keypad.ts

import {Cell, CellLoop, Stream, StreamSink, Unit} from "sodiumjs";
import {Keys} from "../types";

function wireKeypad(sKeypad: StreamSink<Keys>|Stream<Keys>, sClear: Stream<Unit>, cActive?: Cell<boolean>) {
    if (cActive) {
        return wireKeypad(sKeypad.gate(cActive), sClear);
    }

    const cValue = new CellLoop<number>();
    const sKeyUpdate = sKeypad.snapshot(cValue, (key, value) => {
        if (key === Keys.CLEAR) {
            return 0;
        } else {
            const tmp = value * 10;
            return tmp >= 1000
                ? null
                : (key === Keys.ZERO ? tmp :
                    key === Keys.ONE ? tmp + 1 :
                        key === Keys.TWO ? tmp + 2 :
                            key === Keys.THREE ? tmp + 3 :
                                key === Keys.FOUR ? tmp + 4 :
                                    key === Keys.FIVE ? tmp + 5 :
                                        key === Keys.SIX ? tmp + 6 :
                                            key === Keys.SEVEN ? tmp + 7 :
                                                key === Keys.EIGHT ? tmp + 8 :
                                                    tmp + 9);
        }
    }).filterNotNull() as Stream<number>;
    cValue.loop(sKeyUpdate.orElse(sClear.map(u => 0)).hold(0));
    const sBeep = sKeyUpdate.map(() => Unit.UNIT);

    return {sBeep, cValue};
}

export default wireKeypad;