/*
 * 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 <string.h>
#include <stdio.h>
#include <errno.h>

/* BLE */
#include "nimble/ble.h"
#include "host/ble_hs.h"
#include "host/ble_hs_adv.h"
#include "host/ble_uuid.h"
#include "host/ble_att.h"
#include "host/ble_gap.h"
#include "host/ble_gatt.h"
#include "host/ble_l2cap.h"
#include "host/ble_sm.h"
#include "controller/ble_ll.h"

/* RAM HCI transport. */
#include "transport/ram/ble_hci_ram.h"

/* Mandatory services. */
#include "services/gap/ble_svc_gap.h"
#include "services/gatt/ble_svc_gatt.h"

#include "bleuart/bleuart.h"

#include "nimble/nimble_port_tencentos_tiny.h"

static const char device_name[] = "Nimble Uart";

static int bleuart_gap_event(struct ble_gap_event *event, void *arg);

/**
 * Enables advertising with the following parameters:
 *     o General discoverable mode.
 *     o Undirected connectable mode.
 */
static void
bleuart_advertise(void)
{
    struct ble_gap_adv_params adv_params;
    struct ble_hs_adv_fields fields;
    int rc;

    /*
     *  Set the advertisement data included in our advertisements:
     *     o Flags (indicates advertisement type and other general info).
     *     o Advertising tx power.
     *     o 128 bit UUID
     */

    memset(&fields, 0, sizeof fields);

    /* Advertise two flags:
     *     o Discoverability in forthcoming advertisement (general)
     *     o BLE-only (BR/EDR unsupported).
     */
    fields.flags = BLE_HS_ADV_F_DISC_GEN |
                   BLE_HS_ADV_F_BREDR_UNSUP;

    /* Indicate that the TX power level field should be included; have the
     * stack fill this value automatically.  This is done by assiging the
     * special value BLE_HS_ADV_TX_PWR_LVL_AUTO.
     */
    fields.tx_pwr_lvl_is_present = 1;
    fields.tx_pwr_lvl = BLE_HS_ADV_TX_PWR_LVL_AUTO;

    fields.uuids128 = BLE_UUID128(&gatt_svr_svc_uart_uuid.u);
    fields.num_uuids128 = 1;
    fields.uuids128_is_complete = 1;

    rc = ble_gap_adv_set_fields(&fields);
    if (rc != 0) {
        return;
    }

    memset(&fields, 0, sizeof fields);
    fields.name = (uint8_t *)ble_svc_gap_device_name();
    fields.name_len = strlen((char *)fields.name);
    fields.name_is_complete = 1;

    rc = ble_gap_adv_rsp_set_fields(&fields);
    if (rc != 0) {
        return;
    }

    /* Begin advertising. */
    memset(&adv_params, 0, sizeof adv_params);
    adv_params.conn_mode = BLE_GAP_CONN_MODE_UND;
    adv_params.disc_mode = BLE_GAP_DISC_MODE_GEN;
    rc = ble_gap_adv_start(BLE_OWN_ADDR_PUBLIC, NULL, BLE_HS_FOREVER,
                           &adv_params, bleuart_gap_event, NULL);
    if (rc != 0) {
        return;
    }
}

/**
 * The nimble host executes this callback when a GAP event occurs.  The
 * application associates a GAP event callback with each connection that forms.
 * bleuart uses the same callback for all connections.
 *
 * @param event                 The type of event being signalled.
 * @param ctxt                  Various information pertaining to the event.
 * @param arg                   Application-specified argument; unuesd by
 *                                  bleuart.
 *
 * @return                      0 if the application successfully handled the
 *                                  event; nonzero on failure.  The semantics
 *                                  of the return code is specific to the
 *                                  particular GAP event being signalled.
 */
static int
bleuart_gap_event(struct ble_gap_event *event, void *arg)
{
    struct ble_gap_conn_desc desc;
    int rc;

    switch (event->type) {
    case BLE_GAP_EVENT_CONNECT:
        /* A new connection was established or a connection attempt failed. */
        if (event->connect.status == 0) {
            rc = ble_gap_conn_find(event->connect.conn_handle, &desc);
            assert(rc == 0);
            bleuart_set_conn_handle(event->connect.conn_handle);
        }

        if (event->connect.status != 0) {
            /* Connection failed; resume advertising. */
            bleuart_advertise();
        }
        return 0;

    case BLE_GAP_EVENT_DISCONNECT:
        /* Connection terminated; resume advertising. */
        bleuart_advertise();
        return 0;


    case BLE_GAP_EVENT_ADV_COMPLETE:
        /* Advertising terminated; resume advertising. */
        bleuart_advertise();
        return 0;

    case BLE_GAP_EVENT_REPEAT_PAIRING:
        /* We already have a bond with the peer, but it is attempting to
         * establish a new secure link.  This app sacrifices security for
         * convenience: just throw away the old bond and accept the new link.
         */

        /* Delete the old bond. */
        rc = ble_gap_conn_find(event->repeat_pairing.conn_handle, &desc);
        assert(rc == 0);
        ble_store_util_delete_peer(&desc.peer_id_addr);

        /* Return BLE_GAP_REPEAT_PAIRING_RETRY to indicate that the host should
         * continue with the pairing operation.
         */
        return BLE_GAP_REPEAT_PAIRING_RETRY;
    }

    return 0;
}

static void
bleuart_on_sync(void)
{
    /* Begin advertising. */
    bleuart_advertise();
}

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(device_name), device_name, ad, &ad_len);

    ble_gap_adv_set_data(ad, ad_len);
}

int ble_boot(void)
{
    int rc = 0;

    /* Initialize the BLE host. */
    ble_hs_cfg.sync_cb = bleuart_on_sync;
    ble_hs_cfg.store_status_cb = ble_store_util_status_rr;

    rc = bleuart_gatt_svr_init();
    assert(rc == 0);

    /* Set the default device name */
    rc = ble_svc_gap_device_name_set(device_name);
    assert(rc == 0);

    update_ad();

    /* run an event loop for handling the heart rate update events */
    extern void nimble_port_run(void);
    nimble_port_tencentos_tiny_init(nimble_port_run);

    return 0;
}

k_task_t ble_boot_task;
k_stack_t ble_boot_stack[512];

int main(void)
{
    board_init();

    /* Initialize OS */
    tos_knl_init();

    nimble_port_init();

    tos_task_create(&ble_boot_task, "boot", ble_boot, NULL,
                        4,
                        ble_boot_stack, sizeof(ble_boot_stack),
                        0);
    tos_knl_start();
}