/*
 * USBvalve - USB Descriptors for TinyUSB
 *
 * Composite device: CDC (serial) + MSC (mass storage)
 *
 */

#include "tusb.h"
#include "usb_config.h"

//--------------------------------------------------------------------
// Device Descriptor
//--------------------------------------------------------------------
static 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           = USB_VENDORID,
    .idProduct          = USB_PRODUCTID,
    .bcdDevice          = 0x0100,
    .iManufacturer      = 0x01,
    .iProduct           = 0x02,
    .iSerialNumber      = 0x03,
    .bNumConfigurations = 0x01
};

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_MSC,
    ITF_NUM_TOTAL
};

#define EPNUM_CDC_NOTIF  0x81
#define EPNUM_CDC_OUT    0x02
#define EPNUM_CDC_IN     0x82
#define EPNUM_MSC_OUT    0x03
#define EPNUM_MSC_IN     0x83

#define CONFIG_TOTAL_LEN (TUD_CONFIG_DESC_LEN + TUD_CDC_DESC_LEN + TUD_MSC_DESC_LEN)

static uint8_t const desc_configuration[] = {
    // Config descriptor
    TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, 0x00, 100),
    // CDC: Interface Association + CDC Control + CDC Data
    TUD_CDC_DESCRIPTOR(ITF_NUM_CDC, 4, EPNUM_CDC_NOTIF, 8, EPNUM_CDC_OUT, EPNUM_CDC_IN, 64),
    // MSC
    TUD_MSC_DESCRIPTOR(ITF_NUM_MSC, 5, EPNUM_MSC_OUT, EPNUM_MSC_IN, 64),
};

uint8_t const* tud_descriptor_configuration_cb(uint8_t index) {
    (void)index;
    return desc_configuration;
}

//--------------------------------------------------------------------
// String Descriptors
//--------------------------------------------------------------------
static char const* string_desc_arr[] = {
    [0] = (const char[]){0x09, 0x04},  // English
    [1] = USB_MANUF,                    // Manufacturer
    [2] = USB_DESCRIPTOR,               // Product
    [3] = USB_SERIAL,                   // Serial
    [4] = "USBvalve CDC",               // CDC Interface
    [5] = "USBvalve MSC",               // MSC Interface
};

static uint16_t _desc_str[33];

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];
        chr_count = strlen(str);
        if (chr_count > 31) chr_count = 31;

        for (uint8_t i = 0; i < chr_count; i++) {
            _desc_str[1 + i] = str[i];
        }
    }

    // First word is length (including header) and descriptor type
    _desc_str[0] = (TUSB_DESC_STRING << 8) | (2 * chr_count + 2);

    return _desc_str;
}