/*
 * Copyright (C) 2016 Charybdis Development Team
 * Copyright (C) 2016 Jason Volk <jason@zemos.net>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice is present in all copies.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 *
 */

#pragma once
#define HAVE_IRCD_DB_H

// IRCd Database
//
// Please see db/README.md for documentation.
//
namespace ircd::db
{
	struct init;
	struct gopts;
	struct sopts;
	struct cell;
	struct row;
	struct column;
	struct database;
	enum class pos;

	// Errors for the database subsystem. The exceptions that use _HIDENAME
	// are built from RocksDB errors which already have an info string with
	// an included name.
	//
	IRCD_EXCEPTION(ircd::error, error)
	IRCD_EXCEPTION(error, not_found)
	IRCD_EXCEPTION(error, schema_error)
	IRCD_EXCEPTION_HIDENAME(error, corruption)
	IRCD_EXCEPTION_HIDENAME(error, not_supported)
	IRCD_EXCEPTION_HIDENAME(error, invalid_argument)
	IRCD_EXCEPTION_HIDENAME(error, io_error)
	IRCD_EXCEPTION_HIDENAME(error, merge_in_progress)
	IRCD_EXCEPTION_HIDENAME(error, incomplete)
	IRCD_EXCEPTION_HIDENAME(error, shutdown_in_progress)
	IRCD_EXCEPTION_HIDENAME(error, timed_out)
	IRCD_EXCEPTION_HIDENAME(error, aborted)
	IRCD_EXCEPTION_HIDENAME(error, busy)
	IRCD_EXCEPTION_HIDENAME(error, expired)
	IRCD_EXCEPTION_HIDENAME(error, try_again)

	// db subsystem has its own logging facility
	extern struct log::log log;
}

//
// These are forward declarations to objects we may carry a pointer to.
// Users of ircd::db should not have to deal directly with these types.
//
namespace rocksdb
{
	struct DB;
	struct Slice;
	struct Options;
	struct DBOptions;
	struct ColumnFamilyOptions;
	struct PlainTableOptions;
	struct BlockBasedTableOptions;
	struct Cache;
	struct Iterator;
	struct ColumnFamilyHandle;
	struct Snapshot;
}

//
// Misc utils
//
namespace ircd::db
{
	extern const char *const version;

	rocksdb::Slice slice(const string_view &);
	string_view slice(const rocksdb::Slice &);

	bool valid(const rocksdb::Iterator &);
	string_view key(const rocksdb::Iterator &);
	string_view val(const rocksdb::Iterator &);

	std::string path(const std::string &name);
	std::vector<std::string> available();

	void log_rdb_perf_context(const bool &all = true);
}

#include "db/delta.h"
#include "db/database.h"
#include "db/opts.h"
#include "db/column.h"
#include "db/cell.h"
#include "db/row.h"
#include "db/value.h"

namespace ircd::db
{
	std::string merge_operator(const string_view &, const std::pair<string_view, string_view> &);
}

namespace ircd
{
	using db::database;
}

enum class ircd::db::pos
{
    FRONT   = -2,    // .front()    | first element
    PREV    = -1,    // std::prev() | previous element
    END     = 0,     // break;      | exit iteration (or past the end)
    NEXT    = 1,     // continue;   | next element
    BACK    = 2,     // .back()     | last element
};

struct ircd::db::init
{
	init();
	~init() noexcept;
};