/*
 * 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 <limits.h>
#include <src/config.h>
#include <stdio.h>

#include <src/core/connection.h>
#include <src/core/messageHandler.h>
#include <src/core/ticks.h>
#include <src/core/wldr.h>
#include <src/io/addressPair.h>
#include <src/io/ioOperations.h>

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

struct connection {
  const AddressPair *addressPair;
  IoOperations *ops;

  unsigned refCount;

  bool probing_active;
  unsigned probing_interval;
  unsigned counter;
  Ticks last_sent;
  Ticks delay;

  bool wldrAutoStart;  // if true, wldr can be set automatically
                       // by default this value is set to true.
                       // if wldr is activated using a command (config
                       // file/hicnLightControl) this value is set to false so
                       // that a base station can not disable wldr at the client
  Wldr *wldr;
};

Connection *connection_Create(IoOperations *ops) {
  parcAssertNotNull(ops, "Parameter ops must be non-null");
  Connection *conn = parcMemory_AllocateAndClear(sizeof(Connection));
  parcAssertNotNull(conn, "parcMemory_AllocateAndClear(%zu) returned NULL",
                    sizeof(Connection));
  conn->addressPair = ioOperations_GetAddressPair(ops);
  conn->ops = ops;
  conn->refCount = 1;
  conn->wldr = NULL;
  conn->probing_active = false;

  conn->wldrAutoStart = true;
  conn->probing_interval = 0;
  conn->counter = 0;
  conn->last_sent = 0;
  conn->delay = INT_MAX;
  return conn;
}

Connection *connection_Acquire(Connection *connection) {
  parcAssertNotNull(connection, "Parameter conn must be non-null");
  connection->refCount++;
  return connection;
}

void connection_Release(Connection **connectionPtr) {
  parcAssertNotNull(connectionPtr, "Parameter must be non-null double pointer");
  parcAssertNotNull(*connectionPtr,
                    "Parameter must dereference to non-null pointer");
  Connection *conn = *connectionPtr;

  parcAssertTrue(
      conn->refCount > 0,
      "Invalid state, connection reference count should be positive, got 0.");
  conn->refCount--;
  if (conn->refCount == 0) {
    // don't destroy addressPair, its part of ops.
    ioOperations_Release(&conn->ops);
    if (conn->wldr != NULL) {
      wldr_Destroy(&(conn->wldr));
    }
    parcMemory_Deallocate((void **)&conn);
  }
  *connectionPtr = NULL;
}

bool connection_Send(const Connection *conn, Message *message) {
  parcAssertNotNull(conn, "Parameter conn must be non-null");
  parcAssertNotNull(message, "Parameter message must be non-null");

  if (ioOperations_IsUp(conn->ops)) {
    if (message_GetType(message) == MessagePacketType_ContentObject) {
      uint8_t connectionId = (uint8_t)connection_GetConnectionId(conn);
      message_UpdatePathLabel(message, connectionId);
    }
    if (conn->wldr != NULL) {
      wldr_SetLabel(conn->wldr, message);
    } else {
      message_ResetWldrLabel(message);
    }
    return ioOperations_Send(conn->ops, NULL, message);
  }
  return false;
}

static void _sendProbe(Connection *conn, unsigned probeType, uint8_t *message) {
  parcAssertNotNull(conn, "Parameter conn must be non-null");

  if (probeType == PACKET_TYPE_PROBE_REQUEST) {
    Ticks now = ioOperations_SendProbe(conn->ops, probeType, message);
    if (now != 0) {
      conn->last_sent = now;
    }
  } else {
    ioOperations_SendProbe(conn->ops, probeType, message);
  }
}

void connection_Probe(Connection *conn) {
  _sendProbe(conn, PACKET_TYPE_PROBE_REQUEST, NULL);
}

void connection_HandleProbe(Connection *conn, uint8_t *probe,
                            Ticks actualTime) {
  parcAssertNotNull(conn, "Parameter conn must be non-null");
  parcAssertNotNull(probe, "Parameter pkt must be non-null");

  uint8_t probeType = messageHandler_GetProbePacketType(probe);
  if (probeType == PACKET_TYPE_PROBE_REQUEST) {
    _sendProbe(conn, PACKET_TYPE_PROBE_REPLY, probe);
  } else if (probeType == PACKET_TYPE_PROBE_REPLY) {
    Ticks delay = actualTime - conn->last_sent;
    if (delay == 0) {
      delay = 1;
    }
    if (delay < conn->delay) {
      conn->delay = delay;
    }
  } else {
    printf("receivde unkwon probe type\n");
  }
}

uint64_t connection_GetDelay(Connection *conn) { return (uint64_t)conn->delay; }

IoOperations *connection_GetIoOperations(const Connection *conn) {
  return conn->ops;
}

unsigned connection_GetConnectionId(const Connection *conn) {
  parcAssertNotNull(conn, "Parameter conn must be non-null");
  return ioOperations_GetConnectionId(conn->ops);
}

const AddressPair *connection_GetAddressPair(const Connection *conn) {
  parcAssertNotNull(conn, "Parameter conn must be non-null");
  return ioOperations_GetAddressPair(conn->ops);
}

bool connection_IsUp(const Connection *conn) {
  parcAssertNotNull(conn, "Parameter conn must be non-null");
  if (!conn->ops) return false;
  return ioOperations_IsUp(conn->ops);
}

bool connection_IsLocal(const Connection *conn) {
  parcAssertNotNull(conn, "Parameter conn must be non-null");
  return ioOperations_IsLocal(conn->ops);
}

const void *connection_Class(const Connection *conn) {
  parcAssertNotNull(conn, "Parameter conn must be non-null");
  return ioOperations_Class(conn->ops);
}

bool connection_ReSend(const Connection *conn, Message *message,
                       bool notification) {
  parcAssertNotNull(conn, "Parameter conn must be non-null");
  parcAssertNotNull(message, "Parameter message must be non-null");
  bool res = false;

  if (connection_IsUp(conn)) {
    // here the wldr header is alreay set: this message is a retransmission or a
    // notification

    // we need to recompiute the path lable since we always store a pointer to
    // the same message if this message will be sent again to someonelse, the new
    // path label must be computed starting from the orignal labelorignal label.
    // Notice that we heve the same problem in case of PIT aggregation. That case
    // is handled insied the MessageProcessor. This is specific to WLDR
    // retransmittions. This is done only for data packets

    if (message_GetType(message) == MessagePacketType_ContentObject) {
      uint8_t connectionId = (uint8_t)connection_GetConnectionId(conn);
      uint32_t old_path_label = message_GetPathLabel(message);
      message_UpdatePathLabel(message, connectionId);

      res = ioOperations_Send(conn->ops, NULL, message);

      message_SetPathLabel(message, old_path_label);
    } else {
      res = ioOperations_Send(conn->ops, NULL, message);
    }
  }

  if (notification) {
    // the notification is never destroyed
    message_Release(&message);
  }

  return res;
}

void connection_AllowWldrAutoStart(Connection *conn, bool allow) {
  conn->wldrAutoStart = allow;
}

void connection_EnableWldr(Connection *conn) {
  if (!connection_IsLocal(conn)) {
    if (conn->wldr == NULL) {
      printf("----------------- enable wldr\n");
      conn->wldr = wldr_Init();
    }
  }
}

void connection_DisableWldr(Connection *conn) {
  if (!connection_IsLocal(conn)) {
    if (conn->wldr != NULL) {
      printf("----------------- disable wldr\n");
      wldr_Destroy(&(conn->wldr));
      conn->wldr = NULL;
    }
  }
}

bool connection_HasWldr(const Connection *conn) {
  if (conn->wldr == NULL) {
    return false;
  } else {
    return true;
  }
}

bool connection_WldrAutoStartAllowed(const Connection *conn) {
  return conn->wldrAutoStart;
}

void connection_DetectLosses(Connection *conn, Message *message) {
  if (conn->wldr != NULL) wldr_DetectLosses(conn->wldr, conn, message);
}

void connection_HandleWldrNotification(Connection *conn, Message *message) {
  if (conn->wldr != NULL)
    wldr_HandleWldrNotification(conn->wldr, conn, message);
}