#!/bin/bash

# Log file path
LOG_FILE="/opt/phx/log/system_cleanup.log"
EMAIL="y.m.lima19@gmail.com"

# Function to send email notifications
send_email() {
    SUBJECT="$1"
    MESSAGE="$2"
    echo "$MESSAGE" | mail -s "$SUBJECT" "$EMAIL"
}

# Function to log informational messages
log_info() {
    echo "$(date '+%Y-%m-%d %H:%M:%S') [INFO] $1" | tee -a "$LOG_FILE"
}

# Function to log errors and send email notifications
log_error() {
    echo "$(date '+%Y-%m-%d %H:%M:%S') [ERROR] $1" | tee -a "$LOG_FILE" >&2
    send_email "⚠️ System Cleanup Error" "$1"
}

# Start Cleanup
log_info "========== System Cleanup Started =========="

# Clear system cache
log_info "Clearing system cache..."
if sync && echo 3 > /proc/sys/vm/drop_caches; then
    log_info "System cache cleared successfully."
else
    log_error "Failed to clear system cache."
fi

# Clean up packages
log_info "Cleaning up unused packages..."
if apt-get autoremove -y >> "$LOG_FILE" 2>&1; then
    log_info "Unused packages removed."
else
    log_error "Failed to remove unused packages."
fi

log_info "Running apt autoclean..."
if apt-get autoclean -y >> "$LOG_FILE" 2>&1; then
    log_info "Autoclean completed."
else
    log_error "Autoclean failed."
fi

log_info "Running apt clean..."
if apt-get clean >> "$LOG_FILE" 2>&1; then
    log_info "Clean completed."
else
    log_error "Clean failed."
fi

# Clean up system logs
log_info "Cleaning system logs older than 7 days..."
if journalctl --vacuum-time=7d >> "$LOG_FILE" 2>&1; then
    log_info "Old logs cleaned."
else
    log_error "Failed to clean old logs."
fi

# Restart services
log_info "Restarting Docker service..."
if systemctl restart docker; then
    log_info "Docker restarted successfully."
else
    log_error "Failed to restart Docker."
fi

# Kill zombie processes
log_info "Checking for zombie processes..."
ZOMBIES=$(ps aux | grep 'defunct' | grep -v grep)
if [[ -n "$ZOMBIES" ]]; then
    log_info "Found zombie processes. Attempting to kill..."
    if pkill -9 -f 'defunct'; then
        log_info "Zombie processes killed."
    else
        log_error "Failed to kill zombie processes."
    fi
else
    log_info "No zombie processes found."
fi

# Swap check and creation
log_info "Checking swap space..."
if swapon --show | grep -q '/swapfile'; then
    log_info "Swap space is active."
else
    log_info "No swap detected. Creating 2GB swap file..."
    if fallocate -l 2G /swapfile && chmod 600 /swapfile && mkswap /swapfile && swapon /swapfile; then
        log_info "Swap file created and activated."
    else
        log_error "Failed to create swap file."
    fi
fi

# Cleanup completed
log_info "========== System Cleanup Completed =========="
send_email "✅ System Cleanup Successful" "The system cleanup script has completed successfully."