#!/bin/sh
# SecuBox Safe LED Script for MochaBin
# Slow I2C writes with error handling to prevent bus lockup

LED_BASE="/sys/class/leds"
WRITE_DELAY=1  # 300ms between writes to prevent I2C overload
ERROR_BACKOFF=5  # Wait 5s after any error
MAX_ERRORS=3     # Stop after 3 consecutive errors

error_count=0

# Safe LED write with timeout and error detection
led_write() {
    local led="$1"
    local val="$2"
    local path="$LED_BASE/$led/brightness"
    
    [ ! -f "$path" ] && return 1
    
    # Use timeout to prevent hang (busybox compatible)
    echo "$val" > "$path" 2>/dev/null
    local ret=$?
    
    if [ $ret -ne 0 ]; then
        error_count=$((error_count + 1))
        logger -t secubox-led "LED write failed: $led (error $error_count)"
        sleep $ERROR_BACKOFF
        return 1
    fi
    
    error_count=0
    sleep $WRITE_DELAY
    return 0
}

# Set all RGB LEDs to a color (one at a time, slowly)
set_color() {
    local r="$1" g="$2" b="$3"
    
    led_write "red:led1" "$r" || return 1
    led_write "green:led1" "$g" || return 1
    led_write "blue:led1" "$b" || return 1
}

# Set all 3 LED groups
set_all_leds() {
    local r="$1" g="$2" b="$3"
    
    for i in 1 2 3; do
        led_write "red:led$i" "$r" || return 1
        led_write "green:led$i" "$g" || return 1
        led_write "blue:led$i" "$b" || return 1
    done
}

# Health check - simple status colors
get_status_color() {
    # Check basic system health
    local load=$(cat /proc/loadavg | cut -d' ' -f1 | cut -d'.' -f1)
    local mem_free=$(grep MemAvailable /proc/meminfo | awk '{print int($2/1024)}')
    
    # Default: green (healthy)
    local r=0 g=64 b=0
    
    # Warning: yellow (high load or low memory)
    if [ "$load" -gt 4 ] || [ "$mem_free" -lt 256 ]; then
        r=64 g=64 b=0
    fi
    
    # Critical: red (very high load or very low memory)
    if [ "$load" -gt 8 ] || [ "$mem_free" -lt 128 ]; then
        r=64 g=0 b=0
    fi
    
    echo "$r $g $b"
}

# Main loop - update every 10 seconds (very slow)
main() {
    logger -t secubox-led "Safe LED script starting..."
    
    # Initial state: dim green
    set_all_leds 0 32 0
    
    while true; do
        # Check for too many errors
        if [ $error_count -ge $MAX_ERRORS ]; then
            logger -t secubox-led "Too many errors, stopping LED updates"
            exit 1
        fi
        
        # Get status and set color
        read r g b << EOF
$(get_status_color)
EOF
        set_all_leds "$r" "$g" "$b"
        
        # Long sleep between updates
        sleep 10
    done
}

# Handle arguments
case "$1" in
    start)
        main &
        echo $! > /tmp/secubox-led.pid
        ;;
    stop)
        [ -f /tmp/secubox-led.pid ] && kill $(cat /tmp/secubox-led.pid) 2>/dev/null
        rm -f /tmp/secubox-led.pid
        ;;
    status)
        get_status_color
        ;;
    test)
        echo "Testing LED write..."
        set_color 0 32 0 && echo "Green OK"
        sleep 2
        set_color 32 32 0 && echo "Yellow OK"
        sleep 2
        set_color 32 0 0 && echo "Red OK"
        sleep 2
        set_color 0 0 32 && echo "Blue OK"
        sleep 2
        set_color 0 32 0 && echo "Back to green"
        ;;
    *)
        echo "Usage: $0 {start|stop|status|test}"
        ;;
esac