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

#include <mie/ir/func.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

struct cond_codegen_state {
	struct code_generator_state s_base;
	struct mie_value *s_cond;
	struct mie_block *s_true;
	struct mie_block *s_false;
	struct mie_block *s_end;
};

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

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 cond_codegen_state *cond = (struct cond_codegen_state *)state;
	struct mie_func *func = mie_builder_get_current_func(gen->c_builder);
	/* this is either the if-condition, or the if-body for an inline
	 * if-statement */

	if (cond->s_cond) {
		cond->s_true = mie_func_create_block(func, "if.true");
		cond->s_false = mie_func_create_block(func, "if.false");

		mie_builder_br_if(
			gen->c_builder, cond->s_cond, cond->s_true, cond->s_false);
		mie_func_insert_block(func, cond->s_true, NULL);
		mie_builder_set_insert_point(gen->c_builder, cond->s_true);
	}

	codegen_push_generator(gen, CODE_GENERATOR_EXPR, 0, NULL);

	return CODEGEN_RESULT_OK(CODEGEN_R_REPEAT_NODE);
}

static struct code_generator_result gen_block(
	struct ivy_codegen *gen, struct code_generator_state *state,
	struct ivy_ast_node *node, size_t depth)
{
	struct cond_codegen_state *cond = (struct cond_codegen_state *)state;
	struct mie_func *func = mie_builder_get_current_func(gen->c_builder);

	if (cond->s_cond) {
		cond->s_true = mie_func_create_block(func, "if.true");
		cond->s_false = mie_func_create_block(func, "if.false");

		mie_builder_br_if(
			gen->c_builder, cond->s_cond, cond->s_true, cond->s_false);
		mie_func_insert_block(func, cond->s_true, NULL);
		mie_builder_set_insert_point(gen->c_builder, cond->s_true);
	}

	codegen_push_generator(gen, CODE_GENERATOR_BLOCK, 0, NULL);
	return CODEGEN_RESULT_OK(0);
}

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 cond\n");
	struct cond_codegen_state *cond = (struct cond_codegen_state *)state;
	cond->s_end = argp;
	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 cond\n");
	struct cond_codegen_state *cond = (struct cond_codegen_state *)state;
	struct mie_func *func = mie_builder_get_current_func(gen->c_builder);

	mie_builder_br(gen->c_builder, cond->s_end);

	if (cond->s_false) {
		mie_func_insert_block(func, cond->s_false, NULL);
		mie_builder_set_insert_point(gen->c_builder, cond->s_false);
	}

	return IVY_OK;
}

static struct code_generator_result value_received(
	struct ivy_codegen *gen, struct code_generator_state *state,
	struct mie_value *value)
{
	struct cond_codegen_state *cond = (struct cond_codegen_state *)state;
	if (!value) {
		return CODEGEN_RESULT_OK(0);
	}

	struct mie_type *cond_type = mie_value_get_type(value, gen->c_ctx);

	if (cond_type->t_id == MIE_TYPE_INT && cond_type->t_width == 1) {
		/* this is already a boolean */
		cond->s_cond = value;
	} else {
		struct mie_value *zero = mie_ctx_get_int(gen->c_ctx, 0, 32);
		struct mie_value *cmp
			= mie_builder_cmp_neq(gen->c_builder, value, zero, NULL);
		cond->s_cond = cmp;
	}

	return CODEGEN_RESULT_OK(0);
}

struct code_generator cond_generator
	= {.g_type = CODE_GENERATOR_COND,
           .g_state_size = sizeof(struct cond_codegen_state),
           .g_state_init = state_init,
           .g_state_fini = state_fini,
           .g_value_received = value_received,
           .g_expr_generator = gen_expr,
           .g_node_generators = {
		   NODE_CODEGEN(COND, gen_cond),
		   NODE_CODEGEN(BLOCK, gen_block),
	   }};