#ifndef _val_h
#define _val_h

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

typedef struct _val Val;
typedef struct _obj Obj;
typedef struct _state State;

typedef Val (*CFunc)(State *S, int nargs, Val *args);

typedef enum {
	TY_NIL,
	TY_NUM,
	TY_BOOL,
	TY_OBJ,
	TY_CFUNC,
} ValTy;

typedef struct _val {
	ValTy ty;
	union {
		double d;
		bool b;
		Obj *o;
		CFunc f;
	} as;
} Val;


void print_val(Val v);
void println_val(Val v);
const char *typename_str(Val v);

bool is_truthy(Val v);
bool val_equal(Val a, Val b);


typedef enum {
	OTY_STRING,
	OTY_FUNC,
	OTY_ARR,
} ObjTy;

typedef struct _obj {
	ObjTy oty;
} Obj;

typedef struct {
	Obj obj;
	size_t len;
	uint32_t hash;
	char *d;
} ObjString;

#include "chunk.h"

// Constructs a new objstring from the given C string,
// creating its own fresh copy of the data.
ObjString *objstring_copy(State *S, char *src, size_t len);
ObjString *objstring_copy_cstr(State *s, char *str);
// Constructs a new objstring from the given C string,
// taking ownership of the provided data.
ObjString *objstring_take(State *S, char *src, size_t len);

typedef struct {
	Obj obj;
	Chunk ch;
	uint8_t arity;
} ObjFunc;
ObjFunc *objfunc_new(State *S, uint8_t arity);

typedef struct {
	Obj obj;
	size_t len;
	size_t cap;
	Val *d;
} ObjArr;

ObjArr *objarr_new(State *S);
Val objarr_get(State *S, ObjArr *arr, size_t ix);
void objarr_append(State *S, ObjArr *arr, Val v);
void objarr_put(State *S, ObjArr *arr, size_t ix, Val v);
void objarr_insert(State *S, ObjArr *arr, size_t ix, Val v);

#define IS_NIL(x) (x.ty == TY_NIL)
#define IS_NUM(x) (x.ty == TY_NUM)
#define IS_BOOL(x) (x.ty == TY_BOOL)
#define IS_OBJ(x) (x.ty == TY_OBJ)
#define IS_CFUNC(x) (x.ty == TY_CFUNC)

#define IS_STRING(x) (is_obj_ty((x), OTY_STRING))
#define IS_FUNC(x) (is_obj_ty((x), OTY_FUNC))
#define IS_ARR(x) (is_obj_ty((x), OTY_ARR))

#define AS_NUM(x) (x.as.d)
#define AS_BOOL(x) (x.as.b)
#define AS_OBJ(x) (x.as.o)
#define AS_CFUNC(x) (x.as.f)

#define AS_STRING(x) ((ObjString*)AS_OBJ(x))
#define AS_CSTRING(x) (AS_STRING(x)->d)
#define AS_FUNC(x) ((ObjFunc*)AS_OBJ(x))
#define AS_ARR(x) ((ObjArr*)AS_OBJ(x))

#define VAL_NIL ((Val){.ty=TY_NIL})
#define VAL_NUM(x) ((Val){.ty=TY_NUM, .as.d=(x) })
#define VAL_BOOL(x) ((Val){.ty=TY_BOOL, .as.b=(x) })
#define VAL_TRUE VAL_BOOL(1)
#define VAL_FALSE VAL_BOOL(0)
#define VAL_OBJ(x) ((Val){.ty=TY_OBJ, .as.o=(Obj*)(x) })
#define VAL_CFUNC(x) ((Val){.ty=TY_CFUNC, .as.f=(CFunc)(x)})

static inline bool is_obj_ty(Val v, ObjTy t) {
	return IS_OBJ(v) && (AS_OBJ(v)->oty == t);
}

#endif