#!/bin/sh /etc/rc.common
# /etc/init.d/battery-monitor

START=99
STOP=01

CHARGER_FILE="/sys/class/power_supply/pm8916-lbc-chgr/online"
BMS_PATH="/sys/class/power_supply/pm8916-bms-vm"

# Required LEDs
LED_RED="red:charging"
LED_GREEN="green:charging"

# Check if required LEDs exist
check_leds() {
    local missing=""
    
    if [ ! -d "/sys/class/leds/$LED_RED" ]; then
        missing="$missing $LED_RED"
    fi
    
    if [ ! -d "/sys/class/leds/$LED_GREEN" ]; then
        missing="$missing $LED_GREEN"
    fi
    
    if [ -n "$missing" ]; then
        logger -t battery-monitor "LEDs not found, service disabled:$missing"
        return 1
    fi
    
    return 0
}

get_capacity() {
    local voltage=$(cat $BMS_PATH/voltage_now 2>/dev/null)
    local vmax=$(cat $BMS_PATH/voltage_max_design 2>/dev/null)
    local vmin=$(cat $BMS_PATH/voltage_min_design 2>/dev/null)
    
    if [ -n "$voltage" ] && [ -n "$vmax" ] && [ -n "$vmin" ]; then
        awk -v v="$voltage" -v vmax="$vmax" -v vmin="$vmin" \
            'BEGIN {pct = ((v - vmin) / (vmax - vmin)) * 100; 
                    if (pct < 0) pct = 0; 
                    if (pct > 100) pct = 100; 
                    printf "%.0f", pct}'
    else
        echo "50"
    fi
}

show_battery_temp() {
    local capacity=$(get_capacity)
    
    # Clear both LEDs first
    ledcontrol $LED_RED off 2>/dev/null
    ledcontrol $LED_GREEN off 2>/dev/null
    
    # Show battery level with 2 states (button press)
    if [ "$capacity" -lt 50 ]; then
        # Low battery: solid red
        ledcontrol $LED_RED on 2>/dev/null
    else
        # Good battery: solid green
        ledcontrol $LED_GREEN on 2>/dev/null
    fi
    
    logger -t battery-monitor "SIGUSR1: Showing ${capacity}%"
    
    sleep 2
    
    update_led
}

update_led() {
    local charging=$(cat $CHARGER_FILE 2>/dev/null || echo 0)
    
    if [ "$charging" = "1" ]; then
        local capacity=$(get_capacity)
        
        # Clear both LEDs first
        ledcontrol $LED_RED off 2>/dev/null
        ledcontrol $LED_GREEN off 2>/dev/null
        
        # 3 charging states
        if [ "$capacity" -ge 95 ]; then
            # Fully charged: solid green
            ledcontrol $LED_GREEN on 2>/dev/null
            logger -t battery-monitor "Charging complete: ${capacity}%"
        elif [ "$capacity" -ge 50 ]; then
            # Charging medium/high: blinking green
            ledcontrol $LED_GREEN blink 2>/dev/null
            logger -t battery-monitor "Charging: ${capacity}%"
        else
            # Charging low: blinking red
            ledcontrol $LED_RED blink 2>/dev/null
            logger -t battery-monitor "Charging low: ${capacity}%"
        fi
    else
        # Not charging: turn off LEDs
        ledcontrol $LED_RED off 2>/dev/null
        ledcontrol $LED_GREEN off 2>/dev/null
    fi
}

# Main monitoring loop (runs in background)
monitor_loop() {
    # Set up signal handler
    trap 'show_battery_temp' USR1
    
    # Get initial state
    local last_state=$(cat $CHARGER_FILE 2>/dev/null || echo 0)
    update_led
    
    # Poll charger state
    while true; do
        local current_state=$(cat $CHARGER_FILE 2>/dev/null || echo 0)
        
        if [ "$current_state" != "$last_state" ]; then
            logger -t battery-monitor "Charger state changed: $last_state -> $current_state"
            last_state=$current_state
            sleep 1
            update_led
        fi
        
        # Poll every 2 seconds
        sleep 2
    done
}

start() {
    # Exit silently if LEDs don't exist
    check_leds || return 0
    
    # Check if already running
    if [ -f /var/run/battery-monitor.pid ] && kill -0 $(cat /var/run/battery-monitor.pid) 2>/dev/null; then
        logger -t battery-monitor "Already running"
        return 0
    fi
    
    logger -t battery-monitor "Starting with LEDs: $LED_RED, $LED_GREEN"
    
    # Start monitoring loop in background
    monitor_loop &
    
    echo $! > /var/run/battery-monitor.pid
    logger -t battery-monitor "Service started (PID: $!)"
}

stop() {
    if [ -f /var/run/battery-monitor.pid ]; then
        local pid=$(cat /var/run/battery-monitor.pid)
        
        if kill -0 $pid 2>/dev/null; then
            kill $pid 2>/dev/null
            
            # Wait for process to die
            local timeout=5
            while [ $timeout -gt 0 ] && kill -0 $pid 2>/dev/null; do
                sleep 1
                timeout=$((timeout - 1))
            done
            
            # Force kill if still alive
            kill -9 $pid 2>/dev/null
            
            logger -t battery-monitor "Service stopped (PID: $pid)"
        fi
        
        rm -f /var/run/battery-monitor.pid
    fi
    
    # Only try to control LEDs if they exist
    if check_leds 2>/dev/null; then
        ledcontrol $LED_GREEN off 2>/dev/null
        ledcontrol $LED_RED blink 2>/dev/null
        logger -t battery-monitor "Shutdown: Red LED blinking"
    fi
    
    return 0
}

restart() {
    stop
    sleep 1
    start
}