#!/bin/bash

# Aggressive Free System Data (351GB)
# When normal methods don't work

set -e

echo "=== Aggressive Free System Data (351GB) ==="
echo ""
echo "Since normal methods didn't work, we need to be more aggressive."
echo ""

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

echo "🔍 Checking Time Machine configuration..."
TM_DEST=$(defaults read /Library/Preferences/com.apple.TimeMachine LastDestinationID 2>/dev/null || echo "NONE")
if [ "$TM_DEST" != "NONE" ]; then
    echo "   ⚠️  Time Machine destination still configured: $TM_DEST"
    echo "   This means snapshots may still be created!"
    echo ""
    echo "   You MUST remove it in System Settings:"
    echo "   System Settings → Time Machine → Remove backup disk"
    echo ""
    read -p "   Have you removed it? (y/n) " -n 1 -r
    echo ""
    if [[ ! $REPLY =~ ^[Yy]$ ]]; then
        echo "   ⚠️  Please remove it first!"
        exit 1
    fi
else
    echo "   ✅ Time Machine destination removed"
fi
echo ""

echo "🔧 Method 1: Force delete all local snapshots..."
SNAPSHOTS=$(tmutil listlocalsnapshots / 2>/dev/null | grep -v "Snapshots for disk" | grep -v "^$")
if [ -n "$SNAPSHOTS" ]; then
    echo "$SNAPSHOTS" | while read snapshot; do
        if [ -n "$snapshot" ]; then
            SNAP_DATE=$(echo "$snapshot" | sed 's/.*\.\([0-9]\{4\}-[0-9]\{2\}-[0-9]\{2\}-[0-9]\{6\}\)\.backup/\1/')
            if [ -n "$SNAP_DATE" ]; then
                echo "   Deleting: $snapshot"
                sudo tmutil deletelocalsnapshots "$SNAP_DATE" 2>&1 || echo "     ⚠️  Failed (ghost entry)"
            fi
        fi
    done
else
    echo "   No snapshots found"
fi
echo ""

echo "🔧 Method 2: Aggressive thinning (keep only 1GB, 1 day)..."
sudo tmutil thinlocalsnapshots / 1000000000 1 2>&1
echo "   ✓ Completed"
echo ""

echo "🔧 Method 3: Disable Time Machine completely..."
sudo tmutil disable 2>/dev/null || echo "   ⚠️  Could not disable (may already be disabled)"
echo ""

echo "🔧 Method 4: Clear Time Machine database..."
echo "   ⚠️  This will clear Time Machine's local database"
read -p "   Proceed? (y/n) " -n 1 -r
echo ""
if [[ $REPLY =~ ^[Yy]$ ]]; then
    # Backup first
    sudo cp -r /Library/Preferences/com.apple.TimeMachine.plist /Library/Preferences/com.apple.TimeMachine.plist.backup 2>/dev/null || true
    echo "   Backed up preferences"
    
    # Clear local snapshots database
    sudo rm -rf /System/Volumes/Data/.timemachine/* 2>/dev/null || true
    echo "   ✓ Cleared Time Machine local data"
fi
echo ""

echo "🔧 Method 5: Force filesystem sync and purge..."
sync
if command -v purge &> /dev/null; then
    sudo purge
    echo "   ✓ Purged"
fi
echo ""

echo "🔧 Method 6: Use macOS storage optimization..."
echo ""
echo "   ⚠️  CRITICAL: You need to use macOS's built-in tool:"
echo ""
echo "   1. Apple Menu → About This Mac → Storage"
echo "   2. Click 'Manage...'"
echo "   3. Look for 'Optimize Storage' or similar option"
echo "   4. This will release purgeable space"
echo ""
echo "   OR use Terminal:"
echo "   sudo tmutil thinlocalsnapshots / 1000000000 1"
echo "   sudo purge"
echo ""

echo "⏳ Waiting for system to update..."
sleep 15

# Check results
FREE_SPACE_AFTER=$(df / | tail -1 | awk '{print $4}')
FREE_SPACE_GB_AFTER=$(echo "scale=2; $FREE_SPACE_AFTER / 1024 / 1024" | bc)
FREED_GB=$(echo "scale=2; $FREE_SPACE_GB_AFTER - $FREE_SPACE_GB_BEFORE" | bc)

echo ""
echo "=== Results ==="
echo "   Before: ${FREE_SPACE_GB_BEFORE}GB free"
echo "   After:  ${FREE_SPACE_GB_AFTER}GB free"
if (( $(echo "$FREED_GB > 100" | bc -l) )); then
    echo "   ✅ Successfully freed: ${FREED_GB}GB!"
elif (( $(echo "$FREED_GB > 0" | bc -l) )); then
    echo "   ✅ Freed: ${FREED_GB}GB"
else
    echo "   ⚠️  No space freed yet"
fi
echo ""

echo "=== If Still No Change ==="
echo ""
echo "The 351GB in System Data is likely:"
echo "  1. Purgeable space that macOS won't release until needed"
echo "  2. APFS snapshot overhead (the OS update snapshot)"
echo "  3. Reserved space for system operations"
echo ""
echo "Try these:"
echo ""
echo "1. **Create a large file to force purge**:"
echo "   This forces macOS to release purgeable space:"
echo "   dd if=/dev/zero of=~/test_large_file bs=1g count=50"
echo "   (This creates a 50GB file, forcing purge)"
echo "   Then delete it: rm ~/test_large_file"
echo ""
echo "2. **Use Activity Monitor**:"
echo "   Open Activity Monitor → Disk tab"
echo "   Look for 'Purgeable' space"
echo ""
echo "3. **Check Storage Management again**:"
echo "   The System Data may show as 'Purgeable'"
echo "   macOS will release it when space is actually needed"
echo ""
echo "4. **The space may already be available**:"
echo "   Even though System Data shows 351GB, the space"
echo "   may be purgeable and available when needed"
echo ""