/* Simplified HID Mouse descriptor structure */
static const tUSBDHIDMouseDevice g_sMouseDevice =
{
    USB_VID_TI,         // Vendor ID (TI for development)
    USB_PID_MOUSE,      // Product ID
    500,                // max power (mA) × 2
    USB_CONF_ATTR_BUS_PWR,  // bus-powered
    MouseHandler,       // event callback
    g_pui8MouseHIDReportDescriptor,  // HID report descriptor
    sizeof(g_pui8MouseHIDReportDescriptor),
    0                   // language ID placeholder
};

#include "usblib/usblib.h"
#include "usblib/usbhid.h"
#include "usblib/device/usbdhid.h"
#include "usblib/device/usbdhidmouse.h"

/* Callback for USB events from the HID mouse driver */
static uint32_t MouseHandler(void *pvCBData,
                              uint32_t ui32Event,
                              uint32_t ui32MsgData,
                              void *pvMsgData)
{
    switch (ui32Event)
    {
        case USB_EVENT_CONNECTED:
            /* Host connected — USB enumeration complete */
            break;
        case USB_EVENT_DISCONNECTED:
            /* Host removed */
            break;
        case USB_EVENT_TX_COMPLETE:
            /* Previous report sent successfully */
            break;
    }
    return 0;
}

/* HID Mouse device descriptor */
static tUSBDHIDMouseDevice g_sMouseDevice =
{
    USB_VID_TI_1CBE,         // TI Vendor ID (0x1CBE)
    USB_PID_MOUSE,            // TI Mouse PID (0x0025)
    500,                      // 500 mA max power request
    USB_CONF_ATTR_BUS_PWR,    // bus-powered
    MouseHandler,
    (uint8_t *)g_pui8MouseHIDReportDescriptor,
    sizeof(g_pui8MouseHIDReportDescriptor),
    g_pui32MouseStringDescriptors,
    NUM_MOUSE_STRING_DESCRIPTORS
};

/* Initialise USB device stack */
void USB_Init(void)
{
    /* Configure USB pins (PD4=D-, PD5=D+) */
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
    while (!SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOD));
    GPIOPinTypeUSBAnalog(GPIO_PORTD_BASE, GPIO_PIN_4 | GPIO_PIN_5);

    /* Initialise the USB stack in device mode */
    USBStackModeSet(0, eUSBModeForceDevice, 0);
    USBDHIDMouseInit(0, &g_sMouseDevice);
}

/* Send a mouse movement report */
void Mouse_Move(int8_t dx, int8_t dy)
{
    USBDHIDMouseStateChange(&g_sMouseDevice,
                             dx, dy,         // X and Y delta
                             0);             // button state
}

/* In USB ISR — check EP0 setup packet received */
if (HWREG(USB0_BASE + USB_O_IS) & USB_IS_EP0)
{
    uint8_t ui8CSR = HWREG(USB0_BASE + USB_O_CSRL0);

    if (ui8CSR & USB_CSRL0_RXRDY)
    {
        /* Setup packet in FIFO — read 8 bytes */
        /* Standard request format: bmRequestType, bRequest, wValue,
           wIndex, wLength */
    }
}

/* Force device mode (ignore ID pin) */
USBStackModeSet(0, eUSBModeForceDevice, 0);

/* Force host mode */
USBStackModeSet(0, eUSBModeForceHost, 0);

/* Auto-detect via OTG ID pin */
USBStackModeSet(0, eUSBModeOTG, 0);

/*
 * usb_hid_mouse.c
 * Implements a USB HID mouse — SW1 (PF4) moves the cursor right,
 * SW2 (PF0) moves left.
 * Board  : TM4C123GXL EK LaunchPad
 * SDK    : TivaWare_C_Series-2.2.x + usblib
 * Connect micro-USB on the TM4C123 side (right USB port on LaunchPad)
 */

#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "driverlib/sysctl.h"
#include "driverlib/gpio.h"
#include "driverlib/interrupt.h"
#include "driverlib/pin_map.h"
#include "usblib/usblib.h"
#include "usblib/usbhid.h"
#include "usblib/device/usbdhid.h"
#include "usblib/device/usbdhidmouse.h"

/* Forward declaration for mouse device descriptor (defined in usblib examples) */
extern tUSBDHIDMouseDevice g_sMouseDevice;

/* Simple debounce delay */
static void Debounce(void)
{
    SysCtlDelay(SysCtlClockGet() / 3 / 20);  // ~50 ms
}

int main(void)
{
    /* Step 1: 50 MHz clock (USB PLL requires SysCtlClockSet to use PLL) */
    SysCtlClockSet(SYSCTL_SYSDIV_4 | SYSCTL_USE_PLL |
                   SYSCTL_OSC_MAIN | SYSCTL_XTAL_16MHZ);

    /* Step 2: Configure USB D+/D- pins as analog (USB PHY) */
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
    while (!SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOD));
    GPIOPinTypeUSBAnalog(GPIO_PORTD_BASE, GPIO_PIN_4 | GPIO_PIN_5);

    /* Step 3: Configure buttons */
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF);
    while (!SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOF));

    /* Unlock PF0 (NMI-shared) for SW2 */
    HWREG(GPIO_PORTF_BASE + GPIO_O_LOCK) = 0x4C4F434B;
    HWREG(GPIO_PORTF_BASE + GPIO_O_CR)  |= GPIO_PIN_0;

    GPIOPinTypeGPIOInput(GPIO_PORTF_BASE, GPIO_PIN_0 | GPIO_PIN_4);
    GPIOPadConfigSet(GPIO_PORTF_BASE, GPIO_PIN_0 | GPIO_PIN_4,
                     GPIO_STRENGTH_2MA, GPIO_PIN_TYPE_STD_WPU);

    /* Step 4: Initialise USB stack in device mode */
    USBStackModeSet(0, eUSBModeForceDevice, 0);
    USBDHIDMouseInit(0, &g_sMouseDevice);

    IntMasterEnable();

    while (1)
    {
        /* SW1 (PF4 LOW) → move right (+5 X) */
        if (!GPIOPinRead(GPIO_PORTF_BASE, GPIO_PIN_4))
        {
            USBDHIDMouseStateChange(&g_sMouseDevice, 5, 0, 0);
            Debounce();
        }
        /* SW2 (PF0 LOW) → move left (-5 X) */
        if (!GPIOPinRead(GPIO_PORTF_BASE, GPIO_PIN_0))
        {
            USBDHIDMouseStateChange(&g_sMouseDevice, -5, 0, 0);
            Debounce();
        }
    }
}