#include "common.h"
#include "memcached_io.h"

/*
  What happens if no servers exist?
*/
char *memcached_get(memcached_st *ptr, const char *key,
                    size_t key_length,
                    size_t *value_length,
                    uint32_t *flags,
                    memcached_return *error)
{
  return memcached_get_by_key(ptr, NULL, 0, key, key_length,
                              GET_LEN_ARG_UNSPECIFIED, value_length,
                              flags, error);
}

char *memcached_get_len(memcached_st *ptr,
                        const char *key, size_t key_length,
                        uint32_t user_spec_len,
                        size_t *value_length,
                        uint32_t *flags,
                        memcached_return *error)
{
  return memcached_get_by_key(ptr, NULL, 0, key, key_length,
                              user_spec_len, value_length,
                              flags, error);

}

char *memcached_get_by_key(memcached_st *ptr,
                           const char *master_key,
                           size_t master_key_length,
                           const char *key, size_t key_length,
                           uint32_t user_spec_len,
                           size_t *value_length,
                           uint32_t *flags,
                           memcached_return *error)
{
  char *value;
  size_t dummy_length;
  uint32_t dummy_flags;
  memcached_return dummy_error;

  unlikely (ptr->flags & MEM_USE_UDP)
  {
    *error= MEMCACHED_NOT_SUPPORTED;
    return NULL;
  }

  /* Request the key */
  *error= memcached_mget_by_key(ptr,
                                master_key,
                                master_key_length,
                                (const char **)&key, &key_length, 1,
                                user_spec_len);

  value= memcached_fetch(ptr, NULL, NULL,
                         value_length, flags, error);
  /* This is for historical reasons */
  if (*error == MEMCACHED_END)
    *error= MEMCACHED_NOTFOUND;

  (void)memcached_fetch(ptr, NULL, NULL,
                        &dummy_length, &dummy_flags,
                        &dummy_error);
  WATCHPOINT_ASSERT(dummy_length == 0);

  if (value == NULL)
  {
    if (ptr->get_key_failure && *error == MEMCACHED_NOTFOUND)
    {
      memcached_return rc;

      memcached_result_reset(&ptr->result);
      rc= ptr->get_key_failure(ptr, key, key_length, &ptr->result);

      /* On all failure drop to returning NULL */
      if (rc == MEMCACHED_SUCCESS || rc == MEMCACHED_BUFFERED)
      {
        if (rc == MEMCACHED_BUFFERED)
        {
          uint64_t latch; /* We use latch to track the state of the original socket */
          latch= memcached_behavior_get(ptr, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS);
          if (latch == 0)
            memcached_behavior_set(ptr, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS, 1);

          rc= memcached_set(ptr, key, key_length,
                            memcached_result_value(&ptr->result),
                            memcached_result_length(&ptr->result),
                            0, memcached_result_flags(&ptr->result));

          if (rc == MEMCACHED_BUFFERED && latch == 0)
            memcached_behavior_set(ptr, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS, 0);
        }
        else
        {
          rc= memcached_set(ptr, key, key_length,
                            memcached_result_value(&ptr->result),
                            memcached_result_length(&ptr->result),
                            0, memcached_result_flags(&ptr->result));
        }

        if (rc == MEMCACHED_SUCCESS || rc == MEMCACHED_BUFFERED)
        {
          *error= rc;
          *value_length= memcached_result_length(&ptr->result);
          *flags= memcached_result_flags(&ptr->result);
          return memcached_string_c_copy(&ptr->result.value);
        }
      }
    }

  }

  return value;
}

memcached_return memcached_mget(memcached_st *ptr,
                                const char **keys, size_t *key_length,
                                size_t number_of_keys)
{
  return memcached_mget_by_key(ptr, NULL, 0, keys, key_length, number_of_keys,
                               GET_LEN_ARG_UNSPECIFIED);
}

memcached_return memcached_mget_len(memcached_st *ptr,
                                    const char **keys, size_t *key_length,
                                    size_t number_of_keys, uint32_t user_spec_len)
{
  return memcached_mget_by_key(ptr, NULL, 0, keys, key_length, number_of_keys,
                               user_spec_len);
}

static memcached_return binary_mget_by_key(memcached_st *ptr,
                                           unsigned int master_server_key,
                                           bool is_master_key_set,
                                           const char **keys, size_t *key_length,
                                           size_t number_of_keys);

static bool user_specified_length_is_valid(uint32_t user_spec_len)
{
  assert_on_compile(GET_LEN_ARG_UNSPECIFIED == -1U);
  return (user_spec_len > 0 && user_spec_len < GET_LEN_ARG_UNSPECIFIED);
}

memcached_return memcached_mget_by_key(memcached_st *ptr,
                                       const char *master_key,
                                       size_t master_key_length,
                                       const char **keys,
                                       size_t *key_length,
                                       size_t number_of_keys,
                                       uint32_t user_spec_len)
{
  unsigned int x;
  const char *get_command;
  uint8_t get_command_length;
  memcached_return rc= MEMCACHED_NOTFOUND;
  unsigned int master_server_key= (unsigned int)-1; /* 0 is a valid server id! */
  bool is_master_key_set= false;
  bool use_cas = (ptr->flags & MEM_SUPPORT_CAS);
  bool length_specified = (user_spec_len != GET_LEN_ARG_UNSPECIFIED);

   unlikely (ptr->flags & MEM_USE_UDP)
    return MEMCACHED_NOT_SUPPORTED;

  LIBMEMCACHED_MEMCACHED_MGET_START();
  ptr->cursor_server= 0;

  if (number_of_keys == 0)
    return MEMCACHED_NOTFOUND;

  if (ptr->number_of_hosts == 0)
    return MEMCACHED_NO_SERVERS;

  if ((ptr->flags & MEM_VERIFY_KEY) && (memcached_key_test(keys, key_length, number_of_keys) == MEMCACHED_BAD_KEY_PROVIDED))
    return MEMCACHED_BAD_KEY_PROVIDED;

  if (master_key && master_key_length)
  {
    if ((ptr->flags & MEM_VERIFY_KEY) && (memcached_key_test((const char **)&master_key, &master_key_length, 1) == MEMCACHED_BAD_KEY_PROVIDED))
      return MEMCACHED_BAD_KEY_PROVIDED;
    master_server_key= memcached_generate_hash(ptr, master_key, master_key_length);
    is_master_key_set= true;
  }

  if (length_specified) {
    if (ptr->flags & MEM_BINARY_PROTOCOL)
      return MEMCACHED_NOT_SUPPORTED;

    if (!user_specified_length_is_valid(user_spec_len))
      return MEMCACHED_FAILURE;
  }

  /*
    Here is where we pay for the non-block API. We need to remove any data sitting
    in the queue before we start our get.

    It might be optimum to bounce the connection if count > some number.
  */
  for (x= 0; x < ptr->number_of_hosts; x++)
  {
    if (memcached_server_response_count(&ptr->hosts[x]))
    {
      char buffer[MEMCACHED_DEFAULT_COMMAND_SIZE];

      if (ptr->flags & MEM_NO_BLOCK)
        (void)memcached_io_write(&ptr->hosts[x], NULL, 0, 1);

      while(memcached_server_response_count(&ptr->hosts[x]))
        (void)memcached_response(&ptr->hosts[x], buffer, MEMCACHED_DEFAULT_COMMAND_SIZE, &ptr->result);
    }
  }

  if (ptr->flags & MEM_BINARY_PROTOCOL)
    return binary_mget_by_key(ptr, master_server_key, is_master_key_set, keys,
                              key_length, number_of_keys);

  if (length_specified) {
    if (use_cas)
    {
      get_command= "gets_len ";
      get_command_length= 9;
    } else {
      get_command= "get_len ";
      get_command_length= 8;
    }
  } else {
    if (use_cas)
    {
      get_command= "gets ";
      get_command_length= 5;
    } else {
      get_command= "get ";
      get_command_length= 4;
    }
  }

  /*
    If a server fails we warn about errors and start all over with sending keys
    to the server.
  */
  for (x= 0; x < number_of_keys; x++)
  {
    unsigned int server_key;

    if (is_master_key_set)
      server_key= master_server_key;
    else
      server_key= memcached_generate_hash(ptr, keys[x], key_length[x]);

    if (memcached_server_response_count(&ptr->hosts[server_key]) == 0)
    {
      rc= memcached_connect(&ptr->hosts[server_key]);

      if (rc != MEMCACHED_SUCCESS)
        continue;

      if ((memcached_io_write(&ptr->hosts[server_key], get_command, get_command_length, 0)) == -1)
      {
        rc= MEMCACHED_SOME_ERRORS;
        continue;
      }

      if (length_specified) {
        char len[GET_LEN_BUFSZ];
        if (snprintf(len, GET_LEN_BUFSZ, "%d ", user_spec_len) < 0 ||
          (memcached_io_write(&ptr->hosts[server_key], len, strlen(len), 0) == -1))
        {
          rc= MEMCACHED_SOME_ERRORS;
          continue;
        }
      }

      WATCHPOINT_ASSERT(ptr->hosts[server_key].cursor_active == 0);
      memcached_server_response_increment(&ptr->hosts[server_key]);
      WATCHPOINT_ASSERT(ptr->hosts[server_key].cursor_active == 1);
    }

    /* Only called when we have a prefix key */
    if (ptr->prefix_key[0] != 0)
    {
      if ((memcached_io_write(&ptr->hosts[server_key], ptr->prefix_key, ptr->prefix_key_length, 0)) == -1)
      {
        memcached_server_response_reset(&ptr->hosts[server_key]);
        rc= MEMCACHED_SOME_ERRORS;
        continue;
      }
    }

    if ((memcached_io_write(&ptr->hosts[server_key], keys[x], key_length[x], 0)) == -1)
    {
      memcached_server_response_reset(&ptr->hosts[server_key]);
      rc= MEMCACHED_SOME_ERRORS;
      continue;
    }

    if ((memcached_io_write(&ptr->hosts[server_key], " ", 1, 0)) == -1)
    {
      memcached_server_response_reset(&ptr->hosts[server_key]);
      rc= MEMCACHED_SOME_ERRORS;
      continue;
    }

    ptr->last_server_key = server_key;
  }

  /*
    Should we muddle on if some servers are dead?
  */
  for (x= 0; x < ptr->number_of_hosts; x++)
  {
    if (memcached_server_response_count(&ptr->hosts[x]))
    {
      /* We need to do something about non-connnected hosts in the future */
      if ((memcached_io_write(&ptr->hosts[x], "\r\n", 2, 1)) == -1)
      {
        rc= MEMCACHED_SOME_ERRORS;
      }
    }
  }

  LIBMEMCACHED_MEMCACHED_MGET_END();
  return rc;
}


char *memcached_get_from_last(memcached_st *ptr,
                              const char *key,
                              size_t key_length,
                              size_t *value_length,
                              uint32_t *flags,
                              memcached_return *error)
{
  memcached_return rc = MEMCACHED_NOTFOUND;
  char *value = NULL;

  if (memcached_server_response_count(&ptr->hosts[ptr->last_server_key]) == 0) {
    *error = memcached_connect(&ptr->hosts[ptr->last_server_key]);

    if (*error != MEMCACHED_SUCCESS) {
      return value;
    }

    if ((memcached_io_write(&ptr->hosts[ptr->last_server_key], "get ", 4, 0)) == -1) {
      *error = MEMCACHED_SOME_ERRORS;
      return value;
    }
    WATCHPOINT_ASSERT(ptr->hosts[ptr->last_server_key].cursor_active == 0);
    memcached_server_response_increment(&ptr->hosts[ptr->last_server_key]);
    WATCHPOINT_ASSERT(ptr->hosts[ptr->last_server_key].cursor_active == 1);
  }

  /* Only called when we have a prefix key */
  if (ptr->prefix_key[0] != 0) {
    if ((memcached_io_write(&ptr->hosts[ptr->last_server_key], ptr->prefix_key, ptr->prefix_key_length, 0)) == -1) {
      memcached_server_response_reset(&ptr->hosts[ptr->last_server_key]);
      *error = MEMCACHED_SOME_ERRORS;
      return value;
    }
  }

  if ((memcached_io_write(&ptr->hosts[ptr->last_server_key], key, key_length, 0)) == -1) {
    memcached_server_response_reset(&ptr->hosts[ptr->last_server_key]);
    *error = MEMCACHED_SOME_ERRORS;
    return value;
  }

  if ((memcached_io_write(&ptr->hosts[ptr->last_server_key], "\r\n", 2, 1)) == -1) {
    memcached_server_response_reset(&ptr->hosts[ptr->last_server_key]);
    *error = MEMCACHED_SOME_ERRORS;
    return value;
  }

  value = memcached_fetch(ptr, NULL, NULL, value_length, flags, error);

  /* This is for historical reasons */
  if (*error == MEMCACHED_END)
    *error = MEMCACHED_NOTFOUND;

  if (value != NULL) {
    size_t dummy_length;
    uint32_t dummy_flags;
    memcached_return dummy_error;

    (void)memcached_fetch(ptr, NULL, NULL,
                          &dummy_length, &dummy_flags,
                          &dummy_error);
    WATCHPOINT_ASSERT(dummy_length == 0);
  }

  return value;
}

static memcached_return binary_mget_by_key(memcached_st *ptr,
                                           unsigned int master_server_key,
                                           bool is_master_key_set,
                                           const char **keys, size_t *key_length,
                                           size_t number_of_keys)
{
  memcached_return rc= MEMCACHED_NOTFOUND;
  uint32_t x;

  int flush= number_of_keys == 1;

  /*
    If a server fails we warn about errors and start all over with sending keys
    to the server.
  */
  for (x= 0; x < number_of_keys; x++)
  {
    unsigned int server_key;

    if (is_master_key_set)
      server_key= master_server_key;
    else
      server_key= memcached_generate_hash(ptr, keys[x], key_length[x]);

    if (memcached_server_response_count(&ptr->hosts[server_key]) == 0)
    {
      rc= memcached_connect(&ptr->hosts[server_key]);
      if (rc != MEMCACHED_SUCCESS)
        continue;
    }

    protocol_binary_request_getk request= {.bytes= {0}};
    request.message.header.request.magic= PROTOCOL_BINARY_REQ;
    if (number_of_keys == 1)
      request.message.header.request.opcode= PROTOCOL_BINARY_CMD_GETK;
    else
      request.message.header.request.opcode= PROTOCOL_BINARY_CMD_GETKQ;

    memcached_return vk;
    vk= memcached_validate_key_length(ptr->prefix_key_length + key_length[x],
                                      ptr->flags & MEM_BINARY_PROTOCOL);
    unlikely (vk != MEMCACHED_SUCCESS)
    {
      if (x > 0)
        memcached_io_reset(&ptr->hosts[server_key]);
      return vk;
    }

    request.message.header.request.keylen= htons((uint16_t)(ptr->prefix_key_length + key_length[x]));
    request.message.header.request.datatype= PROTOCOL_BINARY_RAW_BYTES;
    request.message.header.request.bodylen= htonl((uint32_t) (ptr->prefix_key_length + key_length[x]));

    if ((memcached_io_write(&ptr->hosts[server_key], request.bytes,
                            sizeof(request.bytes), 0) == -1) ||
        (memcached_io_write(&ptr->hosts[server_key], ptr->prefix_key,
                            ptr->prefix_key_length, 0) == -1) ||
        (memcached_io_write(&ptr->hosts[server_key], keys[x],
                            key_length[x], (char) flush) == -1))
    {
      memcached_server_response_reset(&ptr->hosts[server_key]);
      rc= MEMCACHED_SOME_ERRORS;
      continue;
    }
    memcached_server_response_increment(&ptr->hosts[server_key]);
    if ((x > 0 && x == ptr->io_key_prefetch) &&
        memcached_flush_buffers(ptr) != MEMCACHED_SUCCESS)
      rc= MEMCACHED_SOME_ERRORS;
  }

  /*
   * Send a noop command to flush the buffers
   */
  protocol_binary_request_noop request= {.bytes= {0}};
  request.message.header.request.magic= PROTOCOL_BINARY_REQ;
  request.message.header.request.opcode= PROTOCOL_BINARY_CMD_NOOP;
  request.message.header.request.datatype= PROTOCOL_BINARY_RAW_BYTES;

  for (x= 0; x < ptr->number_of_hosts; x++) {
    if (memcached_server_response_count(&ptr->hosts[x]))
      {
        if (memcached_io_write(&ptr->hosts[x], NULL, 0, 1) == -1)
        {
          memcached_server_response_reset(&ptr->hosts[x]);
          memcached_io_reset(&ptr->hosts[x]);
          rc= MEMCACHED_SOME_ERRORS;
        }

        if (memcached_io_write(&ptr->hosts[x], request.bytes,
			       sizeof(request.bytes), 1) == -1)
        {
          memcached_server_response_reset(&ptr->hosts[x]);
          memcached_io_reset(&ptr->hosts[x]);
          rc= MEMCACHED_SOME_ERRORS;
        }
        memcached_server_response_increment(&ptr->hosts[x]);
      }
  }

  return rc;
}