/*
   * 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 <string.h>
  #include <stdio.h>
  #include <assert.h>
  
  #include "py/parsenumbase.h"
  #include "py/smallint.h"
  #include "py/objint.h"
  #include "py/runtime.h"
  
  #if MICROPY_PY_BUILTINS_FLOAT
  #include <math.h>
  #endif
  
  #if MICROPY_LONGINT_IMPL == MICROPY_LONGINT_IMPL_MPZ
  
  #if MICROPY_PY_SYS_MAXSIZE
  // Export value for sys.maxsize
  #define DIG_MASK ((MPZ_LONG_1 << MPZ_DIG_SIZE) - 1)
  STATIC const mpz_dig_t maxsize_dig[] = {
      #define NUM_DIG 1
      (MP_SSIZE_MAX >> MPZ_DIG_SIZE * 0) & DIG_MASK,
      #if (MP_SSIZE_MAX >> MPZ_DIG_SIZE * 0) > DIG_MASK
       #undef NUM_DIG
       #define NUM_DIG 2
       (MP_SSIZE_MAX >> MPZ_DIG_SIZE * 1) & DIG_MASK,
       #if (MP_SSIZE_MAX >> MPZ_DIG_SIZE * 1) > DIG_MASK
        #undef NUM_DIG
        #define NUM_DIG 3
        (MP_SSIZE_MAX >> MPZ_DIG_SIZE * 2) & DIG_MASK,
        #if (MP_SSIZE_MAX >> MPZ_DIG_SIZE * 2) > DIG_MASK
         #undef NUM_DIG
         #define NUM_DIG 4
         (MP_SSIZE_MAX >> MPZ_DIG_SIZE * 3) & DIG_MASK,
         #if (MP_SSIZE_MAX >> MPZ_DIG_SIZE * 3) > DIG_MASK
          #error cannot encode MP_SSIZE_MAX as mpz
         #endif
        #endif
       #endif
      #endif
  };
  const mp_obj_int_t mp_maxsize_obj = {
      {&mp_type_int},
      {.fixed_dig = 1, .len = NUM_DIG, .alloc = NUM_DIG, .dig = (mpz_dig_t*)maxsize_dig}
  };
  #undef DIG_MASK
  #undef NUM_DIG
  #endif
  
  mp_obj_int_t *mp_obj_int_new_mpz(void) {
      mp_obj_int_t *o = m_new_obj(mp_obj_int_t);
      o->base.type = &mp_type_int;
      mpz_init_zero(&o->mpz);
      return o;
  }
  
  // This routine expects you to pass in a buffer and size (in *buf and buf_size).
  // If, for some reason, this buffer is too small, then it will allocate a
  // buffer and return the allocated buffer and size in *buf and *buf_size. It
  // is the callers responsibility to free this allocated buffer.
  //
  // The resulting formatted string will be returned from this function and the
  // formatted size will be in *fmt_size.
  //
  // This particular routine should only be called for the mpz representation of the int.
  char *mp_obj_int_formatted_impl(char **buf, size_t *buf_size, size_t *fmt_size, mp_const_obj_t self_in,
                                  int base, const char *prefix, char base_char, char comma) {
      assert(MP_OBJ_IS_TYPE(self_in, &mp_type_int));
      const mp_obj_int_t *self = MP_OBJ_TO_PTR(self_in);
  
      size_t needed_size = mp_int_format_size(mpz_max_num_bits(&self->mpz), base, prefix, comma);
      if (needed_size > *buf_size) {
          *buf = m_new(char, needed_size);
          *buf_size = needed_size;
      }
      char *str = *buf;
  
      *fmt_size = mpz_as_str_inpl(&self->mpz, base, prefix, base_char, comma, str);
  
      return str;
  }
  
  mp_obj_t mp_obj_int_from_bytes_impl(bool big_endian, size_t len, const byte *buf) {
      mp_obj_int_t *o = mp_obj_int_new_mpz();
      mpz_set_from_bytes(&o->mpz, big_endian, len, buf);
      return MP_OBJ_FROM_PTR(o);
  }
  
  void mp_obj_int_to_bytes_impl(mp_obj_t self_in, bool big_endian, size_t len, byte *buf) {
      assert(MP_OBJ_IS_TYPE(self_in, &mp_type_int));
      mp_obj_int_t *self = MP_OBJ_TO_PTR(self_in);
      memset(buf, 0, len);
      mpz_as_bytes(&self->mpz, big_endian, len, buf);
  }
  
  int mp_obj_int_sign(mp_obj_t self_in) {
      if (MP_OBJ_IS_SMALL_INT(self_in)) {
          mp_int_t val = MP_OBJ_SMALL_INT_VALUE(self_in);
          if (val < 0) {
              return -1;
          } else if (val > 0) {
              return 1;
          } else {
              return 0;
          }
      }
      mp_obj_int_t *self = MP_OBJ_TO_PTR(self_in);
      if (self->mpz.len == 0) {
          return 0;
      } else if (self->mpz.neg == 0) {
          return 1;
      } else {
          return -1;
      }
  }
  
  mp_obj_t mp_obj_int_unary_op(mp_unary_op_t op, mp_obj_t o_in) {
      mp_obj_int_t *o = MP_OBJ_TO_PTR(o_in);
      switch (op) {
          case MP_UNARY_OP_BOOL: return mp_obj_new_bool(!mpz_is_zero(&o->mpz));
          case MP_UNARY_OP_HASH: return MP_OBJ_NEW_SMALL_INT(mpz_hash(&o->mpz));
          case MP_UNARY_OP_POSITIVE: return o_in;
          case MP_UNARY_OP_NEGATIVE: { mp_obj_int_t *o2 = mp_obj_int_new_mpz(); mpz_neg_inpl(&o2->mpz, &o->mpz); return MP_OBJ_FROM_PTR(o2); }
          case MP_UNARY_OP_INVERT: { mp_obj_int_t *o2 = mp_obj_int_new_mpz(); mpz_not_inpl(&o2->mpz, &o->mpz); return MP_OBJ_FROM_PTR(o2); }
          case MP_UNARY_OP_ABS: {
              mp_obj_int_t *self = MP_OBJ_TO_PTR(o_in);
              if (self->mpz.neg == 0) {
                  return o_in;
              }
              mp_obj_int_t *self2 = mp_obj_int_new_mpz();
              mpz_abs_inpl(&self2->mpz, &self->mpz);
              return MP_OBJ_FROM_PTR(self2);
          }
          default: return MP_OBJ_NULL; // op not supported
      }
  }
  
  mp_obj_t mp_obj_int_binary_op(mp_binary_op_t op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
      const mpz_t *zlhs;
      const mpz_t *zrhs;
      mpz_t z_int;
      mpz_dig_t z_int_dig[MPZ_NUM_DIG_FOR_INT];
  
      // lhs could be a small int (eg small-int + mpz)
      if (MP_OBJ_IS_SMALL_INT(lhs_in)) {
          mpz_init_fixed_from_int(&z_int, z_int_dig, MPZ_NUM_DIG_FOR_INT, MP_OBJ_SMALL_INT_VALUE(lhs_in));
          zlhs = &z_int;
      } else {
          assert(MP_OBJ_IS_TYPE(lhs_in, &mp_type_int));
          zlhs = &((mp_obj_int_t*)MP_OBJ_TO_PTR(lhs_in))->mpz;
      }
  
      // if rhs is small int, then lhs was not (otherwise mp_binary_op handles it)
      if (MP_OBJ_IS_SMALL_INT(rhs_in)) {
          mpz_init_fixed_from_int(&z_int, z_int_dig, MPZ_NUM_DIG_FOR_INT, MP_OBJ_SMALL_INT_VALUE(rhs_in));
          zrhs = &z_int;
      } else if (MP_OBJ_IS_TYPE(rhs_in, &mp_type_int)) {
          zrhs = &((mp_obj_int_t*)MP_OBJ_TO_PTR(rhs_in))->mpz;
  #if MICROPY_PY_BUILTINS_FLOAT
      } else if (mp_obj_is_float(rhs_in)) {
          return mp_obj_float_binary_op(op, mpz_as_float(zlhs), rhs_in);
  #if MICROPY_PY_BUILTINS_COMPLEX
      } else if (MP_OBJ_IS_TYPE(rhs_in, &mp_type_complex)) {
          return mp_obj_complex_binary_op(op, mpz_as_float(zlhs), 0, rhs_in);
  #endif
  #endif
      } else {
          // delegate to generic function to check for extra cases
          return mp_obj_int_binary_op_extra_cases(op, lhs_in, rhs_in);
      }
  
      if (0) {
  #if MICROPY_PY_BUILTINS_FLOAT
      } else if (op == MP_BINARY_OP_TRUE_DIVIDE || op == MP_BINARY_OP_INPLACE_TRUE_DIVIDE) {
          if (mpz_is_zero(zrhs)) {
              goto zero_division_error;
          }
          mp_float_t flhs = mpz_as_float(zlhs);
          mp_float_t frhs = mpz_as_float(zrhs);
          return mp_obj_new_float(flhs / frhs);
  #endif
  
      } else if (op >= MP_BINARY_OP_INPLACE_OR && op < MP_BINARY_OP_CONTAINS) {
          mp_obj_int_t *res = mp_obj_int_new_mpz();
  
          switch (op) {
              case MP_BINARY_OP_ADD:
              case MP_BINARY_OP_INPLACE_ADD:
                  mpz_add_inpl(&res->mpz, zlhs, zrhs);
                  break;
              case MP_BINARY_OP_SUBTRACT:
              case MP_BINARY_OP_INPLACE_SUBTRACT:
                  mpz_sub_inpl(&res->mpz, zlhs, zrhs);
                  break;
              case MP_BINARY_OP_MULTIPLY:
              case MP_BINARY_OP_INPLACE_MULTIPLY:
                  mpz_mul_inpl(&res->mpz, zlhs, zrhs);
                  break;
              case MP_BINARY_OP_FLOOR_DIVIDE:
              case MP_BINARY_OP_INPLACE_FLOOR_DIVIDE: {
                  if (mpz_is_zero(zrhs)) {
                      zero_division_error:
                      mp_raise_msg(&mp_type_ZeroDivisionError, "division by zero");
                  }
                  mpz_t rem; mpz_init_zero(&rem);
                  mpz_divmod_inpl(&res->mpz, &rem, zlhs, zrhs);
                  mpz_deinit(&rem);
                  break;
              }
              case MP_BINARY_OP_MODULO:
              case MP_BINARY_OP_INPLACE_MODULO: {
                  if (mpz_is_zero(zrhs)) {
                      goto zero_division_error;
                  }
                  mpz_t quo; mpz_init_zero(&quo);
                  mpz_divmod_inpl(&quo, &res->mpz, zlhs, zrhs);
                  mpz_deinit(&quo);
                  break;
              }
  
              case MP_BINARY_OP_AND:
              case MP_BINARY_OP_INPLACE_AND:
                  mpz_and_inpl(&res->mpz, zlhs, zrhs);
                  break;
              case MP_BINARY_OP_OR:
              case MP_BINARY_OP_INPLACE_OR:
                  mpz_or_inpl(&res->mpz, zlhs, zrhs);
                  break;
              case MP_BINARY_OP_XOR:
              case MP_BINARY_OP_INPLACE_XOR:
                  mpz_xor_inpl(&res->mpz, zlhs, zrhs);
                  break;
  
              case MP_BINARY_OP_LSHIFT:
              case MP_BINARY_OP_INPLACE_LSHIFT:
              case MP_BINARY_OP_RSHIFT:
              case MP_BINARY_OP_INPLACE_RSHIFT: {
                  mp_int_t irhs = mp_obj_int_get_checked(rhs_in);
                  if (irhs < 0) {
                      mp_raise_ValueError("negative shift count");
                  }
                  if (op == MP_BINARY_OP_LSHIFT || op == MP_BINARY_OP_INPLACE_LSHIFT) {
                      mpz_shl_inpl(&res->mpz, zlhs, irhs);
                  } else {
                      mpz_shr_inpl(&res->mpz, zlhs, irhs);
                  }
                  break;
              }
  
              case MP_BINARY_OP_POWER:
              case MP_BINARY_OP_INPLACE_POWER:
                  if (mpz_is_neg(zrhs)) {
                      #if MICROPY_PY_BUILTINS_FLOAT
                      return mp_obj_float_binary_op(op, mpz_as_float(zlhs), rhs_in);
                      #else
                      mp_raise_ValueError("negative power with no float support");
                      #endif
                  }
                  mpz_pow_inpl(&res->mpz, zlhs, zrhs);
                  break;
  
              default: {
                  assert(op == MP_BINARY_OP_DIVMOD);
                  if (mpz_is_zero(zrhs)) {
                      goto zero_division_error;
                  }
                  mp_obj_int_t *quo = mp_obj_int_new_mpz();
                  mpz_divmod_inpl(&quo->mpz, &res->mpz, zlhs, zrhs);
                  mp_obj_t tuple[2] = {MP_OBJ_FROM_PTR(quo), MP_OBJ_FROM_PTR(res)};
                  return mp_obj_new_tuple(2, tuple);
              }
          }
  
          return MP_OBJ_FROM_PTR(res);
  
      } else {
          int cmp = mpz_cmp(zlhs, zrhs);
          switch (op) {
              case MP_BINARY_OP_LESS:
                  return mp_obj_new_bool(cmp < 0);
              case MP_BINARY_OP_MORE:
                  return mp_obj_new_bool(cmp > 0);
              case MP_BINARY_OP_LESS_EQUAL:
                  return mp_obj_new_bool(cmp <= 0);
              case MP_BINARY_OP_MORE_EQUAL:
                  return mp_obj_new_bool(cmp >= 0);
              case MP_BINARY_OP_EQUAL:
                  return mp_obj_new_bool(cmp == 0);
  
              default:
                  return MP_OBJ_NULL; // op not supported
          }
      }
  }
  
  #if MICROPY_PY_BUILTINS_POW3
  STATIC mpz_t *mp_mpz_for_int(mp_obj_t arg, mpz_t *temp) {
      if (MP_OBJ_IS_SMALL_INT(arg)) {
          mpz_init_from_int(temp, MP_OBJ_SMALL_INT_VALUE(arg));
          return temp;
      } else {
          mp_obj_int_t *arp_p = MP_OBJ_TO_PTR(arg);
          return &(arp_p->mpz);
      }
  }
  
  mp_obj_t mp_obj_int_pow3(mp_obj_t base, mp_obj_t exponent,  mp_obj_t modulus) {
      if (!MP_OBJ_IS_INT(base) || !MP_OBJ_IS_INT(exponent) || !MP_OBJ_IS_INT(modulus)) {
          mp_raise_TypeError("pow() with 3 arguments requires integers");
      } else {
          mp_obj_t result = mp_obj_new_int_from_ull(0); // Use the _from_ull version as this forces an mpz int
          mp_obj_int_t *res_p = (mp_obj_int_t *) MP_OBJ_TO_PTR(result);
  
          mpz_t l_temp, r_temp, m_temp;
          mpz_t *lhs = mp_mpz_for_int(base,     &l_temp);
          mpz_t *rhs = mp_mpz_for_int(exponent, &r_temp);
          mpz_t *mod = mp_mpz_for_int(modulus,  &m_temp);
  
          mpz_pow3_inpl(&(res_p->mpz), lhs, rhs, mod);
  
          if (lhs == &l_temp) { mpz_deinit(lhs); }
          if (rhs == &r_temp) { mpz_deinit(rhs); }
          if (mod == &m_temp) { mpz_deinit(mod); }
          return result;
      }
  }
  #endif
  
  mp_obj_t mp_obj_new_int(mp_int_t value) {
      if (MP_SMALL_INT_FITS(value)) {
          return MP_OBJ_NEW_SMALL_INT(value);
      }
      return mp_obj_new_int_from_ll(value);
  }
  
  mp_obj_t mp_obj_new_int_from_ll(long long val) {
      mp_obj_int_t *o = mp_obj_int_new_mpz();
      mpz_set_from_ll(&o->mpz, val, true);
      return MP_OBJ_FROM_PTR(o);
  }
  
  mp_obj_t mp_obj_new_int_from_ull(unsigned long long val) {
      mp_obj_int_t *o = mp_obj_int_new_mpz();
      mpz_set_from_ll(&o->mpz, val, false);
      return MP_OBJ_FROM_PTR(o);
  }
  
  mp_obj_t mp_obj_new_int_from_uint(mp_uint_t value) {
      // SMALL_INT accepts only signed numbers, so make sure the input
      // value fits completely in the small-int positive range.
      if ((value & ~MP_SMALL_INT_POSITIVE_MASK) == 0) {
          return MP_OBJ_NEW_SMALL_INT(value);
      }
      return mp_obj_new_int_from_ull(value);
  }
  
  mp_obj_t mp_obj_new_int_from_str_len(const char **str, size_t len, bool neg, unsigned int base) {
      mp_obj_int_t *o = mp_obj_int_new_mpz();
      size_t n = mpz_set_from_str(&o->mpz, *str, len, neg, base);
      *str += n;
      return MP_OBJ_FROM_PTR(o);
  }
  
  mp_int_t mp_obj_int_get_truncated(mp_const_obj_t self_in) {
      if (MP_OBJ_IS_SMALL_INT(self_in)) {
          return MP_OBJ_SMALL_INT_VALUE(self_in);
      } else {
          const mp_obj_int_t *self = MP_OBJ_TO_PTR(self_in);
          // hash returns actual int value if it fits in mp_int_t
          return mpz_hash(&self->mpz);
      }
  }
  
  mp_int_t mp_obj_int_get_checked(mp_const_obj_t self_in) {
      if (MP_OBJ_IS_SMALL_INT(self_in)) {
          return MP_OBJ_SMALL_INT_VALUE(self_in);
      } else {
          const mp_obj_int_t *self = MP_OBJ_TO_PTR(self_in);
          mp_int_t value;
          if (mpz_as_int_checked(&self->mpz, &value)) {
              return value;
          } else {
              // overflow
              mp_raise_msg(&mp_type_OverflowError, "overflow converting long int to machine word");
          }
      }
  }
  
  #if MICROPY_PY_BUILTINS_FLOAT
  mp_float_t mp_obj_int_as_float_impl(mp_obj_t self_in) {
      assert(MP_OBJ_IS_TYPE(self_in, &mp_type_int));
      mp_obj_int_t *self = MP_OBJ_TO_PTR(self_in);
      return mpz_as_float(&self->mpz);
  }
  #endif
  
  #endif