/*
 * nanowasm, a tiny WebAssembly/Wasm interpreter
 * Copyright (C) 2023-2025  Xavier Del Campo Romero
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/.
 */

#include <nanowasm/nw.h>
#include <nanowasm/types.h>
#include <nw/interp.h>
#include <nw/io.h>
#include <nw/log.h>
#include <nw/routines.h>
#include <stddef.h>

static enum nw_state get_bytecode(struct nw_interp *const in)
{
    const struct nw_io_cfg *const cfg = &in->cfg.io;
    struct nw_i_sm_b *const b = &in->sm.bytecode;
    const struct nwp_interp_set *const set = in->set;
    static const char *const exc = "invalid opcode";
    const enum nw_state n = nwp_io_read(cfg, &b->io, cfg->user);
    size_t i;

    if (n)
        return n;

    for (i = 0; i < set->n; i++)
        if (b->op == set->opcodes[i])
        {
            b->f = nwp_ops.ops[b->op];
            in->next = nwp_execute;
            return NW_AGAIN;
        }

#ifdef NW_LOG
    nwp_log("%s: %#x\n", exc, (unsigned)b->op);
#endif
    in->exception = exc;
    return NW_FATAL;
}

void nwp_interp_limited(struct nw_interp *const i)
{
    struct nw_i_sm_b *const b = &i->sm.bytecode;
    struct nw_sm_io io = {0};

    io.buf = &b->op;
    io.n = sizeof b->op;
    b->io = io;
    i->next = get_bytecode;
}