/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 <stdbool.h>
#include <stdint.h>

#include "nimble/nimble_port.h"
#include "host/ble_hs.h"
#include "host/util/util.h"
#include "services/gap/ble_svc_gap.h"

static const char gap_name[] = "nimble";

static uint8_t own_addr_type;

static void start_advertise(void);

static void
put_ad(uint8_t ad_type, uint8_t ad_len, const void *ad, uint8_t *buf,
       uint8_t *len)
{
    buf[(*len)++] = ad_len + 1;
    buf[(*len)++] = ad_type;

    memcpy(&buf[*len], ad, ad_len);

    *len += ad_len;
}

static void
update_ad(void)
{
    uint8_t ad[BLE_HS_ADV_MAX_SZ];
    uint8_t ad_len = 0;
    uint8_t ad_flags = BLE_HS_ADV_F_DISC_GEN | BLE_HS_ADV_F_BREDR_UNSUP;

    put_ad(BLE_HS_ADV_TYPE_FLAGS, 1, &ad_flags, ad, &ad_len);
    put_ad(BLE_HS_ADV_TYPE_COMP_NAME, sizeof(gap_name), gap_name, ad, &ad_len);

    ble_gap_adv_set_data(ad, ad_len);
}

static int
gap_event_cb(struct ble_gap_event *event, void *arg)
{
    switch (event->type) {
    case BLE_GAP_EVENT_CONNECT:
        if (event->connect.status) {
            start_advertise();
        }
        break;

    case BLE_GAP_EVENT_DISCONNECT:
        start_advertise();
        break;
    }

    return 0;
}

static void
start_advertise(void)
{
    struct ble_gap_adv_params advp;
    int rc;

    printf("advertise\n");

    update_ad();

    memset(&advp, 0, sizeof advp);
    advp.conn_mode = BLE_GAP_CONN_MODE_UND;
    advp.disc_mode = BLE_GAP_DISC_MODE_GEN;
    rc = ble_gap_adv_start(own_addr_type, NULL, BLE_HS_FOREVER,
                           &advp, gap_event_cb, NULL);
    assert(rc == 0);
}

static void
app_ble_sync_cb(void)
{
    int rc;
    ble_addr_t addr;

    /* generate new non-resolvable private address */

    rc = ble_hs_id_gen_rnd(1, &addr);
    assert(rc == 0);

    /* set generated address */

    rc = ble_hs_id_set_rnd(addr.val);
    assert(rc == 0);

    rc = ble_hs_util_ensure_addr(0);
    assert(rc == 0);

    rc = ble_hs_id_infer_auto(0, &own_addr_type);
    assert(rc == 0);

    start_advertise();
}

void
nimble_host_task(void *param)
{
    ble_hs_cfg.sync_cb = app_ble_sync_cb;

    ble_svc_gap_device_name_set(gap_name);

    nimble_port_run();
}