require( File.join( File.dirname(__FILE__), "../role_generator_helpers" ))

class RolesGenerator < Rails::Generator::NamedBase
  
  include RoleGeneratorHelpers
  
  attr_accessor :roles_model_name, 
                :roles_table_name, 
                :users_table_name, 
                :users_model_name,
                :next_user_id
      
  def initialize(runtime_args, runtime_options = {})
    super
    unless runtime_args.length == 2
      puts "Not enough arguments!"
      puts "Expected: script/generate roles [Role] [User]"
      exit
    end
    
    @roles_model_name = (runtime_args[0] || "Role").classify
    @users_model_name = (runtime_args[1] || "User").classify
    @roles_table_name = @roles_model_name.tableize
    @users_table_name = @users_model_name.tableize
    
    puts "Generating #{@roles_model_name} against #{@users_model_name}"
  end
  
  def manifest
    record do |m|
      modify_or_add_user_fixtures(m)
      add_roles_and_join_table_fixtures(m)
      
      add_method_to_user_model(m)
      
      add_role_model(m)
      add_dependencies_to_application_rb
      add_dependencies_to_test_helper_rb
      add_role_requirement_system(m)
      add_migration(m) unless options[:skip_migration]
    end
  end
  
  def add_role_model(m)
    # add the Role model
    m.template 'role_model.rb.erb', roles_model_filename
  end
  
  def add_method_to_user_model(m)
    content_for_insertion = render_template("_user_functions.erb")
    # modify the User model unless it's already got RoleRequirement code in there
    if insert_content_after(users_model_filename,
                      Regexp.new("class +#{users_model_name}"),
                      content_for_insertion,
                      :unless => lambda { |content| content.include? "def has_role?"; }
                      )
      puts "Added the following to the top of #{users_model_filename}:\n#{content_for_insertion}"
    else
      puts "Not modifying #{users_model_filename} because it appears that the funtion has_role? already exists."
    end
  end
    
  def modify_or_add_user_fixtures(m)
    if (File.exists?(users_fixture_filename))
      users_fixtures_content = File.read users_fixture_filename
      users_fixtures = YAML.load(users_fixtures_content)
      
      begin
        throw "Can't understand whatever is in #{users_fixture_filename}" unless Hash===users_fixtures
        
        unless users_fixtures.has_key?("admin")
          @next_user_id = (users_fixtures.collect{ |k, params| params["id"].to_i}.max||0) + 1
          output = users_fixtures_content + "\n" + render_template("users_admin_fixture_with_roles.yml")
          
          # prevent generator from truncating the whole file if something goes wrong.
          if output.length > users_fixtures_content.length
            File.open(users_fixture_filename, "w") {|f| f.write(output) }
          end
        else
          @next_user_id = users_fixtures["admin"]["id"].to_i
        end
      rescue
        skip_fixtures = true
      end
    else
      # users.yml doesn't exist.  Generate it from scratch
      @next_user_id = 1
      
      m.template 'users_admin_fixture_with_roles.yml',
        File.join('test/fixtures', "#{users_table_name}.yml")
    end

  end
  
  def add_migration(m)
    m.migration_template '001_roles_migration.rb.erb', 'db/migrate', :assigns => {
      :migration_name => "Create#{roles_model_name.pluralize.gsub(/::/, '')}"
    }, :migration_file_name => "create_#{roles_table_name}"
  end
  
  def add_roles_and_join_table_fixtures(m)
    m.template 'roles.yml',
              File.join('test/fixtures', "#{roles_table_name}.yml")
  end
  
  def render_template(name)
    template = File.read( File.join( File.dirname(__FILE__), "templates", name))
    ERB.new(template, nil, "-").result(binding)
  end
  
  def habtm_name; [roles_table_name, users_table_name].sort * "_"; end
  def roles_foreign_key; roles_table_name.singularize.foreign_key; end
  def roles_model_filename;  "app/models/#{roles_model_name.underscore}.rb"; end;
  def users_foreign_key; users_table_name.singularize.foreign_key; end
  def users_fixture_filename;   "test/fixtures/#{users_table_name}.yml"; end;
  protected
    def banner
      "Usage: #{$0} roles RoleModelName [TargetUserModelName]"
    end

end