#!python3

import sys
import evdev
import contextlib

keymap = {
    evdev.ecodes.KEY_1: (b'&', b'1'),
    evdev.ecodes.KEY_2: (b'?', b'2'),
    evdev.ecodes.KEY_3: (b'"', b'3'),
    evdev.ecodes.KEY_4: (b'\'', b'4'),
    evdev.ecodes.KEY_5: (b'(', b'5'),
    evdev.ecodes.KEY_6: (b'-', b'6'),
    evdev.ecodes.KEY_7: (b'?', b'7'),
    evdev.ecodes.KEY_8: (b'_', b'8'),
    evdev.ecodes.KEY_9: (b'?', b'9'),
    evdev.ecodes.KEY_0: (b'?', b'0'),
    evdev.ecodes.KEY_MINUS: (b')', '°'.encode('utf8')),
    evdev.ecodes.KEY_EQUAL: (b'=', b'+'),

    evdev.ecodes.KEY_Q: b'a',
    evdev.ecodes.KEY_W: b'z',
    evdev.ecodes.KEY_E: b'e',
    evdev.ecodes.KEY_R: b'r',
    evdev.ecodes.KEY_T: b't',
    evdev.ecodes.KEY_Y: b'y',
    evdev.ecodes.KEY_U: b'u',
    evdev.ecodes.KEY_I: b'i',
    evdev.ecodes.KEY_O: b'o',
    evdev.ecodes.KEY_P: b'p',

    evdev.ecodes.KEY_A: b'q',
    evdev.ecodes.KEY_S: b's',
    evdev.ecodes.KEY_D: b'd',
    evdev.ecodes.KEY_F: b'f',
    evdev.ecodes.KEY_G: b'g',
    evdev.ecodes.KEY_H: b'h',
    evdev.ecodes.KEY_J: b'j',
    evdev.ecodes.KEY_K: b'k',
    evdev.ecodes.KEY_L: b'l',
    evdev.ecodes.KEY_SEMICOLON: b'm',

    evdev.ecodes.KEY_Z: b'w',
    evdev.ecodes.KEY_X: b'z',
    evdev.ecodes.KEY_C: b'c',
    evdev.ecodes.KEY_V: b'v',
    evdev.ecodes.KEY_B: b'b',
    evdev.ecodes.KEY_N: b'n',
    evdev.ecodes.KEY_M: (b',', b'?'),
    evdev.ecodes.KEY_COMMA: (b';', b'.'),
    evdev.ecodes.KEY_DOT: (b':', b'/'),
    evdev.ecodes.KEY_SLASH: b'!',

    evdev.ecodes.KEY_SPACE: b' ',

}

kpkeys_map = {
    evdev.ecodes.KEY_KP0: '0',
    evdev.ecodes.KEY_KP1: '1',
    evdev.ecodes.KEY_KP2: '2',
    evdev.ecodes.KEY_KP3: '3',
    evdev.ecodes.KEY_KP4: '4',
    evdev.ecodes.KEY_KP5: '5',
    evdev.ecodes.KEY_KP6: '6',
    evdev.ecodes.KEY_KP7: '7',
    evdev.ecodes.KEY_KP8: '8',
    evdev.ecodes.KEY_KP9: '9',
}

def list_devices(name=None):
    devices = [evdev.InputDevice(fn) for fn in evdev.list_devices()]
    for dev in devices:
        #print(dev.fn, dev.name, dev.phys)
        if name and name == dev.name:
            return dev

def read_events(dev=None):
    dev = evdev.InputDevice(dev.fn)
    dev.grab()
    line = ''
    shift = False
    active_keys = dict.fromkeys((
        42, # KEY_LEFTSHIFT
        56, # KEY_LEFTALT
        ), False)
    accumulate = []
    bindata = []
    unidata = []
    try:
        for event in dev.read_loop():
            if event.type == evdev.ecodes.EV_KEY:
                data = evdev.categorize(event)
                #print(data)
                #key = scancodes[data.scancode] if data.scancode in scancodes else str(data.scancode)
                #print('scancode', data.scancode, 'up' if data.keystate ==
                #        data.key_up else 'down')
                if data.scancode in active_keys:
                    active_keys[data.scancode] = data.keystate == data.key_down
                    if data.scancode == 56 and data.keystate == data.key_up:
                        value = int(''.join(accumulate))
                        accumulate = []
                        print('value', value, bytes([value]))
                        bindata.append(bytes([value]))
                        with contextlib.suppress(UnicodeDecodeError):
                            unidata.append(bytes([value]).decode('utf8'))
                        for i in range(6):
                            with contextlib.suppress(UnicodeDecodeError):
                                unidata.append(b''.join(bindata[-i:] + [bytes([value])])
                                        .decode('utf8'))
                                break
                elif data.keystate == data.key_up:
                    continue
                elif data.scancode == 28: # keycode: KEY_ENTER
                    print('end of data scan')
                    bindata = b''.join(bindata)
                    print('bytes', bindata)
                    #print(bindata.decode('utf8'))
                    bindata = []
                else:
                    if active_keys[56]:
                        # if KEY_LEFTALT down, then accumulate binary data
                        accumulate.append(kpkeys_map[data.scancode])
                    elif data.scancode in keymap:
                        key = keymap[data.scancode]
                        if active_keys[42]: # KEY_LEFTSHIFT
                            if len(key) > 1:
                                key = key[1]
                            else:
                                key = key.upper()
                        else:
                            if len(key) > 1:
                                key = key[0]
                        bindata.append(key)
                        unidata.append(key.decode('utf8'))
                    else:
                        print(active_keys, data)
    finally:
        dev.ungrab()


dev = list_devices(name='The Code Corporation CR1000')
print(dev)
read_events(dev)