"""
Code shared by "decodeError.py" and "decodeStatus.py"
"""

import struct

def decode(value: int, interpretation):

    # Pack the input as a short and unpack it as an unsigned short
    value_uint16 = format(value, '016b')  # Format as 16-bit unsigned integer

    bit_list = [int(char) for char in value_uint16]    
    bit_list.reverse()

    interpreted = []
    for (bit, interpretations) in zip(bit_list, interpretation):
        interpreted.append(interpretations[bit])
    return (bit_list, interpreted)

def print_decoded(bit_list, interpreted):
    for (idx, (bit_value, msg)) in enumerate(zip(bit_list, interpreted)):
        print(f"Bit {idx} = {bit_value}: {msg}")

def interactive():

    # Imported here, because curses is not available in Windows. Using the 
    # interactive mode therefore fails on Windows, but at least the single 
    # command mode can be used (which would not be possible if we would import
    # curses at the top level)
    import curses

    stdscr = curses.initscr()
    curses.noecho()
    curses.cbreak()
    stdscr.keypad(True)
    stdscr.scrollok(True)

    stdscr.addstr(">> ")
    stdscr.refresh()

    history = [""]
    ptr = len(history) - 1

    while True:
        c = stdscr.getch()
        if c == curses.KEY_RIGHT:
            (y, x) = stdscr.getyx()
            if x < len(history[ptr]) + 3:
                stdscr.move(y, x+1)
                stdscr.refresh()
        elif c == curses.KEY_LEFT:
            (y, x) = stdscr.getyx()
            if x > 3:
                stdscr.move(y, x-1)
                stdscr.refresh()
        elif c == curses.KEY_UP:
            if ptr > 0:
                ptr -= 1
                stdscr.addch("\r")
                stdscr.clrtoeol() 
                stdscr.addstr(">> " + history[ptr])
        elif c == curses.KEY_DOWN:
            if ptr < len(history) - 1:
                ptr += 1
                stdscr.addch("\r")
                stdscr.clrtoeol() 
                stdscr.addstr(">> " + history[ptr])
        elif c == curses.KEY_ENTER or c == ord('\n') or c == ord('\r'):
            if history[ptr] == 'quit':
                break

            # because of arrow keys move back to the end of the line
            (y, x) = stdscr.getyx()
            stdscr.move(y, 3+len(history[ptr]))

            if history[ptr]:
                (bit_list, interpreted) = decode(history[ptr])
                for (idx, (bit_value, msg)) in enumerate(zip(bit_list, interpreted)):
                    stdscr.addstr(f"\nBit {idx} = {bit_value}: {msg}")
                stdscr.refresh()

            if ptr == len(history) - 1 and history[ptr] != "":
                history += [""]
            else:
                history[-1] = ""
            ptr = len(history) - 1

            stdscr.addstr("\n>> ")
            stdscr.refresh()

        else:
            if ptr < len(history) - 1: # Modifying previous input
                if len(history[-1]) == 0:
                    history[-1] = history[ptr]
                    ptr = len(history) - 1

                else:
                    history += [history[ptr]]
                    ptr = len(history) - 1

            if c == curses.KEY_BACKSPACE:
                if len(history[ptr]) == 0:
                    continue
                (y, x) = stdscr.getyx()
                history[ptr] = history[ptr][0:x-4] + history[ptr][x-3:]
                stdscr.addch("\r")
                stdscr.clrtoeol() 
                stdscr.addstr(">> " + history[ptr])
                stdscr.move(y, x-1)
                stdscr.refresh()

            else:
                (y, x) = stdscr.getyx()
                history[ptr] = history[ptr][0:x-3] + chr(c) + history[ptr][x-3:]
                stdscr.addch("\r")
                stdscr.clrtoeol() 
                stdscr.addstr(">> " + history[ptr])
                stdscr.move(y, x+1)
                stdscr.refresh()

    # to quit
    curses.nocbreak()
    stdscr.keypad(False)
    curses.echo()
    curses.endwin()