/*
   * This file is part of the MicroPython project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2013, 2014 Damien P. George
   * Copyright (c) 2014 Paul Sokolovsky
   *
   * 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 <string.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_LONGLONG
  
  #if MICROPY_PY_SYS_MAXSIZE
  // Export value for sys.maxsize
  const mp_obj_int_t mp_maxsize_obj = {{&mp_type_int}, MP_SSIZE_MAX};
  #endif
  
  mp_obj_t mp_obj_int_from_bytes_impl(bool big_endian, size_t len, const byte *buf) {
      int delta = 1;
      if (!big_endian) {
          buf += len - 1;
          delta = -1;
      }
  
      mp_longint_impl_t value = 0;
      for (; len--; buf += delta) {
          value = (value << 8) | *buf;
      }
      return mp_obj_new_int_from_ll(value);
  }
  
  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 = self_in;
      long long val = self->val;
      if (big_endian) {
          byte *b = buf + len;
          while (b > buf) {
              *--b = val;
              val >>= 8;
          }
      } else {
          for (; len > 0; --len) {
              *buf++ = val;
              val >>= 8;
          }
      }
  }
  
  int mp_obj_int_sign(mp_obj_t self_in) {
      mp_longint_impl_t val;
      if (MP_OBJ_IS_SMALL_INT(self_in)) {
          val = MP_OBJ_SMALL_INT_VALUE(self_in);
      } else {
          mp_obj_int_t *self = self_in;
          val = self->val;
      }
      if (val < 0) {
          return -1;
      } else if (val > 0) {
          return 1;
      } else {
          return 0;
      }
  }
  
  mp_obj_t mp_obj_int_unary_op(mp_unary_op_t op, mp_obj_t o_in) {
      mp_obj_int_t *o = o_in;
      switch (op) {
          case MP_UNARY_OP_BOOL: return mp_obj_new_bool(o->val != 0);
  
          // truncate value to fit in mp_int_t, which gives the same hash as
          // small int if the value fits without truncation
          case MP_UNARY_OP_HASH: return MP_OBJ_NEW_SMALL_INT((mp_int_t)o->val);
  
          case MP_UNARY_OP_POSITIVE: return o_in;
          case MP_UNARY_OP_NEGATIVE: return mp_obj_new_int_from_ll(-o->val);
          case MP_UNARY_OP_INVERT: return mp_obj_new_int_from_ll(~o->val);
          case MP_UNARY_OP_ABS: {
              mp_obj_int_t *self = MP_OBJ_TO_PTR(o_in);
              if (self->val >= 0) {
                  return o_in;
              }
              self = mp_obj_new_int_from_ll(self->val);
              // TODO could overflow long long
              self->val = -self->val;
              return MP_OBJ_FROM_PTR(self);
          }
          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) {
      long long lhs_val;
      long long rhs_val;
  
      if (MP_OBJ_IS_SMALL_INT(lhs_in)) {
          lhs_val = MP_OBJ_SMALL_INT_VALUE(lhs_in);
      } else {
          assert(MP_OBJ_IS_TYPE(lhs_in, &mp_type_int));
          lhs_val = ((mp_obj_int_t*)lhs_in)->val;
      }
  
      if (MP_OBJ_IS_SMALL_INT(rhs_in)) {
          rhs_val = MP_OBJ_SMALL_INT_VALUE(rhs_in);
      } else if (MP_OBJ_IS_TYPE(rhs_in, &mp_type_int)) {
          rhs_val = ((mp_obj_int_t*)rhs_in)->val;
      } else {
          // delegate to generic function to check for extra cases
          return mp_obj_int_binary_op_extra_cases(op, lhs_in, rhs_in);
      }
  
      switch (op) {
          case MP_BINARY_OP_ADD:
          case MP_BINARY_OP_INPLACE_ADD:
              return mp_obj_new_int_from_ll(lhs_val + rhs_val);
          case MP_BINARY_OP_SUBTRACT:
          case MP_BINARY_OP_INPLACE_SUBTRACT:
              return mp_obj_new_int_from_ll(lhs_val - rhs_val);
          case MP_BINARY_OP_MULTIPLY:
          case MP_BINARY_OP_INPLACE_MULTIPLY:
              return mp_obj_new_int_from_ll(lhs_val * rhs_val);
          case MP_BINARY_OP_FLOOR_DIVIDE:
          case MP_BINARY_OP_INPLACE_FLOOR_DIVIDE:
              if (rhs_val == 0) {
                  goto zero_division;
              }
              return mp_obj_new_int_from_ll(lhs_val / rhs_val);
          case MP_BINARY_OP_MODULO:
          case MP_BINARY_OP_INPLACE_MODULO:
              if (rhs_val == 0) {
                  goto zero_division;
              }
              return mp_obj_new_int_from_ll(lhs_val % rhs_val);
  
          case MP_BINARY_OP_AND:
          case MP_BINARY_OP_INPLACE_AND:
              return mp_obj_new_int_from_ll(lhs_val & rhs_val);
          case MP_BINARY_OP_OR:
          case MP_BINARY_OP_INPLACE_OR:
              return mp_obj_new_int_from_ll(lhs_val | rhs_val);
          case MP_BINARY_OP_XOR:
          case MP_BINARY_OP_INPLACE_XOR:
              return mp_obj_new_int_from_ll(lhs_val ^ rhs_val);
  
          case MP_BINARY_OP_LSHIFT:
          case MP_BINARY_OP_INPLACE_LSHIFT:
              return mp_obj_new_int_from_ll(lhs_val << (int)rhs_val);
          case MP_BINARY_OP_RSHIFT:
          case MP_BINARY_OP_INPLACE_RSHIFT:
              return mp_obj_new_int_from_ll(lhs_val >> (int)rhs_val);
  
          case MP_BINARY_OP_POWER:
          case MP_BINARY_OP_INPLACE_POWER: {
              if (rhs_val < 0) {
                  #if MICROPY_PY_BUILTINS_FLOAT
                  return mp_obj_float_binary_op(op, lhs_val, rhs_in);
                  #else
                  mp_raise_ValueError("negative power with no float support");
                  #endif
              }
              long long ans = 1;
              while (rhs_val > 0) {
                  if (rhs_val & 1) {
                      ans *= lhs_val;
                  }
                  if (rhs_val == 1) {
                      break;
                  }
                  rhs_val /= 2;
                  lhs_val *= lhs_val;
              }
              return mp_obj_new_int_from_ll(ans);
          }
  
          case MP_BINARY_OP_LESS:
              return mp_obj_new_bool(lhs_val < rhs_val);
          case MP_BINARY_OP_MORE:
              return mp_obj_new_bool(lhs_val > rhs_val);
          case MP_BINARY_OP_LESS_EQUAL:
              return mp_obj_new_bool(lhs_val <= rhs_val);
          case MP_BINARY_OP_MORE_EQUAL:
              return mp_obj_new_bool(lhs_val >= rhs_val);
          case MP_BINARY_OP_EQUAL:
              return mp_obj_new_bool(lhs_val == rhs_val);
  
          default:
              return MP_OBJ_NULL; // op not supported
      }
  
  zero_division:
      mp_raise_msg(&mp_type_ZeroDivisionError, "division by zero");
  }
  
  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_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_ll(value);
  }
  
  mp_obj_t mp_obj_new_int_from_ll(long long val) {
      mp_obj_int_t *o = m_new_obj(mp_obj_int_t);
      o->base.type = &mp_type_int;
      o->val = val;
      return o;
  }
  
  mp_obj_t mp_obj_new_int_from_ull(unsigned long long val) {
      // TODO raise an exception if the unsigned long long won't fit
      if (val >> (sizeof(unsigned long long) * 8 - 1) != 0) {
          mp_raise_msg(&mp_type_OverflowError, "ulonglong too large");
      }
      mp_obj_int_t *o = m_new_obj(mp_obj_int_t);
      o->base.type = &mp_type_int;
      o->val = val;
      return o;
  }
  
  mp_obj_t mp_obj_new_int_from_str_len(const char **str, size_t len, bool neg, unsigned int base) {
      // TODO this does not honor the given length of the string, but it all cases it should anyway be null terminated
      // TODO check overflow
      mp_obj_int_t *o = m_new_obj(mp_obj_int_t);
      o->base.type = &mp_type_int;
      char *endptr;
      o->val = strtoll(*str, &endptr, base);
      *str = endptr;
      return 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 = self_in;
          return self->val;
      }
  }
  
  mp_int_t mp_obj_int_get_checked(mp_const_obj_t self_in) {
      // TODO: Check overflow
      return mp_obj_int_get_truncated(self_in);
  }
  
  #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 = self_in;
      return self->val;
  }
  #endif
  
  #endif