/*
** Debug library.
** Copyright (C) 2005-2014 Mike Pall. See Copyright Notice in luajit.h
**
** Major portions taken verbatim or adapted from the Lua interpreter.
** Copyright (C) 1994-2008 Lua.org, PUC-Rio. See Copyright Notice in lua.h
*/

#define lib_debug_c
#define LUA_LIB

#include "lua.h"
#include "lauxlib.h"
#include "lualib.h"

#include "lj_obj.h"
#include "lj_gc.h"
#include "lj_err.h"
#include "lj_debug.h"
#include "lj_lib.h"

/* ------------------------------------------------------------------------ */

#define LJLIB_MODULE_debug

LJLIB_CF(debug_getregistry)
{
    copyTV(L, L->top++, registry(L));
    return 1;
}

LJLIB_CF(debug_getmetatable)
{
    lj_lib_checkany(L, 1);
    if (!lua_getmetatable(L, 1)) {
        setnilV(L->top - 1);
    }
    return 1;
}

LJLIB_CF(debug_setmetatable)
{
    lj_lib_checktabornil(L, 2);
    L->top = L->base + 2;
    lua_setmetatable(L, 1);
#if !LJ_52
    setboolV(L->top - 1, 1);
#endif
    return 1;
}

LJLIB_CF(debug_getfenv)
{
    lj_lib_checkany(L, 1);
    lua_getfenv(L, 1);
    return 1;
}

LJLIB_CF(debug_setfenv)
{
    lj_lib_checktab(L, 2);
    L->top = L->base + 2;
    if (!lua_setfenv(L, 1))
        lj_err_caller(L, LJ_ERR_SETFENV);
    return 1;
}

/* ------------------------------------------------------------------------ */

static void settabss(lua_State *L, const char *i, const char *v)
{
    lua_pushstring(L, v);
    lua_setfield(L, -2, i);
}

static void settabsi(lua_State *L, const char *i, int v)
{
    lua_pushinteger(L, v);
    lua_setfield(L, -2, i);
}

static void settabsb(lua_State *L, const char *i, int v)
{
    lua_pushboolean(L, v);
    lua_setfield(L, -2, i);
}

static lua_State *getthread(lua_State *L, int *arg)
{
    if (L->base < L->top && tvisthread(L->base)) {
        *arg = 1;
        return threadV(L->base);
    }
    else {
        *arg = 0;
        return L;
    }
}

static void treatstackoption(lua_State *L, lua_State *L1, const char *fname)
{
    if (L == L1) {
        lua_pushvalue(L, -2);
        lua_remove(L, -3);
    }
    else
        lua_xmove(L1, L, 1);
    lua_setfield(L, -2, fname);
}

LJLIB_CF(debug_getinfo)
{
    lj_Debug ar;
    int arg, opt_f = 0, opt_L = 0;
    lua_State *L1 = getthread(L, &arg);
    const char *options = luaL_optstring(L, arg + 2, "flnSu");
    if (lua_isnumber(L, arg + 1)) {
        if (!lua_getstack(L1, (int)lua_tointeger(L, arg + 1),
                          (lua_Debug *)&ar)) {
            setnilV(L->top - 1);
            return 1;
        }
    }
    else if (L->base + arg < L->top && tvisfunc(L->base + arg)) {
        options = lua_pushfstring(L, ">%s", options);
        setfuncV(L1, L1->top++, funcV(L->base + arg));
    }
    else {
        lj_err_arg(L, arg + 1, LJ_ERR_NOFUNCL);
    }
    if (!lj_debug_getinfo(L1, options, &ar, 1))
        lj_err_arg(L, arg + 2, LJ_ERR_INVOPT);
    lua_createtable(L, 0, 16); /* Create result table. */
    for (; *options; options++) {
        switch (*options) {
        case 'S':
            settabss(L, "source", ar.source);
            settabss(L, "short_src", ar.short_src);
            settabsi(L, "linedefined", ar.linedefined);
            settabsi(L, "lastlinedefined", ar.lastlinedefined);
            settabss(L, "what", ar.what);
            break;
        case 'l':
            settabsi(L, "currentline", ar.currentline);
            break;
        case 'u':
            settabsi(L, "nups", ar.nups);
            settabsi(L, "nparams", ar.nparams);
            settabsb(L, "isvararg", ar.isvararg);
            break;
        case 'n':
            settabss(L, "name", ar.name);
            settabss(L, "namewhat", ar.namewhat);
            break;
        case 'f':
            opt_f = 1;
            break;
        case 'L':
            opt_L = 1;
            break;
        default:
            break;
        }
    }
    if (opt_L)
        treatstackoption(L, L1, "activelines");
    if (opt_f)
        treatstackoption(L, L1, "func");
    return 1; /* Return result table. */
}

LJLIB_CF(debug_getlocal)
{
    int arg;
    lua_State *L1 = getthread(L, &arg);
    lua_Debug ar;
    const char *name;
    int slot = lj_lib_checkint(L, arg + 2);
    if (tvisfunc(L->base + arg)) {
        L->top = L->base + arg + 1;
        lua_pushstring(L, lua_getlocal(L, NULL, slot));
        return 1;
    }
    if (!lua_getstack(L1, lj_lib_checkint(L, arg + 1), &ar))
        lj_err_arg(L, arg + 1, LJ_ERR_LVLRNG);
    name = lua_getlocal(L1, &ar, slot);
    if (name) {
        lua_xmove(L1, L, 1);
        lua_pushstring(L, name);
        lua_pushvalue(L, -2);
        return 2;
    }
    else {
        setnilV(L->top - 1);
        return 1;
    }
}

LJLIB_CF(debug_setlocal)
{
    int arg;
    lua_State *L1 = getthread(L, &arg);
    lua_Debug ar;
    TValue *tv;
    if (!lua_getstack(L1, lj_lib_checkint(L, arg + 1), &ar))
        lj_err_arg(L, arg + 1, LJ_ERR_LVLRNG);
    tv = lj_lib_checkany(L, arg + 3);
    copyTV(L1, L1->top++, tv);
    lua_pushstring(L, lua_setlocal(L1, &ar, lj_lib_checkint(L, arg + 2)));
    return 1;
}

static int debug_getupvalue(lua_State *L, int get)
{
    int32_t n = lj_lib_checkint(L, 2);
    const char *name;
    lj_lib_checkfunc(L, 1);
    name = get ? lua_getupvalue(L, 1, n) : lua_setupvalue(L, 1, n);
    if (name) {
        lua_pushstring(L, name);
        if (!get)
            return 1;
        copyTV(L, L->top, L->top - 2);
        L->top++;
        return 2;
    }
    return 0;
}

LJLIB_CF(debug_getupvalue) { return debug_getupvalue(L, 1); }

LJLIB_CF(debug_setupvalue)
{
    lj_lib_checkany(L, 3);
    return debug_getupvalue(L, 0);
}

LJLIB_CF(debug_upvalueid)
{
    GCfunc *fn = lj_lib_checkfunc(L, 1);
    int32_t n = lj_lib_checkint(L, 2) - 1;
    if ((uint32_t)n >= fn->l.nupvalues)
        lj_err_arg(L, 2, LJ_ERR_IDXRNG);
    setlightudV(L->top - 1, isluafunc(fn) ? (void *)gcref(fn->l.uvptr[n])
                                          : (void *)&fn->c.upvalue[n]);
    return 1;
}

LJLIB_CF(debug_upvaluejoin)
{
    GCfunc *fn[2];
    GCRef *p[2];
    int i;
    for (i = 0; i < 2; i++) {
        int32_t n;
        fn[i] = lj_lib_checkfunc(L, 2 * i + 1);
        if (!isluafunc(fn[i]))
            lj_err_arg(L, 2 * i + 1, LJ_ERR_NOLFUNC);
        n = lj_lib_checkint(L, 2 * i + 2) - 1;
        if ((uint32_t)n >= fn[i]->l.nupvalues)
            lj_err_arg(L, 2 * i + 2, LJ_ERR_IDXRNG);
        p[i] = &fn[i]->l.uvptr[n];
    }
    setgcrefr(*p[0], *p[1]);
    lj_gc_objbarrier(L, fn[0], gcref(*p[1]));
    return 0;
}

#if LJ_52
LJLIB_CF(debug_getuservalue)
{
    TValue *o = L->base;
    if (o < L->top && tvisudata(o))
        settabV(L, o, tabref(udataV(o)->env));
    else
        setnilV(o);
    L->top = o + 1;
    return 1;
}

LJLIB_CF(debug_setuservalue)
{
    TValue *o = L->base;
    if (!(o < L->top && tvisudata(o)))
        lj_err_argt(L, 1, LUA_TUSERDATA);
    if (!(o + 1 < L->top && tvistab(o + 1)))
        lj_err_argt(L, 2, LUA_TTABLE);
    L->top = o + 2;
    lua_setfenv(L, 1);
    return 1;
}
#endif

/* ------------------------------------------------------------------------ */

static const char KEY_HOOK = 'h';

static void hookf(lua_State *L, lua_Debug *ar)
{
    static const char *const hooknames[] = {"call", "return", "line", "count",
                                            "tail return"};
    lua_pushlightuserdata(L, (void *)&KEY_HOOK);
    lua_rawget(L, LUA_REGISTRYINDEX);
    if (lua_isfunction(L, -1)) {
        lua_pushstring(L, hooknames[(int)ar->event]);
        if (ar->currentline >= 0)
            lua_pushinteger(L, ar->currentline);
        else
            lua_pushnil(L);
        lua_call(L, 2, 0);
    }
}

static int makemask(const char *smask, int count)
{
    int mask = 0;
    if (strchr(smask, 'c'))
        mask |= LUA_MASKCALL;
    if (strchr(smask, 'r'))
        mask |= LUA_MASKRET;
    if (strchr(smask, 'l'))
        mask |= LUA_MASKLINE;
    if (count > 0)
        mask |= LUA_MASKCOUNT;
    return mask;
}

static char *unmakemask(int mask, char *smask)
{
    int i = 0;
    if (mask & LUA_MASKCALL)
        smask[i++] = 'c';
    if (mask & LUA_MASKRET)
        smask[i++] = 'r';
    if (mask & LUA_MASKLINE)
        smask[i++] = 'l';
    smask[i] = '\0';
    return smask;
}

LJLIB_CF(debug_sethook)
{
    int arg, mask, count;
    lua_Hook func;
    (void)getthread(L, &arg);
    if (lua_isnoneornil(L, arg + 1)) {
        lua_settop(L, arg + 1);
        func = NULL;
        mask = 0;
        count = 0; /* turn off hooks */
    }
    else {
        const char *smask = luaL_checkstring(L, arg + 2);
        luaL_checktype(L, arg + 1, LUA_TFUNCTION);
        count = luaL_optint(L, arg + 3, 0);
        func = hookf;
        mask = makemask(smask, count);
    }
    lua_pushlightuserdata(L, (void *)&KEY_HOOK);
    lua_pushvalue(L, arg + 1);
    lua_rawset(L, LUA_REGISTRYINDEX);
    lua_sethook(L, func, mask, count);
    return 0;
}

LJLIB_CF(debug_gethook)
{
    char buff[5];
    int mask = lua_gethookmask(L);
    lua_Hook hook = lua_gethook(L);
    if (hook != NULL && hook != hookf) { /* external hook? */
        lua_pushliteral(L, "external hook");
    }
    else {
        lua_pushlightuserdata(L, (void *)&KEY_HOOK);
        lua_rawget(L, LUA_REGISTRYINDEX); /* get hook */
    }
    lua_pushstring(L, unmakemask(mask, buff));
    lua_pushinteger(L, lua_gethookcount(L));
    return 3;
}

/* ------------------------------------------------------------------------ */

LJLIB_CF(debug_debug)
{
    for (;;) {
        char buffer[250];
        fputs("lua_debug> ", stderr);
        if (fgets(buffer, sizeof(buffer), stdin) == 0 ||
            strcmp(buffer, "cont\n") == 0)
            return 0;
        if (luaL_loadbuffer(L, buffer, strlen(buffer), "=(debug command)") ||
            lua_pcall(L, 0, 0, 0)) {
            fputs(lua_tostring(L, -1), stderr);
            fputs("\n", stderr);
        }
        lua_settop(L, 0); /* remove eventual returns */
    }
}

/* ------------------------------------------------------------------------ */

#define LEVELS1 12 /* size of the first part of the stack */
#define LEVELS2 10 /* size of the second part of the stack */

LJLIB_CF(debug_traceback)
{
    int arg;
    lua_State *L1 = getthread(L, &arg);
    const char *msg = lua_tostring(L, arg + 1);
    if (msg == NULL && L->top > L->base + arg)
        L->top = L->base + arg + 1;
    else
        luaL_traceback(L, L1, msg, lj_lib_optint(L, arg + 2, (L == L1)));
    return 1;
}

/* ------------------------------------------------------------------------ */

#include "lj_libdef.h"

LUALIB_API int luaopen_debug(lua_State *L)
{
    LJ_LIB_REG(L, LUA_DBLIBNAME, debug);
    return 1;
}
