require 'wcc/api/rest_client'
require_relative 'message'
require_relative 'series'
require_relative 'speaker'
require_relative 'tag'
require_relative 'playlist'
require_relative 'client/response'

module WCC
  module Media
    class Client < ::WCC::API::RestClient
      class << self
        attr_writer :default
        # The default client.  Set this in an initializer to change the client used
        # by all the WCC::Media models
        def default
          @default ||= new
        end
      end

      PARAMS = %w[
        limit
        offset
        order_by
        sort
        target
      ].freeze

      RESOURCES = {
        'messages' => WCC::Media::Message,
        'series' => WCC::Media::Series,
        'speakers' => WCC::Media::Speaker,
        'tags' => WCC::Media::Tag,
        'playlists' => WCC::Media::Playlist
      }.freeze
      attr_reader(*RESOURCES.keys)

      attr_reader :options

      def initialize(**options)
        options = {
          api_url: 'https://media.watermark.org/api/v1/',
          response_class: Response
        }.merge!(options)
        super(**options)

        RESOURCES.each do |(endpoint, model)|
          instance_variable_set("@#{endpoint}", Resource.new(self, model, @options))
        end
      end

      Resource =
        Struct.new(:client, :model, :options) do
          def find(id)
            resp = client.get("#{model.endpoint}/#{id}")
            resp.assert_ok!
            model.new(resp.body[model.key], resp.headers.freeze)
          end

          def list(**filters)
            query = extract_params(filters)
            query = query.merge!(apply_filters(filters, model.filters))
            resp = client.get(model.endpoint, query)
            resp.assert_ok!
            resp.items.map { |s| model.new(s) }
          end

          private

          def extract_params(filters)
            filters.each_with_object({}) do |(k, _v), h|
              k_s = k.to_s
              h[k_s] = filters.delete(k) if PARAMS.include?(k_s)
            end
          end

          def apply_filters(filters, expected_filters)
            defaults = default_filters(expected_filters) || {}
            filters.each_with_object(defaults) do |(k, v), h|
              k = k.to_s
              raise ArgumentError, "Unknown filter '#{k}'" unless expected_filters.include?(k)

              h["filter[#{k}]"] = v
            end
          end

          def default_filters(expected_filters)
            options[:default_filters]&.each_with_object({}) do |(k, v), h|
              k = k.to_s
              h["filter[#{k}]"] = v if expected_filters.include?(k)
            end
          end
        end
    end
  end
end