<?php
/*
 * 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\Migrations\Configuration;

use Doctrine\DBAL\Connection;
use Doctrine\DBAL\Migrations\MigrationException;
use Doctrine\DBAL\Migrations\OutputWriter;
use Doctrine\DBAL\Migrations\Version;
use Doctrine\DBAL\Schema\Column;
use Doctrine\DBAL\Schema\Table;
use Doctrine\DBAL\Types\Type;

/**
 * Default Migration Configuration object used for configuring an instance of
 * the Migration class. Set the connection, version table name, register migration
 * classes/versions, etc.
 *
 * @license     http://www.opensource.org/licenses/lgpl-license.php LGPL
 * @link        www.doctrine-project.org
 * @since       2.0
 * @author      Jonathan H. Wage <jonwage@gmail.com>
 */
class Configuration
{
    /**
     * Name of this set of migrations
     *
     * @var string
     */
    private $name;

    /**
     * Flag for whether or not the migration table has been created
     *
     * @var boolean
     */
    private $migrationTableCreated = false;

    /**
     * Connection instance to use for migrations
     *
     * @var Connection
     */
    private $connection;

    /**
     * OutputWriter instance for writing output during migrations
     *
     * @var OutputWriter
     */
    private $outputWriter;

    /**
     * The migration table name to track versions in
     *
     * @var string
     */
    private $migrationsTableName = 'doctrine_migration_versions';

    /**
     * The path to a directory where new migration classes will be written
     *
     * @var string
     */
    private $migrationsDirectory;

    /**
     * Namespace the migration classes live in
     *
     * @var string
     */
    private $migrationsNamespace;

    /**
     * Array of the registered migrations
     *
     * @var Version[]
     */
    private $migrations = array();

    /**
     * Construct a migration configuration object.
     *
     * @param Connection   $connection   A Connection instance
     * @param OutputWriter $outputWriter A OutputWriter instance
     */
    public function __construct(Connection $connection, OutputWriter $outputWriter = null)
    {
        $this->connection = $connection;
        if ($outputWriter === null) {
            $outputWriter = new OutputWriter();
        }
        $this->outputWriter = $outputWriter;
    }

    /**
     * Validation that this instance has all the required properties configured
     *
     * @throws MigrationException
     */
    public function validate()
    {
        if (! $this->migrationsNamespace) {
            throw MigrationException::migrationsNamespaceRequired();
        }
        if (! $this->migrationsDirectory) {
            throw MigrationException::migrationsDirectoryRequired();
        }
    }

    /**
     * Set the name of this set of migrations
     *
     * @param string $name The name of this set of migrations
     */
    public function setName($name)
    {
        $this->name = $name;
    }

    /**
     * Returns the name of this set of migrations
     *
     * @return string $name The name of this set of migrations
     */
    public function getName()
    {
        return $this->name;
    }

    /**
     * Returns the OutputWriter instance
     *
     * @return OutputWriter $outputWriter  The OutputWriter instance
     */
    public function getOutputWriter()
    {
        return $this->outputWriter;
    }

    /**
     * Returns a timestamp version as a formatted date
     *
     * @param string $version
     *
     * @return string The formatted version
     */
    public function formatVersion($version)
    {
        return sprintf('%s-%s-%s %s:%s:%s',
            substr($version, 0, 4),
            substr($version, 4, 2),
            substr($version, 6, 2),
            substr($version, 8, 2),
            substr($version, 10, 2),
            substr($version, 12, 2)
        );
    }

    /**
     * Returns the Connection instance
     *
     * @return Connection $connection  The Connection instance
     */
    public function getConnection()
    {
        return $this->connection;
    }

    /**
     * Set the migration table name
     *
     * @param string $tableName The migration table name
     */
    public function setMigrationsTableName($tableName)
    {
        $this->migrationsTableName = $tableName;
    }

    /**
     * Returns the migration table name
     *
     * @return string $migrationsTableName The migration table name
     */
    public function getMigrationsTableName()
    {
        return $this->migrationsTableName;
    }

    /**
     * Set the new migrations directory where new migration classes are generated
     *
     * @param string $migrationsDirectory The new migrations directory
     */
    public function setMigrationsDirectory($migrationsDirectory)
    {
        $this->migrationsDirectory = $migrationsDirectory;
    }

    /**
     * Returns the new migrations directory where new migration classes are generated
     *
     * @return string $migrationsDirectory The new migrations directory
     */
    public function getMigrationsDirectory()
    {
        return $this->migrationsDirectory;
    }

    /**
     * Set the migrations namespace
     *
     * @param string $migrationsNamespace The migrations namespace
     */
    public function setMigrationsNamespace($migrationsNamespace)
    {
        $this->migrationsNamespace = $migrationsNamespace;
    }

    /**
     * Returns the migrations namespace
     *
     * @return string $migrationsNamespace The migrations namespace
     */
    public function getMigrationsNamespace()
    {
        return $this->migrationsNamespace;
    }

    /**
     * Register migrations from a given directory. Recursively finds all files
     * with the pattern VersionYYYYMMDDHHMMSS.php as the filename and registers
     * them as migrations.
     *
     * @param string $path The root directory to where some migration classes live.
     *
     * @return Version[] The array of migrations registered.
     */
    public function registerMigrationsFromDirectory($path)
    {
        $path = realpath($path);
        $path = rtrim($path, '/');
        $files = glob($path . '/Version*.php');
        $versions = array();
        if ($files) {
            foreach ($files as $file) {
                require_once $file;
                $info = pathinfo($file);
                $version = substr($info['filename'], 7);
                $class = $this->migrationsNamespace . '\\' . $info['filename'];
                $versions[] = $this->registerMigration($version, $class);
            }
        }

        return $versions;
    }

    /**
     * Register a single migration version to be executed by a AbstractMigration
     * class.
     *
     * @param string $version The version of the migration in the format YYYYMMDDHHMMSS.
     * @param string $class   The migration class to execute for the version.
     *
     * @return Version
     *
     * @throws MigrationException
     */
    public function registerMigration($version, $class)
    {
        $version = (string) $version;
        $class = (string) $class;
        if (isset($this->migrations[$version])) {
            throw MigrationException::duplicateMigrationVersion($version, get_class($this->migrations[$version]));
        }
        $version = new Version($this, $version, $class);
        $this->migrations[$version->getVersion()] = $version;
        ksort($this->migrations);

        return $version;
    }

    /**
     * Register an array of migrations. Each key of the array is the version and
     * the value is the migration class name.
     *
     *
     * @param array $migrations
     *
     * @return Version[]
     */
    public function registerMigrations(array $migrations)
    {
        $versions = array();
        foreach ($migrations as $version => $class) {
            $versions[] = $this->registerMigration($version, $class);
        }

        return $versions;
    }

    /**
     * Get the array of registered migration versions.
     *
     * @return Version[] $migrations
     */
    public function getMigrations()
    {
        return $this->migrations;
    }

    /**
     * Returns the Version instance for a given version in the format YYYYMMDDHHMMSS.
     *
     * @param string $version The version string in the format YYYYMMDDHHMMSS.
     *
     * @return Version
     *
     * @throws MigrationException Throws exception if migration version does not exist.
     */
    public function getVersion($version)
    {
        if ( ! isset($this->migrations[$version])) {
            throw MigrationException::unknownMigrationVersion($version);
        }

        return $this->migrations[$version];
    }

    /**
     * Check if a version exists.
     *
     * @param string $version
     *
     * @return boolean
     */
    public function hasVersion($version)
    {
        return isset($this->migrations[$version]);
    }

    /**
     * Check if a version has been migrated or not yet
     *
     * @param Version $version
     *
     * @return boolean
     */
    public function hasVersionMigrated(Version $version)
    {
        $this->createMigrationTable();

        $version = $this->connection->fetchColumn("SELECT version FROM " . $this->migrationsTableName . " WHERE version = ?", array($version->getVersion()));

        return $version !== false;
    }

    /**
     * Returns all migrated versions from the versions table, in an array.
     *
     * @return Version[]
     */
    public function getMigratedVersions()
    {
        $this->createMigrationTable();

        $ret = $this->connection->fetchAll("SELECT version FROM " . $this->migrationsTableName);
        $versions = array();
        foreach ($ret as $version) {
            $versions[] = current($version);
        }

        return $versions;
    }

    /**
     * Returns an array of available migration version numbers.
     *
     * @return array
     */
    public function getAvailableVersions()
    {
        $availableVersions = array();
        foreach ($this->migrations as $migration) {
            $availableVersions[] = $migration->getVersion();
        }

        return $availableVersions;
    }

    /**
     * Returns the current migrated version from the versions table.
     *
     * @return string
     */
    public function getCurrentVersion()
    {
        $this->createMigrationTable();

        $where = null;
        if ($this->migrations) {
            $migratedVersions = array();
            foreach ($this->migrations as $migration) {
                $migratedVersions[] = sprintf("'%s'", $migration->getVersion());
            }
            $where = " WHERE version IN (" . implode(', ', $migratedVersions) . ")";
        }

        $sql = sprintf("SELECT version FROM %s%s ORDER BY version DESC",
            $this->migrationsTableName, $where
        );

        $sql = $this->connection->getDatabasePlatform()->modifyLimitQuery($sql, 1);
        $result = $this->connection->fetchColumn($sql);

        return $result !== false ? (string) $result : '0';
    }

    /**
     * Returns the version prior to the current version.
     *
     * @return string|null A version string, or null if the current version is
     *                     the first.
     */
    public function getPrevVersion()
    {
        return $this->getRelativeVersion($this->getCurrentVersion(), -1);
    }

    /**
     * Returns the version following the current version.
     *
     * @return string|null A version string, or null if the current version is
     *                     the latest.
     */
    public function getNextVersion()
    {
        return $this->getRelativeVersion($this->getCurrentVersion(), 1);
    }

    /**
     * Returns the version with the specified offset to the specified version.
     *
     * @return string|null A version string, or null if the specified version
     *                     is unknown or the specified delta is not within the
     *                     list of available versions.
     */
    public function getRelativeVersion($version, $delta)
    {
        $versions = array_keys($this->migrations);
        array_unshift($versions, 0);
        $offset = array_search($version, $versions);
        if ($offset === false || !isset($versions[$offset + $delta])) {
            // Unknown version or delta out of bounds.
            return null;
        }

        return (string) $versions[$offset + $delta];
    }

    /**
     * Returns the version number from an alias.
     *
     * Supported aliases are:
     * - first: The very first version before any migrations have been run.
     * - current: The current version.
     * - prev: The version prior to the current version.
     * - next: The version following the current version.
     * - latest: The latest available version.
     *
     * If an existing version number is specified, it is returned verbatimly.
     *
     * @return string|null A version number, or null if the specified alias
     *                     does not map to an existing version, e.g. if "next"
     *                     is passed but the current version is already the
     *                     latest.
     */
    public function resolveVersionAlias($alias)
    {
        if ($this->hasVersion($alias)) {
            return $alias;
        }
        switch ($alias) {
            case 'first':
                return '0';
            case 'current':
                return $this->getCurrentVersion();
            case 'prev':
                return $this->getPrevVersion();
            case 'next':
                return $this->getNextVersion();
            case 'latest':
                return $this->getLatestVersion();
            default:
                return null;
        }
    }

    /**
     * Returns the total number of executed migration versions
     *
     * @return integer
     */
    public function getNumberOfExecutedMigrations()
    {
        $this->createMigrationTable();

        $result = $this->connection->fetchColumn("SELECT COUNT(version) FROM " . $this->migrationsTableName);

        return $result !== false ? $result : 0;
    }

    /**
     * Returns the total number of available migration versions
     *
     * @return integer
     */
    public function getNumberOfAvailableMigrations()
    {
        return count($this->migrations);
    }

    /**
     * Returns the latest available migration version.
     *
     * @return string The version string in the format YYYYMMDDHHMMSS.
     */
    public function getLatestVersion()
    {
        $versions = array_keys($this->migrations);
        $latest = end($versions);

        return $latest !== false ? (string) $latest : '0';
    }

    /**
     * Create the migration table to track migrations with.
     *
     * @return boolean Whether or not the table was created.
     */
    public function createMigrationTable()
    {
        $this->validate();

        if ($this->migrationTableCreated) {
            return false;
        }

        if ( ! $this->connection->getSchemaManager()->tablesExist(array($this->migrationsTableName))) {
            $columns = array(
                'version' => new Column('version', Type::getType('string'), array('length' => 255)),
            );
            $table = new Table($this->migrationsTableName, $columns);
            $table->setPrimaryKey(array('version'));
            $this->connection->getSchemaManager()->createTable($table);

            $this->migrationTableCreated = true;

            return true;
        }

        $this->migrationTableCreated = true;

        return false;
    }

    /**
     * Returns the array of migrations to executed based on the given direction
     * and target version number.
     *
     * @param string $direction The direction we are migrating.
     * @param string $to        The version to migrate to.
     *
     * @return Version[] $migrations   The array of migrations we can execute.
     */
    public function getMigrationsToExecute($direction, $to)
    {
        if ($direction === 'down') {
            if (count($this->migrations)) {
                $allVersions = array_reverse(array_keys($this->migrations));
                $classes = array_reverse(array_values($this->migrations));
                $allVersions = array_combine($allVersions, $classes);
            } else {
                $allVersions = array();
            }
        } else {
            $allVersions = $this->migrations;
        }
        $versions = array();
        $migrated = $this->getMigratedVersions();
        foreach ($allVersions as $version) {
            if ($this->shouldExecuteMigration($direction, $version, $to, $migrated)) {
                $versions[$version->getVersion()] = $version;
            }
        }

        return $versions;
    }

    /**
     * Check if we should execute a migration for a given direction and target
     * migration version.
     *
     * @param string  $direction The direction we are migrating.
     * @param Version $version   The Version instance to check.
     * @param string  $to        The version we are migrating to.
     * @param array   $migrated  Migrated versions array.
     *
     * @return boolean
     */
    private function shouldExecuteMigration($direction, Version $version, $to, $migrated)
    {
        if ($direction === 'down') {
            if ( ! in_array($version->getVersion(), $migrated)) {
                return false;
            }

            return $version->getVersion() > $to;
        }

        if ($direction === 'up') {
            if (in_array($version->getVersion(), $migrated)) {
                return false;
            }

            return $version->getVersion() <= $to;
        }
    }
}