/*
** binding-mri.cpp
**
** This file is part of mkxp.
**
** Copyright (C) 2013 - 2021 Amaryllis Kulla <ancurio@mapleshrine.eu>
**
** mkxp 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.
**
** mkxp 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 mkxp.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "binding.h"
#include "binding-util.h"
#include "sharedstate.h"
#include "eventthread.h"
#include "filesystem.h"
#include "util.h"
#include "sdl-util.h"
#include "debugwriter.h"
#include "graphics.h"
#include "audio.h"
#include "font.h"
#include "boost-hash.h"

#include "steamshim/steamshim_child.h"

#include <ruby.h>
#include <ruby/encoding.h>

#include <assert.h>
#include <string>
#include <zlib.h>

#include <SDL_filesystem.h>

extern const char module_rpg1[];
extern const char module_rpg2[];
extern const char module_rpg3[];

static void mriBindingExecute();
static void mriBindingTerminate();
static void mriBindingReset();

ScriptBinding scriptBindingImpl =
{
	mriBindingExecute,
	mriBindingTerminate,
	mriBindingReset
};

ScriptBinding *scriptBinding = &scriptBindingImpl;

void tableBindingInit();
void etcBindingInit();
void fontBindingInit();
void bitmapBindingInit();
void spriteBindingInit();
void viewportBindingInit();
void planeBindingInit();
void windowBindingInit();
void tilemapBindingInit();
void windowVXBindingInit();
void tilemapVXBindingInit();

void inputBindingInit();
void audioBindingInit();
void graphicsBindingInit();

void fileIntBindingInit();

RB_METHOD(mriPrint);
RB_METHOD(mriP);
RB_METHOD(mkxpDataDirectory);
RB_METHOD(mkxpPuts);
RB_METHOD(mkxpRawKeyStates);
RB_METHOD(mkxpMouseInWindow);

RB_METHOD(mriRgssMain);
RB_METHOD(mriRgssStop);
RB_METHOD(_kernelCaller);

static void mriBindingInit()
{
	tableBindingInit();
	etcBindingInit();
	fontBindingInit();
	bitmapBindingInit();
	spriteBindingInit();
	viewportBindingInit();
	planeBindingInit();

	if (rgssVer == 1)
	{
		windowBindingInit();
		tilemapBindingInit();
	}
	else
	{
		windowVXBindingInit();
		tilemapVXBindingInit();
	}

	inputBindingInit();
	audioBindingInit();
	graphicsBindingInit();

	fileIntBindingInit();

	if (rgssVer >= 3)
	{
		_rb_define_module_function(rb_mKernel, "rgss_main", mriRgssMain);
		_rb_define_module_function(rb_mKernel, "rgss_stop", mriRgssStop);

		_rb_define_module_function(rb_mKernel, "msgbox",    mriPrint);
		_rb_define_module_function(rb_mKernel, "msgbox_p",  mriP);

		rb_define_global_const("RGSS_VERSION", rb_str_new_cstr("3.0.1"));
	}
	else
	{
		_rb_define_module_function(rb_mKernel, "print", mriPrint);
		_rb_define_module_function(rb_mKernel, "p",     mriP);

		rb_define_alias(rb_singleton_class(rb_mKernel), "_mkxp_kernel_caller_alias", "caller");
		_rb_define_module_function(rb_mKernel, "caller", _kernelCaller);
	}

	if (rgssVer == 1)
		rb_eval_string(module_rpg1);
	else if (rgssVer == 2)
		rb_eval_string(module_rpg2);
	else if (rgssVer == 3)
		rb_eval_string(module_rpg3);
	else
		assert(!"unreachable");

	VALUE mod = rb_define_module("MKXP");
	_rb_define_module_function(mod, "data_directory", mkxpDataDirectory);
	_rb_define_module_function(mod, "puts", mkxpPuts);
	_rb_define_module_function(mod, "raw_key_states", mkxpRawKeyStates);
	_rb_define_module_function(mod, "mouse_in_window", mkxpMouseInWindow);

	/* Load global constants */
	rb_gv_set("MKXP", Qtrue);

	VALUE debug = rb_bool_new(shState->config().editor.debug);
	if (rgssVer == 1)
		rb_gv_set("DEBUG", debug);
	else if (rgssVer >= 2)
		rb_gv_set("TEST", debug);

	rb_gv_set("BTEST", rb_bool_new(shState->config().editor.battleTest));
}

static void
showMsg(const std::string &msg)
{
	shState->eThread().showMessageBox(msg.c_str());
}

static void printP(int argc, VALUE *argv,
                   const char *convMethod, const char *sep)
{
	VALUE dispString = rb_str_buf_new(128);
	ID conv = rb_intern(convMethod);

	for (int i = 0; i < argc; ++i)
	{
		VALUE str = rb_funcall2(argv[i], conv, 0, NULL);
		rb_str_buf_append(dispString, str);

		if (i < argc)
			rb_str_buf_cat2(dispString, sep);
	}

	showMsg(RSTRING_PTR(dispString));
}

RB_METHOD(mriPrint)
{
	RB_UNUSED_PARAM;

	printP(argc, argv, "to_s", "");

	return Qnil;
}

RB_METHOD(mriP)
{
	RB_UNUSED_PARAM;

	printP(argc, argv, "inspect", "\n");

	return Qnil;
}

RB_METHOD(mkxpDataDirectory)
{
	RB_UNUSED_PARAM;
	
	const std::string &path = shState->config().customDataPath;
	const char *s = path.empty() ? "." : path.c_str();

	return rb_str_new_cstr(s);
}

RB_METHOD(mkxpPuts)
{
	RB_UNUSED_PARAM;

	const char *str;
	rb_get_args(argc, argv, "z", &str RB_ARG_END);

	Debug() << str;

	return Qnil;
}

static uint8_t keyStatesMirrorAry[SDL_NUM_SCANCODES];

// points at either EventThread::keyStates (which is continuously updated)
// or keyStatesMirrorAry (which is a frame-local snapshot of the former)
uint8_t *keyStatesMirror = EventThread::keyStates;

RB_METHOD(mkxpRawKeyStates)
{
	RB_UNUSED_PARAM;

	VALUE str = rb_str_new(0, sizeof(EventThread::keyStates));

	// copy keystates to a shadow array so the Input module uses the same snapshot
	memcpy(keyStatesMirrorAry, EventThread::keyStates, sizeof(keyStatesMirrorAry));
	memcpy(RSTRING_PTR(str), keyStatesMirrorAry, sizeof(keyStatesMirrorAry));

	// let the Input module use our snapshot instead (Input will take care of resetting
	// the pointer back to the EventThread array)
	keyStatesMirror = keyStatesMirrorAry;

	return str;
}

RB_METHOD(mkxpMouseInWindow)
{
	RB_UNUSED_PARAM;

	return rb_bool_new(EventThread::mouseState.inWindow);
}

static VALUE rgssMainCb(VALUE block)
{
	rb_funcall2(block, rb_intern("call"), 0, 0);
	return Qnil;
}

static VALUE rgssMainRescue(VALUE arg, VALUE exc)
{
	VALUE *excRet = (VALUE*) arg;

	*excRet = exc;

	return Qnil;
}

static void processReset()
{
	shState->graphics().reset();
	shState->audio().reset();

	shState->rtData().rqReset.clear();
	shState->graphics().repaintWait(shState->rtData().rqResetFinish,
	                                false);
}

RB_METHOD(mriRgssMain)
{
	RB_UNUSED_PARAM;

	while (true)
	{
		VALUE exc = Qnil;

		rb_rescue2((VALUE(*)(ANYARGS)) rgssMainCb, rb_block_proc(),
		           (VALUE(*)(ANYARGS)) rgssMainRescue, (VALUE) &exc,
		           rb_eException, (VALUE) 0);

		if (NIL_P(exc))
			break;

		if (rb_obj_class(exc) == getRbData()->exc[Reset])
			processReset();
		else
			rb_exc_raise(exc);
	}

	return Qnil;
}

RB_METHOD(mriRgssStop)
{
	RB_UNUSED_PARAM;

	while (true)
		shState->graphics().update();

	return Qnil;
}

RB_METHOD(_kernelCaller)
{
	RB_UNUSED_PARAM;

	VALUE trace = rb_funcall2(rb_mKernel, rb_intern("_mkxp_kernel_caller_alias"), 0, 0);

	if (!RB_TYPE_P(trace, RUBY_T_ARRAY))
		return trace;

	long len = RARRAY_LEN(trace);

	if (len < 2)
		return trace;

	/* Remove useless "ruby:1:in 'eval'" */
	rb_ary_pop(trace);

	/* Also remove trace of this helper function */
	rb_ary_shift(trace);

	len -= 2;

	if (len == 0)
		return trace;

	/* RMXP does this, not sure if specific or 1.8 related */
	VALUE args[] = { rb_str_new_cstr(":in `<main>'"), rb_str_new_cstr("") };
	rb_funcall2(rb_ary_entry(trace, len-1), rb_intern("gsub!"), 2, args);

	return trace;
}

RB_METHOD(_steamAchievementUnlock)
{
	RB_UNUSED_PARAM;

	if (!STEAMSHIM_alive())
		return Qnil;

	const char *achv;
	rb_get_args(argc, argv, "z", &achv RB_ARG_END);

	STEAMSHIM_setAchievement(achv, true);
	STEAMSHIM_storeStats();

	return Qnil;
}

RB_METHOD(_mkxp_set_default_font_family)
{
	RB_UNUSED_PARAM;

	const char *family;
	rb_get_args(argc, argv, "z", &family RB_ARG_END);

	shState->fontState().setDefaultFontFamily(family);

	return Qnil;
}

static VALUE newStringUTF8(const char *string, long length)
{
	return rb_enc_str_new(string, length, rb_utf8_encoding());
}

struct evalArg
{
	VALUE string;
	VALUE filename;
};

static VALUE evalHelper(evalArg *arg)
{
	VALUE argv[] = { arg->string, Qnil, arg->filename };
	return rb_funcall2(Qnil, rb_intern("eval"), ARRAY_SIZE(argv), argv);
}

static VALUE evalString(VALUE string, VALUE filename, int *state)
{
	evalArg arg = { string, filename };
	return rb_protect((VALUE (*)(VALUE))evalHelper, (VALUE)&arg, state);
}

static void runCustomScript(const std::string &filename)
{
	std::string scriptData;

	if (!readFileSDL(filename.c_str(), scriptData))
	{
		showMsg(std::string("Unable to open '") + filename + "'");
		return;
	}

	evalString(newStringUTF8(scriptData.c_str(), scriptData.size()),
	           newStringUTF8(filename.c_str(), filename.size()), NULL);
}

VALUE kernelLoadDataInt(const char *filename, bool rubyExc);

struct BacktraceData
{
	/* Maps: Ruby visible filename, To: Actual script name */
	BoostHash<std::string, std::string> scriptNames;
};

#define SCRIPT_SECTION_FMT (rgssVer >= 3 ? "{%04ld}" : "Section%03ld")

static void runRMXPScripts(BacktraceData &btData)
{
	const Config &conf = shState->rtData().config;
	const std::string &scriptPack = conf.game.scripts;

	if (scriptPack.empty())
	{
		showMsg("No game scripts specified (missing Game.ini?)");
		return;
	}

	if (!shState->fileSystem().exists(scriptPack.c_str()))
	{
		showMsg("Unable to open '" + scriptPack + "'");
		return;
	}

	VALUE scriptArray;

	/* We checked if Scripts.rxdata exists, but something might
	 * still go wrong */
	try
	{
		scriptArray = kernelLoadDataInt(scriptPack.c_str(), false);
	}
	catch (const Exception &e)
	{
		showMsg(std::string("Failed to read script data: ") + e.msg);
		return;
	}

	if (!RB_TYPE_P(scriptArray, RUBY_T_ARRAY))
	{
		showMsg("Failed to read script data");
		return;
	}

	rb_gv_set("$RGSS_SCRIPTS", scriptArray);

	long scriptCount = RARRAY_LEN(scriptArray);

	std::string decodeBuffer;
	decodeBuffer.resize(0x1000);

	for (long i = 0; i < scriptCount; ++i)
	{
		VALUE script = rb_ary_entry(scriptArray, i);

		if (!RB_TYPE_P(script, RUBY_T_ARRAY))
			continue;

		VALUE scriptName   = rb_ary_entry(script, 1);
		VALUE scriptString = rb_ary_entry(script, 2);

		int result = Z_OK;
		unsigned long bufferLen;

		while (true)
		{
			unsigned char *bufferPtr =
			        reinterpret_cast<unsigned char*>(const_cast<char*>(decodeBuffer.c_str()));
			const unsigned char *sourcePtr =
			        reinterpret_cast<const unsigned char*>(RSTRING_PTR(scriptString));

			bufferLen = decodeBuffer.length();

			result = uncompress(bufferPtr, &bufferLen,
			                    sourcePtr, RSTRING_LEN(scriptString));

			bufferPtr[bufferLen] = '\0';

			if (result != Z_BUF_ERROR)
				break;

			decodeBuffer.resize(decodeBuffer.size()*2);
		}

		if (result != Z_OK)
		{
			static char buffer[256];
			snprintf(buffer, sizeof(buffer), "Error decoding script %ld: '%s'",
			         i, RSTRING_PTR(scriptName));

			showMsg(buffer);

			break;
		}

		rb_ary_store(script, 3, rb_str_new_cstr(decodeBuffer.c_str()));
	}

	/* Execute preloaded scripts */
	for (std::set<std::string>::iterator i = conf.preloadScripts.begin();
	     i != conf.preloadScripts.end(); ++i)
		runCustomScript(*i);

	VALUE exc = rb_gv_get("$!");
	if (exc != Qnil)
		return;

	while (true)
	{
		for (long i = 0; i < scriptCount; ++i)
		{
			VALUE script = rb_ary_entry(scriptArray, i);
			VALUE scriptDecoded = rb_ary_entry(script, 3);
			VALUE string = newStringUTF8(RSTRING_PTR(scriptDecoded),
			                             RSTRING_LEN(scriptDecoded));

			VALUE fname;
			const char *scriptName = RSTRING_PTR(rb_ary_entry(script, 1));
			char buf[512];
			int len;

			if (conf.useScriptNames)
				len = snprintf(buf, sizeof(buf), "%03ld:%s", i, scriptName);
			else
				len = snprintf(buf, sizeof(buf), SCRIPT_SECTION_FMT, i);

			fname = newStringUTF8(buf, len);
			btData.scriptNames.insert(buf, scriptName);

			int state;
			evalString(string, fname, &state);
			if (state)
				break;
		}

		VALUE exc = rb_gv_get("$!");
		if (rb_obj_class(exc) != getRbData()->exc[Reset])
			break;

		processReset();
	}
}

static void showExc(VALUE exc, const BacktraceData &btData)
{
	VALUE bt = rb_funcall2(exc, rb_intern("backtrace"), 0, NULL);
	VALUE msg = rb_funcall2(exc, rb_intern("message"), 0, NULL);
	VALUE bt0 = rb_ary_entry(bt, 0);
	VALUE name = rb_class_path(rb_obj_class(exc));

	VALUE ds = rb_sprintf("%" PRIsVALUE ": %" PRIsVALUE " (%" PRIsVALUE ")",
	                      bt0, exc, name);
	/* omit "useless" last entry (from ruby:1:in `eval') */
	for (long i = 1, btlen = RARRAY_LEN(bt) - 1; i < btlen; ++i)
		rb_str_catf(ds, "\n\tfrom %" PRIsVALUE, rb_ary_entry(bt, i));
	Debug() << StringValueCStr(ds);

	char *s = RSTRING_PTR(bt0);

	char line[16];
	std::string file(512, '\0');

	char *p = s + strlen(s);
	char *e;

	while (p != s)
		if (*--p == ':')
			break;

	e = p;

	while (p != s)
		if (*--p == ':')
			break;

	/* s         p  e
	 * SectionXXX:YY: in 'blabla' */

	*e = '\0';
	strncpy(line, *p ? p+1 : p, sizeof(line));
	line[sizeof(line)-1] = '\0';
	*e = ':';
	e = p;

	/* s         e
	 * SectionXXX:YY: in 'blabla' */

	*e = '\0';
	strncpy(&file[0], s, file.size());
	*e = ':';

	/* Shrink to fit */
	file.resize(strlen(file.c_str()));
	file = btData.scriptNames.value(file, file);

	std::string ms(640, '\0');
	snprintf(&ms[0], ms.size(), "Script '%s' line %s: %s occured.\n\n%s",
	         file.c_str(), line, RSTRING_PTR(name), RSTRING_PTR(msg));

	showMsg(ms);
}

static void mriBindingExecute()
{
	/* Normally only a ruby executable would do a sysinit,
	 * but not doing it will lead to crashes due to closed
	 * stdio streams on some platforms (eg. Windows) */
	int argc = 0;
	char **argv = 0;
	ruby_sysinit(&argc, &argv);

	ruby_setup();
	rb_enc_set_default_external(rb_enc_from_encoding(rb_utf8_encoding()));

	Config &conf = shState->rtData().config;

	if (!conf.rubyLoadpaths.empty())
	{
		/* Setup custom load paths */
		VALUE lpaths = rb_gv_get(":");

		for (size_t i = 0; i < conf.rubyLoadpaths.size(); ++i)
		{
			std::string &path = conf.rubyLoadpaths[i];

			VALUE pathv = rb_str_new(path.c_str(), path.size());
			rb_ary_push(lpaths, pathv);
		}
	}

	RbData rbData;
	shState->setBindingData(&rbData);
	BacktraceData btData;

	mriBindingInit();


	STEAMSHIM_init();
	_rb_define_module_function(rb_mKernel, "_steam_achievement_unlock",
	                           _steamAchievementUnlock);

	_rb_define_module_function(rb_mKernel, "_mkxp_set_default_font_family",
	                           _mkxp_set_default_font_family);

	std::string &customScript = conf.customScript;
	if (!customScript.empty())
		runCustomScript(customScript);
	else
		runRMXPScripts(btData);

	VALUE exc = rb_errinfo();
	if (!NIL_P(exc) && !rb_obj_is_kind_of(exc, rb_eSystemExit))
		showExc(exc, btData);

	ruby_cleanup(0);


	STEAMSHIM_deinit();


	shState->rtData().rqTermAck.set();
}

static void mriBindingTerminate()
{
	rb_raise(rb_eSystemExit, " ");
}

static void mriBindingReset()
{
	rb_raise(getRbData()->exc[Reset], " ");
}
