require 'httpclient'
require 'json'
require 'active_support/core_ext/string/inflections'
require 'active_support/core_ext/hash/keys'
require 'active_support/core_ext/array/wrap'
require 'telegram/bottable'

module Telegram
  extend Bottable

  class Bot
    class Error < StandardError; end
    class NotFound < Error; end

    autoload :Middleware,         'telegram/bot/middleware'
    autoload :UpdatesController,  'telegram/bot/updates_controller'
    autoload :UpdatesPoller,      'telegram/bot/updates_poller'

    URL_TEMPLATE = 'https://api.telegram.org/bot%s/'.freeze

    class << self
      # Accepts different options to initialize bot.
      def wrap(input)
        case input
        when self then input
        when Array then input.map(&method(__callee__))
        when Hash then
          input = input.stringify_keys
          new input['token'], input['username']
        else
          new(input)
        end
      end
    end

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

    def initialize(token, username = nil)
      @client = HTTPClient.new
      @token = token
      @username = username
      @base_uri = format URL_TEMPLATE, token
    end

    def debug!(dev = STDOUT)
      client.debug_dev = dev
    end

    def debug_off!
      client.debug_dev = nil
    end

    def request(action, data = {})
      res = http_request("#{base_uri}#{action}", data)
      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'] || '-'}"
      # NotFound is raised only for valid responses from Telegram
      raise NotFound, err_msg if 404 == status && result
      raise Error, err_msg
    end

    %w(
      answerInlineQuery
      forwardMessage
      getFile
      getMe
      getUpdates
      getUserProfilePhotos
      sendAudio
      sendChatAction
      sendDocument
      sendLocation
      sendMessage
      sendPhoto
      sendSticker
      sendVideo
      sendVoice
      setWebhook
    ).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
      "#<Telegram::Bot##{object_id}(#{@username})>"
    end
  end
end

require 'telegram/bot/railtie' if defined?(Rails)