/* Aplwc - A Programming Language With Constraints
 *
 * Copyright (C) 2026 Peter Mikkelsen <petermikkelsen10@gmail.com>
 *
 * This file is part of aplwc.
 *
 * Aplwc is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Aplwc is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with aplwc.  If not, see <https://www.gnu.org/licenses/>.
 */

#include <string.h>
#include <stdio.h>
#include <aplwc.h>
#include "aplwc_internal.h"

static void compile(struct aplwc_eval_context *, struct aplwc_ast *);
static void emit(struct aplwc_eval_context *, uint64_t instr);
static void emit_t0(struct aplwc_eval_context *, enum aplwc_instr_tag);
static uint64_t encode_t0(enum aplwc_instr_tag);

void
aplwc_compile(struct aplwc_eval_context *context)
{
	compile(context, context->ast);
}

static void
compile(struct aplwc_eval_context *context, struct aplwc_ast *node)
{
	context->instrs = context->aplwc->alloc(sizeof(*context->instrs));
	memset(context->instrs, 0, sizeof(*context->instrs));
	
	switch(node->tag){
	case APLWC_AST_SYSCMD:
		emit_t0(context, APLWC_INSTR_SYSCMD_CALL);
		break;
	case APLWC_AST_ERROR:
		emit_t0(context, APLWC_INSTR_ERROR);
		break;
	}

	emit_t0(context, APLWC_INSTR_END);
}

static void
emit(struct aplwc_eval_context *context, uint64_t instr)
{
	context->instrs->n_instrs++;
	context->instrs->instrs = context->aplwc->realloc(context->instrs->instrs, sizeof(*context->instrs->instrs) * context->instrs->n_instrs);

	context->instrs->instrs[context->instrs->n_instrs-1] = instr;
}

static void
emit_t0(struct aplwc_eval_context *context, enum aplwc_instr_tag op)
{
	struct aplwc_instr instr = {
		.type = 0,
		.op = op,
	};
	aplwc_encode_instr(&instr);
	emit(context, instr.encoded);
}