#!/bin/bash

# Enable strict error handling
set -euo pipefail
trap 'handle_error $? $LINENO' ERR

# Configuration
BACKUP_SCRIPT="/home/litespeed/mb-backups/backup_all.sh"
LOG_DIR="/home/litespeed/mb-backups/logs/auto"
ACTION_LOG_FILE="${LOG_DIR}/schedule_actions.log"
BACKUP_LOG_PREFIX="${LOG_DIR}/backup_"
PASSWORD_FILE="/etc/restic-password"
LOCK_FILE="/tmp/backup_schedule.lock"
SCHEDULE="0 0 * * *"  # Default to daily at midnight

# Error handling function
handle_error() {
    local exit_code=$1
    local line_no=$2
    log_action "ERROR: Command failed at line ${line_no} with exit code ${exit_code}"
    cleanup_and_exit 1
}

# Cleanup function
cleanup_and_exit() {
    local exit_code=$1
    [ -f "$LOCK_FILE" ] && rm -f "$LOCK_FILE"
    exit "${exit_code}"
}

# Ensure single instance
ensure_single_instance() {
    if [ -f "$LOCK_FILE" ]; then
        if kill -0 "$(cat "$LOCK_FILE")" 2>/dev/null; then
            log_action "ERROR: Another instance is running"
            exit 1
        fi
    fi
    echo $$ > "$LOCK_FILE"
}

# Logging function
log_action() {
    local timestamp=$(date +'%Y-%m-%d %H:%M:%S')
    echo "[$timestamp] $1" | tee -a "$ACTION_LOG_FILE"
}

# Function to configure the cron job
configure_cron_job() {
    if [ ! -f "$PASSWORD_FILE" ]; then
        log_action "ERROR: Restic password file not found"
        return 1
    fi

    local restic_password
    restic_password=$(cat "$PASSWORD_FILE")
    local cmd="RESTIC_PASSWORD='$restic_password' LOG_FILE='${BACKUP_LOG_PREFIX}\$(date +\%Y-\%m-\%d_\%H-\%M-\%S).log' $BACKUP_SCRIPT > \"\$LOG_FILE\" 2>&1 || echo \"\$(date) Backup failed\" >> \"$ACTION_LOG_FILE\""

    # Update the cron job
    (crontab -l 2>/dev/null | grep -v "$BACKUP_SCRIPT"; echo "$SCHEDULE $cmd") | crontab -
    log_action "Scheduled daily backup at midnight with command: $cmd"
}

# Main execution
main() {
    mkdir -p "$LOG_DIR"
    chmod 750 "$LOG_DIR"
    ensure_single_instance
    configure_cron_job
    cleanup_and_exit 0
}

# Execute main function with all arguments
main "$@"