Bot.fs

module CounterBot = 

    type State = int

    type Msg = 
        | Increment
        | Decrement

    let init = 0

    let update msg (state: State) : State = 
        match msg with
        | Increment -> state + 1
        | Decrement -> state - 1


    let view (state: State) =
        Reply.Text { Text = sprintf "Counter state: %i" state }


    let dispatcher update state =
        match update with
        | Message (message, _) -> 
            match message with
            | MessageModel.Text x when x.Text = "+" -> Ok Increment
            | MessageModel.Text x when x.Text = "-" -> Ok Decrement
            | _ -> Reply.Text { Text = "Я жду только '+' или '-'" } |> Error  


module Root = 

    type State =
        | NotStarted
        | Counter of CounterBot.State 


    type Msg = 
        | OpenCounter
        | CounterMsg of CounterBot.Msg


    let init = NotStarted

    let update msg state = 
        match state, msg with
        | NotStarted, _ -> Counter <| CounterBot.init

        | Counter counter, CounterMsg counteMsg -> Counter <| CounterBot.update counteMsg counter
        | Counter _, OpenCounter -> state


    let view state = 
        match state with
        | NotStarted -> Reply.Text { Text = "Not started" }
        | Counter c -> CounterBot.view c


    let dispatcher update state = 
        match state, update with
        | NotStarted, _ -> Ok OpenCounter
        | Counter c, x -> CounterBot.dispatcher x c |> Result.map CounterMsg