#include "../debug.h"
#include "codegen.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

struct return_codegen_state {
	struct code_generator_state s_base;
	unsigned int s_prev_node;
	struct mie_value *s_value;
};

static struct code_generator_result gen_return(
	struct ivy_codegen *gen, struct code_generator_state *state,
	struct ivy_ast_node *node, size_t depth)
{
	struct return_codegen_state *ret = (struct return_codegen_state *)state;
	if (ret->s_prev_node != 0) {
		return CODEGEN_RESULT_ERR(IVY_ERR_BAD_SYNTAX);
	}

	ret->s_prev_node = IVY_AST_RETURN;
	return CODEGEN_RESULT_OK(0);
}

static struct code_generator_result gen_value_expr(
	struct ivy_codegen *gen, struct code_generator_state *state,
	struct ivy_ast_node *node, size_t depth)
{
	struct return_codegen_state *ret = (struct return_codegen_state *)state;
	if (ret->s_prev_node != IVY_AST_RETURN) {
		return CODEGEN_RESULT_ERR(IVY_ERR_BAD_SYNTAX);
	}

	codegen_push_generator(gen, CODE_GENERATOR_EXPR, 0, NULL);

	return CODEGEN_RESULT_OK(CODEGEN_R_REPEAT_NODE);
}

static enum ivy_status state_init(
	struct ivy_codegen *gen, struct code_generator_state *state,
	uintptr_t argv, void *argp)
{
	debug_printf("codegen: start of return\n");
	return IVY_OK;
}

static enum ivy_status state_fini(
	struct ivy_codegen *gen, struct code_generator_state *state,
	struct code_generator_value *result)
{
	debug_printf("codegen: end of return\n");
	struct return_codegen_state *ret = (struct return_codegen_state *)state;

	mie_builder_ret(gen->c_builder, ret->s_value);

	return IVY_OK;
}

static struct code_generator_result value_received(
	struct ivy_codegen *gen, struct code_generator_state *state,
	struct code_generator_value *value)
{
	debug_printf("codegen: return value received\n");

	struct return_codegen_state *ret = (struct return_codegen_state *)state;
	if (ret->s_value || ret->s_prev_node != IVY_AST_RETURN) {
		return CODEGEN_RESULT_ERR(IVY_ERR_BAD_SYNTAX);
	}

	ret->s_value = value->v_value.mie_value;
	ret->s_prev_node = IVY_AST_EXPR;

	return CODEGEN_RESULT_OK(CODEGEN_R_POP_GENERATOR);
}

struct code_generator return_generator = {
	.g_type = CODE_GENERATOR_RETURN,
	.g_state_size = sizeof(struct return_codegen_state),
	.g_state_init = state_init,
	.g_state_fini = state_fini,
	.g_value_received = value_received,
	.g_expr_generator = gen_value_expr,
	.g_node_generators = {
		[IVY_AST_RETURN] = gen_return,
	},
};