text: /*
   * Copyright (C) 2017 BlueKitchen GmbH
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. Neither the name of the copyright holders nor the names of
   *    contributors may be used to endorse or promote products derived
   *    from this software without specific prior written permission.
   * 4. Any redistribution, use, or modification is done solely for
   *    personal benefit and not for any commercial purpose or for
   *    monetary gain.
   *
   * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
   * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
   * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
   * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
   * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
   * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
   * Please inquire about commercial licensing options at 
   * contact@bluekitchen-gmbh.com
   *
   */
  
  #define __BTSTACK_FILE__ "hid_host_demo.c"
  
  /*
   * hid_host_demo.c
   */
  
  /* EXAMPLE_START(hid_host_demo): HID Host Demo
   *
   * @text This example implements an HID Host. For now, it connnects to a fixed device, queries the HID SDP
   * record and opens the HID Control + Interrupt channels
   */
  
  #include <inttypes.h>
  #include <stdio.h>
  
  #include "btstack_config.h"
  #include "btstack.h"
  
  #define MAX_ATTRIBUTE_VALUE_SIZE 300
  
  // SDP
  static uint8_t            hid_descriptor[MAX_ATTRIBUTE_VALUE_SIZE];
  static uint16_t           hid_descriptor_len;
  
  static uint16_t           hid_control_psm;
  static uint16_t           hid_interrupt_psm;
  
  static uint8_t            attribute_value[MAX_ATTRIBUTE_VALUE_SIZE];
  static const unsigned int attribute_value_buffer_size = MAX_ATTRIBUTE_VALUE_SIZE;
  
  // L2CAP
  static uint16_t           l2cap_hid_control_cid;
  static uint16_t           l2cap_hid_interrupt_cid;
  
  // MBP 2016
  static const char * remote_addr_string = "00-1F-20-86-DF-52";
  // iMpulse static const char * remote_addr_string = "64:6E:6C:C1:AA:B5";
  
  static bd_addr_t remote_addr;
  
  static btstack_packet_callback_registration_t hci_event_callback_registration;
  
  // Needed for queries
      typedef enum {
      HID_HOST_IDLE,
      HID_HOST_CONTROL_CONNECTION_ESTABLISHED,
      HID_HOST_W2_REQUEST_OUTPUT_REPORT
  } hid_host_state_t;
  
  static hid_host_state_t hid_host_state = HID_HOST_IDLE;
  
  // Simplified US Keyboard with Shift modifier
  
  #define CHAR_ILLEGAL     0xff
  #define CHAR_RETURN     '\n'
  #define CHAR_ESCAPE      27
  #define CHAR_TAB         '\t'
  #define CHAR_BACKSPACE   0x7f
  
  /**
   * English (US)
   */
  static const uint8_t keytable_us_none [] = {
      CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /*   0-3 */
      'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',                   /*  4-13 */
      'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't',                   /* 14-23 */
      'u', 'v', 'w', 'x', 'y', 'z',                                       /* 24-29 */
      '1', '2', '3', '4', '5', '6', '7', '8', '9', '0',                   /* 30-39 */
      CHAR_RETURN, CHAR_ESCAPE, CHAR_BACKSPACE, CHAR_TAB, ' ',            /* 40-44 */
      '-', '=', '[', ']', '\\', CHAR_ILLEGAL, ';', '\'', 0x60, ',',       /* 45-54 */
      '.', '/', CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,   /* 55-60 */
      CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 61-64 */
      CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 65-68 */
      CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 69-72 */
      CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 73-76 */
      CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 77-80 */
      CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 81-84 */
      '*', '-', '+', '\n', '1', '2', '3', '4', '5',                       /* 85-97 */
      '6', '7', '8', '9', '0', '.', 0xa7,                                 /* 97-100 */
  }; 
  
  static const uint8_t keytable_us_shift[] = {
      CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /*  0-3  */
      'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',                   /*  4-13 */
      'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',                   /* 14-23 */
      'U', 'V', 'W', 'X', 'Y', 'Z',                                       /* 24-29 */
      '!', '@', '#', '$', '%', '^', '&', '*', '(', ')',                   /* 30-39 */
      CHAR_RETURN, CHAR_ESCAPE, CHAR_BACKSPACE, CHAR_TAB, ' ',            /* 40-44 */
      '_', '+', '{', '}', '|', CHAR_ILLEGAL, ':', '"', 0x7E, '<',         /* 45-54 */
      '>', '?', CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,   /* 55-60 */
      CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 61-64 */
      CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 65-68 */
      CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 69-72 */
      CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 73-76 */
      CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 77-80 */
      CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 81-84 */
      '*', '-', '+', '\n', '1', '2', '3', '4', '5',                       /* 85-97 */
      '6', '7', '8', '9', '0', '.', 0xb1,                                 /* 97-100 */
  }; 
  
  
  /* @section Main application configuration
   *
   * @text In the application configuration, L2CAP is initialized 
   */
  
  /* LISTING_START(PanuSetup): Panu setup */
  static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
  static void handle_sdp_client_query_result(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
  
  static void hid_host_setup(void){
  
      // Initialize L2CAP 
      l2cap_init();
  
      // register for HCI events
      hci_event_callback_registration.callback = &packet_handler;
      hci_add_event_handler(&hci_event_callback_registration);
  
      // Disable stdout buffering
      setbuf(stdout, NULL);
  }
  /* LISTING_END */
  
  /* @section SDP parser callback 
   * 
   * @text The SDP parsers retrieves the BNEP PAN UUID as explained in  
   * Section [on SDP BNEP Query example](#sec:sdpbnepqueryExample}.
   */
  
  
  static void handle_sdp_client_query_result(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) {
  
      UNUSED(packet_type);
      UNUSED(channel);
      UNUSED(size);
  
      des_iterator_t attribute_list_it;
      des_iterator_t additional_des_it;
      des_iterator_t prot_it;
      uint8_t       *des_element;
      uint8_t       *element;
      uint32_t       uuid;
      uint8_t        status;
  
      switch (hci_event_packet_get_type(packet)){
          case SDP_EVENT_QUERY_ATTRIBUTE_VALUE:
              if (sdp_event_query_attribute_byte_get_attribute_length(packet) <= attribute_value_buffer_size) {
                  attribute_value[sdp_event_query_attribute_byte_get_data_offset(packet)] = sdp_event_query_attribute_byte_get_data(packet);
                  if ((uint16_t)(sdp_event_query_attribute_byte_get_data_offset(packet)+1) == sdp_event_query_attribute_byte_get_attribute_length(packet)) {
                      switch(sdp_event_query_attribute_byte_get_attribute_id(packet)) {
                          case BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST:
                              for (des_iterator_init(&attribute_list_it, attribute_value); des_iterator_has_more(&attribute_list_it); des_iterator_next(&attribute_list_it)) {                                    
                                  if (des_iterator_get_type(&attribute_list_it) != DE_DES) continue;
                                  des_element = des_iterator_get_element(&attribute_list_it);
                                  des_iterator_init(&prot_it, des_element);
                                  element = des_iterator_get_element(&prot_it);
                                  if (de_get_element_type(element) != DE_UUID) continue;
                                  uuid = de_get_uuid32(element);
                                  switch (uuid){
                                      case BLUETOOTH_PROTOCOL_L2CAP:
                                          if (!des_iterator_has_more(&prot_it)) continue;
                                          des_iterator_next(&prot_it);
                                          de_element_get_uint16(des_iterator_get_element(&prot_it), &hid_control_psm);
                                          printf("HID Control PSM: 0x%04x\n", (int) hid_control_psm);
                                          break;
                                      default:
                                          break;
                                  }
                              }
                              break;
                          case BLUETOOTH_ATTRIBUTE_ADDITIONAL_PROTOCOL_DESCRIPTOR_LISTS:
                              for (des_iterator_init(&attribute_list_it, attribute_value); des_iterator_has_more(&attribute_list_it); des_iterator_next(&attribute_list_it)) {                                    
                                  if (des_iterator_get_type(&attribute_list_it) != DE_DES) continue;
                                  des_element = des_iterator_get_element(&attribute_list_it);
                                  for (des_iterator_init(&additional_des_it, des_element); des_iterator_has_more(&additional_des_it); des_iterator_next(&additional_des_it)) {                                    
                                      if (des_iterator_get_type(&additional_des_it) != DE_DES) continue;
                                      des_element = des_iterator_get_element(&additional_des_it);
                                      des_iterator_init(&prot_it, des_element);
                                      element = des_iterator_get_element(&prot_it);
                                      if (de_get_element_type(element) != DE_UUID) continue;
                                      uuid = de_get_uuid32(element);
                                      switch (uuid){
                                          case BLUETOOTH_PROTOCOL_L2CAP:
                                              if (!des_iterator_has_more(&prot_it)) continue;
                                              des_iterator_next(&prot_it);
                                              de_element_get_uint16(des_iterator_get_element(&prot_it), &hid_interrupt_psm);
                                              printf("HID Interrupt PSM: 0x%04x\n", (int) hid_interrupt_psm);
                                              break;
                                          default:
                                              break;
                                      }
                                  }
                              }
                              break;
                          case BLUETOOTH_ATTRIBUTE_HID_DESCRIPTOR_LIST:
                              for (des_iterator_init(&attribute_list_it, attribute_value); des_iterator_has_more(&attribute_list_it); des_iterator_next(&attribute_list_it)) {
                                  if (des_iterator_get_type(&attribute_list_it) != DE_DES) continue;
                                  des_element = des_iterator_get_element(&attribute_list_it);
                                  for (des_iterator_init(&additional_des_it, des_element); des_iterator_has_more(&additional_des_it); des_iterator_next(&additional_des_it)) {                                    
                                      if (des_iterator_get_type(&additional_des_it) != DE_STRING) continue;
                                      element = des_iterator_get_element(&additional_des_it);
                                      const uint8_t * descriptor = de_get_string(element);
                                      hid_descriptor_len = de_get_data_size(element);
                                      memcpy(hid_descriptor, descriptor, hid_descriptor_len);
                                      printf("HID Descriptor:\n");
                                      printf_hexdump(hid_descriptor, hid_descriptor_len);
                                  }
                              }                        
                              break;
                          default:
                              break;
                      }
                  }
              } else {
                  fprintf(stderr, "SDP attribute value buffer size exceeded: available %d, required %d\n", attribute_value_buffer_size, sdp_event_query_attribute_byte_get_attribute_length(packet));
              }
              break;
              
          case SDP_EVENT_QUERY_COMPLETE:
              if (!hid_control_psm) {
                  printf("HID Control PSM missing\n");
                  break;
              }
              if (!hid_interrupt_psm) {
                  printf("HID Interrupt PSM missing\n");
                  break;
              }
              printf("Setup HID\n");
              status = l2cap_create_channel(packet_handler, remote_addr, hid_control_psm, 48, &l2cap_hid_control_cid);
              if (status){
                  printf("Connecting to HID Control failed: 0x%02x\n", status);
              }
              break;
      }
  }
  
  
  /*
   * @section HID Report Handler
   * 
   * @text Use BTstack's compact HID Parser to process incoming HID Report
   * Iterate over all fields and process fields with usage page = 0x07 / Keyboard
   * Check if SHIFT is down and process first character (don't handle multiple key presses)
   * 
   */
  #define NUM_KEYS 6
  static uint8_t last_keys[NUM_KEYS];
  static void hid_host_handle_interrupt_report(const uint8_t * report, uint16_t report_len){
      // check if HID Input Report
      if (report_len < 1) return;
      if (*report != 0xa1) return; 
      report++;
      report_len--;
      btstack_hid_parser_t parser;
      btstack_hid_parser_init(&parser, hid_descriptor, hid_descriptor_len, BTSTACK_HID_REPORT_TYPE_INPUT, report, report_len);
      int shift = 0;
      uint8_t new_keys[NUM_KEYS];
      memset(new_keys, 0, sizeof(new_keys));
      int     new_keys_count = 0;
      while (btstack_hid_parser_has_more(&parser)){
          uint16_t usage_page;
          uint16_t usage;
          int32_t  value;
          btstack_hid_parser_get_field(&parser, &usage_page, &usage, &value);
          if (usage_page != 0x07) continue;   
          switch (usage){
              case 0xe1:
              case 0xe6:
                  if (value){
                      shift = 1;
                  }
                  continue;
              case 0x00:
                  continue;
              default:
                  break;
          }
          if (usage >= sizeof(keytable_us_none)) continue;
  
          // store new keys
          new_keys[new_keys_count++] = usage;
  
          // check if usage was used last time (and ignore in that case)
          int i;
          for (i=0;i<NUM_KEYS;i++){
              if (usage == last_keys[i]){
                  usage = 0;
              }
          }
          if (usage == 0) continue;
  
          uint8_t key;
          if (shift){
              key = keytable_us_shift[usage];
          } else {
              key = keytable_us_none[usage];
          }
          if (key == CHAR_ILLEGAL) continue;
          if (key == CHAR_BACKSPACE){ 
              printf("\b \b");    // go back one char, print space, go back one char again
              continue;
          }
          printf("%c", key);
      }
      memcpy(last_keys, new_keys, NUM_KEYS);
  }
  
  /*
   * @section Packet Handler
   * 
   * @text The packet handler responds to various HCI Events.
   */
  
  /* LISTING_START(packetHandler): Packet Handler */
  static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)
  {
      /* LISTING_PAUSE */
      uint8_t   event;
      bd_addr_t event_addr;
      uint8_t   status;
      uint16_t  l2cap_cid;
  
      /* LISTING_RESUME */
      switch (packet_type) {
  		case HCI_EVENT_PACKET:
              event = hci_event_packet_get_type(packet);
              switch (event) {            
                  /* @text When BTSTACK_EVENT_STATE with state HCI_STATE_WORKING
                   * is received and the example is started in client mode, the remote SDP HID query is started.
                   */
                  case BTSTACK_EVENT_STATE:
                      if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){
                          printf("Start SDP HID query for remote HID Device.\n");
                          sdp_client_query_uuid16(&handle_sdp_client_query_result, remote_addr, BLUETOOTH_SERVICE_CLASS_HUMAN_INTERFACE_DEVICE_SERVICE);
                      }
                      break;
  
                  /* LISTING_PAUSE */
                  case HCI_EVENT_PIN_CODE_REQUEST:
  					// inform about pin code request
                      printf("Pin code request - using '0000'\n");
                      hci_event_pin_code_request_get_bd_addr(packet, event_addr);
                      gap_pin_code_response(event_addr, "0000");
  					break;
  
                  case HCI_EVENT_USER_CONFIRMATION_REQUEST:
                      // inform about user confirmation request
                      printf("SSP User Confirmation Request with numeric value '%"PRIu32"'\n", little_endian_read_32(packet, 8));
                      printf("SSP User Confirmation Auto accept\n");
                      break;
  
                  /* LISTING_RESUME */
  
                  case L2CAP_EVENT_CHANNEL_OPENED: 
                      status = packet[2];
                      if (status){
                          printf("L2CAP Connection failed: 0x%02x\n", status);
                          break;
                      }
                      l2cap_cid  = little_endian_read_16(packet, 13);
                      if (!l2cap_cid) break;
                      if (l2cap_cid == l2cap_hid_control_cid){
                          status = l2cap_create_channel(packet_handler, remote_addr, hid_interrupt_psm, 48, &l2cap_hid_interrupt_cid);
                          if (status){
                              printf("Connecting to HID Control failed: 0x%02x\n", status);
                              break;
                          }
                          hid_host_state = HID_HOST_CONTROL_CONNECTION_ESTABLISHED;
                      }                        
                      if (l2cap_cid == l2cap_hid_interrupt_cid){
                          printf("HID Connection established\n");
                      }
                      break;
                  case L2CAP_EVENT_CAN_SEND_NOW:
                      switch(hid_host_state){
                          case HID_HOST_W2_REQUEST_OUTPUT_REPORT:{
                              uint8_t header = (HID_MESSAGE_TYPE_GET_REPORT << 4) | HID_REPORT_TYPE_OUTPUT;
                              uint8_t report_id = 0x01;
                              uint8_t report[] = { header, report_id };
                              l2cap_send(l2cap_hid_control_cid, (uint8_t*) report, sizeof(report));
                              break;
                          }
                          default:
                              break;
                      }
                  default:
                      break;
              }
              break;
          case L2CAP_DATA_PACKET:
              // for now, just dump incoming data
              if (channel == l2cap_hid_interrupt_cid){
                  hid_host_handle_interrupt_report(packet,  size);
              } else if (channel == l2cap_hid_control_cid){
                  printf("\nHID Control: ");
                  printf_hexdump(packet, size);
              } else {
                  break;
              }
          default:
              break;
      }
  }
  /* LISTING_END */
  
  
  static uint8_t hid_host_get_output_report(uint16_t control_cid){
      if (hid_host_state != HID_HOST_CONTROL_CONNECTION_ESTABLISHED) return 0;
  
      hid_host_state = HID_HOST_W2_REQUEST_OUTPUT_REPORT;
      l2cap_request_can_send_now_event(control_cid);
      return ERROR_CODE_SUCCESS;
  }
  
  static void show_usage(void){
      bd_addr_t      iut_address;
      gap_local_bd_addr(iut_address);
      printf("\n--- Bluetooth HID Host Test Console %s ---\n", bd_addr_to_str(iut_address));
      printf("o      - get output report\n");
      printf("Ctrl-c - exit\n");
      printf("---\n");
  }
  
  static void stdin_process(char cmd){
      uint8_t status = ERROR_CODE_SUCCESS;
      switch (cmd){
          case 'o':
              printf("Get output report from %s\n", remote_addr_string);
              status = hid_host_get_output_report(l2cap_hid_control_cid);
              break;
          case '\n':
          case '\r':
              break;
          default:
              show_usage();
              break;
      }
      if (status != ERROR_CODE_SUCCESS){
          printf("HID host cmd \'%c\' failed, status 0x%02x\n", cmd, status);
      }
  }
  
  int btstack_main(int argc, const char * argv[]);
  int btstack_main(int argc, const char * argv[]){
  
      (void)argc;
      (void)argv;
  
      hid_host_setup();
  
      // parse human readable Bluetooth address
      sscanf_bd_addr(remote_addr_string, remote_addr);
      btstack_stdin_setup(stdin_process);
      // Turn on the device 
      hci_power_control(HCI_POWER_ON);
      return 0;
  }
  
  /* EXAMPLE_END */
  