#include "tusb.h"

// --- Device Descriptors ---
tusb_desc_device_t const desc_device = {
    .bLength = sizeof(tusb_desc_device_t),
    .bDescriptorType = TUSB_DESC_DEVICE,
    .bcdUSB = 0x0200,  // USB 2.0
    .bDeviceClass = TUSB_CLASS_MISC,
    .bDeviceSubClass = MISC_SUBCLASS_COMMON,
    .bDeviceProtocol = MISC_PROTOCOL_IAD,
    .bMaxPacketSize0 = CFG_TUD_ENDPOINT0_SIZE,

    .idVendor = 0xCAFE,   // Пример VID
    .idProduct = 0x4001,  // Пример PID
    .bcdDevice = 0x0100,

    .iManufacturer = 0x01,
    .iProduct = 0x02,
    .iSerialNumber = 0x03,

    .bNumConfigurations = 0x01};

// Invoked when received GET DEVICE DESCRIPTOR
uint8_t const* tud_descriptor_device_cb(void) {
    return (uint8_t const*)&desc_device;
}

// --- Configuration Descriptor ---
enum { ITF_NUM_CDC = 0, ITF_NUM_CDC_DATA, ITF_NUM_TOTAL };

#define CONFIG_TOTAL_LEN (TUD_CONFIG_DESC_LEN + TUD_CDC_DESC_LEN)

// Полный конфигурационный дескриптор
uint8_t const desc_configuration[] = {
    // Config number, interface count, string index, total length, attributes,
    // power in mA
    TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, 0x00, 100),

    // Interface number, string index, EP notification address and size, EP data
    // address (out, in) and size.
    // EP Notification: 0x81 (In), EP Data Out: 0x02, EP Data In: 0x82 (In)
    // ВАЖНО: Убедитесь, что номера EP не конфликтуют и поддерживаются железом
    // F103
    TUD_CDC_DESCRIPTOR(ITF_NUM_CDC, 4, 0x81, 8, 0x02, 0x82, 64)};

// Invoked when received GET CONFIGURATION DESCRIPTOR
uint8_t const* tud_descriptor_configuration_cb(uint8_t index) {
    (void)index;  // for multiple configurations
    return desc_configuration;
}

// --- String Descriptors ---
char const* string_desc_arr[] = {
    (const char[]){0x09, 0x04},  // 0: is supported language is English (0x0409)
    "TinyUSB",                   // 1: Manufacturer
    "TinyUSB Device",            // 2: Product
    "123456",                    // 3: Serials, should use chip ID
    "TinyUSB CDC",               // 4: CDC Interface
};

static uint16_t _desc_str[32];

// Invoked when received GET STRING DESCRIPTOR request
uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
    (void)langid;
    uint8_t chr_count;

    if (index == 0) {
        memcpy(&_desc_str[1], string_desc_arr[0], 2);
        chr_count = 1;
    } else {
        if (!(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])))
            return NULL;

        const char* str = string_desc_arr[index];

        // Cap at max char
        chr_count = strlen(str);
        if (chr_count > 31) chr_count = 31;

        // Convert ASCII string into UTF-16
        for (uint8_t i = 0; i < chr_count; i++) { _desc_str[1 + i] = str[i]; }
    }

    // first byte is length (including header), second byte is string type
    _desc_str[0] = (TUSB_DESC_STRING << 8) | (2 * chr_count + 2);

    return _desc_str;
}