"""Self-contained curses TUI used to exercise the tmux-shot pipeline.

Arrow keys move the '@' cursor, 'q' quits. No external dependencies beyond
the standard library, so the demo works without any other TUI installed.
"""
import curses


def main(stdscr: "curses._CursesWindow") -> None:
    curses.curs_set(0)
    curses.start_color()
    curses.use_default_colors()
    for i in range(1, 8):
        curses.init_pair(i, i, -1)

    y, x = 5, 10
    while True:
        stdscr.erase()
        stdscr.addstr(0, 0, "tmux-shot demo TUI -- arrows to move, q to quit", curses.A_BOLD)
        for i in range(1, 8):
            stdscr.addstr(2, i * 4, f" {i} ", curses.color_pair(i) | curses.A_REVERSE)
        stdscr.addstr(y, x, "@", curses.color_pair(2) | curses.A_BOLD)
        stdscr.refresh()

        ch = stdscr.getch()
        if ch in (ord("q"), ord("Q")):
            break
        elif ch == curses.KEY_UP:
            y = max(3, y - 1)
        elif ch == curses.KEY_DOWN:
            y += 1
        elif ch == curses.KEY_LEFT:
            x = max(0, x - 1)
        elif ch == curses.KEY_RIGHT:
            x += 1


if __name__ == "__main__":
    curses.wrapper(main)