<?php
/**
 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
 * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 *
 * Licensed under The MIT License
 * For full copyright and license information, please see the LICENSE.txt
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link          http://cakephp.org CakePHP(tm) Project
 * @since         3.0.0
 * @license       http://www.opensource.org/licenses/mit-license.php MIT License
 */
namespace Cake\Database\Schema;

/**
 * Schema management/reflection features for SQLServer.
 */
class SqlserverSchema extends BaseSchema
{

    const DEFAULT_SCHEMA_NAME = 'dbo';

    /**
     * {@inheritDoc}
     */
    public function listTablesSql($config)
    {
        $sql = "SELECT TABLE_NAME
            FROM INFORMATION_SCHEMA.TABLES
            WHERE TABLE_SCHEMA = ?
            AND TABLE_TYPE = 'BASE TABLE'
            ORDER BY TABLE_NAME";
        $schema = empty($config['schema']) ? static::DEFAULT_SCHEMA_NAME : $config['schema'];
        return [$sql, [$schema]];
    }

    /**
     * {@inheritDoc}
     */
    public function describeColumnSql($tableName, $config)
    {
        $sql = "SELECT DISTINCT
            AC.column_id AS [column_id],
            AC.name AS [name],
            TY.name AS [type],
            AC.max_length AS [char_length],
            AC.precision AS [precision],
            AC.scale AS [scale],
            AC.is_identity AS [autoincrement],
            AC.is_nullable AS [null],
            OBJECT_DEFINITION(AC.default_object_id) AS [default]
            FROM sys.[tables] T
            INNER JOIN sys.[schemas] S ON S.[schema_id] = T.[schema_id]
            INNER JOIN sys.[all_columns] AC ON T.[object_id] = AC.[object_id]
            INNER JOIN sys.[types] TY ON TY.[user_type_id] = AC.[user_type_id]
            WHERE T.[name] = ? AND S.[name] = ?
            ORDER BY column_id";

        $schema = empty($config['schema']) ? static::DEFAULT_SCHEMA_NAME : $config['schema'];
        return [$sql, [$tableName, $schema]];
    }

    /**
     * Convert a column definition to the abstract types.
     *
     * The returned type will be a type that
     * Cake\Database\Type can handle.
     *
     * @param string $col The column type
     * @param int|null $length the column length
     * @param int|null $precision The column precision
     * @param int|null $scale The column scale
     * @return array Array of column information.
     * @link http://technet.microsoft.com/en-us/library/ms187752.aspx
     */
    protected function _convertColumn($col, $length = null, $precision = null, $scale = null)
    {
        $col = strtolower($col);
        if (in_array($col, ['date', 'time'])) {
            return ['type' => $col, 'length' => null];
        }
        if (strpos($col, 'datetime') !== false) {
            return ['type' => 'timestamp', 'length' => null];
        }

        if ($col === 'int' || $col === 'integer') {
            return ['type' => 'integer', 'length' => $precision ?: 10];
        }
        if ($col === 'bigint') {
            return ['type' => 'biginteger', 'length' => $precision ?: 20];
        }
        if ($col === 'smallint') {
            return ['type' => 'integer', 'length' => $precision ?: 5];
        }
        if ($col === 'tinyint') {
            return ['type' => 'integer', 'length' => $precision ?: 3];
        }
        if ($col === 'bit') {
            return ['type' => 'boolean', 'length' => null];
        }
        if (strpos($col, 'numeric') !== false ||
            strpos($col, 'money') !== false ||
            strpos($col, 'decimal') !== false
        ) {
            return ['type' => 'decimal', 'length' => $precision, 'precision' => $scale];
        }

        if ($col === 'real' || $col === 'float') {
            return ['type' => 'float', 'length' => null];
        }

        if (strpos($col, 'varchar') !== false && $length < 0) {
            return ['type' => 'text', 'length' => null];
        }

        if (strpos($col, 'varchar') !== false) {
            return ['type' => 'string', 'length' => $length ?: 255];
        }

        if (strpos($col, 'char') !== false) {
            return ['type' => 'string', 'fixed' => true, 'length' => $length];
        }

        if (strpos($col, 'text') !== false) {
            return ['type' => 'text', 'length' => null];
        }

        if ($col === 'image' || strpos($col, 'binary')) {
            return ['type' => 'binary', 'length' => null];
        }

        if ($col === 'uniqueidentifier') {
            return ['type' => 'uuid'];
        }

        return ['type' => 'text', 'length' => null];
    }

    /**
     * {@inheritDoc}
     */
    public function convertColumnDescription(Table $table, $row)
    {
        $field = $this->_convertColumn(
            $row['type'],
            $row['char_length'],
            $row['precision'],
            $row['scale']
        );
        if (!empty($row['default'])) {
            $row['default'] = trim($row['default'], '()');
        }
        if (!empty($row['autoincrement'])) {
            $field['autoIncrement'] = true;
        }
        if ($field['type'] === 'boolean') {
            $row['default'] = (int)$row['default'];
        }

        $field += [
            'null' => $row['null'] === '1' ? true : false,
            'default' => $row['default'],
        ];
        $table->addColumn($row['name'], $field);
    }

    /**
     * {@inheritDoc}
     */
    public function describeIndexSql($tableName, $config)
    {
        $sql = "SELECT
                I.[name] AS [index_name],
                IC.[index_column_id] AS [index_order],
                AC.[name] AS [column_name],
                I.[is_unique], I.[is_primary_key],
                I.[is_unique_constraint]
            FROM sys.[tables] AS T
            INNER JOIN sys.[schemas] S ON S.[schema_id] = T.[schema_id]
            INNER JOIN sys.[indexes] I ON T.[object_id] = I.[object_id]
            INNER JOIN sys.[index_columns] IC ON I.[object_id] = IC.[object_id] AND I.[index_id] = IC.[index_id]
            INNER JOIN sys.[all_columns] AC ON T.[object_id] = AC.[object_id] AND IC.[column_id] = AC.[column_id]
            WHERE T.[is_ms_shipped] = 0 AND I.[type_desc] <> 'HEAP' AND T.[name] = ? AND S.[name] = ?
            ORDER BY I.[index_id], IC.[index_column_id]";

        $schema = empty($config['schema']) ? static::DEFAULT_SCHEMA_NAME : $config['schema'];
        return [$sql, [$tableName, $schema]];
    }

    /**
     * {@inheritDoc}
     */
    public function convertIndexDescription(Table $table, $row)
    {
        $type = Table::INDEX_INDEX;
        $name = $row['index_name'];
        if ($row['is_primary_key']) {
            $name = $type = Table::CONSTRAINT_PRIMARY;
        }
        if ($row['is_unique_constraint'] && $type === Table::INDEX_INDEX) {
            $type = Table::CONSTRAINT_UNIQUE;
        }

        if ($type === Table::INDEX_INDEX) {
            $existing = $table->index($name);
        } else {
            $existing = $table->constraint($name);
        }

        $columns = [$row['column_name']];
        if (!empty($existing)) {
            $columns = array_merge($existing['columns'], $columns);
        }

        if ($type === Table::CONSTRAINT_PRIMARY || $type === Table::CONSTRAINT_UNIQUE) {
            $table->addConstraint($name, [
                'type' => $type,
                'columns' => $columns
            ]);
            return;
        }
        $table->addIndex($name, [
            'type' => $type,
            'columns' => $columns
        ]);
    }

    /**
     * {@inheritDoc}
     */
    public function describeForeignKeySql($tableName, $config)
    {
        $sql = "SELECT FK.[name] AS [foreign_key_name], FK.[delete_referential_action_desc] AS [delete_type],
                FK.[update_referential_action_desc] AS [update_type], C.name AS [column], RT.name AS [reference_table],
                RC.name AS [reference_column]
            FROM sys.foreign_keys FK
            INNER JOIN sys.foreign_key_columns FKC ON FKC.constraint_object_id = FK.object_id
            INNER JOIN sys.tables T ON T.object_id = FKC.parent_object_id
            INNER JOIN sys.tables RT ON RT.object_id = FKC.referenced_object_id
            INNER JOIN sys.schemas S ON S.schema_id = T.schema_id AND S.schema_id = RT.schema_id
            INNER JOIN sys.columns C ON C.column_id = FKC.parent_column_id AND C.object_id = FKC.parent_object_id
            INNER JOIN sys.columns RC ON RC.column_id = FKC.referenced_column_id AND RC.object_id = FKC.referenced_object_id
            WHERE FK.is_ms_shipped = 0 AND T.name = ? AND S.name = ?";

        $schema = empty($config['schema']) ? static::DEFAULT_SCHEMA_NAME : $config['schema'];
        return [$sql, [$tableName, $schema]];
    }

    /**
     * {@inheritDoc}
     */
    public function convertForeignKeyDescription(Table $table, $row)
    {
        $data = [
            'type' => Table::CONSTRAINT_FOREIGN,
            'columns' => [$row['column']],
            'references' => [$row['reference_table'], $row['reference_column']],
            'update' => $this->_convertOnClause($row['update_type']),
            'delete' => $this->_convertOnClause($row['delete_type']),
        ];
        $name = $row['foreign_key_name'];
        $table->addConstraint($name, $data);
    }

    /**
     * {@inheritDoc}
     */
    protected function _foreignOnClause($on)
    {
        $parent = parent::_foreignOnClause($on);
        return $parent === 'RESTRICT' ? parent::_foreignOnClause(Table::ACTION_SET_NULL) : $parent;
    }

    /**
     * {@inheritDoc}
     */
    protected function _convertOnClause($clause)
    {
        switch ($clause) {
            case 'NO_ACTION':
                return Table::ACTION_NO_ACTION;
            case 'CASCADE':
                return Table::ACTION_CASCADE;
            case 'SET_NULL':
                return Table::ACTION_SET_NULL;
            case 'SET_DEFAULT':
                return Table::ACTION_SET_DEFAULT;
        }
        return Table::ACTION_SET_NULL;
    }

    /**
     * {@inheritDoc}
     */
    public function columnSql(Table $table, $name)
    {
        $data = $table->column($name);
        $out = $this->_driver->quoteIdentifier($name);
        $typeMap = [
            'integer' => ' INTEGER',
            'biginteger' => ' BIGINT',
            'boolean' => ' BIT',
            'float' => ' FLOAT',
            'decimal' => ' DECIMAL',
            'date' => ' DATE',
            'time' => ' TIME',
            'datetime' => ' DATETIME',
            'timestamp' => ' DATETIME',
            'uuid' => ' UNIQUEIDENTIFIER'
        ];

        if (isset($typeMap[$data['type']])) {
            $out .= $typeMap[$data['type']];
        }

        if ($data['type'] === 'integer' || $data['type'] === 'biginteger') {
            if ([$name] === $table->primaryKey() || $data['autoIncrement'] === true) {
                unset($data['null'], $data['default']);
                $out .= ' IDENTITY(1, 1)';
            }
        }

        if ($data['type'] === 'text' && $data['length'] !== Table::LENGTH_TINY) {
            $out .= ' NVARCHAR(MAX)';
        }

        if ($data['type'] === 'binary') {
            $out .= ' VARBINARY';

            if ($data['length'] !== Table::LENGTH_TINY) {
                $out .= '(MAX)';
            } else {
                $out .= sprintf('(%s)', Table::LENGTH_TINY);
            }
        }

        if ($data['type'] === 'string' || ($data['type'] === 'text' && $data['length'] === Table::LENGTH_TINY)) {
            $type = ' NVARCHAR';

            if (!empty($data['fixed'])) {
                $type = ' NCHAR';
            }

            if (!isset($data['length'])) {
                $data['length'] = 255;
            }

            $out .= sprintf('%s(%d)', $type, $data['length']);
        }

        if ($data['type'] === 'float' && isset($data['precision'])) {
            $out .= '(' . (int)$data['precision'] . ')';
        }

        if ($data['type'] === 'decimal' &&
            (isset($data['length']) || isset($data['precision']))
        ) {
            $out .= '(' . (int)$data['length'] . ',' . (int)$data['precision'] . ')';
        }

        if (isset($data['null']) && $data['null'] === false) {
            $out .= ' NOT NULL';
        }

        if (isset($data['null']) && $data['null'] === true) {
            $out .= ' DEFAULT NULL';
            unset($data['default']);
        }

        if (isset($data['default']) && $data['type'] !== 'datetime') {
            $default = is_bool($data['default']) ? (int)$data['default'] : $this->_driver->schemaValue($data['default']);
            $out .= ' DEFAULT ' . $default;
        }

        return $out;
    }

    /**
     * {@inheritDoc}
     */
    public function addConstraintSql(Table $table)
    {
        $sqlPattern = 'ALTER TABLE %s ADD %s;';
        $sql = [];

        foreach ($table->constraints() as $name) {
            $constraint = $table->constraint($name);
            if ($constraint['type'] === Table::CONSTRAINT_FOREIGN) {
                $tableName = $this->_driver->quoteIdentifier($table->name());
                $sql[] = sprintf($sqlPattern, $tableName, $this->constraintSql($table, $name));
            }
        }

        return $sql;
    }

    /**
     * {@inheritDoc}
     */
    public function dropConstraintSql(Table $table)
    {
        $sqlPattern = 'ALTER TABLE %s DROP CONSTRAINT %s;';
        $sql = [];

        foreach ($table->constraints() as $name) {
            $constraint = $table->constraint($name);
            if ($constraint['type'] === Table::CONSTRAINT_FOREIGN) {
                $tableName = $this->_driver->quoteIdentifier($table->name());
                $constraintName = $this->_driver->quoteIdentifier($name);
                $sql[] = sprintf($sqlPattern, $tableName, $constraintName);
            }
        }

        return $sql;
    }

    /**
     * {@inheritDoc}
     */
    public function indexSql(Table $table, $name)
    {
        $data = $table->index($name);
        $columns = array_map(
            [$this->_driver, 'quoteIdentifier'],
            $data['columns']
        );
        return sprintf(
            'CREATE INDEX %s ON %s (%s)',
            $this->_driver->quoteIdentifier($name),
            $this->_driver->quoteIdentifier($table->name()),
            implode(', ', $columns)
        );
    }

    /**
     * {@inheritDoc}
     */
    public function constraintSql(Table $table, $name)
    {
        $data = $table->constraint($name);
        $out = 'CONSTRAINT ' . $this->_driver->quoteIdentifier($name);
        if ($data['type'] === Table::CONSTRAINT_PRIMARY) {
            $out = 'PRIMARY KEY';
        }
        if ($data['type'] === Table::CONSTRAINT_UNIQUE) {
            $out .= ' UNIQUE';
        }
        return $this->_keySql($out, $data);
    }

    /**
     * Helper method for generating key SQL snippets.
     *
     * @param string $prefix The key prefix
     * @param array $data Key data.
     * @return string
     */
    protected function _keySql($prefix, $data)
    {
        $columns = array_map(
            [$this->_driver, 'quoteIdentifier'],
            $data['columns']
        );
        if ($data['type'] === Table::CONSTRAINT_FOREIGN) {
            return $prefix . sprintf(
                ' FOREIGN KEY (%s) REFERENCES %s (%s) ON UPDATE %s ON DELETE %s',
                implode(', ', $columns),
                $this->_driver->quoteIdentifier($data['references'][0]),
                $this->_convertConstraintColumns($data['references'][1]),
                $this->_foreignOnClause($data['update']),
                $this->_foreignOnClause($data['delete'])
            );
        }
        return $prefix . ' (' . implode(', ', $columns) . ')';
    }

    /**
     * {@inheritDoc}
     */
    public function createTableSql(Table $table, $columns, $constraints, $indexes)
    {
        $content = array_merge($columns, $constraints);
        $content = implode(",\n", array_filter($content));
        $tableName = $this->_driver->quoteIdentifier($table->name());
        $out = [];
        $out[] = sprintf("CREATE TABLE %s (\n%s\n)", $tableName, $content);
        foreach ($indexes as $index) {
            $out[] = $index;
        }
        return $out;
    }

    /**
     * {@inheritDoc}
     */
    public function truncateTableSql(Table $table)
    {
        $name = $this->_driver->quoteIdentifier($table->name());
        $queries = [
            sprintf('DELETE FROM %s', $name)
        ];

        // Restart identity sequences
        $pk = $table->primaryKey();
        if (count($pk) === 1) {
            $column = $table->column($pk[0]);
            if (in_array($column['type'], ['integer', 'biginteger'])) {
                $queries[] = sprintf(
                    "DBCC CHECKIDENT('%s', RESEED, 0)",
                    $table->name()
                );
            }
        }
        return $queries;
    }
}
