claude-code-checkpoint/src/templates/checkpoint-hook.js

Automatic project snapshots for Claude Code - never lose your work again

export function generateCheckpointHook(config) {
  const { enableVoice, maxCheckpoints } = config;

  return `#!/bin/bash

# Claude Code Checkpoint Hook
# Generated by claude-code-checkpoint
# This hook runs after every Claude operation

# Configuration
CHECKPOINT_BASE_DIR="$HOME/.claude/checkpoint"
DATA_DIR="$CHECKPOINT_BASE_DIR/data"
SCRIPTS_DIR="$CHECKPOINT_BASE_DIR/scripts"
DEBUG_LOG="$HOME/.claude/checkpoint-debug.log"
ENABLE_VOICE=${enableVoice ? 'true' : 'false'}
MAX_CHECKPOINTS=${maxCheckpoints}

# Function to log debug messages
debug_log() {
    echo "[$(date)] $1" >> "$DEBUG_LOG"
}

# Start
debug_log "Checkpoint hook started (npm version)"

# Check if we're in a git repository
if ! git rev-parse --git-dir > /dev/null 2>&1; then
    debug_log "Not in a git repository, skipping checkpoint"
    exit 0
fi

# Get project name
PROJECT_ROOT=$(git rev-parse --show-toplevel 2>/dev/null)
PROJECT_NAME=$(basename "$PROJECT_ROOT")
PROJECT_DATA_DIR="$DATA_DIR/$PROJECT_NAME"

# Ensure directories exist
mkdir -p "$PROJECT_DATA_DIR"

# Check for changes using git status
if [ -z "$(git status --porcelain 2>/dev/null)" ]; then
    debug_log "No changes detected, skipping checkpoint"
    exit 0
fi

# Create state hash of current directory
generate_state_hash() {
    find . -type f \\
        -not -path "./.git/*" \\
        -not -path "./node_modules/*" \\
        -not -path "./dist/*" \\
        -not -path "./build/*" \\
        -not -path "./.next/*" \\
        -not -name ".DS_Store" \\
        -not -name "*.pyc" \\
        -not -path "./__pycache__/*" \\
        -exec stat -f "%m %z %N" {} \\; 2>/dev/null | \\
        sort | shasum -a 256 | cut -d' ' -f1
}

# Get current state
CURRENT_STATE=$(generate_state_hash)
LAST_STATE_FILE="$PROJECT_DATA_DIR/last-state.hash"

# Check if state has changed
if [ -f "$LAST_STATE_FILE" ]; then
    LAST_STATE=$(cat "$LAST_STATE_FILE")
    if [ "$CURRENT_STATE" = "$LAST_STATE" ]; then
        debug_log "No changes since last checkpoint (state unchanged)"
        exit 0
    fi
fi

# Create checkpoint
debug_log "Creating checkpoint for $PROJECT_NAME"

# Get metadata
METADATA_FILE="$PROJECT_DATA_DIR/metadata.json"
if [ ! -f "$METADATA_FILE" ]; then
    echo '{"checkpoints":[]}' > "$METADATA_FILE"
fi

# Get next checkpoint ID
NEXT_ID=$(jq '.checkpoints | length + 1' "$METADATA_FILE")
CHECKPOINT_DIR="$PROJECT_DATA_DIR/checkpoint-$NEXT_ID"

# Create checkpoint directory
mkdir -p "$CHECKPOINT_DIR"

# Generate smart description based on changes
generate_description() {
    local prev_checkpoint=""
    local prev_id=$((NEXT_ID - 1))
    
    if [ "$prev_id" -gt 0 ]; then
        prev_checkpoint="$PROJECT_DATA_DIR/checkpoint-$prev_id"
    fi
    
    if [ -d "$prev_checkpoint" ]; then
        # Compare against previous checkpoint
        CHANGED_FILES=$(diff -rq . "$prev_checkpoint" --exclude=.git --exclude=node_modules --exclude=.next --exclude=dist --exclude=build 2>/dev/null | \
            grep -E "^Files .* differ$" | \
            awk '{print $2}' | \
            sed "s|^./||")
        NEW_FILES=$(diff -rq . "$prev_checkpoint" --exclude=.git --exclude=node_modules --exclude=.next --exclude=dist --exclude=build 2>/dev/null | \
            grep "^Only in \\\\." | \
            awk -F': ' '{print $2}')
    else
        # First checkpoint - compare against git
        CHANGED_FILES=$(git diff --name-only HEAD 2>/dev/null)
        NEW_FILES=$(git ls-files --others --exclude-standard 2>/dev/null)
    fi
    
    # Count changes
    CHANGED_COUNT=$(echo "$CHANGED_FILES" | grep -v '^$' | wc -l | tr -d ' ')
    NEW_COUNT=$(echo "$NEW_FILES" | grep -v '^$' | wc -l | tr -d ' ')
    TOTAL_COUNT=$((CHANGED_COUNT + NEW_COUNT))
    
    if [ "$TOTAL_COUNT" -gt 0 ]; then
        # Get the most significant change
        if [ "$CHANGED_COUNT" -gt 0 ]; then
            FIRST_FILE=$(echo "$CHANGED_FILES" | head -1)
            ACTION="Updated"
        else
            FIRST_FILE=$(echo "$NEW_FILES" | head -1)
            ACTION="Added"
        fi
        
        FILENAME=$(basename "$FIRST_FILE")
        
        if [ "$TOTAL_COUNT" -eq 1 ]; then
            echo "$ACTION $FILENAME"
        else
            echo "Changed $TOTAL_COUNT files including $FILENAME"
        fi
    else
        echo "Claude operation completed"
    fi
}

# Generate description
if [ -n "$CHECKPOINT_MANUAL_DESC" ]; then
    # Use manual description if provided
    DESCRIPTION="$CHECKPOINT_MANUAL_DESC"
else
    # Auto-generate description based on changes
    DESCRIPTION=$(generate_description)
fi
debug_log "Generated description: $DESCRIPTION"

# Copy files using rsync
rsync -a \\
    --exclude='.git' \\
    --exclude='node_modules' \\
    --exclude='dist' \\
    --exclude='build' \\
    --exclude='.next' \\
    --exclude='__pycache__' \\
    --exclude='*.pyc' \\
    --exclude='.DS_Store' \\
    --exclude='*.log' \\
    --exclude='tmp' \\
    --exclude='temp' \\
    "$PROJECT_ROOT/" "$CHECKPOINT_DIR/"

# Update metadata
TIMESTAMP=$(date -u +"%Y-%m-%dT%H:%M:%SZ")
jq --arg id "$NEXT_ID" \\
   --arg desc "$DESCRIPTION" \\
   --arg path "$CHECKPOINT_DIR" \\
   --arg ts "$TIMESTAMP" \\
   '.checkpoints += [{
     "id": ($id | tonumber),
     "description": $desc,
     "path": $path,
     "timestamp": $ts,
     "session_id": "unknown"
   }]' "$METADATA_FILE" > "$METADATA_FILE.tmp" && mv "$METADATA_FILE.tmp" "$METADATA_FILE"

# Save current state
echo "$CURRENT_STATE" > "$LAST_STATE_FILE"

# Enforce max checkpoints if set
if [ "$MAX_CHECKPOINTS" -gt 0 ]; then
    CURRENT_COUNT=$(jq '.checkpoints | length' "$METADATA_FILE")
    if [ "$CURRENT_COUNT" -gt "$MAX_CHECKPOINTS" ]; then
        # Remove oldest checkpoints
        TO_REMOVE=$((CURRENT_COUNT - MAX_CHECKPOINTS))
        debug_log "Removing $TO_REMOVE old checkpoints (max: $MAX_CHECKPOINTS)"
        
        # Get IDs to remove
        OLD_IDS=$(jq -r ".checkpoints | sort_by(.timestamp) | .[0:$TO_REMOVE] | .[].id" "$METADATA_FILE")
        
        for OLD_ID in $OLD_IDS; do
            # Remove checkpoint directory
            OLD_PATH=$(jq -r ".checkpoints[] | select(.id == $OLD_ID) | .path" "$METADATA_FILE")
            rm -rf "$OLD_PATH"
            
            # Remove from metadata
            jq "del(.checkpoints[] | select(.id == $OLD_ID))" "$METADATA_FILE" > "$METADATA_FILE.tmp" && mv "$METADATA_FILE.tmp" "$METADATA_FILE"
        done
    fi
fi

# Voice announcement if enabled (macOS only)
if [ "$ENABLE_VOICE" = "true" ] && [ "$(uname)" = "Darwin" ]; then
    # Add 3.5s delay like the original system
    (sleep 3.5 && say "Checkpoint $NEXT_ID created") &
fi

debug_log "Checkpoint #$NEXT_ID created successfully"
`;
}