' ', $string) as $pair) {
            $parts = explode('=', $pair, 2);

            $options[$parts[0]] = $parts[1] ?? true;
        }

        return $options;
    }
}