/*
** Table 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_table_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_tab.h"
#include "lj_lib.h"

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

#define LJLIB_MODULE_table

LJLIB_CF(table_foreachi)
{
    GCtab *t = lj_lib_checktab(L, 1);
    GCfunc *func = lj_lib_checkfunc(L, 2);
    MSize i, n = lj_tab_len(t);
    for (i = 1; i <= n; i++) {
        cTValue *val;
        setfuncV(L, L->top, func);
        setintV(L->top + 1, i);
        val = lj_tab_getint(t, (int32_t)i);
        if (val) {
            copyTV(L, L->top + 2, val);
        }
        else {
            setnilV(L->top + 2);
        }
        L->top += 3;
        lua_call(L, 2, 1);
        if (!tvisnil(L->top - 1))
            return 1;
        L->top--;
    }
    return 0;
}

LJLIB_CF(table_foreach)
{
    GCtab *t = lj_lib_checktab(L, 1);
    GCfunc *func = lj_lib_checkfunc(L, 2);
    L->top = L->base + 3;
    setnilV(L->top - 1);
    while (lj_tab_next(L, t, L->top - 1)) {
        copyTV(L, L->top + 2, L->top);
        copyTV(L, L->top + 1, L->top - 1);
        setfuncV(L, L->top, func);
        L->top += 3;
        lua_call(L, 2, 1);
        if (!tvisnil(L->top - 1))
            return 1;
        L->top--;
    }
    return 0;
}

LJLIB_ASM(table_getn) LJLIB_REC(.)
{
    lj_lib_checktab(L, 1);
    return FFH_UNREACHABLE;
}

LJLIB_CF(table_maxn)
{
    GCtab *t = lj_lib_checktab(L, 1);
    TValue *array = tvref(t->array);
    Node *node;
    lua_Number m = 0;
    ptrdiff_t i;
    for (i = (ptrdiff_t)t->asize - 1; i >= 0; i--)
        if (!tvisnil(&array[i])) {
            m = (lua_Number)(int32_t)i;
            break;
        }
    node = noderef(t->node);
    for (i = (ptrdiff_t)t->hmask; i >= 0; i--)
        if (!tvisnil(&node[i].val) && tvisnumber(&node[i].key)) {
            lua_Number n = numberVnum(&node[i].key);
            if (n > m)
                m = n;
        }
    setnumV(L->top - 1, m);
    return 1;
}

LJLIB_CF(table_insert) LJLIB_REC(.)
{
    GCtab *t = lj_lib_checktab(L, 1);
    int32_t n, i = (int32_t)lj_tab_len(t) + 1;
    int nargs = (int)((char *)L->top - (char *)L->base);
    if (nargs != 2 * sizeof(TValue)) {
        if (nargs != 3 * sizeof(TValue))
            lj_err_caller(L, LJ_ERR_TABINS);
        /* NOBARRIER: This just moves existing elements around. */
        for (n = lj_lib_checkint(L, 2); i > n; i--) {
            /* The set may invalidate the get pointer, so need to do it first! */
            TValue *dst = lj_tab_setint(L, t, i);
            cTValue *src = lj_tab_getint(t, i - 1);
            if (src) {
                copyTV(L, dst, src);
            }
            else {
                setnilV(dst);
            }
        }
        i = n;
    }
    {
        TValue *dst = lj_tab_setint(L, t, i);
        copyTV(L, dst, L->top - 1); /* Set new value. */
        lj_gc_barriert(L, t, dst);
    }
    return 0;
}

LJLIB_CF(table_remove) LJLIB_REC(.)
{
    GCtab *t = lj_lib_checktab(L, 1);
    int32_t e = (int32_t)lj_tab_len(t);
    int32_t pos = lj_lib_optint(L, 2, e);
    if (!(1 <= pos && pos <= e)) /* Nothing to remove? */
        return 0;
    lua_rawgeti(L, 1, pos); /* Get previous value. */
    /* NOBARRIER: This just moves existing elements around. */
    for (; pos < e; pos++) {
        cTValue *src = lj_tab_getint(t, pos + 1);
        TValue *dst = lj_tab_setint(L, t, pos);
        if (src) {
            copyTV(L, dst, src);
        }
        else {
            setnilV(dst);
        }
    }
    setnilV(lj_tab_setint(L, t, e)); /* Remove (last) value. */
    return 1;                        /* Return previous value. */
}

LJLIB_CF(table_concat)
{
    luaL_Buffer b;
    GCtab *t = lj_lib_checktab(L, 1);
    GCstr *sep = lj_lib_optstr(L, 2);
    MSize seplen = sep ? sep->len : 0;
    int32_t i = lj_lib_optint(L, 3, 1);
    int32_t e = (L->base + 3 < L->top && !tvisnil(L->base + 3))
                    ? lj_lib_checkint(L, 4)
                    : (int32_t)lj_tab_len(t);
    luaL_buffinit(L, &b);
    if (i <= e) {
        for (;;) {
            cTValue *o;
            lua_rawgeti(L, 1, i);
            o = L->top - 1;
            if (!(tvisstr(o) || tvisnumber(o)))
                lj_err_callerv(L, LJ_ERR_TABCAT, lj_typename(o), i);
            luaL_addvalue(&b);
            if (i++ == e)
                break;
            if (seplen)
                luaL_addlstring(&b, strdata(sep), seplen);
        }
    }
    luaL_pushresult(&b);
    return 1;
}

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

static void set2(lua_State *L, int i, int j)
{
    lua_rawseti(L, 1, i);
    lua_rawseti(L, 1, j);
}

static int sort_comp(lua_State *L, int a, int b)
{
    if (!lua_isnil(L, 2)) { /* function? */
        int res;
        lua_pushvalue(L, 2);
        lua_pushvalue(L, a - 1); /* -1 to compensate function */
        lua_pushvalue(L, b - 2); /* -2 to compensate function and `a' */
        lua_call(L, 2, 1);
        res = lua_toboolean(L, -1);
        lua_pop(L, 1);
        return res;
    }
    else { /* a < b? */
        return lua_lessthan(L, a, b);
    }
}

static void auxsort(lua_State *L, int l, int u)
{
    while (l < u) { /* for tail recursion */
        int i, j;
        /* sort elements a[l], a[(l+u)/2] and a[u] */
        lua_rawgeti(L, 1, l);
        lua_rawgeti(L, 1, u);
        if (sort_comp(L, -1, -2)) /* a[u] < a[l]? */
            set2(L, l, u);        /* swap a[l] - a[u] */
        else
            lua_pop(L, 2);
        if (u - l == 1)
            break; /* only 2 elements */
        i = (l + u) / 2;
        lua_rawgeti(L, 1, i);
        lua_rawgeti(L, 1, l);
        if (sort_comp(L, -2, -1)) { /* a[i]<a[l]? */
            set2(L, i, l);
        }
        else {
            lua_pop(L, 1); /* remove a[l] */
            lua_rawgeti(L, 1, u);
            if (sort_comp(L, -1, -2)) /* a[u]<a[i]? */
                set2(L, i, u);
            else
                lua_pop(L, 2);
        }
        if (u - l == 2)
            break;            /* only 3 elements */
        lua_rawgeti(L, 1, i); /* Pivot */
        lua_pushvalue(L, -1);
        lua_rawgeti(L, 1, u - 1);
        set2(L, i, u - 1);
        /* a[l] <= P == a[u-1] <= a[u], only need to sort from l+1 to u-2 */
        i = l;
        j = u - 1;
        for (;;) { /* invariant: a[l..i] <= P <= a[j..u] */
            /* repeat ++i until a[i] >= P */
            while (lua_rawgeti(L, 1, ++i), sort_comp(L, -1, -2)) {
                if (i >= u)
                    lj_err_caller(L, LJ_ERR_TABSORT);
                lua_pop(L, 1); /* remove a[i] */
            }
            /* repeat --j until a[j] <= P */
            while (lua_rawgeti(L, 1, --j), sort_comp(L, -3, -1)) {
                if (j <= l)
                    lj_err_caller(L, LJ_ERR_TABSORT);
                lua_pop(L, 1); /* remove a[j] */
            }
            if (j < i) {
                lua_pop(L, 3); /* pop pivot, a[i], a[j] */
                break;
            }
            set2(L, i, j);
        }
        lua_rawgeti(L, 1, u - 1);
        lua_rawgeti(L, 1, i);
        set2(L, u - 1, i); /* swap pivot (a[u-1]) with a[i] */
        /* a[l..i-1] <= a[i] == P <= a[i+1..u] */
        /* adjust so that smaller half is in [j..i] and larger one in [l..u] */
        if (i - l < u - i) {
            j = l;
            i = i - 1;
            l = i + 2;
        }
        else {
            j = i + 1;
            i = u;
            u = j - 2;
        }
        auxsort(L, j, i); /* call recursively the smaller one */
    }                     /* repeat the routine for the larger one */
}

LJLIB_CF(table_sort)
{
    GCtab *t = lj_lib_checktab(L, 1);
    int32_t n = (int32_t)lj_tab_len(t);
    lua_settop(L, 2);
    if (!tvisnil(L->base + 1))
        lj_lib_checkfunc(L, 2);
    auxsort(L, 1, n);
    return 0;
}

#if LJ_52
LJLIB_PUSH("n")
LJLIB_CF(table_pack)
{
    TValue *array, *base = L->base;
    MSize i, n = (uint32_t)(L->top - base);
    GCtab *t = lj_tab_new(L, n ? n + 1 : 0, 1);
    /* NOBARRIER: The table is new (marked white). */
    setintV(lj_tab_setstr(L, t, strV(lj_lib_upvalue(L, 1))), (int32_t)n);
    for (array = tvref(t->array) + 1, i = 0; i < n; i++)
        copyTV(L, &array[i], &base[i]);
    settabV(L, base, t);
    L->top = base + 1;
    lj_gc_check(L);
    return 1;
}
#endif

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

#include "lj_libdef.h"

LUALIB_API int luaopen_table(lua_State *L)
{
    LJ_LIB_REG(L, LUA_TABLIBNAME, table);
#if LJ_52
    lua_getglobal(L, "unpack");
    lua_setfield(L, -2, "unpack");
#endif
    return 1;
}
