/*
 * SPDX-FileCopyrightText: 2021-2024 Espressif Systems (Shanghai) CO LTD
 *
 * SPDX-License-Identifier: Unlicense OR CC0-1.0
 */
#include < stdint.h>
#include < string.h>
#include < stdbool.h>
#include < stdio.h>
#include < inttypes.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 "driver/uart.h"

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

#define SPP_TAG "SPP_ACCEPTOR_DEMO"
#define SPP_SERVER_NAME "SPP_SERVER"
#define SPP_SHOW_DATA 0
#define SPP_SHOW_SPEED 1
// Выберите, что отображать: данные (0) или скорость (1):
#define SPP_SHOW_MODE SPP_SHOW_SPEED

// Настройки UART для моста Bluetooth SPP < - > TTL UART:
// UART2, порты TX/RX, 9600 8N1, no flow control
#define UART_BRIDGE_PORT        UART_NUM_2
#define UART_BRIDGE_TX_GPIO     17
#define UART_BRIDGE_RX_GPIO     16
#define UART_BRIDGE_BAUD_RATE   9600
#define UART_BRIDGE_RX_BUF_SIZE 1024
#define UART_BRIDGE_TX_BUF_SIZE 1024
#define UART_BRIDGE_CHUNK       256
#define UART_BRIDGE_QUEUE_LEN   8

typedef struct {
    uint8_t data[UART_BRIDGE_CHUNK];
    size_t len;
} uart_bridge_item_t;

static const char local_device_name[] = CONFIG_EXAMPLE_LOCAL_DEVICE_NAME;
static const esp_spp_mode_t esp_spp_mode = ESP_SPP_MODE_CB;
static const bool esp_spp_enable_l2cap_ertm = true;

static struct timeval time_new, time_old;
static long data_num = 0;

static const esp_spp_sec_t sec_mask = ESP_SPP_SEC_AUTHENTICATE;
static const esp_spp_role_t role_slave = ESP_SPP_ROLE_SLAVE;

static QueueHandle_t spp_to_uart_queue = NULL;
static uint32_t spp_conn_handle = 0;
static volatile bool spp_connected = false;
static volatile bool spp_congested = false;

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 print_speed(void)
{
    float time_old_s = time_old.tv_sec + time_old.tv_usec / 1000000.0;
    float time_new_s = time_new.tv_sec + time_new.tv_usec / 1000000.0;
    float time_interval = time_new_s - time_old_s;
    float speed = data_num * 8 / time_interval / 1000.0;
    ESP_LOGI(SPP_TAG, "speed(%fs ~ %fs): %f kbit/s" , time_old_s, time_new_s, speed);
    data_num = 0;
    time_old.tv_sec = time_new.tv_sec;
    time_old.tv_usec = time_new.tv_usec;
}

static void esp_spp_cb(esp_spp_cb_event_t event, esp_spp_cb_param_t *param)
{
    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");
            esp_spp_start_srv(sec_mask, role_slave, 0, SPP_SERVER_NAME);
        } else {
            ESP_LOGE(SPP_TAG, "ESP_SPP_INIT_EVT status:%d", param->init.status);
        }
        break;
    case ESP_SPP_DISCOVERY_COMP_EVT:
        ESP_LOGI(SPP_TAG, "ESP_SPP_DISCOVERY_COMP_EVT");
        break;
    case ESP_SPP_OPEN_EVT:
        ESP_LOGI(SPP_TAG, "ESP_SPP_OPEN_EVT handle:%"PRIu32, param->open.handle);
        spp_conn_handle = param->open.handle;
        spp_congested = false;
        spp_connected = true;
        break;
    case ESP_SPP_CLOSE_EVT:
        ESP_LOGI(SPP_TAG, "ESP_SPP_CLOSE_EVT status:%d handle:%"PRIu32" close_by_remote:%d",
                 param->close.status, param->close.handle, param->close.async);
        spp_connected = false;
        spp_congested = false;
        spp_conn_handle = 0;
        break;
    case ESP_SPP_START_EVT:
        if (param->start.status == ESP_SPP_SUCCESS) {
            ESP_LOGI(SPP_TAG, "ESP_SPP_START_EVT handle:%"PRIu32" sec_id:%d scn:%d",
                     param->start.handle, param->start.sec_id, param->start.scn);
            esp_bt_gap_set_device_name(local_device_name);
            esp_bt_gap_set_scan_mode(ESP_BT_CONNECTABLE, ESP_BT_GENERAL_DISCOVERABLE);
        } else {
            ESP_LOGE(SPP_TAG, "ESP_SPP_START_EVT status:%d", param->start.status);
        }
        break;
    case ESP_SPP_CL_INIT_EVT:
        ESP_LOGI(SPP_TAG, "ESP_SPP_CL_INIT_EVT");
        break;
    case ESP_SPP_DATA_IND_EVT:
        /* Перенаправление данных от Bluetooth SPP в the TTL UART */
        if (param->data_ind.len > 0) {
            const uint8_t *p = param->data_ind.data;
            size_t remaining = param->data_ind.len;
            while (remaining > 0) {
                uart_bridge_item_t item;
                item.len = remaining > UART_BRIDGE_CHUNK ? UART_BRIDGE_CHUNK : remaining;
                memcpy(item.data, p, item.len);
                if (xQueueSend(spp_to_uart_queue, &item, 0) != pdTRUE) {
                    ESP_LOGW(SPP_TAG, "UART TX queue full, dropped %u bytes", (unsigned)item.len);
                }
                p += item.len;
                remaining -= item.len;
            }
        }
#if (SPP_SHOW_MODE == SPP_SHOW_DATA)
        /*
         * Здесь мы отображаем только те данные, длина которых меньше 128.
         * Если вы хотите выводить данные в печать, а скорость передачи данных высокая,
         * настоятельно рекомендуется обрабатывать их в отдельной задаче приложения
         * с более низким приоритетом, а не напрямую в этом callback. Поскольку вывод
         * printf занимает слишком много времени, это может заблокировать стек Bluetooth,
         * а также повлиять на пропускную способность!
         */
        ESP_LOGI(SPP_TAG, "ESP_SPP_DATA_IND_EVT len:%d handle:%"PRIu32,
                 param->data_ind.len, param->data_ind.handle);
        if (param->data_ind.len < 128) {
            ESP_LOG_BUFFER_HEX("", param->data_ind.data, param->data_ind.len);
        }
#else
        gettimeofday(&time_new, NULL);
        data_num += param->data_ind.len;
        if (time_new.tv_sec - time_old.tv_sec >= 3) {
            print_speed();
        }
#endif
        break;
    case ESP_SPP_CONG_EVT:
        spp_congested = param->cong.cong;
        ESP_LOGI(SPP_TAG, "ESP_SPP_CONG_EVT cong:%d", param->cong.cong);
        break;
    case ESP_SPP_WRITE_EVT:
        ESP_LOGI(SPP_TAG, "ESP_SPP_WRITE_EVT");
        break;
    case ESP_SPP_SRV_OPEN_EVT:
        ESP_LOGI(SPP_TAG, "ESP_SPP_SRV_OPEN_EVT status:%d handle:%"PRIu32", rem_bda:[%s]",
                 param->srv_open.status, param->srv_open.handle,
                 bda2str(param->srv_open.rem_bda, bda_str, sizeof(bda_str)));
        spp_conn_handle = param->srv_open.handle;
        spp_congested = false;
        spp_connected = true;
        gettimeofday(&time_old, NULL);
        break;
    case ESP_SPP_SRV_STOP_EVT:
        ESP_LOGI(SPP_TAG, "ESP_SPP_SRV_STOP_EVT");
        break;
    case ESP_SPP_UNINIT_EVT:
        ESP_LOGI(SPP_TAG, "ESP_SPP_UNINIT_EVT");
        break;
    default:
        break;
    }
}

void esp_bt_gap_cb(esp_bt_gap_cb_event_t event, esp_bt_gap_cb_param_t *param)
{
    char bda_str[18] = {0};

    switch (event) {
    case ESP_BT_GAP_AUTH_CMPL_EVT:{
        if (param->auth_cmpl.stat == ESP_BT_STATUS_SUCCESS) {
            ESP_LOGI(SPP_TAG, "authentication success: %s bda:[%s]", param->auth_cmpl.device_name,
                     bda2str(param->auth_cmpl.bda, bda_str, sizeof(bda_str)));
        } 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_EXAMPLE_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: %06"PRIu32,
                           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:%06"PRIu32, 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 bda:[%s]", param->mode_chg.mode,
                 bda2str(param->mode_chg.bda, bda_str, sizeof(bda_str)));
        break;
    default: {
        ESP_LOGI(SPP_TAG, "event: %d", event);
        break;
    }
    }
    return;
}

static void uart_bridge_init(void)
{
    const uart_config_t uart_cfg = {
        .baud_rate  = UART_BRIDGE_BAUD_RATE,
        .data_bits  = UART_DATA_8_BITS,
        .parity     = UART_PARITY_DISABLE,
        .stop_bits  = UART_STOP_BITS_1,
        .flow_ctrl  = UART_HW_FLOWCTRL_DISABLE,
        .source_clk = UART_SCLK_DEFAULT,
    };

    ESP_ERROR_CHECK(uart_driver_install(UART_BRIDGE_PORT, UART_BRIDGE_RX_BUF_SIZE,
                                        UART_BRIDGE_TX_BUF_SIZE, 0, NULL, 0));
    ESP_ERROR_CHECK(uart_param_config(UART_BRIDGE_PORT, &uart_cfg));
    ESP_ERROR_CHECK(uart_set_pin(UART_BRIDGE_PORT, UART_BRIDGE_TX_GPIO, UART_BRIDGE_RX_GPIO,
                                 UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE));
    ESP_LOGI(SPP_TAG, "UART bridge ready: UART2 TX=GPIO%d RX=GPIO%d %d 8N1, no flow control",
             UART_BRIDGE_TX_GPIO, UART_BRIDGE_RX_GPIO, UART_BRIDGE_BAUD_RATE);
}

/* TTL UART -> Bluetooth SPP */
static void uart_to_spp_task(void *arg)
{
    uint8_t buf[UART_BRIDGE_CHUNK];
    for (;;) {
        int len = uart_read_bytes(UART_BRIDGE_PORT, buf, sizeof(buf), pdMS_TO_TICKS(100));
        if (len < = 0) {
            continue;
        }
        if (!spp_connected || spp_conn_handle == 0) {
            continue;
        }
        while (spp_congested && spp_connected) {
            vTaskDelay(pdMS_TO_TICKS(10));
        }
        if (spp_connected && spp_conn_handle != 0) {
            esp_spp_write(spp_conn_handle, len, buf);
        }
    }
}

/* Bluetooth SPP -> TTL UART */
static void spp_to_uart_task(void *arg)
{
    uart_bridge_item_t item;
    for (;;) {
        if (xQueueReceive(spp_to_uart_queue, &item, portMAX_DELAY) == pdTRUE) {
            uart_write_bytes(UART_BRIDGE_PORT, item.data, item.len);
        }
    }
}

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

    uart_bridge_init();
    spp_to_uart_queue = xQueueCreate(UART_BRIDGE_QUEUE_LEN, sizeof(uart_bridge_item_t));
    if (spp_to_uart_queue == NULL) {
        ESP_LOGE(SPP_TAG, "Failed to create UART TX queue");
        return;
    }
    xTaskCreate(uart_to_spp_task, "uart_to_spp", 4096, NULL, 10, NULL);
    xTaskCreate(spp_to_uart_task, "spp_to_uart", 4096, NULL, 10, NULL);

    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 ((ret = esp_bt_controller_init(&bt_cfg)) != ESP_OK) {
        ESP_LOGE(SPP_TAG, "%s initialize controller failed: %s", __func__, esp_err_to_name(ret));
        return;
    }

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

    esp_bluedroid_config_t bluedroid_cfg = BT_BLUEDROID_INIT_CONFIG_DEFAULT();
#if (CONFIG_EXAMPLE_SSP_ENABLED == false)
    bluedroid_cfg.ssp_en = false;
#endif
    if ((ret = esp_bluedroid_init_with_cfg(&bluedroid_cfg)) != ESP_OK) {
        ESP_LOGE(SPP_TAG, "%s initialize bluedroid failed: %s", __func__, esp_err_to_name(ret));
        return;
    }

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

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

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

    esp_spp_cfg_t bt_spp_cfg = {
        .mode = esp_spp_mode,
        .enable_l2cap_ertm = esp_spp_enable_l2cap_ertm,
        .tx_buffer_size = 0, /* Используется только для режима ESP_SPP_MODE_VFS */
    };
    if ((ret = esp_spp_enhanced_init(&bt_spp_cfg)) != ESP_OK) {
        ESP_LOGE(SPP_TAG, "%s spp init failed: %s", __func__, esp_err_to_name(ret));
        return;
    }

#if (CONFIG_EXAMPLE_SSP_ENABLED == true)
    /* Установка параметров по умолчанию для 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

    /*
     * Установка параметров по умолчанию для Legacy Pairing
     * Используется изменяемый pin, ввод pin-кода при 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)));
}