#!/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"

# Function to monitor raw data for debugging
debug_raw_monitor() {
    local port="$1"
    echo ""
    echo "====================================================="
    echo "  RAW DATA MONITOR (Debug Mode)"
    echo "====================================================="
    echo "  Monitoring port: $port"
    echo "  Settings: 9600 baud, 8N1, Raw, No Flow Control"
    echo "-----------------------------------------------------"
    echo "  Sending test command (:GR#) every 2 seconds..."
    echo "  Incoming data will be shown as HEXADECIMAL values."
    echo "  - 0000        : Null bytes (line noise)"
    echo "  - 3a47 5223   : Valid ASCII text"
    echo "-----------------------------------------------------"
    echo "  Press Ctrl+C to Stop Monitoring and Exit."
    echo "====================================================="

    # Configure port explicitly
    # Added -crtscts (no hardware flow control) and -hupcl (no hangup/DTR reset)
    stty -F "$port" 9600 cs8 -cstopb -parenb raw -echo -crtscts clocal -hupcl

    # Start a background loop to ping the telescope so we provoke a response
    # We use a subshell to keep it contained
    (
        while true; do
            echo -ne ":GR#" > "$port" 2>/dev/null
            sleep 2
        done
    ) &
    BG_PID=$!

    # Ensure we kill the background pinger when this function/script stops
    trap "kill $BG_PID 2>/dev/null; exit" INT TERM EXIT

    # Listen to the port and dump hex
    # We use 'od -x' (octal dump -hex) to see exactly what bytes come in
    od -x < "$port"
}

# Function to attempt to auto-detect the telescope
scan_ports() {
    echo "Scanning ports for telescope response (sending :GR#)..."
    FOUND_PORT=""

    # Check common serial device patterns
    for port in /dev/ttyUSB* /dev/ttyS[0-9]; do
        # Check if port exists
        if [ -e "$port" ]; then

            # Try 9600 baud first (Standard Meade)
            # Added clocal -crtscts -hupcl to prevent telescope resets
            if stty -F "$port" 9600 cs8 -cstopb -parenb raw -echo -crtscts clocal -hupcl 2>/dev/null; then

                # Clear any existing data in buffer
                timeout 0.2s cat "$port" >/dev/null 2>&1

                # Send "Get RA" command
                echo -ne ":GR#" > "$port" 2>/dev/null

                # Try to read response
                RESPONSE=$(timeout 1s head -c 10 "$port" 2>/dev/null | tr -d '\0')

                if [[ "$RESPONSE" == *"#"* ]] || [[ "$RESPONSE" =~ [0-9] ]]; then
                    echo "  [FOUND] Telescope detected on $port (Response: $RESPONSE)"
                    FOUND_PORT="$port"
                else
                    echo "  [ ... ] Checked $port (9600) - No valid response"
                fi
            fi

            # If not found, try 19200 baud (Some Northstar clones use this)
            if [ -z "$FOUND_PORT" ]; then
                 stty -F "$port" 19200 cs8 -cstopb -parenb raw -echo -crtscts clocal -hupcl 2>/dev/null
                 timeout 0.2s cat "$port" >/dev/null 2>&1
                 echo -ne ":GR#" > "$port" 2>/dev/null
                 RESPONSE=$(timeout 1s head -c 10 "$port" 2>/dev/null | tr -d '\0')

                 if [[ "$RESPONSE" == *"#"* ]] || [[ "$RESPONSE" =~ [0-9] ]]; then
                    echo "  [FOUND] Telescope detected on $port (19200 baud) (Response: $RESPONSE)"
                    FOUND_PORT="$port"
                    # Reconfigure main script variable if found at different baud
                    stty -F "$port" 19200 cs8 -cstopb -parenb raw -echo -crtscts clocal -hupcl 2>/dev/null
                 fi
            fi
        fi
    done

    if [ ! -z "$FOUND_PORT" ]; then
        echo ""
        echo "Auto-selected likely port: $FOUND_PORT"
        SERIAL_PORT="$FOUND_PORT"
    else
        echo "Scan complete. No obvious telescope response found."

        # Fallback Monitor Prompt
        echo ""
        echo "(!) Connection Troubleshooting:"
        echo "    If the telescope RESETS when scanned, the DTR line is likely active."
        echo "    This script now attempts to disable DTR (-hupcl)."
        read -p "    Start Raw Data Monitor to debug? (y/n): " RUN_DEBUG

        if [[ "$RUN_DEBUG" =~ ^[Yy]$ ]]; then
             # Ask which port to monitor since we didn't find one
             echo ""
             echo "Available Ports:"
             ls /dev/ttyS* /dev/ttyUSB* 2>/dev/null
             read -p "Enter Port to Monitor [default: /dev/ttyS0]: " DEBUG_PORT
             if [ -z "$DEBUG_PORT" ]; then DEBUG_PORT="/dev/ttyS0"; fi

             if [ -e "$DEBUG_PORT" ]; then
                 debug_raw_monitor "$DEBUG_PORT"
                 exit 0 # Exit script after monitoring
             else
                 echo "Error: Port $DEBUG_PORT does not exist."
                 exit 1
             fi
        fi
    fi
}

# -----------------------------------------------------------------
# 1. Setup Serial Port
# -----------------------------------------------------------------
echo "-----------------------------------------------------"
echo "  Telescope Control Interface (Bash)"
echo "-----------------------------------------------------"

# Run the scan function
scan_ports

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
# Added clocal -crtscts -hupcl to prevent resets
stty -F "$SERIAL_PORT" 9600 cs8 -cstopb -parenb raw -echo -crtscts clocal -hupcl

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