import threading
import json
from select import select
from evdev import ecodes, InputDevice


class Keyboard(threading.Thread):
    def __init__(self,next,prev,toggle):
        super(Keyboard, self).__init__()
        self.running = False
        self.prev = prev
        self.next = next
        self.toggle = toggle

    def run(self):
        self.running=True
        self.handleInput()
    def handleInput(self):
        device="/dev/input/by-id/usb-Microsoft_Comfort_Curve_Keyboard_3000-event-kbd"
        device="/dev/input/by-id/usb-_USB_Keyboard-event-kbd"
        try:
            dev = InputDevice(device)
        except Exception as e:
            print("Error accessing input device %s" % device)
            self.running=False
            return
        #dev = InputDevice("/dev/input/by-path/platform-i8042-serio-0-event-kbd")
        VALID_KEYS = [ "KEY_PAGEUP", "KEY_PAGEDOWN", "KEY_F5" ]
        print("Reading keyboard")
        while True:
            r, w, e = select([dev], [], [])
            for ev in dev.read():
                codename = '?'
                if ev.type == ecodes.EV_SYN:
                   continue 
                if ev.value != 0:
                    continue
                if ev.type in ecodes.bytype:
                    codename = ecodes.bytype[ev.type][ev.code]

                if codename == "KEY_PAGEUP":
                    self.prev()
                if codename == "KEY_PAGEDOWN":
                    self.next()
                if codename == "KEY_F5":
                    self.toggle()