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

static enum nw_state store(struct nw_interp *const i)
{
    struct nw_i_sm_store *const s = &i->sm.store;
    const enum nw_state n = nwp_linear_store(i, &s->io, s->addr + s->imm.offset);

    if (n)
        return n;

    nwp_interp_resume(i);
    return NW_AGAIN;
}

static enum nw_state pop_addr(struct nw_interp *const i)
{
    struct nw_i_sm_store *const s = &i->sm.store;
    const enum nw_state n = nwp_stack_pop(i, &s->io);

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

        io.buf = &s->value.i8;
        io.n = sizeof s->value.i8;
        s->io = io;
        i->next = store;
    }

    return NW_AGAIN;
}

static enum nw_state pop_value(struct nw_interp *const i)
{
    struct nw_i_sm_store *const s = &i->sm.store;
    const enum nw_state n = nwp_stack_pop(i, &s->io);

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

        s->value.i8 = nwp_leuint32(&s->value.v32);
        s->io = io;
        s->io.buf = &s->addr;
        s->io.n = sizeof s->addr;
        i->next = pop_addr;
    }

    return NW_AGAIN;
}

static void prepare(struct nw_interp *const i)
{
    const struct nw_i_sm_store s = {0};
    struct nw_i_sm_store *const ps = &i->sm.store;
    struct nw_sm_io *const io = &ps->io;
    struct nw_i_sm_imm_out out;

    out = i->sm.imm.out;
    *ps = s;
    ps->imm = out;
    io->buf = &ps->value.i32;
    io->n = sizeof ps->value.i32;
    i->next = pop_value;
}

void nwp_op_i32_store8(struct nw_interp *const i)
{
    nwp_mem_imm(i, prepare);
}