#include "tusb.h"
#include "usb_descriptors.h"

// String Descriptors
char const* string_desc_arr[] = {
    (const char[]) { 0x09, 0x04 }, // 0: Supported language is English (0x0409)
    "Raspberry Pi",                // 1: Manufacturer
    "Pico Keyboard",               // 2: Product
    "123456",                      // 3: Serials
};

// HID Report Descriptor using standard TinyUSB macros
uint8_t const desc_hid_report[] = {
    TUD_HID_REPORT_DESC_KEYBOARD( HID_REPORT_ID(REPORT_ID_KEYBOARD) )
};

// Invoked when received GET HID REPORT DESCRIPTOR
uint8_t const * tud_hid_descriptor_report_cb(uint8_t instance) {
    (void) instance;
    return desc_hid_report;
}

// Configuration Descriptor
#define CONFIG_TOTAL_LEN  (TUD_CONFIG_DESC_LEN + TUD_HID_DESC_LEN)
#define EPNUM_HID         0x81

uint8_t const desc_configuration[] = {
    // Config number, interface count, string index, total length, attribute, power in mA
    TUD_CONFIG_DESCRIPTOR(1, 1, 0, CONFIG_TOTAL_LEN, TUSB_DESC_CONFIG_ATT_REMOTE_WAKEUP, 100),

    // Interface number, string index, boot protocol, report descriptor len, EP In address, size, polling interval
    TUD_HID_DESCRIPTOR(0, 0, HID_ITF_PROTOCOL_KEYBOARD, sizeof(desc_hid_report), EPNUM_HID, CFG_TUD_HID_EP_BUFSIZE, 10)
};

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

// Device Descriptor
tusb_desc_device_t const desc_device = {
    .bLength            = sizeof(tusb_desc_device_t),
    .bDescriptorType    = TUSB_DESC_DEVICE,
    .bcdUSB             = 0x0200,
    .bDeviceClass       = 0x00,
    .bDeviceSubClass    = 0x00,
    .bDeviceProtocol    = 0x00,
    .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,

    .idVendor           = 0x2E8A, // Raspberry Pi Vid
    .idProduct          = 0x000a, // Pico SDK HID Product Id
    .bcdDevice          = 0x0100,

    .iManufacturer      = 1,
    .iProduct           = 2,
    .iSerialNumber      = 3,
    .bNumConfigurations = 1
};

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

// Invoked when received GET STRING DESCRIPTOR request
uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
    (void) langid;
    static uint16_t _desc_str[32];
    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];
        }
    }

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