module Nyara
  # options:
  #
  # [env]         environment, default is +'development'+
  # [port]        listen port number
  # [workers]     number of workers
  # [host]        host name used in `url_to` helper
  # [root]        root path, default is +Dir.pwd+
  # [views]       views (templates) directory, relative to root, default is +"views"+
  # [public]      static files directory, relative to root, default is +"public"+
  # [x_send_file] header field name for X-Sendfile or X-Accel-Redirect, see Nyara::Controller#send_file for details
  # [session]     see Nyara::Session for sub options
  # [prefer_erb]  use ERB instead of ERubis for +.erb+ templates
  Config = ConfigHash.new
  class << Config
    # clear all settings
    def reset
      clear
      Route.clear
    end

    # init and check configures
    def init
      self['env'] ||= 'development'

      n = (self['port'] || 3000).to_i
      assert n >= 0 && n <= 65535
      self['port'] = n

      n = (self['workers'] || self['worker'] || ((CpuCounter.count + 1)/ 2)).to_i
      assert n > 0 && n < 1000
      self['workers'] = n

      unless self['root']
        set :root, Dir.pwd
      end
      self['root'] = File.expand_path self['root']

      self['views'] = project_path(self['views'] || 'views')
      self['public'] = project_path(self['public'] || 'public')

      if self['public']
        map '/', PublicController
      end
    end

    # get absoute path under project path <br>
    # if +strict+, return nil if path is not under the dir
    def project_path path, strict=true
      path_under 'root', path, strict
    end

    # get absoute path under public path <br>
    # if +strict+, return nil if path is not under the dir
    def public_path path, strict=true
      path_under 'public', path, strict
    end

    # get absoute path under views path <br>
    # if +strict+, return nil if path is not under the dir
    def views_path path, strict=true
      path_under 'views', path, strict
    end

    # get path under the dir configured +Nyara.config[key]+ <br>
    # if +strict+, return nil if path is not under the dir
    def path_under key, path, strict=true
      dir = self[key]
      path = File.expand_path File.join(dir, path)
      if !strict or path.start_with?(dir)
        path
      end
    end

    # pass requests under a prefix to a controller
    def map prefix, controller
      Route.register_controller prefix, controller
    end

    # get environment
    def env
      self['env'].to_s
    end

    def development?
      e = env
      e.empty? or e == 'development'
    end

    def production?
      env == 'production'
    end

    def test?
      env == 'test'
    end

    alias set []=
    alias get []

    def assert expr # :nodoc:
      raise ArgumentError, "expect #{expr.inspect} to be true", caller[1..-1] unless expr
    end

    # todo env aware configure
    def configure &blk
      instance_eval &blk
    end
  end
end

def configure *xs, &blk
  Nyara::Config.configure *xs, &blk
end

configure do
  set 'env', 'development'
  set 'views', 'views'
  set 'public', 'public'
end