#!/bin/bash

# =================================================================
# Bushnell Northstar / Meade Autostar Telescope Control Script
# =================================================================
# Controls a telescope via serial port using Arrow Keys and Number Keys.
# Protocol: Meade LX200 / Autostar Generic
#
# CONTROLS:
#   Arrow Keys : Start moving (North/South/East/West)
#   Spacebar   : STOP Moving (Important!)
#   1-9        : Set Speed (1=Slowest/Guide, 9=Fastest/Slew)
#   q          : Quit the program
# =================================================================

# Default Serial Port (can be changed by user input)
SERIAL_PORT="/dev/ttyS0"

# -----------------------------------------------------------------
# 1. Setup Serial Port
# -----------------------------------------------------------------
echo "-----------------------------------------------------"
echo "  Telescope Control Interface (Bash)"
echo "-----------------------------------------------------"
echo "Available Serial Ports:"
ls /dev/ttyS* /dev/ttyUSB* 2>/dev/null
echo ""
read -p "Enter Serial Port [default: $SERIAL_PORT]: " USER_PORT

if [ ! -z "$USER_PORT" ]; then
    SERIAL_PORT="$USER_PORT"
fi

if [ ! -e "$SERIAL_PORT" ]; then
    echo "Error: Port $SERIAL_PORT does not exist."
    exit 1
fi

# Configure the serial port using stty
# 9600 baud, 8N1 (Standard for Northstar/Autostar), raw mode to prevent buffering
stty -F "$SERIAL_PORT" 9600 cs8 -cstopb -parenb raw -echo

echo "Connected to $SERIAL_PORT at 9600 baud."
echo "Initializing..."

# Send a Stop command just in case
echo -ne ":Q#" > "$SERIAL_PORT"

# -----------------------------------------------------------------
# 2. Control Loop
# -----------------------------------------------------------------
CURRENT_SPEED="Max"

print_ui() {
    clear
    echo "====================================================="
    echo "  TELESCOPE CONTROL PANEL"
    echo "====================================================="
    echo "  Port: $SERIAL_PORT  |  Status: Ready"
    echo "-----------------------------------------------------"
    echo "  [ UP ]    Move North"
    echo "  [DOWN]    Move South"
    echo "  [LEFT]    Move West"
    echo "  [RGHT]    Move East"
    echo "  [SPACE]   STOP ALL MOTORS"
    echo "-----------------------------------------------------"
    echo "  Current Speed Setting: $CURRENT_SPEED"
    echo "  [1-2] Guide (Slowest/Nudge)"
    echo "  [3-5] Center (Slow)"
    echo "  [6-8] Find (Medium)"
    echo "  [9]   Slew (Max Speed)"
    echo "-----------------------------------------------------"
    echo "  Press 'q' to Quit Script"
    echo "====================================================="
}

print_ui

# Loop to capture keystrokes one by one
while true; do
    # Read 1 character silently (-s), 3 chars if it's an escape sequence
    read -rsn1 key

    # If key is empty (sometimes happens), skip
    if [[ -z "$key" ]]; then continue; fi

    # Handle Escape Sequences (Arrow Keys start with ESC)
    if [[ "$key" == $'\x1b' ]]; then
        read -rsn2 key # Read the next 2 characters
        case "$key" in
            '[A') # UP Arrow
                echo -ne ":Mn#" > "$SERIAL_PORT"
                ;;
            '[B') # DOWN Arrow
                echo -ne ":Ms#" > "$SERIAL_PORT"
                ;;
            '[D') # LEFT Arrow
                echo -ne ":Mw#" > "$SERIAL_PORT"
                ;;
            '[C') # RIGHT Arrow
                echo -ne ":Me#" > "$SERIAL_PORT"
                ;;
        esac
    else
        # Handle Standard Keys
        case "$key" in
            # SPACEBAR - The most important key! Stops the telescope.
            ' ')
                echo -ne ":Q#" > "$SERIAL_PORT"
                ;;

            # Speed Controls (Mapped to Meade Standard Rate Commands)
            '1'|'2')
                # Guide Rate (Very Slow / Nudge)
                echo -ne ":RG#" > "$SERIAL_PORT"
                CURRENT_SPEED="Guide (Slowest)"
                print_ui
                ;;
            '3'|'4'|'5')
                # Center Rate (Slow)
                echo -ne ":RC#" > "$SERIAL_PORT"
                CURRENT_SPEED="Center (Slow)"
                print_ui
                ;;
            '6'|'7'|'8')
                # Find Rate (Medium)
                echo -ne ":RM#" > "$SERIAL_PORT"
                CURRENT_SPEED="Find (Medium)"
                print_ui
                ;;
            '9')
                # Slew Rate (Fastest)
                echo -ne ":RS#" > "$SERIAL_PORT"
                CURRENT_SPEED="Slew (Max)"
                print_ui
                ;;

            # Quit Application
            'q')
                echo "Stopping telescope..."
                echo -ne ":Q#" > "$SERIAL_PORT"
                exit 0
                ;;
        esac
    fi
done