#ifndef APFL_VALUE_H
#define APFL_VALUE_H

#ifdef __cplusplus
extern "C" {
#endif

#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>

#include "apfl.h"

#include "bytecode.h"
#include "gc.h"

#include "hashmap.h"

enum value_type {
    VALUE_NIL,
    VALUE_BOOLEAN,
    VALUE_NUMBER,
    VALUE_STRING,
    VALUE_CONST_STRING,
    VALUE_LIST,
    VALUE_DICT,
    VALUE_FUNC,
    VALUE_CFUNC,
    VALUE_USERDATA,
};

struct list_header {
    struct apfl_value *items;
    size_t len;
    size_t cap;
    bool copy_on_write;
};

struct dict_header {
    struct apfl_hashmap map;
    bool copy_on_write;
};

struct subfunction {
    struct matcher *matcher;
    struct instruction_list *body;
};

struct function {
    struct subfunction *subfunctions;
    size_t subfunctions_len;
    size_t subfunctions_cap;
    struct scope *scope;
    struct apfl_string *name;
    int line_defined;
};

struct cfunction {
    apfl_cfunc func;
    struct apfl_value **slots;
    size_t slots_len;
    struct apfl_string *name;
};

typedef struct dict_header *apfl_dict;

struct apfl_value {
    enum value_type type;
    union {
        bool boolean;
        apfl_number number;
        struct apfl_string *string;
        struct apfl_string_view const_string;
        struct list_header *list;
        struct dict_header *dict;
        struct function *func;
        struct cfunction *cfunc;
        void *userdata;
    };
};

enum apfl_value_type apfl_value_type_to_abstract_type(enum value_type);

#define VALUE_IS_A(v, t) (apfl_value_type_to_abstract_type((v).type) == (t))

bool apfl_value_eq(const struct apfl_value, const struct apfl_value);
struct apfl_value apfl_value_move(struct apfl_value *src);
bool apfl_value_format(struct apfl_value, struct apfl_format_writer);
bool apfl_value_print(struct apfl_value, struct apfl_format_writer);
apfl_hash apfl_value_hash(const struct apfl_value);

enum comparison_result {
    CMP_LT,
    CMP_EQ,
    CMP_GT,
    CMP_UNCOMPARABLE,
    CMP_INCOMPATIBLE_TYPES,
};

enum comparison_result apfl_value_cmp(const struct apfl_value a, const struct apfl_value b);

enum get_item_result {
    GET_ITEM_OK,
    GET_ITEM_KEY_DOESNT_EXIST,
    GET_ITEM_NOT_A_CONTAINER,
    GET_ITEM_WRONG_KEY_TYPE,
};

enum get_item_result apfl_value_get_item(struct apfl_value container, struct apfl_value key, struct apfl_value *out);

// Set the Copy On Write flag of a value (if it's a value with such a flag).
// Returns the same value again.
struct apfl_value apfl_value_set_cow_flag(struct apfl_value);

struct list_header *apfl_list_new(struct gc *, size_t initial_cap);

size_t apfl_list_len(struct list_header *);
void apfl_list_deinit(struct apfl_allocator, struct list_header *);

bool
apfl_list_splice(
    struct gc *gc,
    struct list_header **dst_ptr,
    size_t cut_start,
    size_t cut_len,
    const struct apfl_value *other,
    size_t other_len
);

struct dict_header *apfl_dict_new(struct gc *);
bool apfl_dict_set_raw(
    struct gc *gc,
    struct dict_header **_dict,
    struct apfl_value k,
    struct apfl_value v
);
size_t apfl_dict_len(struct dict_header *);
void apfl_dict_deinit(struct dict_header *);

struct function *apfl_func_new(struct gc *, size_t cap, struct scope *, int line_defined);
bool apfl_func_add_subfunc(struct function *, struct instruction_list *, struct matcher *);
bool apfl_func_get_name(struct function *, struct apfl_string_view *name);
void apfl_func_set_name(struct function *, struct apfl_string *name);
void apfl_function_deinit(struct apfl_allocator, struct function *);

struct cfunction *apfl_cfunc_new(struct gc *, apfl_cfunc, size_t nslots);
void apfl_cfunction_deinit(struct apfl_allocator, struct cfunction *);

// Functions for garbage collection
struct gc_object *apfl_value_get_gc_object(struct apfl_value);
void apfl_value_visit_gc_object(struct apfl_value value, gc_visitor cb, void *opaque);
bool apfl_value_add_as_tmproot(struct gc *, struct apfl_value);
void apfl_gc_list_traverse(struct list_header *, gc_visitor, void *);
void apfl_gc_dict_traverse(struct dict_header *, gc_visitor, void *);
void apfl_gc_func_traverse(struct function*, gc_visitor, void *);
void apfl_gc_cfunc_traverse(struct cfunction*, gc_visitor, void *);

#ifdef __cplusplus
}
#endif

#endif