/*
 * Copyright (c) 2017-2019 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>

#include <parc/algol/parc_Memory.h>
#include <parc/assert/parc_Assert.h>

#include <hicn/core/messageHandler.h>
#include <hicn/core/nameBitvector.h>

#include <parc/algol/parc_Hash.h>

#include <hicn/utils/commands.h>

#define NAME_LEN 2

const uint64_t BV_SIZE = 64;
const uint64_t WIDTH = 128;
const uint64_t ONE = 0x1;

// address b000:0000:0000:0001:c000:0000:0000:0001 is encodend as follow
// [bits[0] uint64_t       ] [bits[1] unit64_t       ]
// ^                       ^ ^                       ^
// 63                      0 127                     64
// [1000 0000 ... 0000 1101] [1000 0000 ... 0000 0011] //binary
//    1                  b     1                  c    //hex

struct name_bitvector {
  uint64_t bits[NAME_LEN];
  uint8_t len;
  uint8_t IPversion;
};

NameBitvector *nameBitvector_CreateFromInAddr(uint32_t addr, uint8_t len) {
  NameBitvector *bitvector = parcMemory_AllocateAndClear(sizeof(NameBitvector));
  parcAssertNotNull(bitvector, "parcMemory_AllocateAndClear(%zu) returned NULL",
                    sizeof(NameBitvector));

  bitvector->bits[0] = 0;
  bitvector->bits[1] = 0;

  uint8_t addr_1 = (addr & 0xff000000) >> 24;
  uint8_t addr_2 = (addr & 0x00ff0000) >> 16;
  uint8_t addr_3 = (addr & 0x0000ff00) >> 8;
  uint8_t addr_4 = (addr & 0x000000ff);

  bitvector->bits[0] = (bitvector->bits[0] | addr_4) << 8;
  bitvector->bits[0] = (bitvector->bits[0] | addr_3) << 8;
  bitvector->bits[0] = (bitvector->bits[0] | addr_2) << 8;
  bitvector->bits[0] = (bitvector->bits[0] | addr_1);
  bitvector->bits[0] = bitvector->bits[0] << 32;

  bitvector->len = len;

  bitvector->IPversion = IPv4_TYPE;

  return bitvector;
}

NameBitvector *nameBitvector_CreateFromIn6Addr(struct in6_addr *addr,
                                               uint8_t len) {
  parcAssertNotNull(addr, "addr cannot be null");

  NameBitvector *bitvector = parcMemory_AllocateAndClear(sizeof(NameBitvector));
  parcAssertNotNull(bitvector, "parcMemory_AllocateAndClear(%zu) returned NULL",
                    sizeof(NameBitvector));

  bitvector->bits[0] = 0;
  bitvector->bits[1] = 0;

  for (int i = 0; i < 8; ++i) {
    bitvector->bits[0] = (bitvector->bits[0] << 8) | addr->s6_addr[i];
  }

  for (int i = 8; i < 16; ++i) {
    bitvector->bits[1] = (bitvector->bits[1] << 8) | addr->s6_addr[i];
  }

  bitvector->len = len;

  bitvector->IPversion = IPv6_TYPE;

  return bitvector;
}

NameBitvector *nameBitvector_CreateFromAddress(const Address *prefix,
                                               uint8_t len) {
  parcAssertNotNull(prefix, "prefix cannot be null");

  NameBitvector *bitvector = NULL;
  switch (addressGetType(prefix)) {
    case ADDR_INET: {
      struct sockaddr_in addr;
      addressGetInet(prefix, &addr);
      bitvector = nameBitvector_CreateFromInAddr(addr.sin_addr.s_addr, len);
      break;
    }
    case ADDR_INET6: {
      struct sockaddr_in6 addr;
      addressGetInet6(prefix, &addr);
      bitvector = nameBitvector_CreateFromIn6Addr(&addr.sin6_addr, len);
      break;
    }
    default:
      parcTrapNotImplemented("Unkown packet type");
      break;
  }

  return bitvector;
}

NameBitvector *nameBitvector_Copy(const NameBitvector *original) {
  parcAssertNotNull(original, "original cannot be null");

  NameBitvector *copy = parcMemory_AllocateAndClear(sizeof(NameBitvector));
  parcAssertNotNull(copy, "parcMemory_AllocateAndClear(%zu) returned NULL",
                    sizeof(NameBitvector));

  copy->bits[0] = original->bits[0];
  copy->bits[1] = original->bits[1];
  copy->len = original->len;

  return copy;
}

void nameBitvector_Destroy(NameBitvector **bitvectorPtr) {
  parcAssertNotNull(bitvectorPtr, "Parameter must be non-null double pointer");
  parcAssertNotNull(*bitvectorPtr,
                    "Parameter must dereference to non-null pointer");

  NameBitvector *bv = *bitvectorPtr;
  parcMemory_Deallocate((void **)&(bv));
  *bitvectorPtr = NULL;
}

uint8_t nameBitvector_GetLength(const NameBitvector *name) { return name->len; }

uint32_t nameBitvector_GetHash32(const NameBitvector *name) {
  return parcHash32_Data_Cumulative((const uint8_t *)name->bits, 16, 0);
}

bool nameBitvector_Equals(const NameBitvector *a, const NameBitvector *b) {
  if (a->bits[0] == b->bits[0] && a->bits[1] == b->bits[1] && a->len == b->len)
    return true;
  return false;
}

int nameBitvector_Compare(const NameBitvector *a, const NameBitvector *b) {
  if (a == NULL && b == NULL) {
    return 0;
  }
  if (a == NULL) {
    return -1;
  }
  if (b == NULL) {
    return +1;
  }

  if (a->bits[0] < b->bits[0]) {
    return -1;
  } else if (a->bits[0] > b->bits[0]) {
    return +1;
  } else if (a->bits[1] < b->bits[1]) {
    return -1;
  } else if (a->bits[1] > b->bits[1]) {
    return +1;
  } else if (a->len < b->len) {
    return -1;
  } else if (a->len > b->len) {
    return +1;
  } else {
    return 0;
  }
}

int nameBitvector_testBit(const NameBitvector *name, uint8_t pos, bool *bit) {
  if(pos >= name->len  || pos > (WIDTH -1))
    return -1;

  *bit = (name->bits[pos / BV_SIZE] & (ONE << ((BV_SIZE - 1) - (pos % BV_SIZE))));

  return 0;
}

uint64_t _diff_bit_log2(uint64_t val) {
  // base 2 log of an uint64_t. This is the same as get the position of
  // the highest bit set (or most significant bit set, MSB)
  uint64_t result = 0;

  if (val & 0xFFFFFFFF00000000) {
    val = val >> 32;
    result = result | 32;
  }
  if (val & 0xFFFF0000) {
    val = val >> 16;
    result = result | 16;
  }
  if (val & 0xFF00) {
    val = val >> 8;
    result = result | 8;
  }
  if (val & 0xF0) {
    val = val >> 4;
    result = result | 4;
  }
  if (val & 0xC) {
    val = val >> 2;
    result = result | 2;
  }
  if (val & 0x2) {
    val = val >> 1;
    result = result | 1;
  }
  return result;
}

uint32_t nameBitvector_lpm(const NameBitvector *a,
                          const NameBitvector *b) {
  uint32_t limit;
  uint32_t prefix_len;
  if (a->len < b->len)
    limit = a->len;
  else
    limit = b->len;

  uint64_t diff = a->bits[0] ^ b->bits[0];
  if(diff){
    prefix_len = (uint32_t)(BV_SIZE - (_diff_bit_log2(diff) + 1));
    //printf("if 1 diff = %lu plen = %d\n", diff, prefix_len);
  }else{
    prefix_len = (uint32_t)BV_SIZE;
    diff = a->bits[1] ^ b->bits[1];
    if(diff){
      prefix_len +=   (uint32_t)(BV_SIZE - (_diff_bit_log2(diff) + 1));
      //printf("if 2 diff = %lu plen = %d\n", diff, prefix_len);
    }else{
      prefix_len +=  (uint32_t)BV_SIZE;
    }
  }

  if(prefix_len < limit)
    return prefix_len;
  return limit;
}

void nameBitvector_clear(NameBitvector *a, uint8_t start_from){
  for(uint8_t pos = start_from; pos < WIDTH; pos++)
      a->bits[pos / BV_SIZE] &= ~(ONE << ((BV_SIZE - 1) - (pos % BV_SIZE)));
}

int nameBitvector_ToIPAddress(const NameBitvector *name,
                              ip_prefix_t *prefix) {
  if (name->IPversion == IPv4_TYPE) {
    struct in_addr *addr = (struct in_addr *)(&prefix->address.v4.buffer);
    prefix->family = AF_INET;
    prefix->len = IPV4_ADDR_LEN_BITS;

    uint32_t tmp_addr = name->bits[0] >> 32ULL;
    uint8_t addr_1 = (tmp_addr & 0xff000000) >> 24;
    uint8_t addr_2 = (tmp_addr & 0x00ff0000) >> 16;
    uint8_t addr_3 = (tmp_addr & 0x0000ff00) >> 8;
    uint8_t addr_4 = (tmp_addr & 0x000000ff);

    addr->s_addr = 0;
    addr->s_addr = (addr->s_addr | addr_4) << 8;
    addr->s_addr = (addr->s_addr | addr_3) << 8;
    addr->s_addr = (addr->s_addr | addr_2) << 8;
    addr->s_addr = (addr->s_addr | addr_1);

  } else {
    struct in6_addr *addr = (struct in6_addr *)(&prefix->address.v6.buffer);
    prefix->family = AF_INET6;
    prefix->len = name->len;  // IPV6_ADDR_LEN_BITS;

    for (int i = 0; i < 8; i++) {
      addr->s6_addr[i] = (uint8_t)((name->bits[0] >> 8 * (7 - i)) & 0xFF);
    }

    int x = 0;
    for (int i = 8; i < 16; ++i) {
      addr->s6_addr[i] = (uint8_t)((name->bits[1] >> 8 * (7 - x)) & 0xFF);
      x++;
    }
  }
  return true;
}

void nameBitvector_setLen(NameBitvector *name, uint8_t len) { name->len = len; }

Address *nameBitvector_ToAddress(const NameBitvector *name) {
  if (name->IPversion == IPv4_TYPE) {
    struct sockaddr_in addr;
    addr.sin_family = AF_INET;
    addr.sin_port = htons(1234);

    uint32_t tmp_addr = name->bits[0] >> 32ULL;
    uint8_t addr_1 = (tmp_addr & 0xff000000) >> 24;
    uint8_t addr_2 = (tmp_addr & 0x00ff0000) >> 16;
    uint8_t addr_3 = (tmp_addr & 0x0000ff00) >> 8;
    uint8_t addr_4 = (tmp_addr & 0x000000ff);

    addr.sin_addr.s_addr = 0;
    addr.sin_addr.s_addr = (addr.sin_addr.s_addr | addr_4) << 8;
    addr.sin_addr.s_addr = (addr.sin_addr.s_addr | addr_3) << 8;
    addr.sin_addr.s_addr = (addr.sin_addr.s_addr | addr_2) << 8;
    addr.sin_addr.s_addr = (addr.sin_addr.s_addr | addr_1);

    Address *packetAddr = addressCreateFromInet(&addr);

    return packetAddr;

  } else {
    struct sockaddr_in6 addr;
    addr.sin6_family = AF_INET6;
    addr.sin6_port = htons(1234);
    addr.sin6_scope_id = 0;
    addr.sin6_flowinfo = 0;

    for (int i = 0; i < 8; i++) {
      addr.sin6_addr.s6_addr[i] =
          (uint8_t)((name->bits[0] >> 8 * (7 - i)) & 0xFF);
    }

    int x = 0;
    for (int i = 8; i < 16; ++i) {
      addr.sin6_addr.s6_addr[i] =
          (uint8_t)((name->bits[1] >> 8 * (7 - x)) & 0xFF);
      x++;
    }

    Address *packetAddr = addressCreateFromInet6(&addr);

    return packetAddr;
  }
}

char *nameBitvector_ToString(const NameBitvector *name) {
  char *output = malloc(WIDTH);

  Address *packetAddr = nameBitvector_ToAddress(name);

  char * str = addressToString(packetAddr);
  sprintf(output, "prefix: %s len: %u", str, name->len);
  parcMemory_Deallocate((void **)&str);

  addressDestroy(&packetAddr);

  return output;
}