/*
 * auditd-plugin-clickhouse is an auditd plugin for sending auditd data
 * to clickhouse DB.
 * Copyright (C) 2019-2020 Aleksei Nikiforov <darktemplar@basealt.ru>
 *
 * 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, either version 3 of the License, or
 * (at your option) any later version.
 *
 * 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 <https://www.gnu.org/licenses/>.
 *
 */

#ifndef AUDITD_PLUGIN_CLICKHOUSE_RECORD_HPP
#define AUDITD_PLUGIN_CLICKHOUSE_RECORD_HPP

#include <memory>
#include <map>
#include <functional>
#include <string>
#include <list>

#include <stdint.h>

#include <boost/optional.hpp>

#include <auparse.h>
#include <libaudit.h>

#include <clickhouse-cpp/columns/column.h>

bool check_field_type(auparse_type_t field_type, const std::string &database_type, const std::string &database_field_name);
std::string field_type_to_string(auparse_type_t field_type);

class AbstractRecordField
{
public:
	enum class Type
	{
		Int,
		String,
		InterpretedString,
		InterpretedStringArray
	};

	struct Column
	{
		std::string name;
		clickhouse::ColumnRef value;

		Column(const std::string &l_name, const clickhouse::ColumnRef &l_value)
			: name(l_name),
			value(l_value)
		{
		}
	};

	virtual ~AbstractRecordField() = default;

	virtual void addOrUpdateValue(auparse_state_t *record) = 0;
	virtual std::vector<Column> generateColumnsAndNames() const = 0;
	virtual void addToColumn(const std::vector<Column> &columns) const = 0;
	virtual Type getType() const = 0;

	std::string getName() const { return m_name; }

protected:
	explicit AbstractRecordField(const std::string &name);
	AbstractRecordField(const AbstractRecordField &other) = default;
	AbstractRecordField& operator=(const AbstractRecordField &other) = default;

	std::string m_name;
};

struct AuditRecord
{
	time_t time;
	uint64_t milliseconds;
	uint64_t serial;
	std::string node; // skip processing node from record fields

	std::map<std::string, std::shared_ptr<AbstractRecordField> > fields;
};

class CommonStringRecordField: public AbstractRecordField
{
public:
	virtual std::vector<Column> generateColumnsAndNames() const override;
	virtual void addToColumn(const std::vector<Column> &columns) const override;

protected:
	explicit CommonStringRecordField(const std::string &name);

	boost::optional<std::string> m_value;
};

class StringRecordField: public CommonStringRecordField
{
public:
	static std::shared_ptr<AbstractRecordField> createRecord(const std::string &name);

	virtual void addOrUpdateValue(auparse_state_t *record) override;
	virtual Type getType() const override;

protected:
	explicit StringRecordField(const std::string &name);
};

class InterpretedStringRecordField: public CommonStringRecordField
{
public:
	static std::shared_ptr<AbstractRecordField> createRecord(const std::string &name);

	virtual void addOrUpdateValue(auparse_state_t *record) override;
	virtual Type getType() const override;

protected:
	explicit InterpretedStringRecordField(const std::string &name);
};

class IntegerRecordField: public InterpretedStringRecordField
{
public:
	static std::shared_ptr<AbstractRecordField> createRecord(const std::string &name);

	virtual void addOrUpdateValue(auparse_state_t *record) override;
	virtual std::vector<Column> generateColumnsAndNames() const override;
	virtual void addToColumn(const std::vector<Column> &columns) const override;
	virtual Type getType() const override;

protected:
	explicit IntegerRecordField(const std::string &name);

	boost::optional<int> m_int_value;
};

class InterpretedStringArrayRecordField: public AbstractRecordField
{
public:
	static std::shared_ptr<AbstractRecordField> createRecord(const std::string &name);

	virtual void addOrUpdateValue(auparse_state_t *record) override;
	virtual std::vector<Column> generateColumnsAndNames() const override;
	virtual void addToColumn(const std::vector<Column> &columns) const override;
	virtual Type getType() const override;

protected:
	explicit InterpretedStringArrayRecordField(const std::string &name);

	std::list<std::string> m_names_array;
	std::list<std::string> m_values_array;
};

#endif /* AUDITD_PLUGIN_CLICKHOUSE_RECORD_HPP */