/*
 * Copyright (C) 2014 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__ "le_streamer_client.c"

/*
 * le_streamer_client.c
 */

// *****************************************************************************
/* EXAMPLE_START(le_streamer_client): Connects to 'LE Streamer' and subscribes to test characteristic
 */
// *****************************************************************************

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

#include "btstack.h"

// prototypes
static void handle_gatt_client_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);

typedef enum {
    TC_OFF,
    TC_IDLE,
    TC_W4_SCAN_RESULT,
    TC_W4_CONNECT,
    TC_W4_SERVICE_RESULT,
    TC_W4_CHARACTERISTIC_RX_RESULT,
    TC_W4_CHARACTERISTIC_TX_RESULT,
    TC_W4_ENABLE_NOTIFICATIONS_COMPLETE,
    TC_W4_TEST_DATA
} gc_state_t;

static bd_addr_t cmdline_addr;
static int cmdline_addr_found = 0;

// addr and type of device with correct name
static bd_addr_t      le_streamer_addr;
static bd_addr_type_t le_streamer_addr_type;

static hci_con_handle_t connection_handle;

// On the GATT Server, RX Characteristic is used for receive data via Write, and TX Characteristic is used to send data via Notifications
static uint8_t le_streamer_service_uuid[16]           = { 0x00, 0x00, 0xFF, 0x10, 0x00, 0x00, 0x10, 0x00, 0x80, 0x00, 0x00, 0x80, 0x5F, 0x9B, 0x34, 0xFB};
static uint8_t le_streamer_characteristic_rx_uuid[16] = { 0x00, 0x00, 0xFF, 0x11, 0x00, 0x00, 0x10, 0x00, 0x80, 0x00, 0x00, 0x80, 0x5F, 0x9B, 0x34, 0xFB};
static uint8_t le_streamer_characteristic_tx_uuid[16] = { 0x00, 0x00, 0xFF, 0x12, 0x00, 0x00, 0x10, 0x00, 0x80, 0x00, 0x00, 0x80, 0x5F, 0x9B, 0x34, 0xFB};

static gatt_client_service_t le_streamer_service;
static gatt_client_characteristic_t le_streamer_characteristic_rx;
static gatt_client_characteristic_t le_streamer_characteristic_tx;

static gatt_client_notification_t notification_listener;
static int listener_registered;

static gc_state_t state = TC_OFF;
static btstack_packet_callback_registration_t hci_event_callback_registration;

/*
 * @section Track throughput
 * @text We calculate the throughput by setting a start time and measuring the amount of 
 * data sent. After a configurable REPORT_INTERVAL_MS, we print the throughput in kB/s
 * and reset the counter and start time.
 */

/* LISTING_START(tracking): Tracking throughput */

#define TEST_MODE_WRITE_WITHOUT_RESPONSE 1
#define TEST_MODE_ENABLE_NOTIFICATIONS   2
#define TEST_MODE_DUPLEX                 3

// configure test mode: send only, receive only, full duplex
#define TEST_MODE TEST_MODE_DUPLEX

#define REPORT_INTERVAL_MS 3000

// support for multiple clients
typedef struct {
    char name;
    int le_notification_enabled;
    int  counter;
    char test_data[200];
    int  test_data_len;
    uint32_t test_data_sent;
    uint32_t test_data_start;
} le_streamer_connection_t;

static le_streamer_connection_t le_streamer_connection;

static void test_reset(le_streamer_connection_t * context){
    context->test_data_start = btstack_run_loop_get_time_ms();
    context->test_data_sent = 0;
}

static void test_track_data(le_streamer_connection_t * context, int bytes_sent){
    context->test_data_sent += bytes_sent;
    // evaluate
    uint32_t now = btstack_run_loop_get_time_ms();
    uint32_t time_passed = now - context->test_data_start;
    if (time_passed < REPORT_INTERVAL_MS) return;
    // print speed
    int bytes_per_second = context->test_data_sent * 1000 / time_passed;
    printf("%c: %"PRIu32" bytes -> %u.%03u kB/s\n", context->name, context->test_data_sent, bytes_per_second / 1000, bytes_per_second % 1000);

    // restart
    context->test_data_start = now;
    context->test_data_sent  = 0;
}
/* LISTING_END(tracking): Tracking throughput */


// stramer
static void streamer(le_streamer_connection_t * context){
    if (connection_handle == HCI_CON_HANDLE_INVALID) return;

    // create test data
    context->counter++;
    if (context->counter > 'Z') context->counter = 'A';
    memset(context->test_data, context->counter, context->test_data_len);

    // send
    uint8_t status = gatt_client_write_value_of_characteristic_without_response(connection_handle, le_streamer_characteristic_rx.value_handle, context->test_data_len, (uint8_t*) context->test_data);
    if (status){
        printf("error %02x for write without response!\n", status);
        return;
    } else {
        test_track_data(&le_streamer_connection, context->test_data_len);
    }

    // request again
    gatt_client_request_can_write_without_response_event(handle_gatt_client_event, connection_handle);
}


// returns 1 if name is found in advertisement
static int advertisement_report_contains_name(const char * name, uint8_t * advertisement_report){
    // get advertisement from report event
    const uint8_t * adv_data = gap_event_advertising_report_get_data(advertisement_report);
    uint16_t        adv_len  = gap_event_advertising_report_get_data_length(advertisement_report);
    int             name_len = strlen(name);

    // iterate over advertisement data
    ad_context_t context;
    for (ad_iterator_init(&context, adv_len, adv_data) ; ad_iterator_has_more(&context) ; ad_iterator_next(&context)){
        uint8_t data_type    = ad_iterator_get_data_type(&context);
        uint8_t data_size    = ad_iterator_get_data_len(&context);
        const uint8_t * data = ad_iterator_get_data(&context);
        int i;
        switch (data_type){
            case BLUETOOTH_DATA_TYPE_SHORTENED_LOCAL_NAME:
            case BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME:
                // compare common prefix
                for (i=0; i<data_size && i<name_len;i++){
                    if (data[i] != name[i]) break;
                }
                // prefix match
                return 1;
            default:
                break;
        }
    }
    return 0;
}

static void handle_gatt_client_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
    UNUSED(packet_type);
    UNUSED(channel);
    UNUSED(size);

    uint16_t mtu;
    switch(state){
        case TC_W4_SERVICE_RESULT:
            switch(hci_event_packet_get_type(packet)){
                case GATT_EVENT_SERVICE_QUERY_RESULT:
                    // store service (we expect only one)
                    gatt_event_service_query_result_get_service(packet, &le_streamer_service);
                    break;
                case GATT_EVENT_QUERY_COMPLETE:
                    if (packet[4] != 0){
                        printf("SERVICE_QUERY_RESULT - Error status %x.\n", packet[4]);
                        gap_disconnect(connection_handle);
                        break;  
                    } 
                    // service query complete, look for characteristic
                    state = TC_W4_CHARACTERISTIC_RX_RESULT;
                    printf("Search for LE Streamer RX characteristic.\n");
                    gatt_client_discover_characteristics_for_service_by_uuid128(handle_gatt_client_event, connection_handle, &le_streamer_service, le_streamer_characteristic_rx_uuid);
                    break;
                default:
                    break;
            }
            break;
            
        case TC_W4_CHARACTERISTIC_RX_RESULT:
            switch(hci_event_packet_get_type(packet)){
                case GATT_EVENT_CHARACTERISTIC_QUERY_RESULT:
                    gatt_event_characteristic_query_result_get_characteristic(packet, &le_streamer_characteristic_rx);
                    break;
                case GATT_EVENT_QUERY_COMPLETE:
                    if (packet[4] != 0){
                        printf("CHARACTERISTIC_QUERY_RESULT - Error status %x.\n", packet[4]);
                        gap_disconnect(connection_handle);
                        break;  
                    } 
                    // rx characteristiic found, look for tx characteristic
                    state = TC_W4_CHARACTERISTIC_TX_RESULT;
                    printf("Search for LE Streamer TX characteristic.\n");
                    gatt_client_discover_characteristics_for_service_by_uuid128(handle_gatt_client_event, connection_handle, &le_streamer_service, le_streamer_characteristic_tx_uuid);
                    break;
                default:
                    break;
            }
            break;

        case TC_W4_CHARACTERISTIC_TX_RESULT:
            switch(hci_event_packet_get_type(packet)){
                case GATT_EVENT_CHARACTERISTIC_QUERY_RESULT:
                    gatt_event_characteristic_query_result_get_characteristic(packet, &le_streamer_characteristic_tx);
                    break;
                case GATT_EVENT_QUERY_COMPLETE:
                    if (packet[4] != 0){
                        printf("CHARACTERISTIC_QUERY_RESULT - Error status %x.\n", packet[4]);
                        gap_disconnect(connection_handle);
                        break;  
                    } 
                    // register handler for notifications
                    listener_registered = 1;
                    gatt_client_listen_for_characteristic_value_updates(&notification_listener, handle_gatt_client_event, connection_handle, &le_streamer_characteristic_tx);
                    // setup tracking
                    le_streamer_connection.name = 'A';
                    le_streamer_connection.test_data_len = ATT_DEFAULT_MTU - 3;
                    test_reset(&le_streamer_connection);
                    gatt_client_get_mtu(connection_handle, &mtu);
                    le_streamer_connection.test_data_len = btstack_min(mtu - 3, sizeof(le_streamer_connection.test_data));
                    printf("%c: ATT MTU = %u => use test data of len %u\n", le_streamer_connection.name, mtu, le_streamer_connection.test_data_len);
                    // enable notifications
#if (TEST_MODE & TEST_MODE_ENABLE_NOTIFICATIONS)
                    printf("Start streaming - enable notify on test characteristic.\n");
                    state = TC_W4_ENABLE_NOTIFICATIONS_COMPLETE;
                    gatt_client_write_client_characteristic_configuration(handle_gatt_client_event, connection_handle,
                        &le_streamer_characteristic_tx, GATT_CLIENT_CHARACTERISTICS_CONFIGURATION_NOTIFICATION);
                    break;
#endif
                    state = TC_W4_TEST_DATA;
#if (TEST_MODE & TEST_MODE_WRITE_WITHOUT_RESPONSE)
                    printf("Start streaming - request can send now.\n");
                    gatt_client_request_can_write_without_response_event(handle_gatt_client_event, connection_handle);
#endif
                    break;
                default:
                    break;
            }
            break;

        case TC_W4_ENABLE_NOTIFICATIONS_COMPLETE:
            switch(hci_event_packet_get_type(packet)){
                case GATT_EVENT_QUERY_COMPLETE:
                    printf("Notifications enabled, ATT status %02x\n", gatt_event_query_complete_get_att_status(packet));
                    if (gatt_event_query_complete_get_att_status(packet) != ATT_ERROR_SUCCESS) break;
                    state = TC_W4_TEST_DATA;
#if (TEST_MODE & TEST_MODE_WRITE_WITHOUT_RESPONSE)
                    printf("Start streaming - request can send now.\n");
                    gatt_client_request_can_write_without_response_event(handle_gatt_client_event, connection_handle);
#endif
                    break;
                default:
                    break;
            }
            break;

        case TC_W4_TEST_DATA:
            switch(hci_event_packet_get_type(packet)){
                case GATT_EVENT_NOTIFICATION:
                    test_track_data(&le_streamer_connection, gatt_event_notification_get_value_length(packet));
                    break;
                case GATT_EVENT_QUERY_COMPLETE:
                    break;
                case GATT_EVENT_CAN_WRITE_WITHOUT_RESPONSE:
                    streamer(&le_streamer_connection);
                    break;
                default:
                    printf("Unknown packet type %x\n", hci_event_packet_get_type(packet));
                    break;
            }
            break;

        default:
            printf("error\n");
            break;
    }
    
}

// Either connect to remote specified on command line or start scan for device with "LE Streamer" in advertisement
static void le_streamer_client_start(void){
    if (cmdline_addr_found){
        printf("Connect to %s\n", bd_addr_to_str(cmdline_addr));
        state = TC_W4_CONNECT;
        gap_connect(cmdline_addr, 0);
    } else {
        printf("Start scanning!\n");
        state = TC_W4_SCAN_RESULT;
        gap_set_scan_parameters(0,0x0030, 0x0030);
        gap_start_scan();
    }
}

static void hci_event_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
    UNUSED(channel);
    UNUSED(size);

    if (packet_type != HCI_EVENT_PACKET) return;
    
    uint16_t conn_interval;
    uint8_t event = hci_event_packet_get_type(packet);
    switch (event) {
        case BTSTACK_EVENT_STATE:
            // BTstack activated, get started
            if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING) {
                le_streamer_client_start();
            } else {
                state = TC_OFF;
            }
            break;
        case GAP_EVENT_ADVERTISING_REPORT:
            if (state != TC_W4_SCAN_RESULT) return;
            // check name in advertisement
            if (!advertisement_report_contains_name("LE Streamer", packet)) return;
            // store address and type
            gap_event_advertising_report_get_address(packet, le_streamer_addr);
            le_streamer_addr_type = gap_event_advertising_report_get_address_type(packet);
            // stop scanning, and connect to the device
            state = TC_W4_CONNECT;
            gap_stop_scan();
            printf("Stop scan. Connect to device with addr %s.\n", bd_addr_to_str(le_streamer_addr));
            gap_connect(le_streamer_addr,le_streamer_addr_type);
            break;
        case HCI_EVENT_LE_META:
            // wait for connection complete
            if (hci_event_le_meta_get_subevent_code(packet) !=  HCI_SUBEVENT_LE_CONNECTION_COMPLETE) break;
            if (state != TC_W4_CONNECT) return;
            connection_handle = hci_subevent_le_connection_complete_get_connection_handle(packet);
            // print connection parameters (without using float operations)
            conn_interval = hci_subevent_le_connection_complete_get_conn_interval(packet);
            printf("Connection Interval: %u.%02u ms\n", conn_interval * 125 / 100, 25 * (conn_interval & 3));
            printf("Connection Latency: %u\n", hci_subevent_le_connection_complete_get_conn_latency(packet));  
            // initialize gatt client context with handle, and add it to the list of active clients
            // query primary services
            printf("Search for LE Streamer service.\n");
            state = TC_W4_SERVICE_RESULT;
            gatt_client_discover_primary_services_by_uuid128(handle_gatt_client_event, connection_handle, le_streamer_service_uuid);
            break;
        case HCI_EVENT_DISCONNECTION_COMPLETE:
            // unregister listener
            connection_handle = HCI_CON_HANDLE_INVALID;
            if (listener_registered){
                listener_registered = 0;
                gatt_client_stop_listening_for_characteristic_value_updates(&notification_listener);
            }
            if (cmdline_addr_found){
                printf("Disconnected %s\n", bd_addr_to_str(cmdline_addr));
                return;
            }
            printf("Disconnected %s\n", bd_addr_to_str(le_streamer_addr));
            if (state == TC_OFF) break;
            le_streamer_client_start();
            break;
        default:
            break;
    }
}

#ifdef HAVE_BTSTACK_STDIN
static void usage(const char *name){
    fprintf(stderr, "Usage: %s [-a|--address aa:bb:cc:dd:ee:ff]\n", name);
    fprintf(stderr, "If no argument is provided, LE Streamer Client will start scanning and connect to the first device named 'LE Streamer'.\n");
    fprintf(stderr, "To connect to a specific device use argument [-a].\n\n");
}
#endif

int btstack_main(int argc, const char * argv[]);
int btstack_main(int argc, const char * argv[]){

#ifdef HAVE_BTSTACK_STDIN
    int arg = 1;
    cmdline_addr_found = 0;
    
    while (arg < argc) {
        if(!strcmp(argv[arg], "-a") || !strcmp(argv[arg], "--address")){
            arg++;
            cmdline_addr_found = sscanf_bd_addr(argv[arg], cmdline_addr);
            arg++;
            if (!cmdline_addr_found) exit(1);
            continue;
        }
        usage(argv[0]);
        return 0;
    }
#else
    (void)argc;
    (void)argv;
#endif
    l2cap_init();

    sm_init();
    sm_set_io_capabilities(IO_CAPABILITY_NO_INPUT_NO_OUTPUT);

    // sm_init needed before gatt_client_init
    gatt_client_init();

    hci_event_callback_registration.callback = &hci_event_handler;
    hci_add_event_handler(&hci_event_callback_registration);

    // use different connection parameters: conn interval min/max (* 1.25 ms), slave latency, supervision timeout, CE len min/max (* 0.6125 ms) 
    // gap_set_connection_parameters(0x06, 0x06, 4, 1000, 0x01, 0x06 * 2);

    // turn on!
    hci_power_control(HCI_POWER_ON);

    return 0;
}
/* EXAMPLE_END */