#!/usr/bin/python3
import os  # used to all external commands
import sys  # used to exit the script
import dbus
import dbus.service
import dbus.mainloop.glib
import time
# import thread
import keymap

DBUS_OBJ_BTK_NAME = 'org.thanhle.btkbservice'
DBUS_OBJ_BTK_PATH = '/org/thanhle/btkbservice'

class BtkStringClient():
    # constants
    KEY_DOWN_TIME = 0.01
    KEY_DELAY = 0.01

    def __init__(self):
        # the structure for a bt keyboard input report (size is 10 bytes)
        self.state = [
            0xA1,  # this is an input report
            0x01,  # Usage report = Keyboard
            # Bit array for Modifier keys
            [0,  # Right GUI - Windows Key
                 0,  # Right ALT
                 0,  # Right Shift
                 0,  # Right Control
                 0,  # Left GUI
                 0,  # Left ALT
                 0,  # Left Shift
                 0],  # Left Control
            0x00,  # Vendor reserved
            0x00,  # rest is space for 6 keys
            0x00,
            0x00,
            0x00,
            0x00,
            0x00]
        self.scancodes = {" ": "KEY_SPACE"}
        # connect with the Bluetooth keyboard server
        print("setting up DBus Client")
        self.bus = dbus.SystemBus()
        self.btkservice = self.bus.get_object(DBUS_OBJ_BTK_NAME, DBUS_OBJ_BTK_PATH)
        self.iface = dbus.Interface(self.btkservice, DBUS_OBJ_BTK_NAME)

    def send_key_state(self):
        """sends a single frame of the current key state to the emulator server"""
        bin_str = ""
        element = self.state[2]
        for bit in element:
            bin_str += str(bit)
        self.iface.send_keys(int(bin_str, 2), self.state[4:10])

    def send_key_down(self, scancode):
        """sends a key down event to the server"""
        self.state[4] = scancode
        self.send_key_state()

    def send_key_up(self):
        """sends a key up event to the server"""
        self.state[4] = 0
        self.send_key_state()

    def send_string(self, string_to_send):
        for c in string_to_send:
            cu = c.upper()
            if(cu in self.scancodes):
                scantablekey = self.scancodes[cu]
            else:
                scantablekey = "KEY_"+c.upper()
            print(scantablekey)
            scancode = keymap.keytable[scantablekey]
            self.send_key_down(scancode)
            time.sleep(BtkStringClient.KEY_DOWN_TIME)
            self.send_key_up()
            time.sleep(BtkStringClient.KEY_DELAY)


if __name__ == "__main__":
    if(len(sys.argv) < 2):
        print("Usage: send_string <string to send ")
        exit()
    dc = BtkStringClient()
    string_to_send = sys.argv[1]
    print("Sending " + string_to_send)
    dc.send_string(string_to_send)
    print("Done.")