/*
 *  Baltisot
 *  Copyright (C) 1999-2003 Nicolas "Pixel" Noble
 *
 *  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

/* $Id: BLua.cc,v 1.30 2005-02-17 08:39:06 pixel Exp $ */

#include <stdlib.h>
#include "BLua.h"
#include <lualib.h>

#ifndef BUFFERSIZE
#define BUFFERSIZE	  2048
#endif

extern "C" {
    void do_lua_lock(lua_State * _L) {
	Lua * L;
	try {
	    L = Lua::find(_L);
	} catch (GeneralException e) {
	    return;
	}
	L->lock();
    }
    
    void do_lua_unlock(lua_State * _L) {
	Lua * L;
	try {
    	    L = Lua::find(_L);
	} catch (GeneralException e) {
	    return;
	}
	L->unlock();
    }
}

class LuaStatics : public Base {
  public:
    static const char * getF(lua_State *, void *, size_t *);
    static int putF(lua_State *, const void *, size_t, void *);
    static int luapanic(lua_State *);
    static int trueluapanic(lua_State *) throw(GeneralException);
    static int luaerror(lua_State *);
    static int callwrap(lua_State *, lua_CFunction);
    static int collector(lua_State *);
    static int destructor(lua_State *);

    static int andB(lua_State *);
    static int orB(lua_State *);
    static int xorB(lua_State *);
    static int notB(lua_State *);
    static int hex(lua_State *);
    static int shl(lua_State *);
    static int shr(lua_State *);
};

std::map<lua_State *, Lua *> Lua::lualist;

int LuaStatics::luaerror(lua_State * _L) {
    Lua * L = Lua::find(_L);
    L->push_lua_context();
    L->showerror();
    return 0;
}

int LuaStatics::luapanic(lua_State * L) {
    return trueluapanic(L);
}

int LuaStatics::trueluapanic(lua_State * _L) throw (GeneralException) {
    Lua * L = Lua::find(_L);
    if (L->is_protected())
        return 0;  // luaerror will get it for us...
    L->push_lua_context();
    L->showerror();
    throw LuaException("Unprotected error running Lua code, bailing out; except unstable lua environment.");
}

int LuaStatics::andB(lua_State * _L) {
    Lua * L = Lua::find(_L);
    int n = L->gettop();
    Uint32 a, b;

    if ((n != 2) && !L->isnumber(1) && !L->isnumber(2)) {
	L->error("Incorrect arguments to function `andB'");
    }

    a = L->tonumber(1);
    b = L->tonumber(2);

    L->push((lua_Number) (a & b));

    return 1;
}

int LuaStatics::orB(lua_State * _L) {
    Lua * L = Lua::find(_L);
    int n = L->gettop();
    Uint32 a, b;

    if ((n != 2) && !L->isnumber(1) && !L->isnumber(2)) {
	L->error("Incorrect arguments to function `orB'");
    }

    a = L->tonumber(1);
    b = L->tonumber(2);

    L->push((lua_Number) (a | b));

    return 1;
}

int LuaStatics::xorB(lua_State * _L) {
    Lua * L = Lua::find(_L);
    int n = L->gettop();
    Uint32 a, b;

    if ((n != 2) && !L->isnumber(1) && !L->isnumber(2)) {
	L->error("Incorrect arguments to function `xorB'");
    }

    a = L->tonumber(1);
    b = L->tonumber(2);

    L->push((lua_Number) (a ^ b));

    return 1;
}

int LuaStatics::notB(lua_State * _L) {
    Lua * L = Lua::find(_L);
    int n = L->gettop();
    Uint32 x;

    if ((n != 1) && !L->isnumber()) {
	L->error("Incorrect arguments to function `notB'");
    }

    x = L->tonumber();

    L->push((lua_Number) (~x));

    return 1;
}

int LuaStatics::shl(lua_State * _L) {
    Lua * L = Lua::find(_L);
    int n = L->gettop();
    Uint32 a, b;

    if ((n > 2) && !L->isnumber(1) && ((n == 2) && !L->isnumber(2))) {
	L->error("Incorrect arguments to function `shl'");
    }

    a = L->tonumber(1);
    if (n == 2)
        b = L->tonumber(2);
    else
        b = 1;

    L->push((lua_Number) (a << b));

    return 1;
}

int LuaStatics::shr(lua_State * _L) {
    Lua * L = Lua::find(_L);
    int n = L->gettop();
    Uint32 a, b;

    if ((n > 2) && !L->isnumber(1) && ((n == 2) && !L->isnumber(2))) {
	L->error("Incorrect arguments to function `shr'");
    }

    a = L->tonumber(1);
    if (n == 2)
        b = L->tonumber(2);
    else
        b = 1;

    L->push((lua_Number) (a >> b));

    return 1;
}

int LuaStatics::hex(lua_State * _L) {
    Lua * L = Lua::find(_L);
    int n = L->gettop();
    int x;
    String r;

    if (((n != 1) || (n != 2)) && !L->isnumber(1) && ((n == 2) && !L->isstring(2))) {
	L->error("Incorrect arguments to function `hex'");
    }

    x = L->tonumber(1);
    String fmt = n == 2 ? L->tostring() : "%02x";
    r.set(fmt.to_charp(), x);

    L->push(r);

    return 1;
}

Lua::Lua() : L(lua_open()) {
    lualist[L] = this;
    lua_atpanic(L, LuaStatics::luapanic);
    lua_setcallwrap(L, LuaStatics::callwrap);

    declarefunc("andB", LuaStatics::andB);
    declarefunc("orB", LuaStatics::orB);
    declarefunc("xorB", LuaStatics::xorB);
    declarefunc("notB", LuaStatics::notB);
    declarefunc("shl", LuaStatics::shl);
    declarefunc("shr", LuaStatics::shr);
    declarefunc("hex", LuaStatics::hex);
}

Lua::Lua(lua_State * _L) : L(_L), _protected(false) {
    lualist[L] = this;
    lua_atpanic(L, LuaStatics::luapanic);
}

Lua::~Lua() {
    lua_setgcthreshold(L, 0);
    lua_close(L);
}

bool Lua::is_protected() {
    return _protected;
}

Lua::Lua(const Lua & l) throw (GeneralException) {
    throw GeneralException("Error: can't duplicate a Lua object.");
}

void Lua::open_base() {
    luaopen_base(L);
    lua_pop(L, 1);
}

void Lua::open_table() {
    luaopen_table(L);
    lua_pop(L, 1);
}

void Lua::open_io() {
    luaopen_io(L);
    lua_pop(L, 1);
}

void Lua::open_string() {
    luaopen_string(L);
    lua_pop(L, 1);
}

void Lua::open_math() {
    luaopen_math(L);
    lua_pop(L, 1);
}

void Lua::open_debug() {
    luaopen_debug(L);
    lua_pop(L, 1);
}

void Lua::open_dir() {
    luaopen_dir(L);
    lua_pop(L, 1);
}

void Lua::declarefunc(const String & name, lua_CFunction f, int i) {
    lua_pushstring(L, name.to_charp());
    lua_pushcfunction(L, f);
    lua_settable(L, i);
}

void Lua::call(const String & f, int i, int nargs, int nresults) {
    lua_pushstring(L, f.to_charp());
    lua_gettable(L, i);
    lua_insert(L, -1 - nargs - nresults);
    call(nargs, nresults);
}

void Lua::call(int nargs, int nresults) throw(GeneralException) {
    int r;

    lua_pushcfunction(L, LuaStatics::luaerror);
    lua_insert(L, 1);
    _protected = true;
    r = lua_pcall(L, nargs, nresults, 1);
    _protected = false;
    lua_remove(L, 1);

    switch(r) {
    case 0:
        return;
    case LUA_ERRRUN:
        throw LuaException("Runtime error while running LUA code.");
    case LUA_ERRMEM:
        throw LuaException("Memory allocation error while running LUA code.");
    case LUA_ERRERR:
        throw LuaException("Error in Error function.");
    default:
        throw LuaException("Unknow error while running LUA code.");
    }
}

void Lua::push() {
    lua_pushnil(L);
}

void Lua::push(lua_Number n) {
    lua_pushnumber(L, n);
}

void Lua::push(const String & s) {
    lua_pushlstring(L, s.to_charp(), s.strlen());
}

void Lua::push(bool b) {
    lua_pushboolean(L, b);
}

void Lua::push(char * s, int size) {
    if (size < 0) {
        lua_pushstring(L, s);
    } else {
        lua_pushlstring(L, s, size);
    }
}

void Lua::push(void * p) {
    lua_pushlightuserdata(L, p);
}

void Lua::push(lua_CFunction f, int n) {
    lua_pushcclosure(L, f, n);
}

void Lua::pop(int n) {
    lua_pop(L, n);
}

void Lua::newtable() {
    lua_newtable(L);
}

void * Lua::newuser(size_t s) {
    return lua_newuserdata(L, s);
}

void Lua::settable(int i, bool raw) {
    if (raw) {
        lua_rawset(L, i);
    } else {
        lua_settable(L, i);
    }
}

void Lua::gettable(int i, bool raw) {
    if (raw) {
        lua_rawget(L, i);
    } else {
        lua_gettable(L, i);
    }
}

void Lua::setvar() {
    lua_settable(L, LUA_GLOBALSINDEX);
}

int Lua::gettop() {
    return lua_gettop(L);
}

void Lua::push_lua_context() {
    String whole_msg;
    struct lua_Debug ar;
    bool got_error = false;
    int level = 0;

    do {
        if (lua_getstack(L, level, &ar) == 1) {
            if (lua_getinfo(L, "nSl", &ar) != 0) {
                push(String("at ") + ar.source + ":" + ar.currentline + " (" + (ar.name ? ar.name : "[top]") + ")");
            } else {
                got_error = true;
            }
        } else {
            got_error = true;
        }
        level++;
    } while (!got_error);
}

void Lua::error(const String & msg) {
    push(msg);

    lua_error(L);
}

int Lua::type(int i) {
    return lua_type(L, i);
}

bool Lua::isnil(int i) {
    return lua_isnil(L, i);
}

bool Lua::isboolean(int i) {
    return lua_isboolean(L, i);
}

bool Lua::isnumber(int i) {
    return lua_isnumber(L, i);
}

bool Lua::isstring(int i) {
    return lua_isstring(L, i);
}

bool Lua::istable(int i) {
    return lua_istable(L, i);
}

bool Lua::isfunction(int i) {
    return lua_isfunction(L, i);
}

bool Lua::iscfunction(int i) {
    return lua_iscfunction(L, i);
}

bool Lua::isuserdata(int i) {
    return lua_isuserdata(L, i);
}

bool Lua::islightuserdata(int i) {
    return lua_islightuserdata(L, i);
}

bool Lua::isobject(int i) {
    bool r = false;
    if (istable(i)) {
        push("__obj");
        gettable(i);
        r = isuserdata();
        pop();
    } else {
        r = isnil(i);
    }
    return r;
}

bool Lua::toboolean(int i) {
    return lua_toboolean(L, i);
}

lua_Number Lua::tonumber(int i) {
    return lua_tonumber(L, i);
}

String Lua::tostring(int i) {
    if (isnil(i))
        return String();
    return String(lua_tostring(L, i));
}

lua_CFunction Lua::tocfunction(int i) {
    return lua_tocfunction(L, i);
}

void * Lua::touserdata(int i) {
    return lua_touserdata(L, i);
}

Lua * Lua::tothread(int i) {
    return find(lua_tothread(L, i));
}

struct LoadF {
    Handle * f;
    char buff[BUFFERSIZE];
};

const char * LuaStatics::getF(lua_State * L, void * ud, size_t * size) {
    LoadF *lf = (LoadF *)ud;
    (void)L;

    *size = lf->f->read(lf->buff, BUFFERSIZE);
    return (*size > 0) ? lf->buff : NULL;
}

struct DumpF {
    Handle * f;
};

int LuaStatics::putF(lua_State * L, const void * p, size_t size, void * ud) {
    DumpF *lf = (DumpF *)ud;
    (void)L;

    return lf->f->write(p, size) == size;
}

void Lua::load(Handle * h, bool docall) throw (GeneralException) {
    LoadF lf;
    int status;

    lf.f = h;

    status = lua_load(L, LuaStatics::getF, &lf, h->GetName().to_charp());

    if (status) {
        push_lua_context();
	showerror();
	throw LuaException("Error loading lua chunk from Handle `" + h->GetName() + "'");
    }

    if (docall)
	call();
}

extern "C" void luacmain(lua_State * L, int stripping, lua_Chunkwriter w, void * uD);

void Lua::dump(Handle * h, bool strip) {
    DumpF lf;

    lf.f = h;

    luacmain(L, strip, LuaStatics::putF, &lf);
}

Lua * Lua::thread() {
    return new Lua(lua_newthread(L));
}

int Lua::yield(int nargs) {
    return lua_yield(L, nargs);
}

int Lua::resume(int nresults) {
    return lua_resume(L, nresults);
}

Lua * Lua::find(lua_State * _L) throw (GeneralException) {
    std::map<lua_State *, Lua *>::iterator i;

    if ((i = lualist.find(_L)) == lualist.end()) {
	throw GeneralException("Unable to find the Lua object for this context");
    }

    return i->second;
}

void Lua::showerror() {
    int n = lua_gettop(L);
    int i;
    String t;

    printm(M_ERROR, "Lua object: Got an LUA error, inspecting stack.\n");

    if (n == 0) {
	printm(M_ERROR, "Stack empty\n");
	return;
    }

    for (i = 1; i <= n; i++) {
	switch(lua_type(L, i)) {
	case LUA_TNONE:
	    t = "Invalid";
	    break;
	case LUA_TNIL:
	    t = "(Nil)";
	    break;
	case LUA_TNUMBER:
	    t.set("(Number) %f", lua_tonumber(L, i));
	    break;
	case LUA_TBOOLEAN:
	    t = String("(Bool)   ") + (lua_toboolean(L, i) ? "true" : "false");
	    break;
	case LUA_TSTRING:
	    t = String("(String) ") + lua_tostring(L, i);
	    break;
	case LUA_TTABLE:
	    t = "(Table)";
	    break;
	case LUA_TFUNCTION:
	    t = "(Function)";
	    break;
	default:
	    t = "Unknown";
	}

	printm(M_ERROR, String(i) + ": " + t + "\n");
    }
}

int Lua::getmetatable(int i) {
    return lua_getmetatable(L, i);
}

int Lua::setmetatable(int i) {
    return lua_setmetatable(L, i);
}

int Lua::sethook(lua_Hook func, int mask, int count) {
    return lua_sethook(L, func, mask, count);
}

void Lua::do_break() {
    lua_break(L);
}

void LuaObject::push(Lua * L) throw (GeneralException) {
    if (pushed && wantdestruct) {
	throw GeneralException("Error: object is owned by the LUA script and can not be pushed.");
    }
    L->newtable();
    pushmembers(L);
    pushed = true;
}

void LuaObject::pushme(Lua * L, void * o, bool obj) {
    void ** u;
    bool * b;
    L->push("__obj");
    u = (void **) L->newuser(sizeof(o) + sizeof(bool));
    *u = o;
    b = (bool *) (u + 1);
    *b = obj;
    L->settable(-3, true);
}

void * LuaObject::getme(Lua * L, int i) {
    void ** r = 0;

    if (L->istable(i)) {
        L->push("__obj");
        L->gettable(i, true);
        if (!(r = (void **) L->touserdata()))
	    L->error("Table is not an object.");
	if (!*r)
	    L->error("Object already destroyed.");
        L->pop();
    } else if (L->isnil(i)) {
        r = 0;
    } else {
        L->error("Not an object (not even a table).");
    }
    
    return r ? *r : 0;
}

void LuaObject::pushit(Lua * L, const String & s, lua_CFunction f) {
    L->push(s);
    L->push(f);
    L->settable(-3, true);
}

void LuaObject::pushmeta(Lua * L, const String & s, lua_CFunction f) {
    if (!L->getmetatable()) {
	L->newtable();
    }
    L->push(s);
    L->push(f);
    L->settable();
    L->setmetatable();
}

int LuaStatics::callwrap(lua_State * _L, lua_CFunction func) {
    Lua * L = Lua::find(_L);
    int n;

    try {
        n = func(_L);
    }
    catch (LuaException e) {
        L->error(String("LuaException: ") + e.GetMsg());
    }
    catch (GeneralException e) {
        L->error(String("GeneralException: ") + e.GetMsg());
    }

    return n;
}

int LuaStatics::collector(lua_State * _L) {
    Lua * L = Lua::find(_L);
    void ** u = (void **) L->touserdata();
    bool * obj = (bool *) (u + 1);
//    printm(M_INFO, "From LUA: collecting object\n");
    if (*obj) {
//        printm(M_INFO, "Is object at %p\n", *u);
        Base * b = (Base *) *u;
        delete b;
    } else {
//        printm(M_INFO, "Is struct at %p\n", *u);
        free(*u);
    }
    *u = 0;
    return 0;
}

int LuaStatics::destructor(lua_State * _L) {
    Lua * L = Lua::find(_L);
    Base * b = (Base *) LuaObject::getme(L);
    delete b;
    L->push("__obj");
    L->gettable(-2, true);
    void ** u = (void **) L->touserdata();
    bool * obj = (bool *) (u + 1);
    if (*obj) {
        Base * b = (Base *) *u;
        delete b;
    } else {
        free(*u);
    }
    *u = 0;
    L->pop();
    return 0;
}

void LuaObject::pushdestruct(Lua * L) throw (GeneralException) {
    if (pushed) {
	throw GeneralException("Error: can't push destructor, object already pushed");
    }
    push(L);
    L->push("__obj");
    L->gettable(-2, true);
    pushmeta(L, "__gc", LuaStatics::collector);
    L->pop();
    pushit(L, "destroy", LuaStatics::destructor);

    wantdestruct = true;
}

LuaException::LuaException(String fn) : GeneralException(fn) { }

LuaException::LuaException() { }