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

/****************************************************************************
*
* This file is for bt_spp_vfs_initiator demo. It can discovery servers, connect one device and send data.
* run bt_spp_vfs_initiator demo, the bt_spp_vfs_initiator demo will automatically connect the bt_spp_vfs_acceptor demo,
* then send data.
*
****************************************************************************/

#include <stdint.h>
#include <string.h>
#include <stdbool.h>
#include <stdio.h>
#include "nvs.h"
#include "nvs_flash.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_log.h"
#include "esp_bt.h"
#include "esp_bt_main.h"
#include "esp_gap_bt_api.h"
#include "esp_bt_device.h"
#include "esp_spp_api.h"
#include "spp_task.h"

#include "time.h"
#include "sys/time.h"

#include "esp_vfs.h"
#include "sys/unistd.h"

#define SPP_TAG "SPP_INITIATOR_DEMO"
#define EXAMPLE_DEVICE_NAME "ESP_SPP_INITIATOR"

static const esp_spp_mode_t esp_spp_mode = ESP_SPP_MODE_VFS;

static const esp_spp_sec_t sec_mask = ESP_SPP_SEC_AUTHENTICATE;
static const esp_spp_role_t role_master = ESP_SPP_ROLE_MASTER;

static esp_bd_addr_t peer_bd_addr;
static uint8_t peer_bdname_len;
static char peer_bdname[ESP_BT_GAP_MAX_BDNAME_LEN + 1];
static const char remote_device_name[] = "ESP_SPP_ACCEPTOR";
static const esp_bt_inq_mode_t inq_mode = ESP_BT_INQ_MODE_GENERAL_INQUIRY;
static const uint8_t inq_len = 30;
static const uint8_t inq_num_rsps = 0;

#define SPP_DATA_LEN 20

static char *bda2str(uint8_t * bda, char *str, size_t size)
{
    if (bda == NULL || str == NULL || size < 18) {
        return NULL;
    }

    uint8_t *p = bda;
    sprintf(str, "%02x:%02x:%02x:%02x:%02x:%02x",
            p[0], p[1], p[2], p[3], p[4], p[5]);
    return str;
}

static void spp_write_handle(void * param)
{
    int size = 0;
    int fd = (int)param;
    uint8_t *spp_data = NULL;
    uint16_t i = 0;

    spp_data = malloc(SPP_DATA_LEN);
    if (!spp_data) {
        ESP_LOGE(SPP_TAG, "malloc spp_data failed, fd:%d", fd);
        goto done;
    }

    for (i = 0; i < SPP_DATA_LEN; ++i) {
        spp_data[i] = i;
    }

    do {
        /*
         * The write function is blocked until all the target length of data has been sent to the lower layer
         * successfully an error occurs.
         */
        size = write(fd, spp_data, SPP_DATA_LEN);
        if (size == -1) {
            break;
        } else if ( size == 0) {
            /*write fail due to ringbuf is full, retry after 500 ms*/
            vTaskDelay(500 / portTICK_PERIOD_MS);
        } else {
            ESP_LOGI(SPP_TAG, "fd = %d  data_len = %d", fd, size);
            vTaskDelay(10 / portTICK_PERIOD_MS);
        }
    } while (1);
done:
    if (spp_data) {
        free(spp_data);
    }
    spp_wr_task_shut_down();
}

static bool get_name_from_eir(uint8_t *eir, char *bdname, uint8_t *bdname_len)
{
    uint8_t *rmt_bdname = NULL;
    uint8_t rmt_bdname_len = 0;

    if (!eir) {
        return false;
    }

    rmt_bdname = esp_bt_gap_resolve_eir_data(eir, ESP_BT_EIR_TYPE_CMPL_LOCAL_NAME, &rmt_bdname_len);
    if (!rmt_bdname) {
        rmt_bdname = esp_bt_gap_resolve_eir_data(eir, ESP_BT_EIR_TYPE_SHORT_LOCAL_NAME, &rmt_bdname_len);
    }

    if (rmt_bdname) {
        if (rmt_bdname_len > ESP_BT_GAP_MAX_BDNAME_LEN) {
            rmt_bdname_len = ESP_BT_GAP_MAX_BDNAME_LEN;
        }

        if (bdname) {
            memcpy(bdname, rmt_bdname, rmt_bdname_len);
            bdname[rmt_bdname_len] = '\0';
        }
        if (bdname_len) {
            *bdname_len = rmt_bdname_len;
        }
        return true;
    }

    return false;
}

static void esp_spp_cb(uint16_t e, void *p)
{
    esp_spp_cb_event_t event = e;
    esp_spp_cb_param_t *param = p;
    uint8_t i = 0;
    char bda_str[18] = {0};

    switch (event) {
    case ESP_SPP_INIT_EVT:
        if (param->init.status == ESP_SPP_SUCCESS) {
            ESP_LOGI(SPP_TAG, "ESP_SPP_INIT_EVT");
            /* Enable SPP VFS mode */
            esp_spp_vfs_register();
            esp_bt_dev_set_device_name(EXAMPLE_DEVICE_NAME);
            esp_bt_gap_set_scan_mode(ESP_BT_CONNECTABLE, ESP_BT_GENERAL_DISCOVERABLE);
            esp_bt_gap_start_discovery(inq_mode, inq_len, inq_num_rsps);
        } else {
            ESP_LOGE(SPP_TAG, "ESP_SPP_INIT_EVT status:%d", param->init.status);
        }
        break;
    case ESP_SPP_DISCOVERY_COMP_EVT:
        if (param->disc_comp.status == ESP_SPP_SUCCESS) {
            ESP_LOGI(SPP_TAG, "ESP_SPP_DISCOVERY_COMP_EVT scn_num:%d", param->disc_comp.scn_num);
            for (i = 0; i < param->disc_comp.scn_num; i++) {
                ESP_LOGI(SPP_TAG, "-- [%d] scn:%d service_name:%s", i, param->disc_comp.scn[i],
                         param->disc_comp.service_name[i]);
            }
            /* We only connect to the first found server on the remote SPP acceptor here */
            esp_spp_connect(sec_mask, role_master, param->disc_comp.scn[0], peer_bd_addr);
        } else {
            ESP_LOGE(SPP_TAG, "ESP_SPP_DISCOVERY_COMP_EVT status=%d", param->disc_comp.status);
        }
        break;
    case ESP_SPP_OPEN_EVT:
        if (param->open.status == ESP_SPP_SUCCESS) {
            ESP_LOGI(SPP_TAG, "ESP_SPP_OPEN_EVT handle:%d fd:%d rem_bda:[%s]", param->open.handle, param->open.fd,
                     bda2str(param->open.rem_bda, bda_str, sizeof(bda_str)));
            spp_wr_task_start_up(spp_write_handle, param->open.fd);
        } else {
            ESP_LOGE(SPP_TAG, "ESP_SPP_OPEN_EVT status:%d", param->open.status);
        }
        break;
    case ESP_SPP_CLOSE_EVT:
        ESP_LOGI(SPP_TAG, "ESP_SPP_CLOSE_EVT status:%d handle:%d close_by_remote:%d", param->close.status,
                 param->close.handle, param->close.async);
        break;
    case ESP_SPP_START_EVT:
        ESP_LOGI(SPP_TAG, "ESP_SPP_START_EVT");
        break;
    case ESP_SPP_CL_INIT_EVT:
        if (param->cl_init.status == ESP_SPP_SUCCESS) {
            ESP_LOGI(SPP_TAG, "ESP_SPP_CL_INIT_EVT handle:%d sec_id:%d", param->cl_init.handle, param->cl_init.sec_id);
        } else {
            ESP_LOGE(SPP_TAG, "ESP_SPP_CL_INIT_EVT status:%d", param->cl_init.status);
        }
        break;
    case ESP_SPP_SRV_OPEN_EVT:
        ESP_LOGI(SPP_TAG, "ESP_SPP_SRV_OPEN_EVT");
        break;
    default:
        break;
    }
}

static void esp_bt_gap_cb(esp_bt_gap_cb_event_t event, esp_bt_gap_cb_param_t *param)
{
    switch(event){
    case ESP_BT_GAP_DISC_RES_EVT:
        ESP_LOGI(SPP_TAG, "ESP_BT_GAP_DISC_RES_EVT");
        esp_log_buffer_hex(SPP_TAG, param->disc_res.bda, ESP_BD_ADDR_LEN);
        /* Find the target peer device name in the EIR data */
        for (int i = 0; i < param->disc_res.num_prop; i++){
            if (param->disc_res.prop[i].type == ESP_BT_GAP_DEV_PROP_EIR
                && get_name_from_eir(param->disc_res.prop[i].val, peer_bdname, &peer_bdname_len)){
                esp_log_buffer_char(SPP_TAG, peer_bdname, peer_bdname_len);
                if (strlen(remote_device_name) == peer_bdname_len
                    && strncmp(peer_bdname, remote_device_name, peer_bdname_len) == 0) {
                    memcpy(peer_bd_addr, param->disc_res.bda, ESP_BD_ADDR_LEN);
                    /* Have found the target peer device, cancel the previous GAP discover procedure. And go on
                     * dsicovering the SPP service on the peer device */
                    esp_bt_gap_cancel_discovery();
                    esp_spp_start_discovery(peer_bd_addr);
                }
            }
        }
        break;
    case ESP_BT_GAP_DISC_STATE_CHANGED_EVT:
        ESP_LOGI(SPP_TAG, "ESP_BT_GAP_DISC_STATE_CHANGED_EVT");
        break;
    case ESP_BT_GAP_RMT_SRVCS_EVT:
        ESP_LOGI(SPP_TAG, "ESP_BT_GAP_RMT_SRVCS_EVT");
        break;
    case ESP_BT_GAP_RMT_SRVC_REC_EVT:
        ESP_LOGI(SPP_TAG, "ESP_BT_GAP_RMT_SRVC_REC_EVT");
        break;
    case ESP_BT_GAP_AUTH_CMPL_EVT:{
        if (param->auth_cmpl.stat == ESP_BT_STATUS_SUCCESS) {
            ESP_LOGI(SPP_TAG, "authentication success: %s", param->auth_cmpl.device_name);
            esp_log_buffer_hex(SPP_TAG, param->auth_cmpl.bda, ESP_BD_ADDR_LEN);
        } else {
            ESP_LOGE(SPP_TAG, "authentication failed, status:%d", param->auth_cmpl.stat);
        }
        break;
    }
    case ESP_BT_GAP_PIN_REQ_EVT:{
        ESP_LOGI(SPP_TAG, "ESP_BT_GAP_PIN_REQ_EVT min_16_digit:%d", param->pin_req.min_16_digit);
        if (param->pin_req.min_16_digit) {
            ESP_LOGI(SPP_TAG, "Input pin code: 0000 0000 0000 0000");
            esp_bt_pin_code_t pin_code = {0};
            esp_bt_gap_pin_reply(param->pin_req.bda, true, 16, pin_code);
        } else {
            ESP_LOGI(SPP_TAG, "Input pin code: 1234");
            esp_bt_pin_code_t pin_code;
            pin_code[0] = '1';
            pin_code[1] = '2';
            pin_code[2] = '3';
            pin_code[3] = '4';
            esp_bt_gap_pin_reply(param->pin_req.bda, true, 4, pin_code);
        }
        break;
    }

#if (CONFIG_BT_SSP_ENABLED == true)
    case ESP_BT_GAP_CFM_REQ_EVT:
        ESP_LOGI(SPP_TAG, "ESP_BT_GAP_CFM_REQ_EVT Please compare the numeric value: %d", param->cfm_req.num_val);
        esp_bt_gap_ssp_confirm_reply(param->cfm_req.bda, true);
        break;
    case ESP_BT_GAP_KEY_NOTIF_EVT:
        ESP_LOGI(SPP_TAG, "ESP_BT_GAP_KEY_NOTIF_EVT passkey:%d", param->key_notif.passkey);
        break;
    case ESP_BT_GAP_KEY_REQ_EVT:
        ESP_LOGI(SPP_TAG, "ESP_BT_GAP_KEY_REQ_EVT Please enter passkey!");
        break;
#endif

    case ESP_BT_GAP_MODE_CHG_EVT:
        ESP_LOGI(SPP_TAG, "ESP_BT_GAP_MODE_CHG_EVT mode:%d", param->mode_chg.mode);
        break;

    default:
        break;
    }
}

static void esp_spp_stack_cb(esp_spp_cb_event_t event, esp_spp_cb_param_t *param)
{
    /* To avoid stucking Bluetooth stack, we dispatch the SPP callback event to the other lower priority task */
    spp_task_work_dispatch(esp_spp_cb, event, param, sizeof(esp_spp_cb_param_t), NULL);
}

void app_main(void)
{
    esp_err_t ret = ESP_OK;
    char bda_str[18] = {0};

    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 );

    ESP_ERROR_CHECK(esp_bt_controller_mem_release(ESP_BT_MODE_BLE));

    esp_bt_controller_config_t bt_cfg = BT_CONTROLLER_INIT_CONFIG_DEFAULT();
    if (esp_bt_controller_init(&bt_cfg) != ESP_OK) {
        ESP_LOGE(SPP_TAG, "%s initialize controller failed", __func__);
        return;
    }

    if (esp_bt_controller_enable(ESP_BT_MODE_CLASSIC_BT) != ESP_OK) {
        ESP_LOGE(SPP_TAG, "%s enable controller failed", __func__);
        return;
    }

    if (esp_bluedroid_init() != ESP_OK) {
        ESP_LOGE(SPP_TAG, "%s initialize bluedroid failed", __func__);
        return;
    }

    if (esp_bluedroid_enable() != ESP_OK) {
        ESP_LOGE(SPP_TAG, "%s enable bluedroid failed", __func__);
        return;
    }

    if (esp_bt_gap_register_callback(esp_bt_gap_cb) != ESP_OK) {
        ESP_LOGE(SPP_TAG, "%s gap register failed", __func__);
        return;
    }

    if (esp_spp_register_callback(esp_spp_stack_cb) != ESP_OK) {
        ESP_LOGE(SPP_TAG, "%s spp register failed", __func__);
        return;
    }

    spp_task_task_start_up();
    if (esp_spp_init(esp_spp_mode) != ESP_OK) {
        ESP_LOGE(SPP_TAG, "%s spp init failed", __func__);
        return;
    }

#if (CONFIG_BT_SSP_ENABLED == true)
    /* Set default parameters for Secure Simple Pairing */
    esp_bt_sp_param_t param_type = ESP_BT_SP_IOCAP_MODE;
    esp_bt_io_cap_t iocap = ESP_BT_IO_CAP_IO;
    esp_bt_gap_set_security_param(param_type, &iocap, sizeof(uint8_t));
#endif

    /*
     * Set default parameters for Legacy Pairing
     * Use variable pin, input pin code when pairing
     */
    esp_bt_pin_type_t pin_type = ESP_BT_PIN_TYPE_VARIABLE;
    esp_bt_pin_code_t pin_code;
    esp_bt_gap_set_pin(pin_type, 0, pin_code);

    ESP_LOGI(SPP_TAG, "Own address:[%s]", bda2str((uint8_t *)esp_bt_dev_get_address(), bda_str, sizeof(bda_str)));
}
