#include "tusb.h"
#include "protocol.h"

#include "pico/unique_id.h"

#include <string.h>

#define USB_BCD 0x0200

tusb_desc_device_t const desc_device = {
    .bLength            = sizeof(tusb_desc_device_t),
    .bDescriptorType    = TUSB_DESC_DEVICE,
    .bcdUSB             = USB_BCD,
    .bDeviceClass       = TUSB_CLASS_MISC,
    .bDeviceSubClass    = MISC_SUBCLASS_COMMON,
    .bDeviceProtocol    = MISC_PROTOCOL_IAD,
    .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
    .idVendor           = AUSIO_USB_VID,
    .idProduct          = AUSIO_USB_PID,
    .bcdDevice          = 0x0100,
    .iManufacturer      = 0x01,
    .iProduct           = 0x02,
    .iSerialNumber      = 0x03,
    .bNumConfigurations = 0x01
};

uint8_t const *tud_descriptor_device_cb(void) {
    return (uint8_t const *)&desc_device;
}

/* Vendor page: Report ID1 Input 7 bytes, Report ID2 Output 63 bytes */
uint8_t const desc_hid_report[] = {
    HID_USAGE_PAGE_N(HID_USAGE_PAGE_VENDOR, 2),
    HID_USAGE(0x01),
    HID_COLLECTION(HID_COLLECTION_APPLICATION),
        /* Input report ID 1: 7 data bytes */
        HID_REPORT_ID(AUSIO_REPORT_ID_INPUT)
        HID_USAGE(0x02),
        HID_LOGICAL_MIN(0x00),
        HID_LOGICAL_MAX_N(0xff, 2),
        HID_REPORT_SIZE(8),
        HID_REPORT_COUNT(AUSIO_INPUT_SIZE - 1),
        HID_INPUT(HID_DATA | HID_VARIABLE | HID_ABSOLUTE),
        /* Output report ID 2: 63 data bytes */
        HID_REPORT_ID(AUSIO_REPORT_ID_OUTPUT)
        HID_USAGE(0x03),
        HID_LOGICAL_MIN(0x00),
        HID_LOGICAL_MAX_N(0xff, 2),
        HID_REPORT_SIZE(8),
        HID_REPORT_COUNT(AUSIO_OUTPUT_SIZE - 1),
        HID_OUTPUT(HID_DATA | HID_VARIABLE | HID_ABSOLUTE),
    HID_COLLECTION_END
};

uint8_t const *tud_hid_descriptor_report_cb(uint8_t itf) {
    (void)itf;
    return desc_hid_report;
}

enum {
    ITF_NUM_CDC = 0,
    ITF_NUM_CDC_DATA,
    ITF_NUM_HID,
    ITF_NUM_TOTAL
};

#define EPNUM_CDC_NOTIF   0x81
#define EPNUM_CDC_OUT     0x02
#define EPNUM_CDC_IN      0x82
#define EPNUM_HID_OUT     0x03
#define EPNUM_HID_IN      0x83

#define CONFIG_TOTAL_LEN  (TUD_CONFIG_DESC_LEN + TUD_CDC_DESC_LEN + TUD_HID_INOUT_DESC_LEN)

uint8_t const desc_configuration[] = {
    TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, 0x00, 100),
    TUD_CDC_DESCRIPTOR(ITF_NUM_CDC, 4, EPNUM_CDC_NOTIF, 8, EPNUM_CDC_OUT, EPNUM_CDC_IN, 64),
    TUD_HID_INOUT_DESCRIPTOR(ITF_NUM_HID, 5, HID_ITF_PROTOCOL_NONE,
                             sizeof(desc_hid_report),
                             EPNUM_HID_OUT, EPNUM_HID_IN,
                             CFG_TUD_HID_EP_BUFSIZE, 5)
};

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

enum {
    STRID_LANGID = 0,
    STRID_MANUFACTURER,
    STRID_PRODUCT,
    STRID_SERIAL,
    STRID_CDC,
    STRID_HID,
};

static char const *string_desc_arr[] = {
    (const char[]){0x09, 0x04},
    "Ausiomixer",
    "Ausiomixer HID Mixer",
    NULL,
    "Ausiomixer CDC",
    "Ausiomixer HID",
};

static uint16_t _desc_str[32 + 1];

uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
    (void)langid;
    size_t chr_count = 0;

    switch (index) {
    case STRID_LANGID:
        memcpy(&_desc_str[1], string_desc_arr[0], 2);
        chr_count = 1;
        break;
    case STRID_SERIAL: {
        pico_unique_board_id_t id;
        pico_get_unique_board_id(&id);
        chr_count = 0;
        for (int i = 0; i < PICO_UNIQUE_BOARD_ID_SIZE_BYTES && chr_count < 16; i++) {
            static char const hex[] = "0123456789ABCDEF";
            _desc_str[1 + chr_count++] = (uint16_t)hex[id.id[i] >> 4];
            _desc_str[1 + chr_count++] = (uint16_t)hex[id.id[i] & 0x0f];
        }
        break;
    }
    default:
        if (index >= sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) {
            return NULL;
        }
        {
            const char *str = string_desc_arr[index];
            if (!str) {
                return NULL;
            }
            chr_count = strlen(str);
            if (chr_count > 31) {
                chr_count = 31;
            }
            for (size_t i = 0; i < chr_count; i++) {
                _desc_str[1 + i] = (uint16_t)str[i];
            }
        }
        break;
    }

    _desc_str[0] = (uint16_t)((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
    return _desc_str;
}