#!/bin/bash

# Generic script to install systemd timer for any service backup
# This script should only be called via ./manage install <service>

set -e

# Check if called via manage script
if [ "${CALLED_FROM_MANAGE:-}" != "true" ]; then
    echo "ERROR: This script should not be called directly."
    echo "Use: ./manage install <service_name>"
    exit 1
fi

# Configuration should be sourced before running: source backup.env

# Check arguments
if [ $# -lt 1 ]; then
    echo "Usage: $0 <service_name> [schedule]"
    echo ""
    echo "Examples:"
    echo "  $0 paperless                    # Daily at 3:00 AM (default)"
    echo "  $0 nextcloud \"*-*-* 02:30:00\"   # Daily at 2:30 AM"
    echo "  $0 gitlab \"Mon *-*-* 04:00:00\"  # Weekly on Monday at 4:00 AM"
    echo ""
    echo "Available services with backup.sh:"
    find "$SERVICES_BASE_DIR" -name "backup.sh" -printf "  %h\n" | sed "s|$SERVICES_BASE_DIR/||" 2>/dev/null || echo "  (none found)"
    exit 1
fi

SERVICE_NAME="$1"
SCHEDULE="${2:-$DEFAULT_BACKUP_SCHEDULE}"  # Use default from config

SERVICE_DIR="$SERVICES_BASE_DIR/$SERVICE_NAME"
BACKUP_SCRIPT="$SERVICE_DIR/backup.sh"
BACKUP_DIR="$BACKUP_BASE_DIR"

# Systemd template files
SERVICE_TEMPLATE="service-backup@.service"
TIMER_TEMPLATE="service-backup@.timer"
SYSTEMD_DIR="/etc/systemd/system"

# Instance names
SERVICE_INSTANCE="service-backup@$SERVICE_NAME.service"
TIMER_INSTANCE="service-backup@$SERVICE_NAME.timer"

echo "=== Installing Systemd Timer for $SERVICE_NAME Backup ==="

# Check if running as root
if [ "$EUID" -ne 0 ]; then
    echo "This script needs to be run with sudo for systemd operations"
    echo "Usage: sudo $0 $SERVICE_NAME"
    exit 1
fi

# Check if service directory exists
if [ ! -d "$SERVICE_DIR" ]; then
    echo "ERROR: Service directory not found: $SERVICE_DIR"
    exit 1
fi

# Check if backup script exists
if [ ! -f "$BACKUP_SCRIPT" ]; then
    echo "ERROR: Backup script not found: $BACKUP_SCRIPT"
    echo "Please create a backup.sh script in the service directory"
    exit 1
fi

# Make backup script executable
chmod +x "$BACKUP_SCRIPT"

# Check if template files exist
if [ ! -f "$BACKUP_DIR/service-backup@.service" ]; then
    echo "ERROR: Service template not found: $BACKUP_DIR/service-backup@.service"
    exit 1
fi

if [ ! -f "$BACKUP_DIR/service-backup@.timer" ]; then
    echo "ERROR: Timer template not found: $BACKUP_DIR/service-backup@.timer"
    exit 1
fi

# Stop and disable existing timer if it exists
if systemctl is-active --quiet "$TIMER_INSTANCE" 2>/dev/null; then
    echo "Stopping existing timer..."
    systemctl stop "$TIMER_INSTANCE"
fi

if systemctl is-enabled --quiet "$TIMER_INSTANCE" 2>/dev/null; then
    echo "Disabling existing timer..."
    systemctl disable "$TIMER_INSTANCE"
fi

# Generate service and timer files with substituted variables
echo "Generating service file with current configuration..."
sed -e "s|\${BACKUP_USER}|$BACKUP_USER|g" \
    -e "s|\${SERVICES_BASE_DIR}|$SERVICES_BASE_DIR|g" \
    "$BACKUP_DIR/service-backup@.service" > "/etc/systemd/system/service-backup@.service"
chmod 644 "/etc/systemd/system/service-backup@.service"

echo "Generating timer file with current configuration..."
sed -e "s|\${DEFAULT_BACKUP_SCHEDULE}|$DEFAULT_BACKUP_SCHEDULE|g" \
    "$BACKUP_DIR/service-backup@.timer" > "/etc/systemd/system/service-backup@.timer"
chmod 644 "/etc/systemd/system/service-backup@.timer"

# Create custom timer with specific schedule if different from default
if [ "$SCHEDULE" != "$DEFAULT_BACKUP_SCHEDULE" ]; then
    echo "Creating custom timer with schedule: $SCHEDULE"
    sed "s|OnCalendar=\*-\*-\* 03:00:00|OnCalendar=$SCHEDULE|" \
        "$BACKUP_DIR/service-backup@.timer" > "/etc/systemd/system/$TIMER_INSTANCE"
    chmod 644 "/etc/systemd/system/$TIMER_INSTANCE"
fi

# Reload systemd
echo "Reloading systemd daemon..."
systemctl daemon-reload

# Enable and start timer
echo "Enabling and starting timer for $SERVICE_NAME..."
systemctl enable "service-backup@$SERVICE_NAME.timer"
systemctl start "service-backup@$SERVICE_NAME.timer"

# Create log file with proper permissions
LOG_FILE="$LOG_DIR/$SERVICE_NAME-backup.log"
touch "$LOG_FILE"
chown "$BACKUP_USER:$BACKUP_USER" "$LOG_FILE"

echo ""
echo "✅ Systemd timer installed successfully for $SERVICE_NAME!"
echo ""
echo "📋 Useful commands:"
echo "  Check timer status:     systemctl status service-backup@$SERVICE_NAME.timer"
echo "  View timer schedule:    systemctl list-timers service-backup@$SERVICE_NAME.timer"
echo "  Run backup manually:    systemctl start service-backup@$SERVICE_NAME.service"
echo "  View backup logs:       journalctl -u service-backup@$SERVICE_NAME.service"
echo "  View recent logs:       journalctl -u service-backup@$SERVICE_NAME.service -f"
echo "  Stop timer:             systemctl stop service-backup@$SERVICE_NAME.timer"
echo "  Disable timer:          systemctl disable service-backup@$SERVICE_NAME.timer"
echo ""
echo "📅 Schedule: $SCHEDULE (with up to 5min random delay)"
echo "📝 Logs: Available via journalctl and $LOG_FILE"

echo ""
echo "🔍 Current timer status:"
systemctl status "service-backup@$SERVICE_NAME.timer" --no-pager -l || true