# frozen_string_literal: true

require "http/headers"
require "openssl"
require "socket"
require "http/uri"

module HTTP
  class Options # rubocop:disable Metrics/ClassLength
    @default_socket_class     = TCPSocket
    @default_ssl_socket_class = OpenSSL::SSL::SSLSocket
    @default_timeout_class    = HTTP::Timeout::Null
    @available_features       = {}

    class << self
      attr_accessor :default_socket_class, :default_ssl_socket_class, :default_timeout_class
      attr_reader :available_features

      def new(options = {})
        options.is_a?(self) ? options : super
      end

      def defined_options
        @defined_options ||= []
      end

      def register_feature(name, impl)
        @available_features[name] = impl
      end

      protected

      def def_option(name, reader_only: false, &interpreter)
        defined_options << name.to_sym
        interpreter ||= ->(v) { v }

        if reader_only
          attr_reader name
        else
          attr_accessor name
          protected :"#{name}="
        end

        define_method(:"with_#{name}") do |value|
          dup { |opts| opts.send(:"#{name}=", instance_exec(value, &interpreter)) }
        end
      end
    end

    def initialize(options = {})
      defaults = {
        :response           => :auto,
        :proxy              => {},
        :timeout_class      => self.class.default_timeout_class,
        :timeout_options    => {},
        :socket_class       => self.class.default_socket_class,
        :nodelay            => false,
        :ssl_socket_class   => self.class.default_ssl_socket_class,
        :ssl                => {},
        :keep_alive_timeout => 5,
        :headers            => {},
        :cookies            => {},
        :encoding           => nil,
        :features           => {}
      }

      opts_w_defaults = defaults.merge(options)
      opts_w_defaults[:headers] = HTTP::Headers.coerce(opts_w_defaults[:headers])
      opts_w_defaults.each { |(k, v)| self[k] = v }
    end

    def_option :headers do |new_headers|
      headers.merge(new_headers)
    end

    def_option :cookies do |new_cookies|
      new_cookies.each_with_object cookies.dup do |(k, v), jar|
        cookie = k.is_a?(Cookie) ? k : Cookie.new(k.to_s, v.to_s)
        jar[cookie.name] = cookie.cookie_value
      end
    end

    def_option :encoding do |encoding|
      self.encoding = Encoding.find(encoding)
    end

    def_option :features, :reader_only => true do |new_features|
      # Normalize features from:
      #
      #     [{feature_one: {opt: 'val'}}, :feature_two]
      #
      # into:
      #
      #     {feature_one: {opt: 'val'}, feature_two: {}}
      normalized_features = new_features.each_with_object({}) do |feature, h|
        if feature.is_a?(Hash)
          h.merge!(feature)
        else
          h[feature] = {}
        end
      end

      features.merge(normalized_features)
    end

    def features=(features)
      @features = features.each_with_object({}) do |(name, opts_or_feature), h|
        h[name] = if opts_or_feature.is_a?(Feature)
                    opts_or_feature
                  else
                    unless (feature = self.class.available_features[name])
                      argument_error! "Unsupported feature: #{name}"
                    end
                    feature.new(**opts_or_feature)
                  end
      end
    end

    %w[
      proxy params form json body response
      socket_class nodelay ssl_socket_class ssl_context ssl
      keep_alive_timeout timeout_class timeout_options
    ].each do |method_name|
      def_option method_name
    end

    def_option :follow, :reader_only => true

    def follow=(value)
      @follow =
        case
        when !value                    then nil
        when true == value             then {}
        when value.respond_to?(:fetch) then value
        else argument_error! "Unsupported follow options: #{value}"
        end
    end

    def_option :persistent, :reader_only => true

    def persistent=(value)
      @persistent = value ? HTTP::URI.parse(value).origin : nil
    end

    def persistent?
      !persistent.nil?
    end

    def merge(other)
      h1 = to_hash
      h2 = other.to_hash

      merged = h1.merge(h2) do |k, v1, v2|
        case k
        when :headers
          v1.merge(v2)
        else
          v2
        end
      end

      self.class.new(merged)
    end

    def to_hash
      hash_pairs = self.class.
                   defined_options.
                   flat_map { |opt_name| [opt_name, send(opt_name)] }
      Hash[*hash_pairs]
    end

    def dup
      dupped = super
      yield(dupped) if block_given?
      dupped
    end

    def feature(name)
      features[name]
    end

    protected

    def []=(option, val)
      send(:"#{option}=", val)
    end

    private

    def argument_error!(message)
      raise(Error, message, caller(1..-1))
    end
  end
end