chore: initial commit

lib/modules/lefthook_helpers.sh

@@ -0,0 +1,149 @@
+# Usage: __log <LEVEL> "message"
+# LEVEL can be: TRACE, INFO, WARN, ERROR
+__log() {
+  local level="$1" msg="$2"
+  local format=$'\E[mlefthook: \E[38;5;8m%s\E[m\n'
+  case "$level" in
+  TRACE)
+    if [[ -n "${LEFTHOOK_VERBOSE:-}" ]]; then
+      # shellcheck disable=SC2059
+      printf "$format" "[TRACE] ${msg}" >&2
+    fi
+    ;;
+  INFO)
+    if [[ -n "${LEFTHOOK_VERBOSE:-}" ]]; then
+      # shellcheck disable=SC2059
+      printf "$format" "$msg" >&2
+    fi
+    ;;
+  WARN)
+    # shellcheck disable=SC2059
+    printf "$format" "[WARN] ${msg}" >&2
+    ;;
+  ERROR)
+    # shellcheck disable=SC2059
+    printf "$format" "[ERROR] ${msg}" >&2
+    ;;
+  esac
+}
+
+# Helper to get the current Git hooks directory, supporting worktrees.
+# Returns the absolute path to the hooks directory.
+_get_git_hooks_dir() {
+  # Check if we are inside a Git repository
+  if ! command -v git &> /dev/null; then
+    __log ERROR "Git command not found. Cannot resolve Git hooks directory."
+    return 1
+  fi
+  if ! git rev-parse --is-inside-work-tree >/dev/null 2>&1; then
+    __log ERROR "Not inside a Git repository. Cannot resolve Git hooks directory."
+    return 1
+  fi
+  local GIT_DIR_PATH
+  GIT_DIR_PATH=$(git rev-parse --git-dir)
+  GIT_DIR_PATH=$(realpath "$GIT_DIR_PATH") # Resolve to absolute path
+  echo "${GIT_DIR_PATH}/hooks"
+  return 0
+}
+
+# Function to set up a Git hook as a symlink to a Nix store path.
+# Usage: setup_git_hook <hook_name> <nix_store_hook_path>
+setup_git_hook() {
+  local HOOK_NAME="$1"
+  local NIX_HOOK_PATH="$2"
+  local NIX_STORE_PATTERN="/nix/store/" # Pattern to identify Nix store paths
+
+  local HOOK_DIR
+  HOOK_DIR=$(_get_git_hooks_dir)
+  if [ $? -ne 0 ]; then
+    return 1 # Error from _get_git_hooks_dir
+  fi
+
+  local HOOK_FILE="${HOOK_DIR}/${HOOK_NAME}"
+  local BACKUP_FILE="${HOOK_FILE}.old"
+
+  # Ensure the hooks directory exists
+  mkdir -p "$HOOK_DIR"
+
+  if [ -e "$HOOK_FILE" ]; then # Check if anything exists at the hook path
+    if [ -L "$HOOK_FILE" ]; then # Existing hook is a symlink
+      local CURRENT_TARGET
+      CURRENT_TARGET=$(readlink "$HOOK_FILE")
+
+      if [[ "$CURRENT_TARGET" == "$NIX_HOOK_PATH" ]]; then
+        __log TRACE "Hook '$HOOK_NAME' already exists and points to the correct Nix store path. Doing nothing."
+        return 0
+      elif [[ "$CURRENT_TARGET" == $NIX_STORE_PATTERN* ]]; then
+        __log TRACE "Hook '$HOOK_NAME' is a symlink to a different Nix store path. Replacing it with the new symlink."
+        rm "$HOOK_FILE"
+      else
+        __log INFO "Hook '$HOOK_NAME' is a symlink but not to a Nix store path. Backing up to '$BACKUP_FILE'."
+        mv "$HOOK_FILE" "$BACKUP_FILE"
+      fi
+    elif [ -f "$HOOK_FILE" ]; then # Existing hook is a regular file
+      # Assumption: any non-symlink hook file is not ours
+      __log INFO "Hook '$HOOK_NAME' is an existing regular file (not managed by us). Backing up to '$BACKUP_FILE'."
+      mv "$HOOK_FILE" "$BACKUP_FILE"
+    else # Existing hook is neither a symlink nor a regular file (e.g., directory)
+      __log WARN "Hook '$HOOK_NAME' exists but is not a regular file or symlink. Please check your hooks and remove the hook manually just in case."
+      exit 1
+    fi
+  fi
+
+  __log INFO "Creating symlink for '$HOOK_NAME' to '$NIX_HOOK_PATH'."
+  ln -s "$NIX_HOOK_PATH" "$HOOK_FILE"
+}
+
+# Function to clean up specific Git hooks that are no longer used by Nix.
+# It removes symlinks that point to the Nix store for the given hook names
+# and restores any .old backups if they exist.
+# Usage: cleanup_git_hooks <space-separated-list-of-unused-hook-names>
+cleanup_git_hooks() {
+  local UNUSED_HOOK_NAMES_STR="$1"
+  local NIX_STORE_PATTERN="/nix/store/"
+
+  if [ -z "$UNUSED_HOOK_NAMES_STR" ]; then
+    __log TRACE "No unused hooks specified for cleanup. Doing nothing."
+    return 0
+  fi
+
+  local HOOK_DIR
+  HOOK_DIR=$(_get_git_hooks_dir)
+  if [ $? -ne 0 ]; then
+    return 1 # Error from _get_git_hooks_dir
+  fi
+
+  if [ ! -d "$HOOK_DIR" ]; then
+    __log TRACE "No hooks directory found at '$HOOK_DIR'. Nothing to clean up."
+    return 0
+  fi
+
+  __log TRACE "Cleaning up unused Git hooks in '$HOOK_DIR'..."
+  for HOOK_NAME in $UNUSED_HOOK_NAMES_STR; do
+    local HOOK_FILE_PATH="${HOOK_DIR}/${HOOK_NAME}"
+
+    if [ -L "$HOOK_FILE_PATH" ]; then # Only consider symlinks
+      local TARGET
+      TARGET=$(readlink "$HOOK_FILE_PATH")
+
+      # Check if the symlink points to a Nix store path
+      if [[ "$TARGET" == $NIX_STORE_PATTERN* ]]; then
+        __log INFO "Removing unused Nix-managed hook: '$HOOK_NAME' (points to '$TARGET')"
+        rm "$HOOK_FILE_PATH"
+
+        # Check for a corresponding .old file and restore it if it exists
+        local OLD_HOOK="${HOOK_FILE_PATH}.old"
+        if [ -e "$OLD_HOOK" ]; then
+          __log INFO "Restoring backup: '$OLD_HOOK' to '${HOOK_FILE_PATH}'"
+          mv "$OLD_HOOK" "$HOOK_FILE_PATH"
+        fi
+      else
+        __log TRACE "Hook '$HOOK_NAME' is a symlink but not to a Nix store path. Skipping cleanup (it's not our managed symlink)."
+      fi
+    elif [ -e "$HOOK_FILE_PATH" ]; then
+      __log TRACE "Hook '$HOOK_NAME' exists but is not a symlink (not managed by us). Skipping cleanup."
+    else
+      __log TRACE "Hook '$HOOK_NAME' does not exist. Skipping cleanup."
+    fi
+  done
+}