/*
 * 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 <nw/io.h>
#include <nw/interp.h>
#include <nw/linear.h>
#include <nw/stack.h>
#include <nw/log.h>
#include <nw/ops.h>
#include <nw/routines.h>

static enum nw_state push(struct nw_interp *const i)
{
    struct nw_i_sm_load *const l = &i->sm.load;
    const enum nw_state n = nwp_stack_push(i, &l->io);

    if (n)
        return n;

    i->push_type = NW_TYPE_I32;
    nwp_interp_resume(i);
    return NW_AGAIN;
}

static enum nw_state load(struct nw_interp *const i)
{
    struct nw_i_sm_load *const l = &i->sm.load;
    const enum nw_state n = nwp_linear_load(i, &l->io, l->addr + l->imm.offset);

    if (n)
        return n;
    else
    {
        struct nw_sm_io io = {0};

        l->value.i32 = nwp_leuint32(&l->value.v32);
        io.buf = &l->value.i32;
        io.n = sizeof l->value.i32;
        l->io = io;
        i->next = push;
    }

    i->next = push;
    return NW_AGAIN;
}

static enum nw_state pop_addr(struct nw_interp *const i)
{
    struct nw_i_sm_load *const l = &i->sm.load;
    const enum nw_state n = nwp_stack_pop(i, &l->io);

    if (n)
        return n;
    else
    {
        struct nw_sm_io io = {0};

        io.buf = &l->value.i32;
        io.n = sizeof l->value.i32;
        l->io = io;
        i->next = load;
    }

    return NW_AGAIN;
}

static void prepare(struct nw_interp *const i)
{
    struct nw_i_sm_imm_out imm = i->sm.imm.out;
    struct nw_i_sm_load *const pl = &i->sm.load, l = {0};

    l.imm = imm;
    l.io.buf = &pl->addr;
    l.io.n = sizeof pl->addr;
    *pl = l;
    i->next = pop_addr;
}

void nwp_op_i32_load(struct nw_interp *const i)
{
    nwp_mem_imm(i, prepare);
}