#ifndef _LANG_CODEGEN_H_
#define _LANG_CODEGEN_H_

#include "var-map.h"

#include <blue/core/queue.h>
#include <ivy/lang/ast.h>
#include <ivy/lang/lex.h>
#include <mie/builder.h>
#include <mie/ctx.h>

struct ivy_codegen;
struct ivy_ast_node;

struct mie_value;
struct mie_func;

struct codegen_var;

#define CODEGEN_RESULT_OK(flags)                                               \
	(struct code_generator_result)                                         \
	{                                                                      \
		.r_status = (IVY_OK), .r_flags = (flags)                       \
	}
#define CODEGEN_RESULT_ERR(status)                                             \
	(struct code_generator_result)                                         \
	{                                                                      \
		.r_status = (status), .r_flags = (0)                           \
	}

#define __AST_INDEX(type)        IVY_AST_##type
#define NODE_CODEGEN(type, func) [__AST_INDEX(type)] = func

enum code_generator_flags {
	CODEGEN_F_IGNORE_RESULT = 0x01u,
};

enum code_generator_type {
	CODE_GENERATOR_NONE = 0,
	CODE_GENERATOR_UNIT,
	CODE_GENERATOR_BLOCK,
	CODE_GENERATOR_EXPR,
	CODE_GENERATOR_VAR,
	CODE_GENERATOR_MSG,
	CODE_GENERATOR_FSTRING,
	CODE_GENERATOR_LAMBDA,
	CODE_GENERATOR_RETURN,
};

enum code_generator_scope_type {
	CODE_GENERATOR_SCOPE_NONE = 0,
	CODE_GENERATOR_SCOPE_UNIT,
	CODE_GENERATOR_SCOPE_FUNC,
	CODE_GENERATOR_SCOPE_BLOCK,
};

struct code_generator_result {
	enum ivy_status r_status;

	enum code_generator_result_flags {
		CODEGEN_R_REPEAT_NODE = 0x01u,
		CODEGEN_R_POP_GENERATOR = 0x02u,
	} r_flags;
};

struct codegen_value {
	b_queue_entry v_entry;
	struct ivy_ast_node *v_node;
	struct mie_value *v_value;
};

struct code_generator_state;

typedef enum ivy_status (*code_generator_state_init_callback)(
	struct ivy_codegen *, struct code_generator_state *, uintptr_t, void *);
typedef enum ivy_status (*code_generator_state_fini_callback)(
	struct ivy_codegen *, struct code_generator_state *, struct mie_value **);
typedef struct code_generator_result (*code_generator_callback)(
	struct ivy_codegen *);
typedef struct code_generator_result (*code_generator_node_callback)(
	struct ivy_codegen *, struct code_generator_state *,
	struct ivy_ast_node *, size_t);
typedef struct code_generator_result (*code_generator_value_received_callback)(
	struct ivy_codegen *, struct code_generator_state *, struct mie_value *);
typedef enum ivy_status (*code_generator_define_variable_callback)(
	struct ivy_codegen *, struct code_generator_state *, const char *,
	const struct codegen_var *);
typedef enum ivy_status (*code_generator_resolve_variable_callback)(
	struct ivy_codegen *, struct code_generator_state *, const char *,
	struct codegen_var *);
typedef enum ivy_status (*code_generator_capture_variable_callback)(
	struct ivy_codegen *, struct code_generator_state *, const char *,
	struct codegen_var *);

struct code_generator {
	enum code_generator_type g_type;
	size_t g_state_size;

	code_generator_state_init_callback g_state_init;
	code_generator_state_fini_callback g_state_fini;
	code_generator_node_callback g_node_generators[IVY_AST_TYPE_COUNT];
	code_generator_node_callback g_expr_generator;
	code_generator_value_received_callback g_value_received;
	code_generator_define_variable_callback g_define_var;
	code_generator_resolve_variable_callback g_resolve_var;
	code_generator_capture_variable_callback g_capture_var;
};

struct code_generator_state {
	b_queue_entry s_entry;
	uintptr_t s_argv;
	void *s_argp;
	const struct code_generator *s_gen;
	struct ivy_ast_node *s_root;
	size_t s_depth;
};

struct ivy_codegen {
	b_queue c_values;
	b_queue c_state;
	b_queue c_scope;
	struct mie_builder *c_builder;
	struct mie_ctx *c_ctx;
	struct mie_module *c_module;
};

extern const struct code_generator *get_code_generator(
	enum code_generator_type type);
extern const struct code_generator *get_root_code_generator(
	enum ivy_ast_node_type type);

extern enum ivy_status codegen_push_generator(
	struct ivy_codegen *gen, enum code_generator_type gen_type,
	uintptr_t argv, void *argp);
extern enum ivy_status codegen_pop_generator(
	struct ivy_codegen *gen, struct mie_value **result);

extern struct codegen_value *codegen_value_create(
	struct ivy_ast_node *node, struct mie_value *val);
extern void codegen_value_destroy(struct codegen_value *val);

extern void codegen_push_value(struct ivy_codegen *gen, struct codegen_value *val);
extern struct codegen_value *codegen_pop_value(struct ivy_codegen *gen);

extern enum ivy_status codegen_define_variable(
	struct ivy_codegen *gen, const char *ident, const struct codegen_var *var);
extern enum ivy_status codegen_resolve_variable(
	struct ivy_codegen *gen, const char *ident, struct codegen_var *out);
extern struct mie_value *codegen_load_variable(
	struct ivy_codegen *gen, struct codegen_var *var);

#endif