import t, c
import drivers.usb.usb as usb
import drivers.usb.hid.hid as hid
import drivers.usb.uhci as uhci
import drivers.serial.uart.serial as serial

MOUSE_BUF_SIZE: t.CDefine = 1024

class usb_mouse_packet(t.CStruct):
    buttons: t.CUInt8T
    dx: t.CInt16T
    dy: t.CInt16T
    wheel: t.CInt8T

mse_buf: t.CArray[usb_mouse_packet, MOUSE_BUF_SIZE]
mse_buf_head: t.CInt = 0
mse_buf_tail: t.CInt = 0
mse_buf_count: t.CInt = 0
mse_dev: usb.usb_device | t.CPtr = None
mse_report: hid.hid_mouse_report
mse_initialized: t.CInt = 0
mse_slot_id: t.CInt = -1

def init() -> t.CInt:
    global mse_dev, mse_initialized, mse_slot_id
    dev: usb.usb_device | t.CPtr = usb.find_hid_device(0x02)
    if dev is None:
        serial.puts("[usb_mse] no USB mouse found\n")
        return -1
    mse_dev = dev
    if hid.init_mouse(dev) != 0:
        serial.puts("[usb_mse] init failed\n")
        return -2
    mse_initialized = 1
    serial.puts("[usb_mse] initialized\n")
    mse_slot_id = uhci.register_int_callback(c.Addr(_on_int_complete))
    if mse_slot_id < 0:
        serial.puts("[usb_mse] register callback failed\n")
        mse_initialized = 0
        return -3
    uhci.schedule_int_transfer(mse_slot_id, dev.addr, dev.ep_in, dev.ls, t.CUInt8T(dev.ep_in_max), dev.ep_in_toggle, c.Addr(mse_report))
    return 0

def _on_int_complete() -> t.CInt:
    global mse_buf_head, mse_buf_tail, mse_buf_count
    if mse_initialized == 0: return 0
    if mse_report.dx != 0 or mse_report.dy != 0 or mse_report.buttons != 0:
        if mse_buf_count < MOUSE_BUF_SIZE:
            mse_buf[mse_buf_tail].buttons = mse_report.buttons
            mse_buf[mse_buf_tail].dx = t.CInt16T(mse_report.dx)
            mse_buf[mse_buf_tail].dy = t.CInt16T(mse_report.dy)
            mse_buf[mse_buf_tail].wheel = mse_report.wheel
            mse_buf_tail = mse_buf_tail + 1
            if mse_buf_tail >= MOUSE_BUF_SIZE:
                mse_buf_tail = 0
            mse_buf_count += 1
    dev: usb.usb_device | t.CPtr = mse_dev
    if dev is not None and mse_slot_id >= 0:
        uhci.schedule_int_transfer(mse_slot_id, dev.addr, dev.ep_in, dev.ls, t.CUInt8T(dev.ep_in_max), dev.ep_in_toggle, c.Addr(mse_report))
    return 0

def has_data() -> t.CInt:
    if mse_buf_count > 0: return 1
    return 0

def read_packet(out: usb_mouse_packet | t.CPtr) -> t.CInt:
    global mse_buf_head, mse_buf_count
    if mse_buf_count == 0: return -1
    out.buttons = mse_buf[mse_buf_head].buttons
    out.dx = mse_buf[mse_buf_head].dx
    out.dy = mse_buf[mse_buf_head].dy
    out.wheel = mse_buf[mse_buf_head].wheel
    mse_buf_head = mse_buf_head + 1
    if mse_buf_head >= MOUSE_BUF_SIZE:
        mse_buf_head = 0
    mse_buf_count -= 1
    return 0