// For more information see https://aka.ms/fsharp-console-apps

open System
open System.IO
open System.Net.Http
open System.Threading
open System.Threading.Tasks
open Microsoft.FSharp.Control
open Newtonsoft.Json
open Telegram.Bot
open Telegram.Bot.Polling
open Telegram.Bot.Types
open Telegram.Bot.Types.Enums

type BotConfig = {
  token: string
  chanelId: int64
  adminChatId: int64
}

let ReadConfig =
  File.ReadAllText >> JsonConvert.DeserializeObject<BotConfig>

let CreateConfig (name: string) =
  match Environment.GetEnvironmentVariable(name) with
  | null ->  raise <| ApplicationException("Missing config path env")
  | path  -> ReadConfig <| path

let CreateBot (config: BotConfig, http: HttpClient) =
  TelegramBotClient(config.token, http)

let config = CreateConfig <| "SBPB_CONFIG_PATH";
let botClient = CreateBot <| (config, new HttpClient())

let shouldReply (u: Update) =
  u.Type = UpdateType.Message && u.Message.Chat.Id = config.adminChatId

let updateHandle (bc: ITelegramBotClient) (u: Update) (ct: CancellationToken): Task =
  match u with
  | _ when shouldReply u -> bc.SendTextMessageAsync(config.chanelId, u.Message.Text, cancellationToken = ct)
  | _ -> Task.CompletedTask

let handlePollingError (bc: ITelegramBotClient) (e: Exception) (t: CancellationToken) =
  printfn $"{e.Message}\n{e.StackTrace}"
  Task.CompletedTask
  
let receiverOptions = ReceiverOptions(AllowedUpdates = Array.zeroCreate<UpdateType> 0) 

botClient.StartReceiving(updateHandle,handlePollingError,receiverOptions)

Console.ReadKey() |> ignore