# frozen_string_literal: true

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

module OAuth
  module RequestProxy
    class Base
      include OAuth::Helper

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

      attr_accessor :request, :options, :unsigned_parameters

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

      ## OAuth parameters

      def oauth_callback
        [parameters["oauth_callback"]].flatten.first
      end

      def oauth_consumer_key
        [parameters["oauth_consumer_key"]].flatten.first
      end

      def oauth_nonce
        [parameters["oauth_nonce"]].flatten.first
      end

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

      def oauth_signature_method
        [parameters["oauth_signature_method"]].flatten.first
      end

      def oauth_timestamp
        [parameters["oauth_timestamp"]].flatten.first
      end

      def oauth_token
        [parameters["oauth_token"]].flatten.first
      end

      # OAuth 1.0a only: value returned to the Consumer after user authorization
      # and required when exchanging a Request Token for an Access Token.
      # Not present in OAuth 1.0 flows.
      def oauth_verifier
        [parameters["oauth_verifier"]].flatten.first
      end

      def oauth_version
        [parameters["oauth_version"]].flatten.first
      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| !signature_and_unsigned_parameters.include?(k) }
      end

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

      def non_oauth_parameters
        parameters.select { |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.port}" if (u.scheme.casecmp("http").zero? && u.port != 80) || (u.scheme.casecmp("https").zero? && u.port != 443)}#{(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?
          params = if with_oauth
            parameters
          else
            non_oauth_parameters
          end

          [uri, normalize(params)].join("?")
        else
          warn("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.select! { |k, _v| k =~ /^oauth_/ }

          return oauth_params
        end

        {}
      end

      # Utility to make parameter values array-style (or keep nil) so that
      # subclasses can rely on array values for parameter merging/signing.
      # Mirrors the implementation previously present in
      # ActionDispatchRequest#wrap_values.
      def wrap_values(hash)
        return {} unless hash
        hash.each_with_object({}) do |(k, v), acc|
          acc[k] = (v.is_a?(Array) || v.nil?) ? v : [v]
        end
      end
    end
  end
end
