// SPDX-FileCopyrightText: In 2019, Chris Pressey, the original author of this work, placed it into the public domain.
// SPDX-License-Identifier: Unlicense
// For more information, please refer to <https://unlicense.org/>


import { makeGame, updateGame } from './game.js';


/* --[ InputContext objects ]-------------------------------------------------------- */


function makeInputContext() {
    return Immutable.Map({
        game: makeGame(),
        leftPressed: false,
        rightPressed: false,
        thrustPressed: false,
        firePressed: false
    });
}


// Reducer that takes an InputContext and an Action and returns a new InputContext.
// Action must be one of: FRAME_READY | COIN_INSERTED
function updateInputContext(inputContext, action) {
    if (typeof inputContext === 'undefined') return makeInputContext();

    const game = inputContext.get("game");

    if (action.type === 'FRAME_READY') {
        const leftPressed = inputContext.get("leftPressed");
        const rightPressed = inputContext.get("rightPressed");
        const thrustPressed = inputContext.get("thrustPressed");
        const firePressed = inputContext.get("firePressed");
        const startPressed = inputContext.get("startPressed");

        const game2 = (action.leftPressed !== leftPressed ||
            action.rightPressed !== rightPressed ||
            action.thrustPressed !== thrustPressed ||
            action.firePressed !== firePressed ||
            action.startPressed !== startPressed) ?
                updateGame(game, {
                    type: "CONTROLS_CHANGED",
                    leftPressed: action.leftPressed,
                    rightPressed: action.rightPressed,
                    thrustPressed: action.thrustPressed,
                    firePressed: action.firePressed,
                    startPressed: action.startPressed,
                    prev: {
                        leftPressed: leftPressed,
                        rightPressed: rightPressed,
                        thrustPressed: thrustPressed,
                        firePressed: firePressed,
                        startPressed: startPressed
                    }
                }) : game;

        const game3 = updateGame(game2, { type: "FRAME_READY" });

        return inputContext.set("game", game3)
                           .set("leftPressed", action.leftPressed)
                           .set("rightPressed", action.rightPressed)
                           .set("thrustPressed", action.thrustPressed)
                           .set("firePressed", action.firePressed)
                           .set("startPressed", action.startPressed);
    } else if (action.type === 'COIN_INSERTED') {
        return inputContext.set("game", updateGame(game, action));
    }
    throw new Error("Unhandled action: " + action.type);
}

export { updateInputContext };