/******************************************************************************
 *
 *  Copyright (C) 2014 Google, Inc.
 *
 *  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 <assert.h>

#include "osi/include/allocator.h"
#include "bt_types.h"
#include "buffer_allocator.h"
#include "hcidefs.h"
#include "hcimsgs.h"
#include "hci_internals.h"
#include "hci_layer.h"
#include "hci_packet_factory.h"

static const allocator_t *buffer_allocator;

static BT_HDR *make_packet(size_t data_size);
static BT_HDR *make_command_no_params(uint16_t opcode);
static BT_HDR *make_command(uint16_t opcode, size_t parameter_size, uint8_t **stream_out);

// Interface functions

static BT_HDR *make_reset(void) {
  return make_command_no_params(HCI_RESET);
}

static BT_HDR *make_read_buffer_size(void) {
  return make_command_no_params(HCI_READ_BUFFER_SIZE);
}

static BT_HDR *make_host_buffer_size(uint16_t acl_size, uint8_t sco_size, uint16_t acl_count, uint16_t sco_count) {
  uint8_t *stream;
  const uint8_t parameter_size = 2 + 1 + 2 + 2; // from each of the parameters
  BT_HDR *packet = make_command(HCI_HOST_BUFFER_SIZE, parameter_size, &stream);

  UINT16_TO_STREAM(stream, acl_size);
  UINT8_TO_STREAM(stream, sco_size);
  UINT16_TO_STREAM(stream, acl_count);
  UINT16_TO_STREAM(stream, sco_count);
  return packet;
}

static BT_HDR *make_read_local_version_info(void) {
  return make_command_no_params(HCI_READ_LOCAL_VERSION_INFO);
}

static BT_HDR *make_read_bd_addr(void) {
  return make_command_no_params(HCI_READ_BD_ADDR);
}

static BT_HDR *make_read_local_supported_commands(void) {
  return make_command_no_params(HCI_READ_LOCAL_SUPPORTED_CMDS);
}

static BT_HDR *make_read_local_extended_features(uint8_t page_number) {
  uint8_t *stream;
  const uint8_t parameter_size = 1;
  BT_HDR *packet = make_command(HCI_READ_LOCAL_EXT_FEATURES, parameter_size, &stream);

  UINT8_TO_STREAM(stream, page_number);
  return packet;
}

static BT_HDR *make_write_simple_pairing_mode(uint8_t mode) {
  uint8_t *stream;
  const uint8_t parameter_size = 1;
  BT_HDR *packet = make_command(HCI_WRITE_SIMPLE_PAIRING_MODE, parameter_size, &stream);

  UINT8_TO_STREAM(stream, mode);
  return packet;
}

static BT_HDR *make_write_secure_connections_host_support(uint8_t mode) {
  uint8_t *stream;
  const uint8_t parameter_size = 1;
  BT_HDR *packet = make_command(HCI_WRITE_SECURE_CONNS_SUPPORT, parameter_size, &stream);

  UINT8_TO_STREAM(stream, mode);
  return packet;
}

static BT_HDR *make_set_event_mask(const bt_event_mask_t *event_mask) {
  uint8_t *stream;
  uint8_t parameter_size = sizeof(bt_event_mask_t);
  BT_HDR *packet = make_command(HCI_SET_EVENT_MASK, parameter_size, &stream);

  ARRAY8_TO_STREAM(stream, event_mask->as_array);
  return packet;
}

static BT_HDR *make_ble_write_host_support(uint8_t supported_host, uint8_t simultaneous_host) {
  uint8_t *stream;
  const uint8_t parameter_size = 1 + 1;
  BT_HDR *packet = make_command(HCI_WRITE_LE_HOST_SUPPORT, parameter_size, &stream);

  UINT8_TO_STREAM(stream, supported_host);
  UINT8_TO_STREAM(stream, simultaneous_host);
  return packet;
}

static BT_HDR *make_ble_read_white_list_size(void) {
  return make_command_no_params(HCI_BLE_READ_WHITE_LIST_SIZE);
}

static BT_HDR *make_ble_read_buffer_size(void) {
  return make_command_no_params(HCI_BLE_READ_BUFFER_SIZE);
}

static BT_HDR *make_ble_read_supported_states(void) {
  return make_command_no_params(HCI_BLE_READ_SUPPORTED_STATES);
}

static BT_HDR *make_ble_read_local_supported_features(void) {
  return make_command_no_params(HCI_BLE_READ_LOCAL_SPT_FEAT);
}

static BT_HDR *make_ble_read_resolving_list_size(void) {
  return make_command_no_params(HCI_BLE_READ_RESOLVING_LIST_SIZE);
}

static BT_HDR *make_ble_read_suggested_default_data_length(void) {
    return make_command_no_params(HCI_BLE_READ_DEFAULT_DATA_LENGTH);
}

static BT_HDR *make_ble_set_event_mask(const bt_event_mask_t *event_mask) {
  uint8_t *stream;
  uint8_t parameter_size = sizeof(bt_event_mask_t);
  BT_HDR *packet = make_command(HCI_BLE_SET_EVENT_MASK, parameter_size, &stream);

  ARRAY8_TO_STREAM(stream, event_mask->as_array);
  return packet;
}

// Internal functions

static BT_HDR *make_command_no_params(uint16_t opcode) {
  return make_command(opcode, 0, NULL);
}

static BT_HDR *make_command(uint16_t opcode, size_t parameter_size, uint8_t **stream_out) {
  BT_HDR *packet = make_packet(HCI_COMMAND_PREAMBLE_SIZE + parameter_size);

  uint8_t *stream = packet->data;
  UINT16_TO_STREAM(stream, opcode);
  UINT8_TO_STREAM(stream, parameter_size);

  if (stream_out != NULL)
    *stream_out = stream;

  return packet;
}

static BT_HDR *make_packet(size_t data_size) {
  BT_HDR *ret = (BT_HDR *)buffer_allocator->alloc(sizeof(BT_HDR) + data_size);
  assert(ret);
  ret->event = 0;
  ret->offset = 0;
  ret->layer_specific = 0;
  ret->len = data_size;
  return ret;
}

static const hci_packet_factory_t interface = {
  make_reset,
  make_read_buffer_size,
  make_host_buffer_size,
  make_read_local_version_info,
  make_read_bd_addr,
  make_read_local_supported_commands,
  make_read_local_extended_features,
  make_write_simple_pairing_mode,
  make_write_secure_connections_host_support,
  make_set_event_mask,
  make_ble_write_host_support,
  make_ble_read_white_list_size,
  make_ble_read_buffer_size,
  make_ble_read_supported_states,
  make_ble_read_local_supported_features,
  make_ble_read_resolving_list_size,
  make_ble_read_suggested_default_data_length,
  make_ble_set_event_mask
};

const hci_packet_factory_t *hci_packet_factory_get_interface() {
  buffer_allocator = buffer_allocator_get_interface();
  return &interface;
}