#!/usr/bin/python

# based on ratmenu(1) for compatibility, but uses curses directly.
# One day it could/should evolve into doing curses and X...

import optparse
import itertools
import curses
import sys
import time
import os

# def group_into_pairs(iterable):
#     """Group a list into pairs.  There should a neater way..."""
#     return map(lambda x: list(x[1])[1], 
#                itertools.groupby(enumerate(iterable), 
#                                  lambda x: int(x[0]/2)))

def group_into_pairs(iterable):
    return list(itertools.izip(*[iter(iterable)]*2))


def redraw(stdscr, cmdlist, target_line):
    for line, (label, cmd) in enumerate(cmdlist):
        stdscr.addstr(line, 0, label, line != target_line or curses.A_REVERSE)

# keys documented in the ratmenu manpage
up_keys = [ ord('k'), curses.KEY_UP, curses.KEY_BACKSPACE, ord('-') ]
down_keys = [ ord('j'), curses.KEY_DOWN, ord(' '), ord('\t'), ord('+') ]
select_keys = [ ord('l'), curses.KEY_RIGHT, curses.KEY_ENTER, ord('\n') ]
back_keys = [ ord('h'), curses.KEY_LEFT ]
exit_keys = [ ord('q'), 27 ] # esc

def cursesui(stdscr, cmdlist):
    selected_line = 0
    curses.curs_set(0)
    while True:
        redraw(stdscr, cmdlist, selected_line)
        # stdscr.refresh()
        c = stdscr.getch()
        if c == ord('q'): return
        elif c in down_keys:
            selected_line = (selected_line + 1) % len(cmdlist)
        elif c in up_keys:
            selected_line = (selected_line - 1) % len(cmdlist)
        elif c in select_keys:
            return selected_line
        elif c in back_keys:
            return -1
        elif c in exit_keys:
            return None
        else:
            stdscr.addstr(9, 9, str(c))


if __name__ == "__main__":
    parser = optparse.OptionParser(usage="%prog: see ratmenu(1)")
    for compat_option in ["display", "font", "label"]:
        parser.add_option("--%s" % compat_option, 
                          help="ignored for compatibility")
    parser.add_option("--fg",
                      help="foreground color (not yet)")
    parser.add_option("--bg",
                      help="foreground color (not yet)")
    parser.add_option("--io",
                      help="start from somewhere other than the top (1-based)")
    parser.add_option("--style", choices=["snazzy", "dreary"], default="snazzy",
                      help="move cursor vs. move items")
    parser.add_option("--align", choices=["left", "center", "right"], default="left",
                      help="menu item text alignment")
    parser.add_option("--shell", default="/bin/sh",
                      help="alternative shell (default and fallback is /bin/sh)")
    parser.add_option("--back",
                      help="command to back out to previous menu")
    parser.add_option("--persist", action="store_true",
                      help="ignored for compatibility")
    # and we get --version for free
    options, args = parser.parse_args()
    
    cmdlist = group_into_pairs(args)

    selection = curses.wrapper(cursesui, cmdlist)

    if selection is None:
        sys.exit()
    elif selection == -1:
        if options.back:
            os.execv(options.shell, ["sh", "-c", options.back])
        else:
            sys.exit("hit back, but no --back supplied")
    else:
        label, cmd = cmdlist[selection]
        os.execv(options.shell, ["sh", "-c", cmd])