#ifndef clox_value_h
#define clox_value_h

#include <string.h>

#include "common.h"

typedef struct Obj Obj;
typedef struct ObjString ObjString;

#ifdef NAN_BOXING
#define SIGN_BIT ((uint64_t)0b1000000000000000000000000000000000000000000000000000000000000000)
#define QNAN ((uint64_t)0b0111111111111100000000000000000000000000000000000000000000000000)

#define TAG_NIL 0b01
#define TAG_FALSE 0b10
#define TAG_TRUE 0b11

typedef uint64_t Value;

#define IS_BOOL(value) (((value) | 0b01) == TRUE_VAL)
#define IS_NIL(value) ((value) == NIL_VAL)
#define IS_NUMBER(value) (((value) & QNAN) != QNAN)
#define IS_OBJ(value) (((value) & (QNAN | SIGN_BIT)) == (QNAN | SIGN_BIT))

#define AS_OBJ(value) ((Obj*)(uintptr_t)((value) & ~(SIGN_BIT | QNAN)))
#define AS_BOOL(value) ((value) == TRUE_VAL)
#define AS_NUMBER(value) valueToNum(value)

#define BOOL_VAL(value) ((value) ? TRUE_VAL : FALSE_VAL)
#define FALSE_VAL ((Value)(uint64_t)(QNAN | TAG_FALSE))
#define TRUE_VAL ((Value)(uint64_t)(QNAN | TAG_TRUE))
#define NIL_VAL ((Value)(uint64_t)(QNAN | TAG_NIL))
#define NUMBER_VAL(value) numToValue(value)
#define OBJ_VAL(object) ((Value)(SIGN_BIT | QNAN | (uint64_t)(uintptr_t)(object)))

static inline double valueToNum(Value value)
{
    double num;
    memcpy(&num, &value, sizeof(Value));
    return num;
}

static inline Value numToValue(double num)
{
    Value value;
    memcpy(&value, &num, sizeof(double));
    return value;
}
#else
typedef enum {
    VAL_BOOL,
    VAL_NIL,
    VAL_NUMBER,
    VAL_OBJ,
} ValueType;

typedef struct {
    ValueType type;
    union {
        bool boolean;
        double number;
        Obj* obj;
    } as;
} Value;

#define IS_BOOL(value) ((value).type == VAL_BOOL)
#define IS_NIL(value) ((value).type == VAL_NIL)
#define IS_NUMBER(value) ((value).type == VAL_NUMBER)
#define IS_OBJ(value) ((value).type == VAL_OBJ)

#define AS_OBJ(value) ((value).as.obj)
#define AS_BOOL(value) ((value).as.boolean)
#define AS_NUMBER(value) ((value).as.number)

#define BOOL_VAL(value) ((Value){ .type = VAL_BOOL, .as = { .boolean = value } })
#define NIL_VAL ((Value){ .type = VAL_NIL, .as = { .number = 0 } })
#define NUMBER_VAL(value) ((Value){ .type = VAL_NUMBER, .as = { .number = value } })
#define OBJ_VAL(object) ((Value){ .type = VAL_OBJ, .as = { .obj = (Obj*)object } })
#endif

typedef struct {
    int capacity;
    int count;
    Value* values;
} ValueArray;

bool valuesEqual(Value a, Value b);
void initValueArray(ValueArray* array);
void writeValueArray(ValueArray* array, Value value);
void freeValueArray(ValueArray* array);
void printValue(Value value);

#endif // clox_value_h