/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2013, 2014 Damien P. George
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include <stdlib.h>
#include <assert.h>

#include "py/runtime.h"

/******************************************************************************/
/* slice object */

#if MICROPY_PY_BUILTINS_SLICE

STATIC void slice_print(const mp_print_t *print, mp_obj_t o_in, mp_print_kind_t kind) {
 (void)kind;
 mp_obj_slice_t *o = MP_OBJ_TO_PTR(o_in);
 mp_print_str(print, "slice(");
 mp_obj_print_helper(print, o->start, PRINT_REPR);
 mp_print_str(print, ", ");
 mp_obj_print_helper(print, o->stop, PRINT_REPR);
 mp_print_str(print, ", ");
 mp_obj_print_helper(print, o->step, PRINT_REPR);
 mp_print_str(print, ")");
}

#if MICROPY_PY_BUILTINS_SLICE_INDICES
STATIC mp_obj_t slice_indices(mp_obj_t self_in, mp_obj_t length_obj) {
 mp_int_t length = mp_obj_int_get_checked(length_obj);
 mp_bound_slice_t bound_indices;
 mp_obj_slice_indices(self_in, length, &bound_indices);

 mp_obj_t results[3] = {
 MP_OBJ_NEW_SMALL_INT(bound_indices.start),
 MP_OBJ_NEW_SMALL_INT(bound_indices.stop),
 MP_OBJ_NEW_SMALL_INT(bound_indices.step),
 };
 return mp_obj_new_tuple(3, results);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(slice_indices_obj, slice_indices);
#endif

#if MICROPY_PY_BUILTINS_SLICE_ATTRS
STATIC void slice_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
 if (dest[0] != MP_OBJ_NULL) {
 // not load attribute
 return;
 }
 mp_obj_slice_t *self = MP_OBJ_TO_PTR(self_in);

 if (attr == MP_QSTR_start) {
 dest[0] = self->start;
 } else if (attr == MP_QSTR_stop) {
 dest[0] = self->stop;
 } else if (attr == MP_QSTR_step) {
 dest[0] = self->step;
 #if MICROPY_PY_BUILTINS_SLICE_INDICES
 } else if (attr == MP_QSTR_indices) {
 dest[0] = MP_OBJ_FROM_PTR(&slice_indices_obj);
 dest[1] = self_in;
 #endif
 }
}
#endif

#if MICROPY_PY_BUILTINS_SLICE_INDICES && !MICROPY_PY_BUILTINS_SLICE_ATTRS
STATIC const mp_rom_map_elem_t slice_locals_dict_table[] = {
 { MP_ROM_QSTR(MP_QSTR_indices), MP_ROM_PTR(&slice_indices_obj) },
};
STATIC MP_DEFINE_CONST_DICT(slice_locals_dict, slice_locals_dict_table);
#endif

const mp_obj_type_t mp_type_slice = {
 { &mp_type_type },
 .name = MP_QSTR_slice,
 .print = slice_print,
 #if MICROPY_PY_BUILTINS_SLICE_ATTRS
 .attr = slice_attr,
 #elif MICROPY_PY_BUILTINS_SLICE_INDICES
 .locals_dict = (mp_obj_dict_t *)&slice_locals_dict,
 #endif
};

mp_obj_t mp_obj_new_slice(mp_obj_t ostart, mp_obj_t ostop, mp_obj_t ostep) {
 mp_obj_slice_t *o = m_new_obj(mp_obj_slice_t);
 o->base.type = &mp_type_slice;
 o->start = ostart;
 o->stop = ostop;
 o->step = ostep;
 return MP_OBJ_FROM_PTR(o);
}

// Return the real index and step values for a slice when applied to a sequence of
// the given length, resolving missing components, negative values and values off
// the end of the sequence.
void mp_obj_slice_indices(mp_obj_t self_in, mp_int_t length, mp_bound_slice_t *result) {
 mp_obj_slice_t *self = MP_OBJ_TO_PTR(self_in);
 mp_int_t start, stop, step;

 if (self->step == mp_const_none) {
 step = 1;
 } else {
 step = mp_obj_get_int(self->step);
 if (step == 0) {
 mp_raise_ValueError(MP_ERROR_TEXT("slice step can't be zero"));
 }
 }

 if (step > 0) {
 // Positive step
 if (self->start == mp_const_none) {
 start = 0;
 } else {
 start = mp_obj_get_int(self->start);
 if (start < 0) {
 start += length;
 }
 start = MIN(length, MAX(start, 0));
 }

 if (self->stop == mp_const_none) {
 stop = length;
 } else {
 stop = mp_obj_get_int(self->stop);
 if (stop < 0) {
 stop += length;
 }
 stop = MIN(length, MAX(stop, 0));
 }
 } else {
 // Negative step
 if (self->start == mp_const_none) {
 start = length - 1;
 } else {
 start = mp_obj_get_int(self->start);
 if (start < 0) {
 start += length;
 }
 start = MIN(length - 1, MAX(start, -1));
 }

 if (self->stop == mp_const_none) {
 stop = -1;
 } else {
 stop = mp_obj_get_int(self->stop);
 if (stop < 0) {
 stop += length;
 }
 stop = MIN(length - 1, MAX(stop, -1));
 }
 }

 result->start = start;
 result->stop = stop;
 result->step = step;
}

#endif