/*
 *	PROGRAM:	JRD Access Method
 *	MODULE:		DbImplementation.cpp
 *	DESCRIPTION:	Database implementation
 *
 *  The contents of this file are subject to the Initial
 *  Developer's Public License Version 1.0 (the "License");
 *  you may not use this file except in compliance with the
 *  License. You may obtain a copy of the License at
 *  http://www.ibphoenix.com/main.nfs?a=ibphoenix&page=ibp_idpl.
 *
 *  Software distributed under the License is distributed AS IS,
 *  WITHOUT WARRANTY OF ANY KIND, either express or implied.
 *  See the License for the specific language governing rights
 *  and limitations under the License.
 *
 *  The Original Code was created by Alexander Peshkoff
 *  for the Firebird Open Source RDBMS project.
 *
 *  Copyright (c) 2009 Alexander Peshkoff <peshkoff@mail.ru>
 *  and all contributors signed below.
 *
 *  All Rights Reserved.
 *  Contributor(s): ______________________________________.
 */

#include "firebird.h"
#include "../jrd/common.h"
#include "../common/classes/DbImplementation.h"

#include "../jrd/ods.h"

namespace {

static const UCHAR CpuIntel = 0;
static const UCHAR CpuAmd = 1;
static const UCHAR CpuUltraSparc = 2;
static const UCHAR CpuPowerPc = 3;
static const UCHAR CpuPowerPc64 = 4;
static const UCHAR CpuMipsel = 5;
static const UCHAR CpuMips = 6;
static const UCHAR CpuArm = 7;
static const UCHAR CpuIa64 = 8;
static const UCHAR CpuS390 = 9;
static const UCHAR CpuS390x = 10;
static const UCHAR CpuSh = 11;
static const UCHAR CpuSheb = 12;
static const UCHAR CpuHppa = 13;

static const UCHAR OsWindows = 0;
static const UCHAR OsLinux = 1;
static const UCHAR OsDarwin = 2;
static const UCHAR OsSolaris = 3;
static const UCHAR OsHpux = 4;
static const UCHAR OsAix = 5;
static const UCHAR OsMms = 6;
static const UCHAR OsFreeBsd = 7;
static const UCHAR OsNetBsd = 8;

static const UCHAR CcMsvc = 0;
static const UCHAR CcGcc = 1;
static const UCHAR CcXlc = 2;
static const UCHAR CcAcc = 3;
static const UCHAR CcSunStudio = 4;
static const UCHAR CcIcc = 5;

static const UCHAR EndianLittle = 0;
static const UCHAR EndianBig = 1;
static const UCHAR EndianMask = 1;

const char* hardware[] = {
	"Intel/i386",
	"AMD/Intel/x64",
	"UltraSparc",
	"PowerPC",
	"PowerPC64",
	"MIPSEL",
	"MIPS",
	"ARM",
	"IA64",
	"s390",
	"s390x",
	"SH",
	"SHEB",
	"HPPA"
};

const char* operatingSystem[] = {
	"Windows",
	"Linux",
	"Darwin",
	"Solaris",
	"HPUX",
	"AIX",
	"MVS",
	"FreeBSD",
	"NetBSD"
};

const char* compiler[] = {
	"MSVC",
	"gcc",
	"xlC",
	"aCC",
	"SunStudio",
	"icc"
};

// This table lists pre-fb3 imlementation codes
const UCHAR backwardTable[FB_NELEM(hardware) * FB_NELEM(operatingSystem)] =
{
//				Intel	AMD		Sparc	PPC		PPC64	MIPSEL	MIPS	ARM		IA64	s390	s390x	SH		SHEB	HPPA
/* Windows */	50,		68,		0,		0,		0,		0,		0,		0,		0,		0,		0,		0,		0,		0,
/* Linux */		60,		66,		65,		69,		0,		71,		72,		75, 	76,		79, 	78,		80,		81,		0,
/* Darwin */	70,		73,		0,		63,		77,		0,		0,		0,		0,		0,		0,		0,		0,		0,
/* Solaris */	0,		0,		30,		0,		0,		0,		0,		0,		0,		0,		0,		0,		0,		0,
/* HPUX */		0,		0,		0,		0,		0,		0,		0,		0,		0,		0,		0,		0,		0,		31,
/* AIX */		0,		0,		0,		35,		0,		0,		0,		0,		0,		0,		0,		0,		0,		0,
/* MVS */		0,		0,		0,		0,		0,		0,		0,		0,		0,		0,		0,		0,		0,		0,
/* FreeBSD */	61,		67,		0,		0,		0,		0,		0,		0,		0,		0,		0,		0,		0,		0,
/* NetBSD */	62,		0,		0,		0,		0,		0,		0,		0,		0,		0,		0,		0,		0,		0
};

const UCHAR backEndianess[FB_NELEM(hardware)] =
{
//	Intel	AMD		Sparc	PPC		PPC64	MIPSEL	MIPS	ARM		IA64	s390	s390x	SH		SHEB	HPPA
	0,		0,		1,		1,		1,		0,		1,		0,		0,		1,		1,		0,		1,		1,
};

} // anonymous namespace

namespace Firebird {

DbImplementation::DbImplementation(const Ods::header_page* h)
	: di_cpu(h->hdr_cpu), di_os(h->hdr_os), di_cc(h->hdr_cc), di_flags(h->hdr_compatibility_flags)
{
}

#define GET_ARRAY_ELEMENT(array, elem) ((elem) < FB_NELEM(array) ? array[(elem)] : "** Unknown **")

const char* DbImplementation::cpu() const
{
	return GET_ARRAY_ELEMENT(hardware, di_cpu);
}

const char* DbImplementation::os() const
{
	return GET_ARRAY_ELEMENT(operatingSystem, di_os);
}

const char* DbImplementation::cc() const
{
	return GET_ARRAY_ELEMENT(compiler, di_cc);
}

string DbImplementation::implementation() const
{
	string rc("Firebird/");
	rc += os();
	rc += "/";
	rc += cpu();
	return rc;
}

const char* DbImplementation::endianess() const
{
	return di_flags & EndianMask == EndianBig ? "big" : "little";
}

const DbImplementation DbImplementation::current(
		FB_CPU, FB_OS, FB_CC,
#ifdef WORDS_BIGENDIAN
		EndianBig);
#else
		EndianLittle);
#endif

bool DbImplementation::compatible(const DbImplementation& v)
{
	return di_flags == v.di_flags;
}

void DbImplementation::store(Ods::header_page* h) const
{
	h->hdr_cpu = di_cpu;
	h->hdr_os = di_os;
	h->hdr_cc = di_cc;
	h->hdr_compatibility_flags = di_flags;
}

void DbImplementation::stuff(UCHAR** info) const
{
	UCHAR* p = *info;
	*p++ = di_cpu;
	*p++ = di_os;
	*p++ = di_cc;
	*p++ = di_flags;
	*info = p;
}

DbImplementation DbImplementation::pick(const UCHAR* info)
{
	//DbImplementation(UCHAR p_cpu, UCHAR p_os, UCHAR p_cc, UCHAR p_flags)
	return DbImplementation(info[0], info[1], info[2], info[3]);
}

DbImplementation DbImplementation::fromBackwardCompatibleByte(UCHAR bcImpl)
{
	for (UCHAR os = 0; os < FB_NELEM(operatingSystem); ++os)
	{
		for (UCHAR hw = 0; hw < FB_NELEM(hardware); ++hw)
		{
			USHORT ind = USHORT(os) * FB_NELEM(hardware) + USHORT(hw);
			if (backwardTable[ind] == bcImpl)
			{
				return DbImplementation(hw, os, 0xFF, backEndianess[hw] ? EndianBig : EndianLittle);
			}
		}
	}

	return DbImplementation(0xFF, 0xFF, 0xFF, 0x80);
}

UCHAR DbImplementation::backwardCompatibleImplementation() const
{
	if (di_cpu >= FB_NELEM(hardware) || di_os >= FB_NELEM(operatingSystem))
	{
		return 0;
	}

	return backwardTable[USHORT(di_os) * FB_NELEM(hardware) + USHORT(di_cpu)];
}

} // namespace Firebird