# frozen_string_literal: true

require "forwardable"
require "uri"

module HTTPX::Transcoder
  module Form
    module_function

    PARAM_DEPTH_LIMIT = 32

    class Encoder
      extend Forwardable

      def_delegator :@raw, :to_s

      def_delegator :@raw, :to_str

      def_delegator :@raw, :bytesize

      def initialize(form)
        @raw = form.each_with_object("".b) do |(key, val), buf|
          HTTPX::Transcoder.normalize_keys(key, val) do |k, v|
            buf << "&" unless buf.empty?
            buf << URI.encode_www_form_component(k)
            buf << "=#{URI.encode_www_form_component(v.to_s)}" unless v.nil?
          end
        end
      end

      def content_type
        "application/x-www-form-urlencoded"
      end
    end

    module Decoder
      module_function

      def call(response, *)
        URI.decode_www_form(response.to_s).each_with_object({}) do |(field, value), params|
          HTTPX::Transcoder.normalize_query(params, field, value, PARAM_DEPTH_LIMIT)
        end
      end
    end

    def encode(form)
      Encoder.new(form)
    end

    def decode(response)
      content_type = response.content_type.mime_type

      raise HTTPX::Error, "invalid form mime type (#{content_type})" unless content_type == "application/x-www-form-urlencoded"

      Decoder
    end
  end
end