/* $Id$ */

/** @file squirrel.cpp the implementation of the Squirrel class. It handles all Squirrel-stuff and gives a nice API back to work with. */

#include <squirrel.h>

#include <stdarg.h>

#include "../stdafx.h"

#include "../debug.h"

#include "squirrel.hpp"

#include "squirrel_std.hpp"

#include "../fileio_func.h"

#include <sqstdaux.h>

#include <../squirrel/sqpcheader.h>

#include <../squirrel/sqvm.h>

void Squirrel::CompileError(HSQUIRRELVM vm, const SQChar *desc, const SQChar *source, SQInteger line, SQInteger column)

{

	SQChar buf[1024];

#ifdef _SQ64

	scsnprintf(buf, lengthof(buf), _SC("Error %s:%ld/%ld: %s"), source, line, column, desc);

#else

	scsnprintf(buf, lengthof(buf), _SC("Error %s:%d/%d: %s"), source, line, column, desc);

#endif

	/* Check if we have a custom print function */

	SQPrintFunc *func = ((Squirrel *)sq_getforeignptr(vm))->print_func;

	if (func == NULL) {

		scfprintf(stderr, _SC("%s"), buf);

	} else {

		(*func)(true, buf);

	}

}

void Squirrel::ErrorPrintFunc(HSQUIRRELVM vm, const SQChar *s, ...)

{

	va_list arglist;

	SQChar buf[1024];

	va_start(arglist, s);

	scvsnprintf(buf, lengthof(buf), s, arglist);

	va_end(arglist);

	/* Check if we have a custom print function */

	SQPrintFunc *func = ((Squirrel *)sq_getforeignptr(vm))->print_func;

	if (func == NULL) {

		scfprintf(stderr, _SC("%s"), buf);

	} else {

		(*func)(true, buf);

	}

}

void Squirrel::RunError(HSQUIRRELVM vm, const SQChar *error)

{

	/* Set the print function to something that prints to stderr */

	SQPRINTFUNCTION pf = sq_getprintfunc(vm);

	sq_setprintfunc(vm, &Squirrel::ErrorPrintFunc);

	/* Check if we have a custom print function */

	SQChar buf[1024];

	scsnprintf(buf, lengthof(buf), _SC("Your script made an error: %s\n"), error);

	SQPrintFunc *func = ((Squirrel *)sq_getforeignptr(vm))->print_func;

	if (func == NULL) {

		scfprintf(stderr, _SC("%s"), buf);

	} else {

		(*func)(true, buf);

	}

	/* Print below the error the stack, so the users knows what is happening */

	sqstd_printcallstack(vm);

	/* Reset the old print function */

	sq_setprintfunc(vm, pf);

}

SQInteger Squirrel::_RunError(HSQUIRRELVM vm)

{

	const SQChar *sErr = 0;

	if (sq_gettop(vm) >= 1) {

		if (SQ_SUCCEEDED(sq_getstring(vm, -1, &sErr))) {

			Squirrel::RunError(vm, sErr);

			return 0;

		}

	}

	Squirrel::RunError(vm, _SC("unknown error"));

	return 0;

}

void Squirrel::PrintFunc(HSQUIRRELVM vm, const SQChar *s, ...)

{

	va_list arglist;

	SQChar buf[1024];

	va_start(arglist, s);

	scvsnprintf(buf, lengthof(buf) - 2, s, arglist);

	va_end(arglist);

	scstrcat(buf, _SC("\n"));

	/* Check if we have a custom print function */

	SQPrintFunc *func = ((Squirrel *)sq_getforeignptr(vm))->print_func;

	if (func == NULL) {

		scprintf(_SC("%s"), buf);

	} else {

		(*func)(false, buf);

	}

}

void Squirrel::AddMethod(const char *method_name, SQFUNCTION proc, uint nparam, const char *params, void *userdata, int size)

{

	sq_pushstring(this->vm, OTTD2FS(method_name), -1);

	if (size != 0) {

		void *ptr = sq_newuserdata(vm, size);

		memcpy(ptr, userdata, size);

	}

	sq_newclosure(this->vm, proc, size != 0 ? 1 : 0);

	if (nparam != 0) sq_setparamscheck(this->vm, nparam, OTTD2FS(params));

	sq_setnativeclosurename(this->vm, -1, OTTD2FS(method_name));

	sq_newslot(this->vm, -3, SQFalse);

}

void Squirrel::AddConst(const char *var_name, int value)

{

	sq_pushstring(this->vm, OTTD2FS(var_name), -1);

	sq_pushinteger(this->vm, value);

	sq_newslot(this->vm, -3, SQTrue);

}

void Squirrel::AddClassBegin(const char *class_name)

{

	sq_pushroottable(this->vm);

	sq_pushstring(this->vm, OTTD2FS(class_name), -1);

	sq_newclass(this->vm, SQFalse);

}

void Squirrel::AddClassBegin(const char *class_name, const char *parent_class)

{

	sq_pushroottable(this->vm);

	sq_pushstring(this->vm, OTTD2FS(class_name), -1);

	sq_pushstring(this->vm, OTTD2FS(parent_class), -1);

	if (SQ_FAILED(sq_get(this->vm, -3))) {

		DEBUG(misc, 0, "[squirrel] Failed to initialize class '%s' based on parent class '%s'", class_name, parent_class);

		DEBUG(misc, 0, "[squirrel] Make sure that '%s' exists before trying to define '%s'", parent_class, class_name);

		return;

	}

	sq_newclass(this->vm, SQTrue);

}

void Squirrel::AddClassEnd()

{

	sq_newslot(vm, -3, SQFalse);

	sq_pop(vm, 1);

}

bool Squirrel::MethodExists(HSQOBJECT instance, const char *method_name)

{

	int top = sq_gettop(this->vm);

	/* Go to the instance-root */

	sq_pushobject(this->vm, instance);

	/* Find the function-name inside the script */

	sq_pushstring(this->vm, OTTD2FS(method_name), -1);

	if (SQ_FAILED(sq_get(this->vm, -2))) {

		sq_settop(this->vm, top);

		return false;

	}

	sq_settop(this->vm, top);

	return true;

}

bool Squirrel::Resume(int suspend)

{

	sq_resumecatch(this->vm, suspend);

	return this->vm->_suspended != 0;

}

bool Squirrel::CallMethod(HSQOBJECT instance, const char *method_name, HSQOBJECT *ret, int suspend)

{

	/* Store the current top */

	int top = sq_gettop(this->vm);

	/* Go to the instance-root */

	sq_pushobject(this->vm, instance);

	/* Find the function-name inside the script */

	sq_pushstring(this->vm, OTTD2FS(method_name), -1);

	if (SQ_FAILED(sq_get(this->vm, -2))) {

		DEBUG(misc, 0, "[squirrel] Could not find '%s' in the class", method_name);

		sq_settop(this->vm, top);

		return false;

	}

	/* Call the method */

	sq_pushobject(this->vm, instance);

	sq_call(this->vm, 1, ret == NULL ? SQFalse : SQTrue, SQTrue, suspend);

	if (ret != NULL) sq_getstackobj(vm, -1, ret);

	/* Reset the top */

	sq_settop(this->vm, top);

	return this->vm->_suspended != 0;

}

/* static */ bool Squirrel::CreateClassInstanceVM(HSQUIRRELVM vm, const char *class_name, void *real_instance, HSQOBJECT *instance, SQRELEASEHOOK release_hook)

{

	int oldtop = sq_gettop(vm);

	/* First, find the class */

	sq_pushroottable(vm);

	sq_pushstring(vm, OTTD2FS(class_name), -1);

	if (SQ_FAILED(sq_get(vm, -2))) {

		DEBUG(misc, 0, "[squirrel] Failed to find class by the name '%s'", class_name);

		sq_settop(vm, oldtop);

		return false;

	}

	/* Create the instance */

	if (SQ_FAILED(sq_createinstance(vm, -1))) {

		DEBUG(misc, 0, "[squirrel] Failed to create instance for class '%s'", class_name);

		sq_settop(vm, oldtop);

		return false;

	}

	if (instance != NULL) {

		/* Find our instance */

		sq_getstackobj(vm, -1, instance);

		/* Add a reference to it, so it survives for ever */

		sq_addref(vm, instance);

	}

	sq_remove(vm, -2); // Class-name

	sq_remove(vm, -2); // Root-table

	/* Store it in the class */

	sq_setinstanceup(vm, -1, real_instance);

	if (release_hook != NULL) sq_setreleasehook(vm, -1, release_hook);

	if (instance != NULL) sq_settop(vm, oldtop);

	return true;

}

bool Squirrel::CreateClassInstance(const char *class_name, void *real_instance, HSQOBJECT *instance)

{

	return Squirrel::CreateClassInstanceVM(this->vm, class_name, real_instance, instance, NULL);

}

Squirrel::Squirrel()

{

	this->vm = sq_open(1024);

	this->print_func = NULL;

	this->global_pointer = NULL;

	/* Handle compile-errors ourself, so we can display it nicely */

	sq_setcompilererrorhandler(this->vm, &Squirrel::CompileError);

	sq_notifyallexceptions(this->vm, SQTrue);

	/* Set a good print-function */

	sq_setprintfunc(this->vm, &Squirrel::PrintFunc);

	/* Handle runtime-errors ourself, so we can display it nicely */

	sq_newclosure(this->vm, &Squirrel::_RunError, 0);

	sq_seterrorhandler(this->vm);

	/* Set the foreigh pointer, so we can always find this instance from within the VM */

	sq_setforeignptr(this->vm, this);

	sq_pushroottable(this->vm);

	squirrel_register_global_std(this);

}

class SQFile {

private:

	FILE *file;

	size_t size;

	size_t pos;

public:

	SQFile(FILE *file, size_t size) : file(file), size(size), pos(0) {}

	size_t Read(void *buf, size_t elemsize, size_t count)

	{

		assert(elemsize != 0);

		if (this->pos + (elemsize * count) > this->size) {

			count = (this->size - this->pos) / elemsize;

		}

		if (count == 0) return 0;

		size_t ret = fread(buf, elemsize, count, this->file);

		this->pos += ret * elemsize;

		return ret;

	}

};

static SQInteger _io_file_lexfeed_ASCII(SQUserPointer file)

{

	char c;

	if (((SQFile *)file)->Read(&c, sizeof(c), 1) > 0) return c;

	return 0;

}

static SQInteger _io_file_lexfeed_UTF8(SQUserPointer file)

{

	static const SQInteger utf8_lengths[16] =

	{

		1, 1, 1, 1, 1, 1, 1, 1, /* 0000 to 0111 : 1 byte (plain ASCII) */

		0, 0, 0, 0,             /* 1000 to 1011 : not valid */

		2, 2,                   /* 1100, 1101 : 2 bytes */

		3,                      /* 1110 : 3 bytes */

		4                       /* 1111 : 4 bytes */

	};

	static unsigned char byte_masks[5] = {0, 0, 0x1F, 0x0F, 0x07};

	unsigned char inchar;

	SQInteger c = 0;

	if (((SQFile *)file)->Read(&inchar, sizeof(inchar), 1) != 1) return 0;

	c = inchar;

	if (c >= 0x80) {

		SQInteger tmp;

		SQInteger codelen = utf8_lengths[c >> 4];

		if (codelen == 0) return 0;

		tmp = c & byte_masks[codelen];

		for (SQInteger n = 0; n < codelen - 1; n++) {

			tmp <<= 6;

			if (((SQFile *)file)->Read(&inchar, sizeof(inchar), 1) != 1) return 0;

			tmp |= inchar & 0x3F;

		}

		c = tmp;

	}

	return c;

}

static SQInteger _io_file_lexfeed_UCS2_LE(SQUserPointer file)

{

	wchar_t c;

	if (((SQFile *)file)->Read(&c, sizeof(c), 1) > 0) return (SQChar)c;

	return 0;

}

static SQInteger _io_file_lexfeed_UCS2_BE(SQUserPointer file)

{

	unsigned short c;

	if (((SQFile *)file)->Read(&c, sizeof(c), 1) > 0) {

		c = ((c >> 8) & 0x00FF)| ((c << 8) & 0xFF00);

		return (SQChar)c;

	}

	return 0;

}

static SQInteger _io_file_read(SQUserPointer file, SQUserPointer buf, SQInteger size)

{

	SQInteger ret = ((SQFile *)file)->Read(buf, 1, size);

	if (ret == 0) return -1;

	return ret;

}

/* static */ SQRESULT Squirrel::LoadFile(HSQUIRRELVM vm, const char *filename, SQBool printerror)

{

	size_t size;

	FILE *file = FioFOpenFile(filename, "rb", AI_DIR, &size);

	SQInteger ret;

	unsigned short us;

	unsigned char uc;

	SQLEXREADFUNC func;

	if (file != NULL) {

		SQFile f(file, size);

		ret = fread(&us, 1, sizeof(us), file);

		/* Most likely an empty file */

		if (ret != 2) us = 0;

		switch (us) {

			case SQ_BYTECODE_STREAM_TAG: { // BYTECODE

				fseek(file, -2, SEEK_CUR);

				if (SQ_SUCCEEDED(sq_readclosure(vm, _io_file_read, &f))) {

					FioFCloseFile(file);

					return SQ_OK;

				}

				FioFCloseFile(file);

				return sq_throwerror(vm, _SC("Couldn't read bytecode"));

			}

			case 0xFFFE: func = _io_file_lexfeed_UCS2_BE; break; // UTF-16 little endian

			case 0xFEFF: func = _io_file_lexfeed_UCS2_LE; break; // UTF-16 big endian

			case 0xBBEF: // UTF-8

				if (fread(&uc, 1, sizeof(uc), file) == 0) {

					FioFCloseFile(file);

					return sq_throwerror(vm, _SC("I/O error"));

				}

				if (uc != 0xBF) {

					FioFCloseFile(file);

					return sq_throwerror(vm, _SC("Unrecognized encoding"));

				}

				func = _io_file_lexfeed_UTF8;

				break;

			default: func = _io_file_lexfeed_ASCII; fseek(file, -2, SEEK_CUR); break; // ASCII

		}

		if (SQ_SUCCEEDED(sq_compile(vm, func, &f, OTTD2FS(filename), printerror))) {

			FioFCloseFile(file);

			return SQ_OK;

		}

		FioFCloseFile(file);

		return SQ_ERROR;

	}

	return sq_throwerror(vm, _SC("cannot open the file"));

}

/* static */ bool Squirrel::LoadScript(HSQUIRRELVM vm, const char *script, bool in_root)

{

	/* Make sure we are always in the root-table */

	if (in_root) sq_pushroottable(vm);

	/* Load and run the script */

	if (SQ_SUCCEEDED(LoadFile(vm, script, SQTrue))) {

		sq_push(vm, -2);

		if (SQ_SUCCEEDED(sq_call(vm, 1, SQFalse, SQTrue))) {

			sq_pop(vm, 1);

			return true;

		}

	}

	DEBUG(misc, 0, "[squirrel] Failed to compile '%s'", script);

	return false;

}

bool Squirrel::LoadScript(const char *script)

{

	return LoadScript(this->vm, script);

}

Squirrel::~Squirrel()

{

	/* Clean up the stuff */

	sq_pop(this->vm, 1);

	sq_close(this->vm);

}

void Squirrel::InsertResult(bool result)

{

	sq_pushbool(this->vm, result);

	vm->GetAt(vm->_stackbase + vm->_suspended_target) = vm->GetUp(-1);

	vm->Pop();

}

void Squirrel::InsertResult(int result)

{

	sq_pushinteger(this->vm, result);

	vm->GetAt(vm->_stackbase + vm->_suspended_target) = vm->GetUp(-1);

	vm->Pop();

}