const logger = require('./logger');
const blinkstick = require('blinkstick');

const LEDS_ALL = 'all';

const MODE_SET = 'set';
const MODE_MORPH = 'morph';
const MODE_BLINK = 'blink';
const MODE_PULSE = 'pulse';
const MODE_POWEROFF = 'poweroff';

const LEDS_ANIMATED = [];
const LEDS_STOP = [];

// find connected blinkstick(s)
async function findBlinkstick(index) {
    let blinksticks = blinkstick.findAll();
    if (blinksticks.length === 0) {
        throw new Error('could not find any blinkstick');
    }
    if (index === undefined) {
        index = 0;
    }
    if (index <= blinksticks.length) {
        return blinksticks[index];
    }
}

// simple animation (set the color / morph to color)
async function simple(config) {
    await stopLedsAccordingly(config);
    config.timestamp = new Date().getTime();
    let indices = getIndices(config);
    for (let index = 0; index < indices.length; index++) {
        await setLedAnimated(indices[index]);
        await singleAnimation(JSON.parse(JSON.stringify(config)), indices[index]);
        await clearLedState(indices[index]);
    }
    return {
        status: 'ok',
        color: config.color,
        indices: indices,
        time: (new Date().getTime() - config.timestamp) + 'ms'
    };
}

// complex animation (pulse / blink)
async function complex(config) {
    if (config.timestamp === undefined) {
        await stopLedsAccordingly(config);
        config.timestamp = new Date().getTime();
    }
    let indices = getIndices(config);
    for (let index = 0; index < indices.length; index++) {
        if (shouldLedFinish(config)) {
            await clearLedState(indices[index]);
            return {status: 'ok', time: (new Date().getTime() - config.timestamp) + 'ms'};
        }
        await setLedAnimated(indices[index]);
        await singleAnimation(JSON.parse(JSON.stringify(config)), indices[index]);
        config.repetitions.done++;
    }
    return complex(config);
}

// power the blinkstick (or just a specific led) off
async function powerOff(config) {
    config.timestamp = new Date().getTime();
    let indices = getIndices(config);
    await forceStop();
    for (let index = 0; index < indices.length; index++) {
        await singleAnimation(JSON.parse(JSON.stringify(config)), indices[index]);
        logger.info('led \'' + indices[index] + '\' powered off');
    }
    if (config.options.index === LEDS_ALL) {
        const blinkstick = await findBlinkstick();
        blinkstick.stop();
        blinkstick.turnOff();
        logger.info('blinkstick powered off');
    }
    return {status: 'ok', indices: indices, time: (new Date().getTime() - config.timestamp) + 'ms'};
}

// animations
async function singleAnimation(config, index) {
    config.options.index = index;
    const blinkstick = await findBlinkstick();
    return await new Promise((resolve, reject) => {
        logger.debug('changing color of led \'' + config.options.index + '\' to \'' + config.color + '\' (mode: ' + config.mode + ')...');
        switch (config.mode) {
            case MODE_MORPH:
                blinkstick.morph(config.color, config.options, callback);
                break;
            case MODE_BLINK:
                blinkstick.blink(config.color, config.options, callback);
                break;
            case MODE_PULSE:
                blinkstick.pulse(config.color, config.options, callback);
                break;
            default:
                blinkstick.setColor(config.color, config.options, callback);
                break;
        }

        function callback(err) {
            if (err) {
                reject(new Error('changing color of led \'' + config.options.index + '\' to \'' + config.color + '\' encountered an error > ' + err));
            }
            logger.debug('changed color of led \'' + config.options.index + '\' to \'' + config.color + '\' (mode: ' + config.mode + ')');
            resolve();
        }
    });
}

async function stopLedsAccordingly(config) {
    if (config.options.index === LEDS_ALL) {
        return await powerOff({
            id: Math.random(),
            mode: MODE_POWEROFF,
            color: '#000000',
            options: {index: LEDS_ALL}
        });
    }
    return stopLedAnimation(config.options.index);
}

async function forceStop() {
    LEDS_STOP.push(LEDS_ALL);
    return await new Promise((resolve, reject) => {
        waitForAllAnimationsEnd(() => {
            resolve();
        });
    });
}

function shouldLedFinish(config) {
    if (isLedStopping(config.options.index)) {
        return true;
    }
    if (config.mode === MODE_BLINK || config.mode === MODE_PULSE) {
        return config.repetitions.max !== 0 && config.repetitions.done >= config.repetitions.max;
    }
    return false;
}

// led / index helper functions
function getIndices(blinkstickConfig) {
    if (blinkstickConfig.options.index === LEDS_ALL) {
        return [0, 1, 2, 3, 4, 5, 6, 7];
    }
    return [blinkstickConfig.options.index];
}

function setLedAnimated(index) {
    if (isLedAnimated(index)) {
        return;
    }
    LEDS_ANIMATED.push(index);
}

function setLedStopping(index) {
    if (!isLedAnimated(index) || isLedStopping(index)) {
        return;
    }
    LEDS_STOP.push(index);
}

function clearLedState(index) {
    if (index === LEDS_ALL) {
        LEDS_ANIMATED.length = 0;
        return;
    }
    LEDS_ANIMATED.splice(LEDS_ANIMATED.indexOf(index), 1);
}

function isLedAnimated(index) {
    return LEDS_ANIMATED.includes(index);
}

function isLedStopping(index) {
    if (LEDS_STOP.includes(LEDS_ALL)) {
        return true;
    }
    return LEDS_STOP.includes(index);
}

function stopLedAnimation(index) {
    setLedStopping(index);
    return new Promise((resolve, reject) => {
        waitForAnimationEnd(index, () => {
            resolve();
        });
    });
}

function waitForAnimationEnd(index, callback) {
    if (!isLedAnimated(index)) {
        LEDS_STOP.splice(LEDS_STOP.indexOf(index), 1);
        return callback();
    }
    setTimeout(() => {
        waitForAnimationEnd(index, callback);
    }, 100);
}

function waitForAllAnimationsEnd(callback) {
    if (LEDS_ANIMATED.length === 0) {
        LEDS_STOP.length = 0;
        return callback();
    }
    setTimeout(() => {
        waitForAllAnimationsEnd(callback);
    }, 100);
}

function isInfiniteAnimation(config) {
    if (config.mode !== MODE_BLINK && config.mode !== MODE_PULSE) {
        return false;
    }
    return config.repetitions.max === 0;
}

// exports
module.exports = {
    simple,
    complex,
    powerOff,
    isInfiniteAnimation,
    LEDS_ALL,
    MODE_SET,
    MODE_MORPH,
    MODE_BLINK,
    MODE_PULSE,
    MODE_POWEROFF
};