#include "codegen.h"

#include <mie/ir/func.h>
#include <mie/ir/module.h>

struct cascade_codegen_state {
	struct code_generator_state s_base;
	struct mie_value *s_recipient;
	struct mie_value *s_result;
};

static struct code_generator_result gen_cascade(
	struct ivy_codegen *gen, struct code_generator_state *state,
	struct ivy_ast_node *node, size_t depth)
{
	return CODEGEN_RESULT_OK(0);
}

static struct code_generator_result gen_msg(
	struct ivy_codegen *gen, struct code_generator_state *state,
	struct ivy_ast_node *node, size_t depth)
{
	struct cascade_codegen_state *cascade
		= (struct cascade_codegen_state *)state;

	codegen_push_generator(
		gen, CODE_GENERATOR_MSG, CODEGEN_F_IGNORE_RESULT,
		cascade->s_recipient);
	return CODEGEN_RESULT_OK(CODEGEN_R_REPEAT_NODE);
}

static struct code_generator_result gen_expr(
	struct ivy_codegen *gen, struct code_generator_state *state,
	struct ivy_ast_node *node, size_t depth)
{
	struct cascade_codegen_state *cascade
		= (struct cascade_codegen_state *)state;

	if (cascade->s_recipient) {
		return CODEGEN_RESULT_ERR(IVY_ERR_BAD_SYNTAX);
	}

	codegen_push_generator(
		gen, CODE_GENERATOR_EXPR, CODEGEN_F_IGNORE_RESULT, NULL);
	return CODEGEN_RESULT_OK(CODEGEN_R_REPEAT_NODE);
}

static enum ivy_status state_fini(
	struct ivy_codegen *gen, struct code_generator_state *state,
	struct code_generator_value *result)
{
	struct cascade_codegen_state *cascade
		= (struct cascade_codegen_state *)state;

	code_generator_value_set_mie_value(result, cascade->s_result);
	return IVY_OK;
}

static struct code_generator_result value_received(
	struct ivy_codegen *gen, struct code_generator_state *state,
	struct code_generator_value *value)
{
	struct cascade_codegen_state *cascade
		= (struct cascade_codegen_state *)state;
	struct mie_value *mie_value = code_generator_value_get_mie_value(value);
	if (!cascade->s_recipient) {
		cascade->s_recipient = mie_value;
	}

	cascade->s_result = mie_value;
	return CODEGEN_RESULT_OK(0);
}

struct code_generator cascade_generator = {
	.g_type = CODE_GENERATOR_CASCADE,
	.g_state_size = sizeof(struct cascade_codegen_state),
	.g_state_fini = state_fini,
	.g_value_received = value_received,
	.g_node_generators = {
		NODE_CODEGEN(CASCADE, gen_cascade),
		NODE_CODEGEN(MSG, gen_msg),
	},
	.g_expr_generator = gen_expr,
};