#ifndef BDL_OBJECTS_H
#define BDL_OBJECTS_H

#include "string_view.h"
#include "darray.h"
#include "chunk.h"

typedef enum ObjectType {
    OBJ_TYPE_NIL,
    OBJ_TYPE_TRUE,
    OBJ_TYPE_FALSE,
    OBJ_TYPE_FIXNUM,
    OBJ_TYPE_SYMBOL,
    OBJ_TYPE_STRING,
    OBJ_TYPE_PAIR,
    OBJ_TYPE_LAMBDA,
    OBJ_TYPE_ERR,
} ObjectType;

typedef struct Object Object;

typedef struct Closure {
    // Non-owning reference to a chunk.
    Chunk *chunk;
    // Captured values for this closure.
    Object *values;
} Closure;

// typdef struct ConsCell {
//     struct Object *car;
//     struct Object *cdr;
// } ConsCell;

typedef struct Object {
    ObjectType type;
    bool marked;
    union {
        // OBJ_TYPE_FIXNUM
        ssize_t fixnum;

        // OBJ_TYPE_STRING
        // OBJ_TYPE_SYMBOL
        char *text;

        // OBJ_TYPE_PAIR
        // ConsCell *cons_cell;

        // OBJ_TYPE_LAMBDA
        Closure *closure;
    };
} Object;

Object make_string(StringView sv);
Object make_symbol(StringView sv);
Object make_lambda(Chunk *chunk);
void object_display(Object obj);
void object_free(Object *obj);
bool object_equal(Object a, Object b);
Object object_copy(Object src);

// Value initialization.
#define NIL_VAL         ((Object){.type = OBJ_TYPE_NIL})
#define TRUE_VAL        ((Object){.type = OBJ_TYPE_TRUE})
#define FALSE_VAL       ((Object){.type = OBJ_TYPE_FALSE})
#define FIXNUM_VAL(VAL) ((Object){.type = OBJ_TYPE_FIXNUM, .fixnum = VAL})
#define BOOL_VAL(VAL)   ((VAL) ? TRUE_VAL : FALSE_VAL)

// Value extraction.
#define AS_FIXNUM(VAL) ((VAL).fixnum)

// Type checking.
#define IS_NIL(VAL)    ((VAL).type == OBJ_TYPE_NIL)
#define IS_TRUE(VAL)   ((VAL).type != OBJ_TYPE_FALSE)
#define IS_FALSE(VAL)  ((VAL).type == OBJ_TYPE_FALSE)
#define IS_FIXNUM(VAL) ((VAL).type == OBJ_TYPE_FIXNUM)
#define IS_STRING(VAL) ((VAL).type == OBJ_TYPE_STRING)
#define IS_SYMBOL(VAL) ((VAL).type == OBJ_TYPE_SYMBOL)
#define IS_LAMBDA(VAL) ((VAL).type == OBJ_TYPE_LAMBDA)

#endif // BDL_OBJECTS_H