#!/bin/bash
#
# Full System Backup Script using rsync
# Backs up entire server to local Mac storage
#
# Usage: ./system-backup.sh
#

set -e  # Exit on error

# Configuration
SERVER="ubuntu@51.89.231.46"
BACKUP_DIR="/Volumes/SSD/Aimpress_Cloud_Prod/system-backup"
LOG_FILE="$BACKUP_DIR/backup-$(date +%Y%m%d-%H%M%S).log"
TIMESTAMP=$(date +"%Y-%m-%d %H:%M:%S")

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m' # No Color

# Functions
log() {
    echo "[$TIMESTAMP] $1" | tee -a "$LOG_FILE"
}

log_success() {
    echo -e "${GREEN}[$TIMESTAMP] ✓ $1${NC}" | tee -a "$LOG_FILE"
}

log_error() {
    echo -e "${RED}[$TIMESTAMP] ✗ $1${NC}" | tee -a "$LOG_FILE"
}

log_warning() {
    echo -e "${YELLOW}[$TIMESTAMP] ⚠ $1${NC}" | tee -a "$LOG_FILE"
}

# Create backup directory if it doesn't exist
mkdir -p "$BACKUP_DIR"

log "========================================="
log "Starting Full System Backup"
log "Server: $SERVER"
log "Backup Location: $BACKUP_DIR"
log "========================================="

# Check if server is reachable
log "Checking server connection..."
if ! ssh -o ConnectTimeout=10 "$SERVER" "echo 'Server is reachable'" > /dev/null 2>&1; then
    log_error "Cannot connect to server $SERVER"
    exit 1
fi
log_success "Server is reachable"

# Check available disk space
log "Checking available disk space..."
AVAILABLE_SPACE=$(df -h /Volumes/SSD | tail -1 | awk '{print $4}')
log "Available space on Mac: $AVAILABLE_SPACE"

SERVER_USAGE=$(ssh "$SERVER" "df -h / | tail -1 | awk '{print \$3}'")
log "Server disk usage: $SERVER_USAGE"

# Rsync options
RSYNC_OPTS=(
    -avz                    # Archive mode, verbose, compress
    --progress              # Show progress
    --delete                # Delete files that don't exist on source
    --delete-excluded       # Delete excluded files on destination
    --partial               # Keep partially transferred files
    --partial-dir=.rsync-partial  # Store partial transfers
    --human-readable        # Human readable numbers
    --stats                 # Show transfer statistics
)

# Exclude patterns
EXCLUDE_PATTERNS=(
    # System and temporary
    "/proc/*"
    "/sys/*"
    "/dev/*"
    "/run/*"
    "/tmp/*"
    "/var/tmp/*"
    "/lost+found"

    # Swap and memory
    "/swapfile"
    "/swap.img"
    "*.swap"

    # Docker runtime (will be synced via Syncthing)
    "/var/lib/docker/overlay2/*"
    "/var/lib/docker/containers/*/logs/*"

    # Large cache and logs
    "/var/cache/*"
    "/var/log/*.gz"
    "/var/log/*.old"
    "*.log.1"
    "*.log.2"

    # Already synced by Syncthing
    "/opt/.stfolder"
    "/opt/.stversions"
    "/data/.stfolder"
    "/data/.stversions"
    "/home/ubuntu/.stfolder"
    "/home/ubuntu/.stversions"

    # Temporary build files
    "*.tmp"
    "*.temp"
    ".cache/*"

    # System sockets
    "*.sock"
    "*.socket"
)

# Build exclude arguments
EXCLUDE_ARGS=()
for pattern in "${EXCLUDE_PATTERNS[@]}"; do
    EXCLUDE_ARGS+=("--exclude=$pattern")
done

log "Starting rsync backup..."
log_warning "This may take a long time depending on server size and network speed"

# Perform backup
if rsync "${RSYNC_OPTS[@]}" "${EXCLUDE_ARGS[@]}" \
    "$SERVER:/" \
    "$BACKUP_DIR/" \
    2>&1 | tee -a "$LOG_FILE"; then

    log_success "Backup completed successfully!"

    # Calculate backup size
    BACKUP_SIZE=$(du -sh "$BACKUP_DIR" | cut -f1)
    log "Backup size: $BACKUP_SIZE"

    # Create backup metadata
    cat > "$BACKUP_DIR/.backup-metadata.txt" << EOF
Backup Date: $(date)
Server: $SERVER
Backup Location: $BACKUP_DIR
Backup Size: $BACKUP_SIZE
Status: Success
EOF

    log_success "Metadata saved to $BACKUP_DIR/.backup-metadata.txt"

else
    log_error "Backup failed! Check log file: $LOG_FILE"
    exit 1
fi

log "========================================="
log "Backup Summary"
log "Log file: $LOG_FILE"
log "Backup location: $BACKUP_DIR"
log "========================================="

log_success "All done! System backup completed."

# Cleanup old logs (keep last 30)
log "Cleaning up old log files..."
cd "$BACKUP_DIR"
ls -tp backup-*.log 2>/dev/null | tail -n +31 | xargs -I {} rm -- {} 2>/dev/null || true
log_success "Cleanup completed"

exit 0