<?php

return
        $code = <<<CODE
<?php

use yii\db\Migration;

/**
 * Handles the creation for table `post_tag`.
 * Has foreign keys to the tables:
 *
 * - `post`
 * - `tag`
 */
class {$class} extends Migration
{
    /**
     * @inheritdoc
     */
    public function up()
    {
        \$this->createTable('post_tag', [
            'post_id' => \$this->integer(),
            'tag_id' => \$this->integer(),
            'PRIMARY KEY(post_id, tag_id)',
        ]);

        // creates index for column `post_id`
        \$this->createIndex(
            'idx-post_tag-post_id',
            'post_tag',
            'post_id'
        );

        // add foreign key for table `post`
        \$this->addForeignKey(
            'fk-post_tag-post_id',
            'post_tag',
            'post_id',
            'post',
            'id',
            'CASCADE'
        );

        // creates index for column `tag_id`
        \$this->createIndex(
            'idx-post_tag-tag_id',
            'post_tag',
            'tag_id'
        );

        // add foreign key for table `tag`
        \$this->addForeignKey(
            'fk-post_tag-tag_id',
            'post_tag',
            'tag_id',
            'tag',
            'id',
            'CASCADE'
        );
    }

    /**
     * @inheritdoc
     */
    public function down()
    {
        // drops foreign key for table `post`
        \$this->dropForeignKey(
            'fk-post_tag-post_id',
            'post_tag'
        );

        // drops index for column `post_id`
        \$this->dropIndex(
            'idx-post_tag-post_id',
            'post_tag'
        );

        // drops foreign key for table `tag`
        \$this->dropForeignKey(
            'fk-post_tag-tag_id',
            'post_tag'
        );

        // drops index for column `tag_id`
        \$this->dropIndex(
            'idx-post_tag-tag_id',
            'post_tag'
        );

        \$this->dropTable('post_tag');
    }
}

CODE;