<?php
/*
 *  $Id$
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This software consists of voluntary contributions made by many individuals
 * and is licensed under the LGPL. For more information, see
 * <http://www.doctrine-project.org>.
 */

namespace Doctrine\DBAL\Schema;

use \Doctrine\DBAL\Types;
use \Doctrine\DBAL\DBALException;
use \Doctrine\DBAL\Platforms\AbstractPlatform;

/**
 * Base class for schema managers. Schema managers are used to inspect and/or
 * modify the database schema/structure.
 *
 * @license     http://www.opensource.org/licenses/lgpl-license.php LGPL
 * @author      Konsta Vesterinen <kvesteri@cc.hut.fi>
 * @author      Lukas Smith <smith@pooteeweet.org> (PEAR MDB2 library)
 * @author      Roman Borschel <roman@code-factory.org>
 * @author      Jonathan H. Wage <jonwage@gmail.com>
 * @author      Benjamin Eberlei <kontakt@beberlei.de>
 * @version     $Revision$
 * @since       2.0
 */
abstract class AbstractSchemaManager
{
    /**
     * Holds instance of the Doctrine connection for this schema manager
     *
     * @var \Doctrine\DBAL\Connection
     */
    protected $_conn;

    /**
     * Holds instance of the database platform used for this schema manager
     *
     * @var \Doctrine\DBAL\Platforms\AbstractPlatform
     */
    protected $_platform;

    /**
     * Constructor. Accepts the Connection instance to manage the schema for
     *
     * @param \Doctrine\DBAL\Connection $conn
     */
    public function __construct(\Doctrine\DBAL\Connection $conn)
    {
        $this->_conn = $conn;
        $this->_platform = $this->_conn->getDatabasePlatform();
    }

    /**
     * Return associated platform.
     *
     * @return \Doctrine\DBAL\Platform\AbstractPlatform
     */
    public function getDatabasePlatform()
    {
        return $this->_platform;
    }

    /**
     * Try any method on the schema manager. Normally a method throws an 
     * exception when your DBMS doesn't support it or if an error occurs.
     * This method allows you to try and method on your SchemaManager
     * instance and will return false if it does not work or is not supported.
     *
     * <code>
     * $result = $sm->tryMethod('dropView', 'view_name');
     * </code>
     *
     * @return mixed
     */
    public function tryMethod()
    {
        $args = func_get_args();
        $method = $args[0];
        unset($args[0]);
        $args = array_values($args);

        try {
            return call_user_func_array(array($this, $method), $args);
        } catch (\Exception $e) {
            return false;
        }
    }

    /**
     * List the available databases for this connection
     *
     * @return array $databases
     */
    public function listDatabases()
    {
        $sql = $this->_platform->getListDatabasesSql();

        $databases = $this->_conn->fetchAll($sql);

        return $this->_getPortableDatabasesList($databases);
    }

    /**
     * List the available sequences for this connection
     *
     * @return Sequence[]
     */
    public function listSequences($database = null)
    {
        if (is_null($database)) {
            $database = $this->_conn->getDatabase();
        }
        $sql = $this->_platform->getListSequencesSql($database);

        $sequences = $this->_conn->fetchAll($sql);

        return $this->_getPortableSequencesList($sequences);
    }

    /**
     * List the columns for a given table.
     *
     * In contrast to other libraries and to the old version of Doctrine,
     * this column definition does try to contain the 'primary' field for
     * the reason that it is not portable accross different RDBMS. Use
     * {@see listTableIndexes($tableName)} to retrieve the primary key
     * of a table. We're a RDBMS specifies more details these are held
     * in the platformDetails array.
     *
     * @param string $table The name of the table.
     * @return Column[]
     */
    public function listTableColumns($table)
    {
        $sql = $this->_platform->getListTableColumnsSql($table);

        $tableColumns = $this->_conn->fetchAll($sql);

        return $this->_getPortableTableColumnList($tableColumns);
    }

    /**
     * List the indexes for a given table returning an array of Index instances.
     *
     * Keys of the portable indexes list are all lower-cased.
     *
     * @param string $table The name of the table
     * @return Index[] $tableIndexes
     */
    public function listTableIndexes($table)
    {
        $sql = $this->_platform->getListTableIndexesSql($table);

        $tableIndexes = $this->_conn->fetchAll($sql);

        return $this->_getPortableTableIndexesList($tableIndexes, $table);
    }

    /**
     * Return a list of all tables in the current database
     *
     * @return array
     */
    public function listTableNames()
    {
        $sql = $this->_platform->getListTablesSql();

        $tables = $this->_conn->fetchAll($sql);

        return $this->_getPortableTablesList($tables);
    }

    /**
     * List the tables for this connection
     *
     * @return Table[]
     */
    public function listTables()
    {
        $tableNames = $this->listTableNames();

        $tables = array();
        foreach ($tableNames AS $tableName) {
            $tables[] = $this->listTableDetails($tableName);
        }

        return $tables;
    }

    /**
     * @param  string $tableName
     * @return Table
     */
    public function listTableDetails($tableName)
    {
        $columns = $this->listTableColumns($tableName);
        $foreignKeys = array();
        if ($this->_platform->supportsForeignKeyConstraints()) {
            $foreignKeys = $this->listTableForeignKeys($tableName);
        }
        $indexes = $this->listTableIndexes($tableName);

        $idGeneratorType = Table::ID_NONE;
        foreach ($columns AS $column) {
            if ($column->hasPlatformOption('autoincrement') && $column->getPlatformOption('autoincrement')) {
                $idGeneratorType = Table::ID_IDENTITY;
            }
        }

        return new Table($tableName, $columns, $indexes, $foreignKeys, $idGeneratorType, array());
    }

    /**
     * List the views this connection has
     *
     * @return View[]
     */
    public function listViews()
    {
        $database = $this->_conn->getDatabase();
        $sql = $this->_platform->getListViewsSql($database);
        $views = $this->_conn->fetchAll($sql);

        return $this->_getPortableViewsList($views);
    }

    /**
     * List the foreign keys for the given table
     *
     * @param string $table  The name of the table
     * @return ForeignKeyConstraint[]
     */
    public function listTableForeignKeys($table, $database = null)
    {
        if (is_null($database)) {
            $database = $this->_conn->getDatabase();
        }
        $sql = $this->_platform->getListTableForeignKeysSql($table, $database);
        $tableForeignKeys = $this->_conn->fetchAll($sql);

        return $this->_getPortableTableForeignKeysList($tableForeignKeys);
    }

    /* drop*() Methods */

    /**
     * Drops a database.
     * 
     * NOTE: You can not drop the database this SchemaManager is currently connected to.
     *
     * @param string $database The name of the database to drop
     */
    public function dropDatabase($database)
    {
        $this->_execSql($this->_platform->getDropDatabaseSql($database));
    }

    /**
     * Drop the given table
     *
     * @param string $table The name of the table to drop
     */
    public function dropTable($table)
    {
        $this->_execSql($this->_platform->getDropTableSql($table));
    }

    /**
     * Drop the index from the given table
     *
     * @param Index|string $index  The name of the index
     * @param string|Table $table The name of the table
     */
    public function dropIndex($index, $table)
    {
        if($index instanceof Index) {
            $index = $index->getName();
        }

        $this->_execSql($this->_platform->getDropIndexSql($index, $table));
    }

    /**
     * Drop the constraint from the given table
     *
     * @param Constraint $constraint
     * @param string $table   The name of the table
     */
    public function dropConstraint(Constraint $constraint, $table)
    {
        $this->_execSql($this->_platform->getDropConstraintSql($constraint, $table));
    }

    /**
     * Drops a foreign key from a table.
     *
     * @param ForeignKeyConstraint|string $table The name of the table with the foreign key.
     * @param Table|string $name  The name of the foreign key.
     * @return boolean $result
     */
    public function dropForeignKey($foreignKey, $table)
    {
        $this->_execSql($this->_platform->getDropForeignKeySql($foreignKey, $table));
    }

    /**
     * Drops a sequence with a given name.
     *
     * @param string $name The name of the sequence to drop.
     */
    public function dropSequence($name)
    {
        $this->_execSql($this->_platform->getDropSequenceSql($name));
    }

    /**
     * Drop a view
     *
     * @param string $name The name of the view
     * @return boolean $result
     */
    public function dropView($name)
    {
        $this->_execSql($this->_platform->getDropViewSql($name));
    }

    /* create*() Methods */

    /**
     * Creates a new database.
     *
     * @param string $database The name of the database to create.
     */
    public function createDatabase($database)
    {
        $this->_execSql($this->_platform->getCreateDatabaseSql($database));
    }

    /**
     * Create a new table.
     *
     * @param Table $table
     * @param int $createFlags
     */
    public function createTable(Table $table)
    {
        $createFlags = AbstractPlatform::CREATE_INDEXES|AbstractPlatform::CREATE_FOREIGNKEYS;
        $this->_execSql($this->_platform->getCreateTableSql($table, $createFlags));
    }

    /**
     * Create a new sequence
     *
     * @param Sequence $sequence
     * @throws Doctrine\DBAL\ConnectionException     if something fails at database level
     */
    public function createSequence($sequence)
    {
        $this->_execSql($this->_platform->getCreateSequenceSql($sequence));
    }

    /**
     * Create a constraint on a table
     *
     * @param Constraint $constraint
     * @param string|Table $table
     */
    public function createConstraint(Constraint $constraint, $table)
    {
        $this->_execSql($this->_platform->getCreateConstraintSql($constraint, $table));
    }

    /**
     * Create a new index on a table
     *
     * @param Index     $index
     * @param string    $table         name of the table on which the index is to be created
     */
    public function createIndex(Index $index, $table)
    {
        $this->_execSql($this->_platform->getCreateIndexSql($index, $table));
    }

    /**
     * Create a new foreign key
     *
     * @param ForeignKeyConstraint  $foreignKey    ForeignKey instance
     * @param string|Table          $table         name of the table on which the foreign key is to be created
     */
    public function createForeignKey(ForeignKeyConstraint $foreignKey, $table)
    {
        $this->_execSql($this->_platform->getCreateForeignKeySql($foreignKey, $table));
    }

    /**
     * Create a new view
     *
     * @param View $view
     */
    public function createView(View $view)
    {
        $this->_execSql($this->_platform->getCreateViewSql($view->getName(), $view->getSql()));
    }

    /* dropAndCreate*() Methods */

    /**
     * Drop and create a constraint
     *
     * @param Constraint    $constraint
     * @param string        $table
     * @see dropConstraint()
     * @see createConstraint()
     */
    public function dropAndCreateConstraint(Constraint $constraint, $table)
    {
        $this->tryMethod('dropConstraint', $constraint, $table);
        $this->createConstraint($constraint, $table);
    }

    /**
     * Drop and create a new index on a table
     *
     * @param string|Table $table         name of the table on which the index is to be created
     * @param Index $index
     */
    public function dropAndCreateIndex(Index $index, $table)
    {
        $this->tryMethod('dropIndex', $index->getName(), $table);
        $this->createIndex($index, $table);
    }

    /**
     * Drop and create a new foreign key
     *
     * @param ForeignKeyConstraint  $foreignKey    associative array that defines properties of the foreign key to be created.
     * @param string|Table          $table         name of the table on which the foreign key is to be created
     */
    public function dropAndCreateForeignKey(ForeignKeyConstraint $foreignKey, $table)
    {
        $this->tryMethod('dropForeignKey', $foreignKey, $table);
        $this->createForeignKey($foreignKey, $table);
    }

    /**
     * Drop and create a new sequence
     *
     * @param Sequence $sequence
     * @throws Doctrine\DBAL\ConnectionException     if something fails at database level
     */
    public function dropAndCreateSequence(Sequence $sequence)
    {
        $this->tryMethod('createSequence', $seqName, $start, $allocationSize);
        $this->createSequence($seqName, $start, $allocationSize);
    }

    /**
     * Drop and create a new table.
     *
     * @param Table $table
     */
    public function dropAndCreateTable(Table $table)
    {
        $this->tryMethod('dropTable', $table->getName());
        $this->createTable($table);
    }

    /**
     * Drop and creates a new database.
     *
     * @param string $database The name of the database to create.
     */
    public function dropAndCreateDatabase($database)
    {
        $this->tryMethod('dropDatabase', $database);
        $this->createDatabase($database);
    }

    /**
     * Drop and create a new view
     *
     * @param View $view
     */
    public function dropAndCreateView(View $view)
    {
        $this->tryMethod('dropView', $view->getName());
        $this->createView($view);
    }

    /* alterTable() Methods */

    /**
     * Alter an existing tables schema
     *
     * @param TableDiff $tableDiff
     */
    public function alterTable(TableDiff $tableDiff)
    {
        $queries = $this->_platform->getAlterTableSql($tableDiff);
        if (is_array($queries) && count($queries)) {
            foreach ($queries AS $ddlQuery) {
                $this->_execSql($ddlQuery);
            }
        }
    }

    /**
     * Rename a given table to another name
     *
     * @param string $name     The current name of the table
     * @param string $newName  The new name of the table
     */
    public function renameTable($name, $newName)
    {
        $tableDiff = new TableDiff($name);
        $tableDiff->newName = $newName;
        $this->alterTable($tableDiff);
    }

    /**
     * Methods for filtering return values of list*() methods to convert
     * the native DBMS data definition to a portable Doctrine definition
     */

    protected function _getPortableDatabasesList($databases)
    {
        $list = array();
        foreach ($databases as $key => $value) {
            if ($value = $this->_getPortableDatabaseDefinition($value)) {
                $list[] = $value;
            }
        }
        return $list;
    }

    protected function _getPortableDatabaseDefinition($database)
    {
        return $database;
    }

    protected function _getPortableFunctionsList($functions)
    {
        $list = array();
        foreach ($functions as $key => $value) {
            if ($value = $this->_getPortableFunctionDefinition($value)) {
                $list[] = $value;
            }
        }
        return $list;
    }

    protected function _getPortableFunctionDefinition($function)
    {
        return $function;
    }

    protected function _getPortableTriggersList($triggers)
    {
        $list = array();
        foreach ($triggers as $key => $value) {
            if ($value = $this->_getPortableTriggerDefinition($value)) {
                $list[] = $value;
            }
        }
        return $list;
    }

    protected function _getPortableTriggerDefinition($trigger)
    {
        return $trigger;
    }

    protected function _getPortableSequencesList($sequences)
    {
        $list = array();
        foreach ($sequences as $key => $value) {
            if ($value = $this->_getPortableSequenceDefinition($value)) {
                $list[] = $value;
            }
        }
        return $list;
    }

    /**
     * @param array $sequence
     * @return Sequence
     */
    protected function _getPortableSequenceDefinition($sequence)
    {
        throw DBALException::notSupported('Sequences');
    }

    /**
     * Independent of the database the keys of the column list result are lowercased.
     *
     * The name of the created column instance however is kept in its case.
     *
     * @param  array $tableColumns
     * @return array
     */
    protected function _getPortableTableColumnList($tableColumns)
    {
        $list = array();
        foreach ($tableColumns as $key => $column) {
            if ($column = $this->_getPortableTableColumnDefinition($column)) {
                $name = strtolower($column->getName());
                $list[$name] = $column;
            }
        }
        return $list;
    }

    /**
     * Get Table Column Definition
     *
     * @param array $tableColumn
     * @return Column
     */
    abstract protected function _getPortableTableColumnDefinition($tableColumn);

    /**
     * Aggregate and group the index results according to the required data result.
     *
     * @param  array $tableIndexRows
     * @param  string $tableName
     * @return array
     */
    protected function _getPortableTableIndexesList($tableIndexRows, $tableName=null)
    {
        $result = array();
        foreach($tableIndexRows AS $tableIndex) {
            $indexName = $keyName = $tableIndex['key_name'];
            if($tableIndex['primary']) {
                $keyName = 'primary';
            }
            $keyName = strtolower($keyName);

            if(!isset($result[$keyName])) {
                $result[$keyName] = array(
                    'name' => $indexName,
                    'columns' => array($tableIndex['column_name']),
                    'unique' => $tableIndex['non_unique'] ? false : true,
                    'primary' => $tableIndex['primary'],
                );
            } else {
                $result[$keyName]['columns'][] = $tableIndex['column_name'];
            }
        }

        $indexes = array();
        foreach($result AS $indexKey => $data) {
            $indexes[$indexKey] = new Index($data['name'], $data['columns'], $data['unique'], $data['primary']);
        }

        return $indexes;
    }

    protected function _getPortableTablesList($tables)
    {
        $list = array();
        foreach ($tables as $key => $value) {
            if ($value = $this->_getPortableTableDefinition($value)) {
                $list[] = $value;
            }
        }
        return $list;
    }

    protected function _getPortableTableDefinition($table)
    {
        return $table;
    }

    protected function _getPortableUsersList($users)
    {
        $list = array();
        foreach ($users as $key => $value) {
            if ($value = $this->_getPortableUserDefinition($value)) {
                $list[] = $value;
            }
        }
        return $list;
    }

    protected function _getPortableUserDefinition($user)
    {
        return $user;
    }

    protected function _getPortableViewsList($views)
    {
        $list = array();
        foreach ($views as $key => $value) {
            if ($view = $this->_getPortableViewDefinition($value)) {
                $viewName = strtolower($view->getName());
                $list[$viewName] = $view;
            }
        }
        return $list;
    }

    protected function _getPortableViewDefinition($view)
    {
        return false;
    }

    protected function _getPortableTableForeignKeysList($tableForeignKeys)
    {
        $list = array();
        foreach ($tableForeignKeys as $key => $value) {
            if ($value = $this->_getPortableTableForeignKeyDefinition($value)) {
                $list[] = $value;
            }
        }
        return $list;
    }

    protected function _getPortableTableForeignKeyDefinition($tableForeignKey)
    {
        return $tableForeignKey;
    }

    protected function _execSql($sql)
    {
        foreach ((array) $sql as $query) {
            $this->_conn->executeUpdate($query);
        }
    }

    /**
     * Create a schema instance for the current database.
     * 
     * @return Schema
     */
    public function createSchema()
    {
        $sequences = array();
        if($this->_platform->supportsSequences()) {
            $sequences = $this->listSequences();
        }
        $tables = $this->listTables();

        return new Schema($tables, $sequences, $this->createSchemaConfig());
    }

    /**
     * Create the configuration for this schema.
     *
     * @return SchemaConfig
     */
    public function createSchemaConfig()
    {
        $schemaConfig = new SchemaConfig();
        $schemaConfig->setExplicitForeignKeyIndexes($this->_platform->createsExplicitIndexForForeignKeys());
        $schemaConfig->setMaxIdentifierLength($this->_platform->getMaxIdentifierLength());

        return $schemaConfig;
    }
}