/*
 * SPDX-FileCopyrightText: 2015-2022 Espressif Systems (Shanghai) CO LTD
 *
 * SPDX-License-Identifier: CC0-1.0
 */

#include <stdio.h>
#include <string.h>
#include "esp_system.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_log.h"
#include "esp_err.h"
#include "usb/usb_host.h"
#include "usb/cdc_acm_host.h"

#define EXAMPLE_USB_HOST_PRIORITY 20
#define EXAMPLE_USB_DEVICE_VID    0x303A  // 0x303A:0x4001 (TinyUSB CDC device)
#define EXAMPLE_USB_DEVICE_PID    0x4001

static const char *TAG = "USB-CDC";

/* ------------------------------- Callbacks -------------------------------- */
static void handle_rx(uint8_t *data, size_t data_len, void *arg)
{
    ESP_LOGI(TAG, "Data received");
    ESP_LOG_BUFFER_HEXDUMP(TAG, data, data_len, ESP_LOG_INFO);
}

void usb_lib_task(void *arg)
{
    while (1) {
        //Start handling system events
        uint32_t event_flags;
        usb_host_lib_handle_events(portMAX_DELAY, &event_flags);
        if (event_flags & USB_HOST_LIB_EVENT_FLAGS_NO_CLIENTS) {
            ESP_LOGI(TAG, "All clients deregistered");
            ESP_ERROR_CHECK(usb_host_device_free_all());
        }
        if (event_flags & USB_HOST_LIB_EVENT_FLAGS_ALL_FREE) {
            break;
        }
    }

    //Clean up USB Host
    ESP_ERROR_CHECK(usb_host_uninstall());
    vTaskDelete(NULL);
}

/* ---------------------------------- Main ---------------------------------- */
void app_main(void)
{
    //Install USB Host driver. Should only be called once in entire application
    ESP_LOGI(TAG, "Installing USB Host");
    usb_host_config_t host_config = {
        .skip_phy_setup = false,
        .intr_flags = ESP_INTR_FLAG_LEVEL1,
    };
    ESP_ERROR_CHECK(usb_host_install(&host_config));

    // Create a task that will handle USB library events
    xTaskCreate(usb_lib_task, "usb_lib", 4096, xTaskGetCurrentTaskHandle(), EXAMPLE_USB_HOST_PRIORITY, NULL);

    ESP_LOGI(TAG, "Installing CDC-ACM driver");
    ESP_ERROR_CHECK(cdc_acm_host_install(NULL));

    ESP_LOGI(TAG, "Opening CDC ACM device 0x%04X:0x%04X", EXAMPLE_USB_DEVICE_VID, EXAMPLE_USB_DEVICE_PID);
    cdc_acm_dev_hdl_t cdc_dev;
    const cdc_acm_host_device_config_t dev_config = {
        .connection_timeout_ms = 5000,
        .out_buffer_size = 64,
        .user_arg = NULL,
        .event_cb = NULL,
        .data_cb = handle_rx
    };
    ESP_ERROR_CHECK(cdc_acm_host_open(EXAMPLE_USB_DEVICE_VID, EXAMPLE_USB_DEVICE_PID, 0, &dev_config, &cdc_dev));
    assert(cdc_dev);
    cdc_acm_host_desc_print(cdc_dev);
    vTaskDelay(100);

    // Test sending and receiving: Send AT commands, responses are handled in handle_rx callback
    static char text1[] = "AT\r";
    ESP_ERROR_CHECK(cdc_acm_host_data_tx_blocking(cdc_dev, (uint8_t *)text1, strlen(text1), 1000));
    vTaskDelay(100);

    static char text2[] = "AT+GSN\r";
    ESP_ERROR_CHECK(cdc_acm_host_data_tx_blocking(cdc_dev, (uint8_t *)text2, strlen(text2), 1000));
    vTaskDelay(100);

    // Test Line Coding commands: Get current line coding, change it 9600 7N1 and read again
    ESP_LOGI(TAG, "Setting up line coding");

    cdc_acm_line_coding_t line_coding;
    ESP_ERROR_CHECK(cdc_acm_host_line_coding_get(cdc_dev, &line_coding));
    ESP_LOGI(TAG, "Line Get: Rate: %d, Stop bits: %d, Parity: %d, Databits: %d", line_coding.dwDTERate,
             line_coding.bCharFormat, line_coding.bParityType, line_coding.bDataBits);

    line_coding.dwDTERate = 9600;
    line_coding.bDataBits = 7;
    line_coding.bParityType = 1;
    line_coding.bCharFormat = 1;
    ESP_ERROR_CHECK(cdc_acm_host_line_coding_set(cdc_dev, &line_coding));
    ESP_LOGI(TAG, "Line Set: Rate: %d, Stop bits: %d, Parity: %d, Databits: %d", line_coding.dwDTERate,
             line_coding.bCharFormat, line_coding.bParityType, line_coding.bDataBits);

    ESP_ERROR_CHECK(cdc_acm_host_line_coding_get(cdc_dev, &line_coding));
    ESP_LOGI(TAG, "Line Get: Rate: %d, Stop bits: %d, Parity: %d, Databits: %d", line_coding.dwDTERate,
             line_coding.bCharFormat, line_coding.bParityType, line_coding.bDataBits);

    ESP_ERROR_CHECK(cdc_acm_host_set_control_line_state(cdc_dev, true, false));

    ESP_LOGI(TAG, "Example finished successfully!");
}