/**

 * Relational pipes

 * Copyright © 2019 František Kučera (Frantovo.cz, GlobalCode.info)

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation, version 3.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program. If not, see <http://www.gnu.org/licenses/>.

 */

#pragma once

#include <relpipe/writer/AttributeMetadata.h>

#include <relpipe/writer/typedefs.h>

namespace relpipe {

namespace tr {

namespace sql {

class Parameter {

public:

	relpipe::writer::string_t value;

	// TODO: relpipe::writer::TypeId type;

};

class Statement {

public:

	virtual ~Statement() {

	}

	/**

	 * output relation name;

	 * if empty, the SQL code (DML, DDL) will be executed, but no relational output will be generated

	 */

	relpipe::writer::string_t relation;

	/**

	 * SQL code, usually some SELECT;

	 * might be also DML or DDL

	 */

	relpipe::writer::string_t sql;

	std::vector<Parameter> parameters;

};

enum class KeepFile {

	/** The file will be kept even if it was created during this transformation, so all the input data will stay on the disk. */

	Always,

	/** The file will be deleted at the end of this transformation – even if the file already existed. This is potentially dangerous, because we can unintentionally delete a database file. */

	Never,

	/** The file will be kept only if it was already present before the transformation. */

	Automatic

};

/**

 * Allows copying relations from the input stream to the output stream.

 * Such relations are specified by a regular expression.

 * We can also specify the regex replacement string and rename such relations. 

 */

class CopyRelations {

public:

	CopyRelations(const relpipe::writer::string_t pattern, const relpipe::writer::string_t replacement, const relpipe::writer::boolean_t replace) : pattern(pattern), replacement(replacement), replace(replace) {

	}

	virtual ~CopyRelations() {

	}

	const relpipe::writer::string_t pattern;

	const relpipe::writer::string_t replacement;

	const relpipe::writer::boolean_t replace;

};

class Configuration {

public:

	/**

	 * By default, this transformation runs in-memory.

	 * If 'file' is not empty, this transformation will operate on an .sqlite file.

	 * The file will be created if it does not exist.

	 */

	relpipe::writer::string_t file;

	/**

	 * see KeepFile documentation

	 */

	KeepFile keepFile = KeepFile::Automatic;

	std::vector<Statement> statements;

	/**

	 * SQL script to be executed before the relational input.

	 */

	std::wistream* sqlBeforeRelational = nullptr;

	/**

	 * SQL script to be executed after the relational input.

	 */

	std::wistream* sqlAfterRelational = nullptr;

	std::vector<CopyRelations> copyRelations;

	virtual ~Configuration() {

	}

};

}

}

}