require "oauth/request_proxy"
require "oauth/helper"

module OAuth::RequestProxy
  class Base
    include OAuth::Helper

    def self.proxies(klass)
      OAuth::RequestProxy.available_proxies[klass] = self
    end

    attr_accessor :request, :options, :unsigned_parameters

    def initialize(request, options = {})
      @request = request
      @unsigned_parameters = (options[:unsigned_parameters] || []).map {|param| param.to_s}
      @options = options
    end

    ## OAuth parameters

    def oauth_callback
      parameters["oauth_callback"]
    end

    def oauth_consumer_key
      parameters["oauth_consumer_key"]
    end

    def oauth_nonce
      parameters["oauth_nonce"]
    end

    def oauth_signature
      # TODO can this be nil?
      [parameters["oauth_signature"]].flatten.first || ""
    end

    def oauth_signature_method
      case parameters["oauth_signature_method"]
      when Array
        parameters["oauth_signature_method"].first
      else
        parameters["oauth_signature_method"]
      end
    end

    def oauth_timestamp
      parameters["oauth_timestamp"]
    end

    def oauth_token
      parameters["oauth_token"]
    end

    def oauth_verifier
      parameters["oauth_verifier"]
    end

    def oauth_version
      parameters["oauth_version"]
    end

    # TODO deprecate these
    alias_method :consumer_key,     :oauth_consumer_key
    alias_method :token,            :oauth_token
    alias_method :nonce,            :oauth_nonce
    alias_method :timestamp,        :oauth_timestamp
    alias_method :signature,        :oauth_signature
    alias_method :signature_method, :oauth_signature_method

    ## Parameter accessors

    def parameters
      raise NotImplementedError, "Must be implemented by subclasses"
    end

    def parameters_for_signature
      parameters.select { |k,v| not signature_and_unsigned_parameters.include?(k) }
    end

    def oauth_parameters
      parameters.select { |k,v| OAuth::PARAMETERS.include?(k) }.reject { |k,v| v == "" }
    end

    def non_oauth_parameters
      parameters.reject { |k,v| OAuth::PARAMETERS.include?(k) }
    end

    def signature_and_unsigned_parameters
      unsigned_parameters+["oauth_signature"]
    end

    # See 9.1.2 in specs
    def normalized_uri
      u = URI.parse(uri)
      "#{u.scheme.downcase}://#{u.host.downcase}#{(u.scheme.downcase == 'http' && u.port != 80) || (u.scheme.downcase == 'https' && u.port != 443) ? ":#{u.port}" : ""}#{(u.path && u.path != '') ? u.path : '/'}"
    end

    # See 9.1.1. in specs Normalize Request Parameters
    def normalized_parameters
      normalize(parameters_for_signature)
    end

    def sign(options = {})
      OAuth::Signature.sign(self, options)
    end

    def sign!(options = {})
      parameters["oauth_signature"] = sign(options)
      @signed = true
      signature
    end

    # See 9.1 in specs
    def signature_base_string
      base = [method, normalized_uri, normalized_parameters]
      base.map { |v| escape(v) }.join("&")
    end

    # Has this request been signed yet?
    def signed?
      @signed
    end

    # URI, including OAuth parameters
    def signed_uri(with_oauth = true)
      if signed?
        if with_oauth
          params = parameters
        else
          params = non_oauth_parameters
        end

        [uri, normalize(params)] * "?"
      else
        STDERR.puts "This request has not yet been signed!"
      end
    end

    # Authorization header for OAuth
    def oauth_header(options = {})
      header_params_str = oauth_parameters.map { |k,v| "#{k}=\"#{escape(v)}\"" }.join(", ")

      realm = "realm=\"#{options[:realm]}\", " if options[:realm]
      "OAuth #{realm}#{header_params_str}"
    end

    def query_string_blank?
      if uri = request.env["REQUEST_URI"]
        uri.split("?", 2)[1].nil?
      else
        request.query_string.match(/\A\s*\z/)
      end
    end

  protected

    def header_params
      %w( X-HTTP_AUTHORIZATION Authorization HTTP_AUTHORIZATION ).each do |header|
        next unless request.env.include?(header)

        header = request.env[header]
        next unless header[0,6] == "OAuth "

        # parse the header into a Hash
        oauth_params = OAuth::Helper.parse_header(header)

        # remove non-OAuth parameters
        oauth_params.reject! { |k,v| k !~ /^oauth_/ }

        return oauth_params
      end

      return {}
    end
  end
end