/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * 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 2
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */

#include "ags/shared/script/cc_error.h"
#include "ags/shared/script/cc_script.h"
#include "ags/shared/script/script_common.h"
#include "ags/shared/util/stream.h"
#include "ags/shared/util/string_compat.h"
#include "ags/globals.h"

namespace AGS3 {

using AGS::Shared::Stream;

// [IKM] I reckon this function is almost identical to fgetstring in string_utils
void freadstring(char **strptr, Stream *in) {
	static char ibuffer[300];
	int idxx = 0;

	while ((ibuffer[idxx] = in->ReadInt8()) != 0)
		idxx++;

	if (ibuffer[0] == 0) {
		strptr[0] = nullptr;
		return;
	}

	strptr[0] = (char *)malloc(strlen(ibuffer) + 1);
	strcpy(strptr[0], ibuffer);
}

void fwritestring(const char *strptr, Stream *out) {
	if (strptr == nullptr) {
		out->WriteByte(0);
	} else {
		out->Write(strptr, strlen(strptr) + 1);
	}
}

ccScript *ccScript::CreateFromStream(Shared::Stream *in) {
	ccScript *scri = new ccScript();
	if (!scri->Read(in)) {
		delete scri;
		return nullptr;
	}
	return scri;
}

ccScript::ccScript() {
	globaldata = nullptr;
	globaldatasize = 0;
	code = nullptr;
	codesize = 0;
	strings = nullptr;
	stringssize = 0;
	fixuptypes = nullptr;
	fixups = nullptr;
	numfixups = 0;
	importsCapacity = 0;
	imports = nullptr;
	numimports = 0;
	exportsCapacity = 0;
	exports = nullptr;
	export_addr = nullptr;
	numexports = 0;
	instances = 0;
	sectionNames = nullptr;
	sectionOffsets = nullptr;
	numSections = 0;
	capacitySections = 0;
}

ccScript::ccScript(const ccScript &src) {
	globaldatasize = src.globaldatasize;
	if (globaldatasize > 0) {
		globaldata = (char *)malloc(globaldatasize);
		memcpy(globaldata, src.globaldata, globaldatasize);
	} else {
		globaldata = nullptr;
	}

	codesize = src.codesize;
	if (codesize > 0) {
		code = (int32_t *)malloc(codesize * sizeof(int32_t));
		memcpy(code, src.code, sizeof(int32_t) * codesize);
	} else {
		code = nullptr;
	}

	stringssize = src.stringssize;
	if (stringssize > 0) {
		strings = (char *)malloc(stringssize);
		memcpy(strings, src.strings, stringssize);
	} else {
		strings = nullptr;
	}

	numfixups = src.numfixups;
	if (numfixups > 0) {
		fixuptypes = (char *)malloc(numfixups);
		fixups = (int32_t *)malloc(numfixups * sizeof(int32_t));
		memcpy(fixuptypes, src.fixuptypes, numfixups);
		memcpy(fixups, src.fixups, numfixups * sizeof(int32_t));
	} else {
		fixups = nullptr;
		fixuptypes = nullptr;
	}

	importsCapacity = src.numimports;
	numimports = src.numimports;
	if (numimports > 0) {
		imports = (char **)malloc(sizeof(char *) * numimports);
		for (int i = 0; i < numimports; ++i)
			imports[i] = ags_strdup(src.imports[i]);
	} else {
		imports = nullptr;
	}

	exportsCapacity = src.numexports;
	numexports = src.numexports;
	if (numexports > 0) {
		exports = (char **)malloc(sizeof(char *) * numexports);
		export_addr = (int32_t *)malloc(sizeof(int32_t) * numexports);
		for (int i = 0; i < numexports; ++i) {
			exports[i] = ags_strdup(src.exports[i]);
			export_addr[i] = src.export_addr[i];
		}
	} else {
		exports = nullptr;
		export_addr = nullptr;
	}

	capacitySections = src.numSections;
	numSections = src.numSections;
	if (numSections > 0) {
		sectionNames = (char **)malloc(numSections * sizeof(char *));
		sectionOffsets = (int32_t *)malloc(numSections * sizeof(int32_t));
		for (int i = 0; i < numSections; ++i) {
			sectionNames[i] = ags_strdup(src.sectionNames[i]);
			sectionOffsets[i] = src.sectionOffsets[i];
		}
	} else {
		numSections = 0;
		sectionNames = nullptr;
		sectionOffsets = nullptr;
	}

	instances = 0;
}

ccScript::~ccScript() {
	Free();
}

void ccScript::Write(Shared::Stream *out) {
	int n;
	out->Write(_G(scfilesig), 4);
	out->WriteInt32(SCOM_VERSION);
	out->WriteInt32(globaldatasize);
	out->WriteInt32(codesize);
	out->WriteInt32(stringssize);
	if (globaldatasize > 0)
		out->WriteArray(globaldata, globaldatasize, 1);
	if (codesize > 0)
		out->WriteArrayOfInt32(code, codesize);
	if (stringssize > 0)
		out->WriteArray(strings, stringssize, 1);
	out->WriteInt32(numfixups);
	if (numfixups > 0) {
		out->WriteArray(fixuptypes, numfixups, 1);
		out->WriteArrayOfInt32(fixups, numfixups);
	}
	out->WriteInt32(numimports);
	for (n = 0; n < numimports; n++)
		fwritestring(imports[n], out);
	out->WriteInt32(numexports);
	for (n = 0; n < numexports; n++) {
		fwritestring(exports[n], out);
		out->WriteInt32(export_addr[n]);
	}
	out->WriteInt32(numSections);
	for (n = 0; n < numSections; n++) {
		fwritestring(sectionNames[n], out);
		out->WriteInt32(sectionOffsets[n]);
	}
	out->WriteInt32(ENDFILESIG);
}

bool ccScript::Read(Shared::Stream *in) {
	instances = 0;
	int n;
	char gotsig[5];
	_G(currentline) = -1;
	// MACPORT FIX: swap 'size' and 'nmemb'
	in->Read(gotsig, 4);
	gotsig[4] = 0;

	int fileVer = in->ReadInt32();

	if ((strcmp(gotsig, _G(scfilesig)) != 0) || (fileVer > SCOM_VERSION)) {
		cc_error("file was not written by ccScript::Write or seek position is incorrect");
		return false;
	}

	globaldatasize = in->ReadInt32();
	codesize = in->ReadInt32();
	stringssize = in->ReadInt32();

	if (globaldatasize > 0) {
		globaldata = (char *)malloc(globaldatasize);
		// MACPORT FIX: swap
		in->Read(globaldata, globaldatasize);
	} else
		globaldata = nullptr;

	if (codesize > 0) {
		code = (int32_t *)malloc(codesize * sizeof(int32_t));
		// MACPORT FIX: swap

		// 64 bit: Read code into 8 byte array, necessary for being able to perform
		// relocations on the references.
		in->ReadArrayOfInt32(code, codesize);
	} else
		code = nullptr;

	if (stringssize > 0) {
		strings = (char *)malloc(stringssize);
		// MACPORT FIX: swap
		in->Read(strings, stringssize);
	} else
		strings = nullptr;

	numfixups = in->ReadInt32();
	if (numfixups > 0) {
		fixuptypes = (char *)malloc(numfixups);
		fixups = (int32_t *)malloc(numfixups * sizeof(int32_t));
		// MACPORT FIX: swap 'size' and 'nmemb'
		in->Read(fixuptypes, numfixups);
		in->ReadArrayOfInt32(fixups, numfixups);
	} else {
		fixups = nullptr;
		fixuptypes = nullptr;
	}

	numimports = in->ReadInt32();

	imports = (char **)malloc(sizeof(char *) * numimports);
	for (n = 0; n < numimports; n++)
		freadstring(&imports[n], in);

	numexports = in->ReadInt32();
	exports = (char **)malloc(sizeof(char *) * numexports);
	export_addr = (int32_t *)malloc(sizeof(int32_t) * numexports);
	for (n = 0; n < numexports; n++) {
		freadstring(&exports[n], in);
		export_addr[n] = in->ReadInt32();
	}

	if (fileVer >= 83) {
		// read in the Sections
		numSections = in->ReadInt32();
		sectionNames = (char **)malloc(numSections * sizeof(char *));
		sectionOffsets = (int32_t *)malloc(numSections * sizeof(int32_t));
		for (n = 0; n < numSections; n++) {
			freadstring(&sectionNames[n], in);
			sectionOffsets[n] = in->ReadInt32();
		}
	} else {
		numSections = 0;
		sectionNames = nullptr;
		sectionOffsets = nullptr;
	}

	if (in->ReadInt32() != (int32)ENDFILESIG) {
		cc_error("internal error rebuilding script");
		return false;
	}
	return true;
}

void ccScript::Free() {
	if (globaldata != nullptr)
		free(globaldata);

	if (code != nullptr)
		free(code);

	if (strings != nullptr)
		free(strings);

	if (fixups != nullptr && numfixups > 0)
		free(fixups);

	if (fixuptypes != nullptr && numfixups > 0)
		free(fixuptypes);

	globaldata = nullptr;
	code = nullptr;
	strings = nullptr;
	fixups = nullptr;
	fixuptypes = nullptr;

	int aa;
	for (aa = 0; aa < numimports; aa++) {
		if (imports[aa] != nullptr)
			free(imports[aa]);
	}

	for (aa = 0; aa < numexports; aa++)
		free(exports[aa]);

	for (aa = 0; aa < numSections; aa++)
		free(sectionNames[aa]);

	if (sectionNames != nullptr) {
		free(sectionNames);
		free(sectionOffsets);
		sectionNames = nullptr;
		sectionOffsets = nullptr;
	}

	if (imports != nullptr) {
		free(imports);
		free(exports);
		free(export_addr);
		imports = nullptr;
		exports = nullptr;
		export_addr = nullptr;
	}
	numimports = 0;
	numexports = 0;
	numSections = 0;
}

const char *ccScript::GetSectionName(int32_t offs) {

	int i;
	for (i = 0; i < numSections; i++) {
		if (sectionOffsets[i] < offs)
			continue;
		break;
	}

	// if no sections in script, return unknown
	if (i == 0)
		return "(unknown section)";

	return sectionNames[i - 1];
}

} // namespace AGS3