_rake_does_task_list_need_generating () {
    [[ ! -f .rake_tasks ]] || [[ Rakefile -nt .rake_tasks ]] || { _is_rails_app && _tasks_changed }

  }

  _is_rails_app () {
    [[ -e "bin/rails" ]] || [[ -e "script/rails" ]]
  }
  
  _tasks_changed () {
    local -a files
    files=(lib/tasks lib/tasks/**/*(N))
  
    for file in $files; do
      if [[ "$file" -nt .rake_tasks ]]; then
        return 0
      fi
    done
  
    return 1

  }
  
  _rake_generate () {
    rake --silent --tasks | cut -d " " -f 2 > .rake_tasks
  }
  
  _rake () {

    if [[ -f Rakefile ]]; then

      if _rake_does_task_list_need_generating; then

        echo "
  Generating .rake_tasks..." >&2

        _rake_generate
      fi

      compadd $(cat .rake_tasks)

    fi
  }

  compdef _rake rake

  
  rake_refresh () {
    [[ -f .rake_tasks ]] && rm -f .rake_tasks
  
    echo "Generating .rake_tasks..." >&2
    _rake_generate
    cat .rake_tasks
  }