#
# Based on code from MiddleMan Proxy: 
#  https://github.com/middleman/middleman-proxy/blob/master/lib/middleman-proxy.rb
#
# Which in turn looks to be based on Apple Code:
#  # ===========================================================================
#  # Original Project:   Abbot - SproutCore Build Tools
#  # Copyright: ©2009 Apple Inc.
#  #            portions copyright @2006-2011 Strobe Inc.
#  #            and contributors
#  # ===========================================================================

begin
  require 'net/https'
  HTTPS_ENABLED = true
rescue LoadError => e
  require 'net/http'
  HTTPS_ENABLED = false
end

#require "net/http"
require "uri"

module Gumdrop
  
  def self.handle_proxy(proxy, proxy_url, env)
    if proxy[:secure] && !HTTPS_ENABLED
      log.warn "~ WARNING: HTTPS is not supported on your system, using HTTP instead.\n"
      log.warn "   If you are using Ubuntu, you can run `apt-get install libopenssl-ruby`\n"
      proxy[:secure] = false
    end

    origin_host = env['SERVER_NAME'] # capture the origin host for cookies
    http_method = env['REQUEST_METHOD'].to_s.downcase
    url = proxy[:path_info] #proxy_url #env['PATH_INFO']
    params = env['QUERY_STRING']
    
    log.info "PROXY: -> #{url}"

    # collect headers...
    headers = {}
    env.each do |key, value|
      next unless key =~ /^HTTP_/
      key = key.gsub(/^HTTP_/,'').downcase.sub(/^\w/){|l| l.upcase}.gsub(/_(\w)/){|l| "-#{$1.upcase}"} # remove HTTP_, dasherize and titleize
      if !key.eql? "Version"
        headers[key] = value
      end
    end

    # Rack documentation says CONTENT_TYPE and CONTENT_LENGTH aren't prefixed by HTTP_
    headers['Content-Type'] = env['CONTENT_TYPE'] if env['CONTENT_TYPE']

    length = env['CONTENT_LENGTH']
    headers['Content-Length'] = length if length

    http_host, http_port = proxy[:to].split(':')
    http_port = proxy[:secure] ? '443' : '80' if http_port.nil?

    # added 4/23/09 per Charles Jolley, corrects problem
    # when making requests to virtual hosts
    headers['Host'] = "#{http_host}:#{http_port}"

    if proxy[:url]
      url = url.sub(/^#{Regexp.escape proxy_url}/, proxy[:url])
    end

    http_path = [url]
    http_path << params if params && params.size>0
    http_path = http_path.join('?')

    response = nil
    no_body_method = %w(get copy head move options trace)

    done = false
    tries = 0
    until done
      http = ::Net::HTTP.new(http_host, http_port)

      if proxy[:secure]
        http.use_ssl = true
        http.verify_mode = OpenSSL::SSL::VERIFY_NONE
      end

      http.start do |web|
        if no_body_method.include?(http_method)
          response = web.send(http_method, http_path, headers)
        else
          http_body = env['rack.input']
          http_body.rewind # May not be necessary but can't hurt

          req = Net::HTTPGenericRequest.new(http_method.upcase,
                                              true, true, http_path, headers)
          req.body_stream = http_body if length.to_i > 0
          response = web.request(req)
        end
      end

      status = response.code # http status code
      protocol = proxy[:secure] ? 'https' : 'http'

      log.log "~ PROXY: #{http_method.upcase} #{status} #{url} -> #{protocol}://#{http_host}:#{http_port}#{http_path}\n"

      # display and construct specific response headers
      response_headers = {}
      ignore_headers = ['transfer-encoding', 'keep-alive', 'connection']
      response.each do |key, value|
        next if ignore_headers.include?(key.downcase)
        # If this is a cookie, strip out the domain.  This technically may
        # break certain scenarios where services try to set cross-domain
        # cookies, but those services should not be doing that anyway...
        value.gsub!(/domain=[^\;]+\;? ?/,'') if key.downcase == 'set-cookie'
        # Location headers should rewrite the hostname if it is included.
        value.gsub!(/^http:\/\/#{http_host}(:[0-9]+)?\//, "http://#{http_host}/") if key.downcase == 'location'
        # content-length is returning char count not bytesize
        if key.downcase == 'content-length'
          if response.body.respond_to?(:bytesize)
            value = response.body.bytesize.to_s
          elsif response.body.respond_to?(:size)
            value = response.body.size.to_s
          else
            value = '0'
          end
        end

        #$stderr << "   #{key}: #{value}\n"

        response_headers[key] = value
      end

      if [301, 302, 303, 307].include?(status.to_i) && proxy[:redirect] != false
        log.warn '~ REDIRECTING: '+response_headers['location']+"\n"

        uri = URI.parse(response_headers['location']);
        http_host = uri.host
        http_port = uri.port
        http_path = uri.path
        http_path += '?'+uri.query if uri.query

        tries += 1
        if tries > 10
          raise "Too many redirects!"
        end
      else
        done = true
      end
    end

    # Thin doesn't like null bodies
    response_body = response.body || ''
    #::Rack::Utils::HeaderHash.new(response_headers)
    return [status.to_i, response_headers, response_body.to_s]
  end
  
end