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

module Telegram
  module Bot
    class Client
      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 = {}) # rubocop:disable PerceivedComplexity
        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 = "#{res.reason}: #{result && result['description'] || '-'}"
        if result
          # NotFound is raised only for valid responses from Telegram
          raise NotFound, err_msg if 404 == status
          raise StaleChat, err_msg if StaleChat.match_response?(result)
        end
        raise Error, err_msg
      end

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

        answerCallbackQuery
        forwardMessage
        getChat
        getChatAdministrators
        getChatMember
        getChatMembersCount
        getFile
        getMe
        getUserProfilePhotos
        kickChatMember
        leaveChat
        sendAudio
        sendChatAction
        sendContact
        sendDocument
        sendLocation
        sendMessage
        sendPhoto
        sendSticker
        sendVenue
        sendVideo
        sendVoice
        unbanChatMember

        editMessageCaption
        editMessageReplyMarkup
        editMessageText

        answerInlineQuery

        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