#!/bin/bash
# Migrate a project from the old copy-based model to the additive extension model.
# Usage: ./migrate-project.sh /path/to/project
set -e

FRAMEWORK_DIR="$HOME/.automaton"
PROJECT_DIR="${1}"

if [ -z "$PROJECT_DIR" ]; then
  echo "Usage: $0 /path/to/project"
  exit 1
fi

PROJECT_AUTOMATON="$PROJECT_DIR/.automaton"

if [ ! -d "$PROJECT_AUTOMATON" ]; then
  echo "No .automaton/ directory found at $PROJECT_AUTOMATON"
  echo "Nothing to migrate."
  exit 0
fi

EXTENSIONS_DIR="$PROJECT_AUTOMATON/extensions"
DELETED=()
MOVED=()
KEPT=()
ERRORS=()

# Directories in the framework that projects may have copied
SCAN_DIRS=("prompts" "contracts" "scripts")

# Function to diff a file with its global counterpart
diff_file() {
  local project_file="$1"
  local global_file="$2"
  if [ ! -f "$global_file" ]; then
    return 2  # file doesn't exist in global
  fi
  if diff -q "$project_file" "$global_file" >/dev/null 2>&1; then
    return 0  # identical
  else
    return 1  # different
  fi
}

# Check root-level framework files
echo "Scanning $PROJECT_AUTOMATON for stale framework files..."
echo ""

for dir in "${SCAN_DIRS[@]}"; do
  project_dir="$PROJECT_AUTOMATON/$dir"
  global_dir="$FRAMEWORK_DIR/$dir"

  if [ ! -d "$project_dir" ]; then
    continue
  fi

  # Find all files in the project's copy of this directory
  while IFS= read -r -d '' project_file; do
    rel_path="${project_file#$PROJECT_AUTOMATON/}"
    global_file="$FRAMEWORK_DIR/$rel_path"

    if diff_file "$project_file" "$global_file"; then
      # Identical to global — safe to delete
      rm "$project_file"
      DELETED+=("$rel_path")
      echo "  DELETED  $rel_path (identical to global)"
    elif [ $? -eq 1 ]; then
      # Different from global — move to extensions/
      ext_path="$EXTENSIONS_DIR/$dir/$(basename "$project_file")"
      mkdir -p "$(dirname "$ext_path")"
      mv "$project_file" "$ext_path"
      MOVED+=("$rel_path -> extensions/$dir/$(basename "$project_file")")
      echo "  MOVED    $rel_path → extensions/$dir/$(basename "$project_file") (customized)"
    fi
  done < <(find "$project_dir" -type f -print0 2>/dev/null || true)

  # Remove empty directories after moving/deleting files
  rmdir "$project_dir" 2>/dev/null || true
done

# Check for other stale root-level files (templates/, references/, etc.)
while IFS= read -r -d '' project_file; do
  rel_path="${project_file#$PROJECT_AUTOMATON/}"
  global_file="$FRAMEWORK_DIR/$rel_path"

  # Skip protected files
  basename_file=$(basename "$rel_path")
  if [ "$basename_file" = ".agent.md" ] || [ "$basename_file" = ".rules.md" ]; then
    KEPT+=("$rel_path")
    continue
  fi

  if [ ! -f "$global_file" ]; then
    continue  # not a framework file, skip
  fi

  if diff_file "$project_file" "$global_file"; then
    rm "$project_file"
    DELETED+=("$rel_path")
    echo "  DELETED  $rel_path (identical to global)"
  elif [ $? -eq 1 ]; then
    ext_path="$EXTENSIONS_DIR/$(basename "$rel_path")"
    mkdir -p "$(dirname "$ext_path")"
    mv "$project_file" "$ext_path"
    MOVED+=("$rel_path -> extensions/$(basename "$rel_path")")
    echo "  MOVED    $rel_path → extensions/$(basename "$rel_path") (customized)"
  fi
done < <(find "$PROJECT_AUTOMATON" -maxdepth 1 -type f -name "*.md" -o -name "*.sh" -print0 2>/dev/null || true)

# Report
echo ""
echo "=== Migration Summary ==="
echo "  Deleted:  ${#DELETED[@]} (identical to global, removed)"
echo "  Moved:    ${#MOVED[@]} (customized, moved to extensions/)"
echo "  Kept:     ${#KEPT[@]} (.agent.md and .rules.md preserved)"

if [ ${#ERRORS[@]} -gt 0 ]; then
  echo "  Errors:   ${#ERRORS[@]}"
  for err in "${ERRORS[@]}"; do
    echo "    - $err"
  done
fi

echo ""
echo "Migration complete."