A simple rack app with response builder hack.

rack_test_app.rb

require 'pathname'
require 'pp'

class HTTPResponseBuilder
  STATUS_CODES = {100 => "Continue",
    101 => "Switching Protocols",
    200 => "OK",
    201 => "Created",
    202 => "Accepted",
    203 => "Non-Authoritative Information",
    204 => "No Content",
    205 => "Reset Content",
    206 => "Partial Content",
    300 => "Multiple Choices",
    301 => "Moved Permanently",
    302 => "Found",
    303 => "See Other",
    304 => "Not Modified",
    305 => "Use Proxy",
    307 => "Temporary Redirect",
    400 => "Bad Request",
    401 => "Unauthorized",
    402 => "Payment Required",
    403 => "Forbidden",
    404 => "Not Found",
    405 => "Method Not Allowed",
    406 => "Not Acceptable",
    407 => "Proxy Authentication Required",
    408 => "Request Time-out",
    409 => "Conflict",
    410 => "Gone",
    411 => "Length Required",
    412 => "Precondition Failed",
    413 => "Request Entity Too Large",
    414 => "Request-URI Too Large",
    415 => "Unsupported Media Type",
    416 => "Requested range not satisfiable",
    417 => "Expectation Failed",
    500 => "Internal Server Error",
    501 => "Not Implemented",
    502 => "Bad Gateway",
    503 => "Service Unavailable",
    504 => "Gateway Time-out",
    505 => "HTTP Version not supported"}

  def valid_code? (code)
    STATUS_CODES.has_key?(code)
  end

  def set_code (code)
    if valid_code?(code) || code.nil?
      @code = code
    else
      raise("Invalid HTTP status code input: #{code}")
    end
  end

  def add_head (field_name, field_value)
    @head[field_name] = field_value
  end

  def add_head_content_type (mime_type)
    # TODO: check valid mime-types
    add_head("Content-Type", mime_type)
  end

  def add_head_content_length (length)
    add_head("Content-Length", length.to_s)
  end

  def date_rfc_1123 ()
    datetime = Time.now
    datetime.gmtime.strftime("%a, %d %b %Y %H:%M:%S GMT")
  end

  def add_head_date (date=date_rfc_1123)
    add_head("Date", date)
  end

  def add_data (data)
    @data.push(data)
  end

  def initialize (code=nil, head={}, data=[])
    @code = set_code(code)
    @head = head
    @data = data
  end

  def to_rack_plain (status_code)
    unless valid_code?(status_code)
      raise("Invalid HTTP status code input: #{status_code}")
    end
    set_code(status_code)
    text = STATUS_CODES[@code]
    @data.push(text)
    add_head_content_length(text.bytesize)
    add_head_content_type("text/plain")
    add_head_date()
    return [@code, @head, @data]
  end

  def to_rack ()
    unless valid_code?(@code)
      raise("Invalid HTTP status code: #{@code}")
    end
    @data = @data.join
    add_head_content_length(@data.bytesize)
    add_head_date()
    return [@code, @head, [@data]]
  end
end

#FIXME: use Rack::Response

class App
  @@mime_type_of_ext = {".ico" => "image/vnd.microsoft.icon",
    ".text" => "text/plain",
    ".txt" => "text/plain",
    ".html" => "text/html",
    ".htm" => "text/html"}

  def get_file (reqs, resp)
    pp "reqs.path = " + reqs.path

    fp = Pathname.new("." + reqs.path)
    
    case fp.to_s
    when "./"
      fp = Pathname.new("./index.html")
    when "./favicon.ico"
      fp = Pathname.new("./Images/favicon.ico")
    end
    
    # FIXME: use Rack::File

    # dn = File.dirname(fp)
    # fn = File.basename(fp)
    # ex = File.extname(fp)

    pp "filepath  = " + fp.to_s
    pp "dirname   = " + fp.dirname.to_s
    pp "basename  = " + fp.basename.to_s
    pp "extension = " + fp.extname.to_s

    if fp.exist?
      resp.set_code(200)
      fp.open('r') do |fd|
        resp.add_data(fd.read)
      end
    else
      return resp.to_rack_plain(404)
    end

    resp.add_head_content_type(@@mime_type_of_ext[fp.extname.to_s])
    # pp resp.to_rack
    return resp.to_rack
  end

  def call (env)
    resp = HTTPResponseBuilder.new()
    reqs = Rack::Request.new(env)

    get_file(reqs, resp)
  end
end