#include "tusb.h"
#include "class/msc/msc.h"
#include "device/usbd.h"
/* A combination of interfaces must have a unique product id, since PC will save device driver after the first plug.
 * Same VID/PID with different interface e.g MSC (first), then CDC (later) will possibly cause system error on PC.
 *
 * Auto ProductID layout's Bitmap:
 *   [MSB]         HID | MSC | CDC          [LSB]
 */
#define _PID_MAP(itf, n) ((CFG_TUD_##itf) << (n))
#define USB_PID (0x4000 | _PID_MAP(CDC, 0) | _PID_MAP(MSC, 1) | _PID_MAP(HID, 2) | \
                 _PID_MAP(MIDI, 3) | _PID_MAP(VENDOR, 4))

#define USB_VID 0x0c45
#define USB_BCD 0x6840

// Bus 003 Device 075: ID 0c45:6840 Microdia USB2.0 DSP

//--------------------------------------------------------------------+
// Device Descriptors
//--------------------------------------------------------------------+
tusb_desc_device_t const desc_device =
    {
        .bLength = sizeof(tusb_desc_device_t),
        .bDescriptorType = TUSB_DESC_DEVICE,
        .bcdUSB = USB_BCD,

        // Use Interface Association Descriptor (IAD) for CDC
        // As required by USB Specs IAD's subclass must be common class (2) and protocol must be IAD (1)
        .bDeviceClass = TUSB_CLASS_MISC,
        .bDeviceSubClass = MISC_SUBCLASS_COMMON,
        .bDeviceProtocol = MISC_PROTOCOL_IAD,

        .bMaxPacketSize0 = CFG_TUD_ENDPOINT0_SIZE,

        .idVendor = USB_VID,
        .idProduct = USB_PID,
        .bcdDevice = 0x0100,

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

        .bNumConfigurations = 0x01};

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

//--------------------------------------------------------------------+
// Configuration Descriptor
//--------------------------------------------------------------------+

enum
{
  ITF_NUM_MSC,
  ITF_NUM_TOTAL
};

#define EPNUM_MSC_OUT 0x01
#define EPNUM_MSC_IN 0x81

#define CONFIG_TOTAL_LEN (TUD_CONFIG_DESC_LEN + TUD_MSC_DESC_LEN)

// full speed configuration
uint8_t const desc_fs_configuration[] =
    {
        // Config number, interface count, string index, total length, attribute, power in mA
        TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, 0x00, 100),

        // Interface number, string index, EP Out & EP In address, EP size
        TUD_MSC_DESCRIPTOR(ITF_NUM_MSC, 3, EPNUM_MSC_OUT, EPNUM_MSC_IN, 64),
};

#if TUD_OPT_HIGH_SPEED
// Per USB specs: high speed capable device must report device_qualifier and other_speed_configuration

// high speed configuration
uint8_t const desc_hs_configuration[] =
    {
        // Config number, interface count, string index, total length, attribute, power in mA
        TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, 0x00, 100),
        // Interface number, string index, EP Out & EP In address, EP size
        TUD_MSC_DESCRIPTOR(ITF_NUM_MSC, 3, EPNUM_MSC_OUT, EPNUM_MSC_IN, 512),
};

// other speed configuration
uint8_t desc_other_speed_config[CONFIG_TOTAL_LEN];

// device qualifier is mostly similar to device descriptor since we don't change configuration based on speed
tusb_desc_device_qualifier_t const desc_device_qualifier =
    {
        .bLength = sizeof(tusb_desc_device_qualifier_t),
        .bDescriptorType = TUSB_DESC_DEVICE_QUALIFIER,
        .bcdUSB = USB_BCD,

        .bDeviceClass = TUSB_CLASS_MISC,
        .bDeviceSubClass = MISC_SUBCLASS_COMMON,
        .bDeviceProtocol = MISC_PROTOCOL_IAD,

        .bMaxPacketSize0 = CFG_TUD_ENDPOINT0_SIZE,
        .bNumConfigurations = 0x01,
        .bReserved = 0x00};

// Invoked when received GET DEVICE QUALIFIER DESCRIPTOR request
// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete.
// device_qualifier descriptor describes information about a high-speed capable device that would
// change if the device were operating at the other speed. If not highspeed capable stall this request.
uint8_t const *tud_descriptor_device_qualifier_cb(void)
{
  return (uint8_t const *)&desc_device_qualifier;
}

// Invoked when received GET OTHER SEED CONFIGURATION DESCRIPTOR request
// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
// Configuration descriptor in the other speed e.g if high speed then this is for full speed and vice versa
uint8_t const *tud_descriptor_other_speed_configuration_cb(uint8_t index)
{
  (void)index; // for multiple configurations

  // if link speed is high return fullspeed config, and vice versa
  // Note: the descriptor type is OHER_SPEED_CONFIG instead of CONFIG
  memcpy(desc_other_speed_config,
         (tud_speed_get() == TUSB_SPEED_HIGH) ? desc_fs_configuration : desc_hs_configuration,
         CONFIG_TOTAL_LEN);

  desc_other_speed_config[1] = TUSB_DESC_OTHER_SPEED_CONFIG;

  return desc_other_speed_config;
}

#endif // highspeed

// Invoked when received GET CONFIGURATION DESCRIPTOR
// Application return pointer to descriptor
// Descriptor contents must exist long enough for transfer to complete
uint8_t const *tud_descriptor_configuration_cb(uint8_t index)
{
  (void)index; // for multiple configurations

#if TUD_OPT_HIGH_SPEED
  // Although we are highspeed, host may be fullspeed.
  return (tud_speed_get() == TUSB_SPEED_HIGH) ? desc_hs_configuration : desc_fs_configuration;
#else
  return desc_fs_configuration;
#endif
}

//--------------------------------------------------------------------+
// String Descriptors
//--------------------------------------------------------------------+

/*
T:  Bus=03 Lev=03 Prnt=04 Port=00 Cnt=01 Dev#= 75 Spd=480 MxCh= 0
D:  Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=0c45 ProdID=6840 Rev=01.00
S:  Product=USB2.0 DSP
S:  SerialNumber=USB2.0 DSP
C:  #Ifs= 1 Cfg#= 1 Atr=c0 MxPwr=500mA
I:  If#= 0 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50 Driver=usb-storage
E:  Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=81(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms


*/

// array of pointer to string descriptors
char const *string_desc_arr[] =
    {
        (const char[]){0x09, 0x04}, // 0: is supported language is English (0x0409)
        "D8S EURL",                 // 1: Manufacturer
        "USB2.0 DSP",               // 2: Product
        "USB2.0 DSP",               // 3: MSC Interface
};

static uint16_t _desc_str[32];

// Invoked when received GET STRING DESCRIPTOR request
// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
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
  {
    // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
    // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors

    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 = (uint8_t)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] = (uint16_t)((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));

  return _desc_str;
}