#!/bin/bash
# Script to set up automatic PC shutdown with day-specific time windows
# Monday-Wednesday: Shutdown between 21:00-05:00
# Thursday-Sunday: Shutdown between 22:00-05:00
# Handles sudo privileges automatically

set -e # Exit on any error

# Function to show usage
show_usage() {
	echo "Day-Specific Auto-Shutdown Setup for Arch Linux"
	echo "==============================================="
	echo "Usage: $0 [enable|status]"
	echo ""
	echo "Commands:"
	echo "  enable   - Set up automatic shutdown with day-specific windows (default)"
	echo "  status   - Show current status"
	echo ""
	echo "Shutdown Schedule:"
	echo "  Monday-Wednesday: 21:00-05:00"
	echo "  Thursday-Sunday:  22:00-05:00"
	echo ""
	echo "NOTE: There is no 'disable' option. This is intentional."
	echo "      The shutdown timer is protected by a monitor service."
	echo ""
}

# Function to check and request sudo privileges
check_sudo() {
	if [[ $EUID -ne 0 ]]; then
		echo "This script requires sudo privileges to manage systemd services."
		echo "Requesting sudo access..."
		exec sudo "$0" "$@"
	fi
}

# Get the actual user (even when running with sudo)
if [[ -n $SUDO_USER ]]; then
	ACTUAL_USER="$SUDO_USER"
	USER_HOME="/home/$SUDO_USER"
else
	ACTUAL_USER="$USER"
	USER_HOME="$HOME"
fi

# Function to show current status
show_current_status() {
	echo "Day-Specific Auto-Shutdown Status"
	echo "================================="
	echo "Current Date: $(date)"
	echo "User: $ACTUAL_USER"
	echo ""

	local timer_exists=false

	# Check if files exist
	if [[ -f "/etc/systemd/system/day-specific-shutdown.timer" ]]; then
		timer_exists=true
		echo "✓ Timer file exists"
	else
		echo "✗ Timer file missing"
	fi

	if [[ -f "/etc/systemd/system/day-specific-shutdown.service" ]]; then
		echo "✓ Service file exists"
	else
		echo "✗ Service file missing"
	fi

	if [[ -f "/usr/local/bin/day-specific-shutdown-manager.sh" ]]; then
		echo "✓ Management script exists"
	else
		echo "✗ Management script missing"
	fi

	if [[ -f "/usr/local/bin/shutdown-timer-monitor.sh" ]]; then
		echo "✓ Monitor script exists"
	else
		echo "✗ Monitor script missing"
	fi

	echo ""

	# Check systemd status
	if $timer_exists; then
		if systemctl is-enabled day-specific-shutdown.timer &>/dev/null; then
			echo "✓ Timer is enabled"
			if systemctl is-active day-specific-shutdown.timer &>/dev/null; then
				echo "✓ Timer is active"
				echo ""
				echo "Next scheduled shutdown check:"
				systemctl list-timers day-specific-shutdown.timer --no-pager 2>/dev/null | grep day-specific-shutdown || echo "Timer information not available"
			else
				echo "✗ Timer is not active"
			fi
		else
			echo "✗ Timer is not enabled"
		fi
	else
		echo "Status: NOT CONFIGURED"
	fi

	echo ""

	# Check monitor service status
	echo "Monitor Service Status:"
	if systemctl is-enabled shutdown-timer-monitor.service &>/dev/null; then
		echo "✓ Monitor is enabled"
		if systemctl is-active shutdown-timer-monitor.service &>/dev/null; then
			echo "✓ Monitor is active (will re-enable timer if disabled)"
		else
			echo "✗ Monitor is not active"
		fi
	else
		echo "✗ Monitor is not enabled"
	fi

	echo ""
	echo "Shutdown Schedule:"
	echo "  Monday-Wednesday: 21:00-05:00"
	echo "  Thursday-Sunday:  22:00-05:00"
	echo ""
	echo "NOTE: The shutdown timer is protected by a monitor service."
	echo "      If you try to disable the timer, it will be automatically re-enabled."
	echo ""
}

# Function to create the shutdown service
create_shutdown_service() {
	echo ""
	echo "1. Creating Systemd Shutdown Service..."
	echo "======================================"

	local service_file="/etc/systemd/system/day-specific-shutdown.service"

	cat >"$service_file" <<'EOF'
[Unit]
Description=Automatic PC shutdown with day-specific time windows
DefaultDependencies=false
Before=shutdown.target reboot.target halt.target

[Service]
Type=oneshot
ExecStart=/usr/local/bin/day-specific-shutdown-check.sh
TimeoutStartSec=0
StandardOutput=journal
StandardError=journal
EOF

	echo "✓ Created systemd service: $service_file"
}

# Function to create the shutdown timer
create_shutdown_timer() {
	echo ""
	echo "2. Creating Systemd Shutdown Timer..."
	echo "==================================="

	local timer_file="/etc/systemd/system/day-specific-shutdown.timer"

	cat >"$timer_file" <<'EOF'
[Unit]
Description=Timer for automatic PC shutdown with day-specific windows
Requires=day-specific-shutdown.service

[Timer]
OnCalendar=*-*-* 21:00:00
OnCalendar=*-*-* 21:30:00
OnCalendar=*-*-* 22:00:00
OnCalendar=*-*-* 22:30:00
OnCalendar=*-*-* 23:00:00
OnCalendar=*-*-* 23:30:00
OnCalendar=*-*-* 00:00:00
OnCalendar=*-*-* 00:30:00
OnCalendar=*-*-* 01:00:00
OnCalendar=*-*-* 01:30:00
OnCalendar=*-*-* 02:00:00
OnCalendar=*-*-* 02:30:00
OnCalendar=*-*-* 03:00:00
OnCalendar=*-*-* 03:30:00
OnCalendar=*-*-* 04:00:00
OnCalendar=*-*-* 04:30:00
OnCalendar=*-*-* 05:00:00
Persistent=false
AccuracySec=1s
WakeSystem=false
RandomizedDelaySec=0

[Install]
WantedBy=timers.target
EOF

	echo "✓ Created systemd timer: $timer_file"
}

# Function to create management script
create_management_script() {
	echo ""
	echo "3. Creating Management Script..."
	echo "=============================="

	local script_file="/usr/local/bin/day-specific-shutdown-manager.sh"

	cat >"$script_file" <<'EOF'
#!/bin/bash
# Day-Specific Auto-Shutdown Manager
# Provides easy management of the day-specific shutdown feature

TIMER_NAME="day-specific-shutdown.timer"
SERVICE_NAME="day-specific-shutdown.service"

show_status() {
    echo "Day-Specific Auto-Shutdown Status"
    echo "================================="
    
    if systemctl is-enabled "$TIMER_NAME" &>/dev/null; then
        echo "Status: ENABLED"
        if systemctl is-active "$TIMER_NAME" &>/dev/null; then
            echo "Timer: ACTIVE"
        else
            echo "Timer: INACTIVE"
        fi
    else
        echo "Status: NOT ENABLED"
    fi
    
    echo ""
    echo "Shutdown Schedule:"
    echo "  Monday-Wednesday: 21:00-05:00"
    echo "  Thursday-Sunday:  22:00-05:00"
    
    echo ""
    echo "Next scheduled checks:"
    systemctl list-timers "$TIMER_NAME" --no-pager 2>/dev/null | grep "$TIMER_NAME" || echo "Timer not active"
    
    echo ""
    echo "Recent logs:"
    journalctl -u "$SERVICE_NAME" --no-pager -n 5 2>/dev/null || echo "No recent logs"
}

case "$1" in
    "status")
        show_status
        ;;
    "logs")
        echo "Day-Specific Auto-Shutdown Logs"
        echo "==============================="
        journalctl -u "$SERVICE_NAME" --no-pager -n 20
        ;;
    *)
        echo "Day-Specific Auto-Shutdown Manager"
        echo "Usage: $0 {status|logs}"
        echo ""
        echo "Commands:"
        echo "  status   - Show current status and next shutdown checks"
        echo "  logs     - Show recent shutdown logs"
        echo ""
        echo "Shutdown Schedule:"
        echo "  Monday-Wednesday: 21:00-05:00"
        echo "  Thursday-Sunday:  22:00-05:00"
        echo ""
        show_status
        ;;
esac
EOF

	chmod +x "$script_file"
	echo "✓ Created management script: $script_file"
}

# Function to create smart shutdown check script
create_shutdown_check_script() {
	echo ""
	echo "4. Creating Smart Shutdown Check Script..."
	echo "========================================"

	local check_script="/usr/local/bin/day-specific-shutdown-check.sh"

	cat >"$check_script" <<'EOF'
#!/bin/bash
# Smart day-specific shutdown check script
# Different shutdown windows based on day of week:
# Monday-Wednesday: 21:00-05:00
# Thursday-Sunday: 22:00-05:00

# Get current time and day
current_hour=$(date +%H)
current_minute=$(date +%M)
current_time_minutes=$((10#$current_hour * 60 + 10#$current_minute))
day_of_week=$(date +%u)  # 1=Monday, 7=Sunday
day_name=$(date +%A)

# Convert time to minutes for easier comparison
# 21:00 = 1260 minutes, 22:00 = 1320 minutes, 05:00 = 300 minutes
# 00:00 = 0 minutes, 05:00 = 300 minutes

logger -t day-specific-shutdown "Checking shutdown conditions at $(date) - Day: $day_name ($day_of_week), Time: $current_hour:$current_minute"

# Determine if we should shutdown based on day and time
should_shutdown=false

if [[ $day_of_week -ge 1 ]] && [[ $day_of_week -le 3 ]]; then
    # Monday (1), Tuesday (2), Wednesday (3): shutdown window 21:00-05:00
    logger -t day-specific-shutdown "Today is $day_name - checking 21:00-05:00 window"
    
    # Check if time is between 21:00 (1260 minutes) and 23:59 (1439 minutes)
    # OR between 00:00 (0 minutes) and 05:00 (300 minutes)
    if [[ $current_time_minutes -ge 1260 ]] || [[ $current_time_minutes -le 300 ]]; then
        should_shutdown=true
        if [[ $current_time_minutes -ge 1260 ]]; then
            logger -t day-specific-shutdown "Time $current_hour:$current_minute is within evening shutdown window (21:00-23:59)"
        else
            logger -t day-specific-shutdown "Time $current_hour:$current_minute is within morning shutdown window (00:00-05:00)"
        fi
    else
        logger -t day-specific-shutdown "Time $current_hour:$current_minute is outside shutdown window (21:00-05:00)"
    fi
else
    # Thursday (4), Friday (5), Saturday (6), Sunday (7): shutdown window 22:00-05:00
    logger -t day-specific-shutdown "Today is $day_name - checking 22:00-05:00 window"
    
    # Check if time is between 22:00 (1320 minutes) and 23:59 (1439 minutes)
    # OR between 00:00 (0 minutes) and 05:00 (300 minutes)
    if [[ $current_time_minutes -ge 1320 ]] || [[ $current_time_minutes -le 300 ]]; then
        should_shutdown=true
        if [[ $current_time_minutes -ge 1320 ]]; then
            logger -t day-specific-shutdown "Time $current_hour:$current_minute is within evening shutdown window (22:00-23:59)"
        else
            logger -t day-specific-shutdown "Time $current_hour:$current_minute is within morning shutdown window (00:00-05:00)"
        fi
    else
        logger -t day-specific-shutdown "Time $current_hour:$current_minute is outside shutdown window (22:00-05:00)"
    fi
fi

if [[ $should_shutdown == true ]]; then
    echo "$(date): Executing shutdown - current time $current_hour:$current_minute is within shutdown window for $day_name"
    logger -t day-specific-shutdown "Executing scheduled shutdown at $(date)"
    /usr/bin/systemctl poweroff
else
    echo "$(date): Skipping shutdown - not within shutdown window for $day_name (current: $current_hour:$current_minute)"
    logger -t day-specific-shutdown "Skipped shutdown - not within shutdown window for $day_name (current: $current_hour:$current_minute)"
fi
EOF

	chmod +x "$check_script"
	echo "✓ Created smart shutdown check script: $check_script"
}

# Function to enable the timer
enable_timer() {
	echo ""
	echo "5. Enabling Shutdown Timer..."
	echo "============================"

	# Reload systemd daemon
	systemctl daemon-reload
	echo "✓ Reloaded systemd daemon"

	# Enable the timer
	systemctl enable day-specific-shutdown.timer
	echo "✓ Enabled day-specific-shutdown timer"

	# Start the timer
	systemctl start day-specific-shutdown.timer
	echo "✓ Started day-specific-shutdown timer"
}

# Function to install the monitor service
install_monitor_service() {
	echo ""
	echo "6. Installing Shutdown Timer Monitor Service..."
	echo "=============================================="

	local monitor_script="/usr/local/bin/shutdown-timer-monitor.sh"
	local monitor_service="/etc/systemd/system/shutdown-timer-monitor.service"
	local monitor_timer="/etc/systemd/system/shutdown-timer-monitor-watchdog.timer"
	local monitor_watchdog_service="/etc/systemd/system/shutdown-timer-monitor-watchdog.service"

	# Create the monitor script
	cat >"$monitor_script" <<'EOF'
#!/bin/bash
# Shutdown timer monitor script
# Watches the day-specific-shutdown timer and re-enables it if disabled
# Also ensures the monitor service itself stays running

set -euo pipefail

LOG_FILE="/var/log/shutdown-timer-monitor.log"
TIMER_NAME="day-specific-shutdown.timer"
SERVICE_NAME="day-specific-shutdown.service"
MONITOR_SERVICE="shutdown-timer-monitor.service"
CHECK_INTERVAL=30

log_message() {
    echo "$(date '+%Y-%m-%d %H:%M:%S') - $1" | tee -a "$LOG_FILE" >&2
}

timer_needs_restoration() {
    if ! systemctl is-enabled "$TIMER_NAME" &>/dev/null; then
        log_message "Timer $TIMER_NAME is not enabled"
        return 0
    fi
    if ! systemctl is-active "$TIMER_NAME" &>/dev/null; then
        log_message "Timer $TIMER_NAME is not active"
        return 0
    fi
    if [[ ! -f "/etc/systemd/system/$TIMER_NAME" ]]; then
        log_message "Timer unit file missing"
        return 0
    fi
    if [[ ! -f "/etc/systemd/system/$SERVICE_NAME" ]]; then
        log_message "Service unit file missing"
        return 0
    fi
    if [[ ! -f "/usr/local/bin/day-specific-shutdown-check.sh" ]]; then
        log_message "Check script missing"
        return 0
    fi
    return 1
}

restore_timer() {
    log_message "Shutdown timer tampering detected - initiating restoration"
    systemctl daemon-reload
    if ! systemctl is-enabled "$TIMER_NAME" &>/dev/null; then
        log_message "Re-enabling $TIMER_NAME"
        systemctl enable "$TIMER_NAME" 2>/dev/null || true
    fi
    if ! systemctl is-active "$TIMER_NAME" &>/dev/null; then
        log_message "Re-starting $TIMER_NAME"
        systemctl start "$TIMER_NAME" 2>/dev/null || true
    fi
    if systemctl is-active "$TIMER_NAME" &>/dev/null; then
        log_message "Timer restoration completed successfully"
    else
        log_message "WARNING: Timer restoration may have failed"
    fi
}

log_message "=== Shutdown Timer Monitor Started ==="
log_message "Monitoring timer: $TIMER_NAME"

if timer_needs_restoration; then
    log_message "Initial check: Timer needs restoration"
    restore_timer
else
    log_message "Initial check: Timer is properly configured"
fi

while true; do
    if timer_needs_restoration; then
        restore_timer
    fi
    sleep "$CHECK_INTERVAL"
done
EOF

	chmod +x "$monitor_script"
	echo "✓ Created monitor script: $monitor_script"

	# Create the monitor service with RefuseManualStop to prevent manual stopping
	cat >"$monitor_service" <<'EOF'
[Unit]
Description=Shutdown Timer Monitor and Auto-Restore Service
After=network-online.target day-specific-shutdown.timer
Wants=network-online.target
# Make it hard to stop - refuse manual stop/restart
RefuseManualStop=true
RefuseManualStart=false

[Service]
Type=simple
User=root
ExecStart=/usr/local/bin/shutdown-timer-monitor.sh
Restart=always
RestartSec=5
# Restart even on success exit
RestartForceExitStatus=0 1 2 SIGTERM SIGKILL
StandardOutput=journal
StandardError=journal
Environment=PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
NoNewPrivileges=false
PrivateTmp=true
MemoryMax=50M
CPUQuota=10%

[Install]
WantedBy=multi-user.target
EOF

	echo "✓ Created monitor service: $monitor_service"

	# Create a watchdog timer that ensures the monitor stays running
	cat >"$monitor_watchdog_service" <<'EOF'
[Unit]
Description=Watchdog for Shutdown Timer Monitor
After=multi-user.target

[Service]
Type=oneshot
ExecStart=/bin/bash -c 'systemctl is-active shutdown-timer-monitor.service || systemctl start shutdown-timer-monitor.service'
ExecStart=/bin/bash -c 'systemctl is-active day-specific-shutdown.timer || systemctl start day-specific-shutdown.timer'
EOF

	echo "✓ Created watchdog service: $monitor_watchdog_service"

	cat >"$monitor_timer" <<'EOF'
[Unit]
Description=Watchdog Timer for Shutdown Timer Monitor
After=multi-user.target

[Timer]
OnBootSec=60
OnUnitActiveSec=60
Persistent=true

[Install]
WantedBy=timers.target
EOF

	echo "✓ Created watchdog timer: $monitor_timer"

	# Reload and enable everything
	systemctl daemon-reload
	systemctl enable shutdown-timer-monitor.service
	systemctl enable shutdown-timer-monitor-watchdog.timer
	systemctl start shutdown-timer-monitor.service
	systemctl start shutdown-timer-monitor-watchdog.timer
	echo "✓ Enabled and started shutdown-timer-monitor.service"
	echo "✓ Enabled and started shutdown-timer-monitor-watchdog.timer"
}

# Function to test the setup
test_setup() {
	echo ""
	echo "7. Testing Setup..."
	echo "=================="

	echo "Service files:"
	if [[ -f "/etc/systemd/system/day-specific-shutdown.service" ]]; then
		echo "✓ Service file exists"
	else
		echo "✗ Service file missing"
	fi

	if [[ -f "/etc/systemd/system/day-specific-shutdown.timer" ]]; then
		echo "✓ Timer file exists"
	else
		echo "✗ Timer file missing"
	fi

	if [[ -f "/etc/systemd/system/shutdown-timer-monitor.service" ]]; then
		echo "✓ Monitor service file exists"
	else
		echo "✗ Monitor service file missing"
	fi

	echo ""
	echo "Timer status:"
	if systemctl is-enabled day-specific-shutdown.timer &>/dev/null; then
		echo "✓ Timer is enabled"
	else
		echo "✗ Timer is not enabled"
	fi

	if systemctl is-active day-specific-shutdown.timer &>/dev/null; then
		echo "✓ Timer is active"
	else
		echo "✗ Timer is not active"
	fi

	echo ""
	echo "Monitor status:"
	if systemctl is-enabled shutdown-timer-monitor.service &>/dev/null; then
		echo "✓ Monitor is enabled"
	else
		echo "✗ Monitor is not enabled"
	fi

	if systemctl is-active shutdown-timer-monitor.service &>/dev/null; then
		echo "✓ Monitor is active"
	else
		echo "✗ Monitor is not active"
	fi

	echo ""
	echo "Watchdog timer status:"
	if systemctl is-enabled shutdown-timer-monitor-watchdog.timer &>/dev/null; then
		echo "✓ Watchdog timer is enabled"
	else
		echo "✗ Watchdog timer is not enabled"
	fi

	if systemctl is-active shutdown-timer-monitor-watchdog.timer &>/dev/null; then
		echo "✓ Watchdog timer is active"
	else
		echo "✗ Watchdog timer is not active"
	fi

	echo ""
	echo "Next scheduled checks:"
	systemctl list-timers day-specific-shutdown.timer --no-pager 2>/dev/null | head -5 | grep day-specific-shutdown || echo "Timer information not available"
}

# Function to show final instructions
show_instructions() {
	echo ""
	echo "================================================="
	echo "Day-Specific Auto-Shutdown Setup Complete"
	echo "================================================="
	echo "Summary:"
	echo "✓ Systemd service created (/etc/systemd/system/day-specific-shutdown.service)"
	echo "✓ Systemd timer created (/etc/systemd/system/day-specific-shutdown.timer)"
	echo "✓ Management script created (/usr/local/bin/day-specific-shutdown-manager.sh)"
	echo "✓ Smart check script created (/usr/local/bin/day-specific-shutdown-check.sh)"
	echo "✓ Timer enabled and started"
	echo "✓ Monitor service installed (protects timer from being disabled)"
	echo "✓ Watchdog timer installed (restarts monitor if stopped)"
	echo ""
	echo "Shutdown Schedule:"
	echo "  Monday-Wednesday: 21:00-05:00 (9:00 PM to 5:00 AM)"
	echo "  Thursday-Sunday:  22:00-05:00 (10:00 PM to 5:00 AM)"
	echo ""
	echo "Management commands:"
	echo "  sudo day-specific-shutdown-manager.sh status   - Check status"
	echo "  sudo day-specific-shutdown-manager.sh logs     - View shutdown logs"
	echo ""
	echo "How it works:"
	echo "• Timer checks every 30 minutes during potential shutdown windows"
	echo "• Smart logic determines shutdown eligibility based on day and time"
	echo "• Monitor service watches the timer and re-enables it if disabled"
	echo "• Watchdog timer restarts the monitor every 60 seconds if stopped"
	echo "• Monitor has RefuseManualStop=true to prevent easy stopping"
	echo "• There is NO disable option - this is intentional for digital wellbeing"
	echo ""
	echo "WARNING: This will automatically shutdown your PC during designated hours."
	echo "Make sure to save your work before the shutdown windows!"
	echo ""
}

# Function to prompt for confirmation
confirm_setup() {
	echo ""
	echo "WARNING: Day-Specific Auto-Shutdown Confirmation"
	echo "==============================================="
	echo "This will set up your PC to automatically shutdown during specific time windows."
	echo ""
	echo "Shutdown Schedule:"
	echo "  Monday-Wednesday: 21:00-05:00 (9:00 PM to 5:00 AM)"
	echo "  Thursday-Sunday:  22:00-05:00 (10:00 PM to 5:00 AM)"
	echo ""
	echo "Important considerations:"
	echo "- Any unsaved work will be lost during shutdown windows"
	echo "- Running processes will be terminated"
	echo "- Downloads/uploads in progress will be interrupted"
	echo "- You'll need to manually power on your PC each day"
	echo "- Timer checks every 30 minutes during potential shutdown windows"
	echo "- There is NO disable option - this is protected by a monitor service"
	echo ""
	read -r -p "Do you want to proceed? (y/N): " confirm

	case "$confirm" in
	[yY] | [yY][eE][sS])
		echo "Proceeding with setup..."
		return 0
		;;
	*)
		echo "Setup cancelled."
		exit 0
		;;
	esac
}

# Main execution flow for enable
enable_midnight_shutdown() {
	echo "Day-Specific Auto-Shutdown Setup for Arch Linux"
	echo "==============================================="
	echo "Current Date: $(date)"
	echo "User: $ACTUAL_USER"
	echo "Target user: $ACTUAL_USER"
	echo "User home: $USER_HOME"

	# Confirm setup
	confirm_setup

	# Create systemd files
	create_shutdown_service
	create_shutdown_timer
	create_management_script
	create_shutdown_check_script

	# Enable and start timer
	enable_timer

	# Install monitor service (protects timer from being disabled)
	install_monitor_service

	# Test setup
	test_setup

	# Show instructions
	show_instructions
}

# Parse command line arguments
case "${1:-enable}" in
"enable")
	check_sudo "$@"
	enable_midnight_shutdown
	;;
"status")
	check_sudo "$@"
	show_current_status
	;;
"help" | "-h" | "--help")
	show_usage
	;;
*)
	echo "Error: Unknown command '$1'"
	echo ""
	show_usage
	exit 1
	;;
esac