#!/bin/bash

# Cleanup Ghost Time Machine Snapshot
# Sometimes snapshots appear in the list but don't actually exist or take space

set -e

echo "=== Cleanup Ghost Time Machine Snapshot ==="
echo ""

# Check current free space
FREE_SPACE=$(df / | tail -1 | awk '{print $4}')
FREE_SPACE_GB=$(echo "scale=2; $FREE_SPACE / 1024 / 1024" | bc)
echo "Current free space: ${FREE_SPACE_GB}GB"
echo ""

# List snapshots
SNAPSHOTS=$(tmutil listlocalsnapshots / 2>/dev/null | grep -v "Snapshots for disk" | grep -v "^$")
if [ -z "$SNAPSHOTS" ]; then
    echo "✅ No snapshots found - all clean!"
    exit 0
fi

echo "Found snapshot(s):"
echo "$SNAPSHOTS" | sed 's/^/  - /'
echo ""

# The snapshot might be a ghost entry. Let's try several methods:

echo "Attempting cleanup methods..."
echo ""

# Method 1: Try deleting with date format
echo "Method 1: Delete by date..."
echo "$SNAPSHOTS" | while read snapshot; do
    if [ -n "$snapshot" ]; then
        # Extract date: com.apple.TimeMachine.2025-12-31-101235.backup -> 2025-12-31-101235
        SNAP_DATE=$(echo "$snapshot" | sed 's/.*\.\([0-9]\{4\}-[0-9]\{2\}-[0-9]\{2\}-[0-9]\{6\}\)\.backup/\1/')
        if [ -n "$SNAP_DATE" ]; then
            echo "  Trying: sudo tmutil deletelocalsnapshots $SNAP_DATE"
            if sudo tmutil deletelocalsnapshots "$SNAP_DATE" 2>/dev/null; then
                echo "  ✅ Success!"
            else
                echo "  ⚠️  Failed (may be ghost entry)"
            fi
        fi
    fi
done

echo ""

# Method 2: Thin all snapshots (aggressive)
echo "Method 2: Aggressive thinning..."
sudo tmutil thinlocalsnapshots / 1000000000 1 2>&1 || true
echo "  ✓ Thinning completed"

echo ""

# Method 3: Check if it's actually taking space
echo "Method 3: Checking if snapshot actually exists..."
APFS_SNAPSHOTS=$(diskutil apfs listSnapshots / 2>/dev/null | grep -i "timemachine" || echo "")
if [ -z "$APFS_SNAPSHOTS" ]; then
    echo "  ℹ️  Snapshot not found in APFS snapshot list"
    echo "  This confirms it's likely a ghost entry in Time Machine's database"
    echo ""
    echo "  The snapshot entry may persist in Time Machine's database but:"
    echo "  - It's not taking up space (space was already freed)"
    echo "  - It will likely clear when Time Machine successfully backs up"
    echo "  - Or it may clear on the next macOS update/restart"
fi

echo ""

# Final check
sleep 2
REMAINING=$(tmutil listlocalsnapshots / 2>/dev/null | grep -v "Snapshots for disk" | grep -v "^$" | wc -l | tr -d ' ')

if [ "$REMAINING" -gt 0 ]; then
    echo "⚠️  Snapshot still listed, but this is likely a ghost entry."
    echo ""
    echo "✅ Good news: Your space was already freed (${FREE_SPACE_GB}GB free)!"
    echo ""
    echo "The ghost entry should clear when:"
    echo "  1. Time Machine successfully completes a backup"
    echo "  2. macOS updates"
    echo "  3. Or it may persist but won't cause issues"
    echo ""
    echo "You can safely ignore it - it's not taking up space."
else
    echo "✅ Snapshot successfully removed!"
fi

echo ""