/*
 * SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD
 *
 * SPDX-License-Identifier: Unlicense OR CC0-1.0
 */

#include "esp_log.h"
#include "nvs_flash.h"
/* BLE */
#include "nimble/nimble_port.h"
#include "nimble/nimble_port_freertos.h"
#include "host/ble_hs.h"
#include "host/util/util.h"
#include "console/console.h"
#include "services/gap/ble_svc_gap.h"
#include "services/gatt/ble_svc_gatt.h"
#include "ble_spp_server.h"
#include "driver/uart.h"

static const char *tag = "NimBLE_SPP_BLE_PRPH";
static int ble_spp_server_gap_event(struct ble_gap_event *event, void *arg);
static uint8_t own_addr_type;
int gatt_svr_register(void);
QueueHandle_t spp_common_uart_queue = NULL;
int connection_handle[CONFIG_BT_NIMBLE_MAX_CONNECTIONS + 1];
static uint16_t ble_spp_svc_gatt_read_val_handle;

void ble_store_config_init(void);

/**
 * Logs information about a connection to the console.
 */
static void
ble_spp_server_print_conn_desc(struct ble_gap_conn_desc *desc)
{
    MODLOG_DFLT(INFO, "handle=%d our_ota_addr_type=%d our_ota_addr=",
                desc->conn_handle, desc->our_ota_addr.type);
    print_addr(desc->our_ota_addr.val);
    MODLOG_DFLT(INFO, " our_id_addr_type=%d our_id_addr=",
                desc->our_id_addr.type);
    print_addr(desc->our_id_addr.val);
    MODLOG_DFLT(INFO, " peer_ota_addr_type=%d peer_ota_addr=",
                desc->peer_ota_addr.type);
    print_addr(desc->peer_ota_addr.val);
    MODLOG_DFLT(INFO, " peer_id_addr_type=%d peer_id_addr=",
                desc->peer_id_addr.type);
    print_addr(desc->peer_id_addr.val);
    MODLOG_DFLT(INFO, " conn_itvl=%d conn_latency=%d supervision_timeout=%d "
                "encrypted=%d authenticated=%d bonded=%d\n",
                desc->conn_itvl, desc->conn_latency,
                desc->supervision_timeout,
                desc->sec_state.encrypted,
                desc->sec_state.authenticated,
                desc->sec_state.bonded);
}

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

    /**
     *  Set the advertisement data included in our advertisements:
     *     o Flags (indicates advertisement type and other general info).
     *     o Advertising tx power.
     *     o Device name.
     *     o 16-bit service UUIDs (alert notifications).
     */

    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 assigning 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;

    name = ble_svc_gap_device_name();
    fields.name = (uint8_t *)name;
    fields.name_len = strlen(name);
    fields.name_is_complete = 1;

    fields.uuids16 = (ble_uuid16_t[]) {
        BLE_UUID16_INIT(BLE_SVC_SPP_UUID16)
    };
    fields.num_uuids16 = 1;
    fields.uuids16_is_complete = 1;

    rc = ble_gap_adv_set_fields(&fields);
    if (rc != 0) {
        MODLOG_DFLT(ERROR, "error setting advertisement data; rc=%d\n", rc);
        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(own_addr_type, NULL, BLE_HS_FOREVER,
                           &adv_params, ble_spp_server_gap_event, NULL);
    if (rc != 0) {
        MODLOG_DFLT(ERROR, "error enabling advertisement; rc=%d\n", rc);
        return;
    }
}

/**
 * The nimble host executes this callback when a GAP event occurs.  The
 * application associates a GAP event callback with each connection that forms.
 * ble_spp_server 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; unused by
 *                                  ble_spp_server.
 *
 * @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
ble_spp_server_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. */
        MODLOG_DFLT(INFO, "connection %s; status=%d ",
                    event->connect.status == 0 ? "established" : "failed",
                    event->connect.status);
        if (event->connect.status == 0) {
            rc = ble_gap_conn_find(event->connect.conn_handle, &desc);
            assert(rc == 0);
            ble_spp_server_print_conn_desc(&desc);
            connection_handle[event->connect.conn_handle] = event->connect.conn_handle;
        }
        MODLOG_DFLT(INFO, "\n");
        if (event->connect.status != 0 || CONFIG_BT_NIMBLE_MAX_CONNECTIONS > 1) {
            /* Connection failed or if multiple connection allowed; resume advertising. */
            ble_spp_server_advertise();
        }
        return 0;

    case BLE_GAP_EVENT_DISCONNECT:
        MODLOG_DFLT(INFO, "disconnect; reason=%d ", event->disconnect.reason);
        ble_spp_server_print_conn_desc(&event->disconnect.conn);
        MODLOG_DFLT(INFO, "\n");

        connection_handle[event->disconnect.conn.conn_handle] = -1;

        /* Connection terminated; resume advertising. */
        ble_spp_server_advertise();
        return 0;

    case BLE_GAP_EVENT_CONN_UPDATE:
        /* The central has updated the connection parameters. */
        MODLOG_DFLT(INFO, "connection updated; status=%d ",
                    event->conn_update.status);
        rc = ble_gap_conn_find(event->conn_update.conn_handle, &desc);
        assert(rc == 0);
        ble_spp_server_print_conn_desc(&desc);
        MODLOG_DFLT(INFO, "\n");
        return 0;

    case BLE_GAP_EVENT_ADV_COMPLETE:
        MODLOG_DFLT(INFO, "advertise complete; reason=%d",
                    event->adv_complete.reason);
        ble_spp_server_advertise();
        return 0;

    case BLE_GAP_EVENT_MTU:
        MODLOG_DFLT(INFO, "mtu update event; conn_handle=%d cid=%d mtu=%d\n",
                    event->mtu.conn_handle,
                    event->mtu.channel_id,
                    event->mtu.value);
        return 0;

    default:
        return 0;
    }
}

static void
ble_spp_server_on_reset(int reason)
{
    MODLOG_DFLT(ERROR, "Resetting state; reason=%d\n", reason);
}

static void
ble_spp_server_on_sync(void)
{
    int rc;

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

    /* Figure out address to use while advertising (no privacy for now) */
    rc = ble_hs_id_infer_auto(0, &own_addr_type);
    if (rc != 0) {
        MODLOG_DFLT(ERROR, "error determining address type; rc=%d\n", rc);
        return;
    }

    /* Printing ADDR */
    uint8_t addr_val[6] = {0};
    rc = ble_hs_id_copy_addr(own_addr_type, addr_val, NULL);

    MODLOG_DFLT(INFO, "Device Address: ");
    print_addr(addr_val);
    MODLOG_DFLT(INFO, "\n");
    /* Begin advertising. */
    ble_spp_server_advertise();
}

void ble_spp_server_host_task(void *param)
{
    ESP_LOGI(tag, "BLE Host Task Started");
    /* This function will return only when nimble_port_stop() is executed */
    nimble_port_run();

    nimble_port_freertos_deinit();
}

/* Callback function for custom service */
static int  ble_svc_gatt_handler(uint16_t conn_handle, uint16_t attr_handle, struct ble_gatt_access_ctxt *ctxt, void *arg)
{
    switch (ctxt->op) {
    case BLE_GATT_ACCESS_OP_READ_CHR:
        ESP_LOGI(tag, "Callback for read");
        break;

    case BLE_GATT_ACCESS_OP_WRITE_CHR:
        ESP_LOGI(tag, "Data received in write event,conn_handle = %x,attr_handle = %x", conn_handle, attr_handle);
        break;

    default:
        ESP_LOGI(tag, "\nDefault Callback");
        break;
    }
    return 0;
}

/* Define new custom service */
static const struct ble_gatt_svc_def new_ble_svc_gatt_defs[] = {
    {
        /*** Service: SPP */
        .type = BLE_GATT_SVC_TYPE_PRIMARY,
        .uuid = BLE_UUID16_DECLARE(BLE_SVC_SPP_UUID16),
        .characteristics = (struct ble_gatt_chr_def[])
        { {
                /* Support SPP service */
                .uuid = BLE_UUID16_DECLARE(BLE_SVC_SPP_CHR_UUID16),
                .access_cb = ble_svc_gatt_handler,
                .val_handle = &ble_spp_svc_gatt_read_val_handle,
                .flags = BLE_GATT_CHR_F_READ | BLE_GATT_CHR_F_WRITE | BLE_GATT_CHR_F_NOTIFY | BLE_GATT_CHR_F_INDICATE,
            }, {
                0, /* No more characteristics */
            }
        },
    },
    {
        0, /* No more services. */
    },
};

static void
gatt_svr_register_cb(struct ble_gatt_register_ctxt *ctxt, void *arg)
{
    char buf[BLE_UUID_STR_LEN];

    switch (ctxt->op) {
    case BLE_GATT_REGISTER_OP_SVC:
        MODLOG_DFLT(DEBUG, "registered service %s with handle=%d\n",
                    ble_uuid_to_str(ctxt->svc.svc_def->uuid, buf),
                    ctxt->svc.handle);
        break;

    case BLE_GATT_REGISTER_OP_CHR:
        MODLOG_DFLT(DEBUG, "registering characteristic %s with "
                    "def_handle=%d val_handle=%d\n",
                    ble_uuid_to_str(ctxt->chr.chr_def->uuid, buf),
                    ctxt->chr.def_handle,
                    ctxt->chr.val_handle);
        break;

    case BLE_GATT_REGISTER_OP_DSC:
        MODLOG_DFLT(DEBUG, "registering descriptor %s with handle=%d\n",
                    ble_uuid_to_str(ctxt->dsc.dsc_def->uuid, buf),
                    ctxt->dsc.handle);
        break;

    default:
        assert(0);
        break;
    }
}

int gatt_svr_init(void)
{
    int rc = 0;
    ble_svc_gap_init();
    ble_svc_gatt_init();

    rc = ble_gatts_count_cfg(new_ble_svc_gatt_defs);

    if (rc != 0) {
        return rc;
    }

    rc = ble_gatts_add_svcs(new_ble_svc_gatt_defs);
    if (rc != 0) {
        return rc;
    }

    return 0;
}


void ble_server_uart_task(void *pvParameters)
{
    ESP_LOGI(tag, "BLE server UART_task started\n");
    uart_event_t event;
    int rc = 0;
    for (;;) {
        //Waiting for UART event.
        if (xQueueReceive(spp_common_uart_queue, (void * )&event, (TickType_t)portMAX_DELAY))            {
            switch (event.type) {
            //Event of UART receving data
            case UART_DATA:
                if (event.size) {
                    static uint8_t ntf[1];
                    ntf[0] = 90;
                    for ( int i = 0; i <= CONFIG_BT_NIMBLE_MAX_CONNECTIONS; i++) {
                        if (connection_handle[i] != -1) {
                            struct os_mbuf *txom;
                            txom = ble_hs_mbuf_from_flat(ntf, sizeof(ntf));
                            rc = ble_gatts_notify_custom(connection_handle[i],
                                                         ble_spp_svc_gatt_read_val_handle,
                                                         txom);
                            if ( rc == 0 ) {
                                ESP_LOGI(tag, "Notification sent successfully");
                            } else {
                                ESP_LOGI(tag, "Error in sending notification rc = %d", rc);
                            }
                        }
                    }
                }
                break;
            default:
                break;
            }
        }
    }
    vTaskDelete(NULL);
}
static void ble_spp_uart_init(void)
{
    uart_config_t uart_config = {
        .baud_rate = 115200,
        .data_bits = UART_DATA_8_BITS,
        .parity = UART_PARITY_DISABLE,
        .stop_bits = UART_STOP_BITS_1,
        .flow_ctrl = UART_HW_FLOWCTRL_RTS,
        .rx_flow_ctrl_thresh = 122,
        .source_clk = UART_SCLK_DEFAULT,
    };
    //Install UART driver, and get the queue.
    uart_driver_install(UART_NUM_0, 4096, 8192, 10, &spp_common_uart_queue, 0);
    //Set UART parameters
    uart_param_config(UART_NUM_0, &uart_config);
    //Set UART pins
    uart_set_pin(UART_NUM_0, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE);
    xTaskCreate(ble_server_uart_task, "uTask", 4096, (void *)UART_NUM_0, 8, NULL);
}


void
app_main(void)
{
    int rc;

    /* Initialize NVS — it is used to store PHY calibration data */
    esp_err_t ret = nvs_flash_init();
    if (ret == ESP_ERR_NVS_NO_FREE_PAGES || ret == ESP_ERR_NVS_NEW_VERSION_FOUND) {
        ESP_ERROR_CHECK(nvs_flash_erase());
        ret = nvs_flash_init();
    }
    ESP_ERROR_CHECK(ret);

    ret = nimble_port_init();
    if (ret != ESP_OK) {
        MODLOG_DFLT(ERROR, "Failed to init nimble %d \n", ret);
        return;
    }

    /* Initialize connection_handle array */
    for (int i = 0; i <= CONFIG_BT_NIMBLE_MAX_CONNECTIONS; i++) {
        connection_handle[i] = -1;
    }

    /* Initialize uart driver and start uart task */
    ble_spp_uart_init();

    /* Initialize the NimBLE host configuration. */
    ble_hs_cfg.reset_cb = ble_spp_server_on_reset;
    ble_hs_cfg.sync_cb = ble_spp_server_on_sync;
    ble_hs_cfg.gatts_register_cb = gatt_svr_register_cb;
    ble_hs_cfg.store_status_cb = ble_store_util_status_rr;

    ble_hs_cfg.sm_io_cap = CONFIG_EXAMPLE_IO_TYPE;
#ifdef CONFIG_EXAMPLE_BONDING
    ble_hs_cfg.sm_bonding = 1;
#endif
#ifdef CONFIG_EXAMPLE_MITM
    ble_hs_cfg.sm_mitm = 1;
#endif
#ifdef CONFIG_EXAMPLE_USE_SC
    ble_hs_cfg.sm_sc = 1;
#else
    ble_hs_cfg.sm_sc = 0;
#endif
#ifdef CONFIG_EXAMPLE_BONDING
    ble_hs_cfg.sm_our_key_dist = 1;
    ble_hs_cfg.sm_their_key_dist = 1;
#endif

    /* Register custom service */
    rc = gatt_svr_init();
    assert(rc == 0);

    /* Set the default device name. */
    rc = ble_svc_gap_device_name_set("nimble-ble-spp-svr");
    assert(rc == 0);

    /* XXX Need to have template for store */
    ble_store_config_init();

    nimble_port_freertos_init(ble_spp_server_host_task);
}