require 'json'
require 'httpclient'
require 'active_support/core_ext/string/inflections'
require 'active_support/core_ext/hash/keys'

module Telegram
  module Bot
    class Client # rubocop:disable ClassLength
      URL_TEMPLATE = 'https://api.telegram.org/bot%s/'.freeze

      autoload :TypedResponse, 'telegram/bot/client/typed_response'
      extend Initializers
      prepend Async
      prepend Botan::ClientHelpers
      include DebugClient

      class << self
        def by_id(id)
          Telegram.bots[id]
        end

        # Prepend TypedResponse module.
        def typed_response!
          prepend TypedResponse
        end

        # Encodes nested hashes as json.
        def prepare_body(body)
          body = body.dup
          body.each do |k, val|
            body[k] = val.to_json if val.is_a?(Hash) || val.is_a?(Array)
          end
        end

        def prepare_async_args(action, body = {})
          [action.to_s, Async.prepare_hash(prepare_body(body))]
        end
      end

      attr_reader :client, :token, :username, :base_uri

      def initialize(token = nil, username = nil, **options)
        @client = HTTPClient.new
        @token = token || options[:token]
        @username = username || options[:username]
        @base_uri = format URL_TEMPLATE, self.token
      end

      def request(action, body = {})
        res = http_request("#{base_uri}#{action}", self.class.prepare_body(body))
        status = res.status
        return JSON.parse(res.body) if 300 > status
        result = JSON.parse(res.body) rescue nil # rubocop:disable RescueModifier
        err_msg = result && result['description'] || '-'
        if result
          # This errors are raised only for valid responses from Telegram
          case status
          when 403 then raise Forbidden, err_msg
          when 404 then raise NotFound, err_msg
          end
        end
        raise Error, "#{res.reason}: #{err_msg}"
      end

      # Splited to the sections similar to API docs.
      %w(
        deleteWebhook
        getUpdates
        getWebhookInfo
        setWebhook

        answerCallbackQuery
        deleteChatPhoto
        exportChatInviteLink
        forwardMessage
        getChat
        getChatAdministrators
        getChatMember
        getChatMembersCount
        getFile
        getMe
        getUserProfilePhotos
        kickChatMember
        leaveChat
        pinChatMessage
        promoteChatMember
        restrictChatMember
        sendAudio
        sendChatAction
        sendContact
        sendDocument
        sendLocation
        sendMessage
        sendPhoto
        sendVenue
        sendVideo
        sendVideoNote
        sendVoice
        setChatDescription
        setChatPhoto
        setChatTitle
        unbanChatMember
        unpinChatMessage

        deleteMessage
        editMessageCaption
        editMessageReplyMarkup
        editMessageText

        sendSticker
        getStickerSet
        uploadStickerFile
        createNewStickerSet
        addStickerToSet
        setStickerPositionInSet
        deleteStickerFromSet

        answerInlineQuery

        sendInvoice
        answerShippingQuery
        answerPreCheckoutQuery

        getGameHighScores
        sendGame
        setGameScore
      ).each do |method|
        define_method(method.underscore) { |*args| request(method, *args) }
      end

      # Endpoint for low-level request. For easy host highjacking & instrumentation.
      # Params are not used directly but kept for instrumentation purpose.
      # You probably don't want to use this method directly.
      def http_request(uri, body)
        client.post(uri, body)
      end

      def inspect
        "#<#{self.class.name}##{object_id}(#{@username})>"
      end
    end
  end
end