#ifndef _TURMIT_H_
#define _TURMIT_H_

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>

/**@Todo For the moment there is no way to track wether a variable is used
 * or not in result processing */

typedef unsigned long long int turmit_int;
typedef struct turmit_op_s turmit_op_t;
typedef struct turmit_s turmit_t;
typedef struct turmit_sym_s turmit_sym_t;
typedef void (*turmit_op_f)(turmit_t*);

#define SCUR(t) (t->stack[t->stack_cur])
#define SDEC(t) (t->stack_cur = (t->stack_cur>0?t->stack_cur:t->stack_sz) -1)
#define SINC(t) (t->stack_cur = (t->stack_cur + 1) % t->stack_sz)
#define SPOP(t) (__SPOP(t))
#define SPUSH(t, v) (t->stack[SINC(t)] = v % t->int_max)


#define TURMIT_EXPR_MAX_SZ	0xFFFFFFFF

#define TURMIT_LAZY		0
#define TURMIT_AUTOCOMP		1

#define TURMIT_OK		0
#define TURMIT_ERROR		-1

#define TURMIT_SYM_OP		1
#define TURMIT_SYM_VAL		2
#define TURMIT_SYM_VAR		3

#define TURMIT_VAR_L		"xyrgb"

#define TURMIT_OPSYM(NAME) {#NAME, NULL, turmit_op_##NAME}
#define TURMIT_OPSYMALIAS(NAME, alias) {#NAME, alias, turmit_op_##NAME}


// OPSYMALIAS has to be first !
#define TURMIT_OP_LST {\
	TURMIT_OPSYMALIAS(add, "+"),\
	TURMIT_OPSYMALIAS(sub, "-"),\
	TURMIT_OPSYMALIAS(mul, "*"),\
	TURMIT_OPSYMALIAS(div, "/"),\
	TURMIT_OPSYMALIAS(mod, "%"),\
	TURMIT_OPSYMALIAS(bin_or, "|"),\
	TURMIT_OPSYMALIAS(bin_and, "&"),\
	TURMIT_OPSYMALIAS(bin_xor, "^"),\
	TURMIT_OPSYMALIAS(lshift, "<<"),\
	TURMIT_OPSYM(mem_sz),\
	TURMIT_OPSYM(dup),\
	TURMIT_OPSYM(pop),\
	TURMIT_OPSYM(swp),\
	TURMIT_OPSYM(jmp),\
	TURMIT_OPSYM(jz),\
	TURMIT_OPSYM(jcmp),\
	NULL,\
}

struct turmit_sym_s
{
	char *str;
	char *alias;
	turmit_op_f op_fun;
};

union turmit_op_u
{
	turmit_op_f op;
	turmit_int val;
	short var; /*!< interpreted % 5 */
};

struct turmit_op_s
{
	union turmit_op_u op;
	/** 0 for NULL, 1 if operation pointer, 2 if value, 3 if variable */
	short value;
};

struct turmit_s
{
	char *expr;
	unsigned char flags;
	ssize_t int_max;

	turmit_op_t *op_expr;
	ssize_t op_expr_sz;
	ssize_t op_cur;

	ssize_t stack_sz;
	turmit_int *stack;
	ssize_t stack_cur;

	/**@brief 0 if no error
	 * @note only for compilation error for the moment
	 */
	char err;
	char *err_str;
};

inline static turmit_int __SPOP(turmit_t *t) {
	turmit_int r = t->stack[t->stack_cur];
	SDEC(t);
	return r;
}


#define TURMIT_OP(NAME) void turmit_op_##NAME (turmit_t *turmit)

/**@brief Allocate memory and initialise a turmit
 * @param const char* The turmit expression
 * @param unsigned char One of TURMIT_LAZY or TURMIT_AUTOCOMP.
 * @return A pointer on the new turmit
 */
turmit_t *turmit_alloc(ssize_t stack_sz, ssize_t int_max, const char *expr,
	unsigned char flags);

/**@brief Initialize a turmit
 * @param turmit_t* The turmit to initialize
 * @param const char* The turmit expression
 * @param unsigned char One of TURMIT_LAZY or TURMIT_AUTOCOMP.
 * @return The pointer on the turmit
 */
turmit_t *turmit_init(turmit_t *turmit, ssize_t stack_sz, ssize_t int_max,
	const char *expr, unsigned char flags);

turmit_t *turmit_copy(turmit_t *turmit);

void turmit_clean(turmit_t *turmit);

/**@brief Free memory of a turmit
 * @param turmit the turmit to free
 */
void turmit_free(turmit_t *turmit);

/**@brief Exec a turmit expr
 * @param turmit_t* Concerned turmit
 * @param turmit_int* Arguments ( see @ref TURMIT_VAL_L )
 * @return Processed value
 */
turmit_int turmit_exec(turmit_t *turmit, const turmit_int args[5]);

/**@brief Populate turmit_t.op_expr and set op_expr_sz
 * @return 0 if no errors
 */
int turmit_compile(turmit_t *turmit);

void _turmit_stack_dump(turmit_t *turmit);

TURMIT_OP(mem_sz);

TURMIT_OP(add);

TURMIT_OP(sub);

TURMIT_OP(bin_and);

TURMIT_OP(dup);

TURMIT_OP(lshift);

TURMIT_OP(mod);

TURMIT_OP(mul);

TURMIT_OP(div);

TURMIT_OP(bin_or);

TURMIT_OP(bin_xor);

TURMIT_OP(pop);

TURMIT_OP(swp);

TURMIT_OP(jmp);

TURMIT_OP(jz);

TURMIT_OP(jcmp);

#endif