// requirements
const logger = require('./logger');
const config = require('../config.json');
const util = require('util');

// third party requirements
const blinkstick = require('blinkstick');
const hexcolor = require('hex-color-regex');

// constants
// const LEDS = [0, 1, 2, 3, 4, 5, 6, 7];
const LEDS_ALL = 'index_all';
const RANDOM = 'random';
const ANIMATION_STATE_INPROGRESS = 1;
const ANIMATION_STATE_FINISH = 0;

// variables
let led;
const LEDS = new Map();

function findBlinkstick() {
    return new Promise((resolve, reject) => {
        led = blinkstick.findFirst();
        if (led !== undefined && led !== null) {
            return resolve(led);
        }
        return reject('could not find any blinkstick');
    });
}

// light it up
async function illuminate(blinkstickConfig) {
    led = await findBlinkstick();
    let indices = getIndices(blinkstickConfig);
    for (let index = 0; index < indices.length; index++) {
        try {
            await setLedState(indices[index], ANIMATION_STATE_INPROGRESS);
            await singleAnimation(JSON.parse(JSON.stringify(blinkstickConfig)), indices[index]);
        } catch (err) {
            logger.error(err);
        }
    }
}

// turn the blinkstick or specified led off
async function powerOff(index) {
    led = await findBlinkstick();
    // check for NaN
    if (index !== index) {
        index = LEDS_ALL;
    }
    let config = {color: '#000000', mode: 'poweroff', options: {index: index}};
    let indices = getIndices(config);
    for (let index = 0; index < indices.length; index++) {
        try {
            await singleAnimation(JSON.parse(JSON.stringify(config)), indices[index]);
        } catch (err) {
            logger.error(err);
        }
    }
    if (index !== LEDS_ALL) {
        logger.info('led \'' + index + '\' powered off');
        return;
    }
    led.stop();
    led.turnOff();
    logger.info('blinkstick powered off');
}

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

        function callback(err) {
            clearLedState(config.options.index);
            if (err) {
                reject('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();
        }
    });
}

// start pulsing
function startPulsing(blinkstickConfig) {
    return new Promise((resolve, reject) => {
        let animation = getAnimation(blinkstickConfig);
        if (animation?.state === ANIMATION_STATE_FINISH || (blinkstickConfig.options.pulse.max > 0 && animation.done === blinkstickConfig.options.pulse.max)) {
            clearAnimationProperties(blinkstickConfig);
            return resolve('finished pulsing \'' + blinkstickConfig.color + '\'');
        }
        let currentAnimation = getAnimationByIndex(blinkstickConfig?.options?.index);
        if (currentAnimation !== undefined && currentAnimation.id !== blinkstickConfig.id) {
            stopAnimation(currentAnimation)
                .then(logger.info)
                .then(() => {
                    startPulsing(blinkstickConfig, resolve, reject)
                })
                .catch(logger.error);
            return;
        }
        animation = setAnimationProperties(blinkstickConfig);
        led.pulse(blinkstickConfig.color, blinkstickConfig.options, (err) => {
            if (err) {
                clearAnimationProperties(blinkstickConfig);
                return reject('error pulsing ' + msg + ' > ' + err);
            }
            animation.done++;
            logger.debug('pulsed ' + msg + ' ' + animation.done + '/' + blinkstickConfig.options.pulse.max + ' times');
            startPulsing(blinkstickConfig)
                .catch(reject);
        });
    });
}

// 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];
}

async function setLedState(index, state) {
    await stopLedAnimation(index);
    LEDS.set(index, state);
}

function clearLedState(index) {
    LEDS.delete(index);
}

function isLedAnimated(index) {
    return (LEDS.get(index) || LEDS.get(LEDS_ALL)) !== undefined;
}

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

function waitForAnimationEnd(index, callback) {
    if (!isLedAnimated(index)) {
        return callback();
    }
    setTimeout(() => {
        waitForAnimationEnd(index, callback);
    }, 100);
}

// color / parser functions
function parseColor(value) {
    if (!value || value === RANDOM) {
        return RANDOM;
    }
    let parsedColor = parseRGBColor(value);
    if (!parsedColor) {
        parsedColor = parseHexColor(value);
    }
    return parsedColor || function () {
        logger.warn('could not parse color value \'' + value + '\', defaulting to \'' + config.api.post.color.default + '\'');
        return config.api.post.color.default;
    }();
}

function parseRGBColor(value) {
    if (value.indexOf(',') === -1 && isRGBValue(value)) {
        return convertRGBToHex(parseInt(value) || 0, 0, 0);
    } else {
        const splittedValues = value.split(',');
        let color = {};
        for (let index = 0; index < splittedValues.length; index++) {
            const value = splittedValues[index];
            if (index === 0) {
                color.red = parseInt(value) || 0;
            } else if (index === 1) {
                color.green = parseInt(value) || 0;
            } else if (index === 2) {
                color.blue = parseInt(value) || 0;
            }
        }
        if (isRGBValue(color.red) && isRGBValue(color.green) && isRGBValue(color.blue)) {
            return convertRGBToHex(color.red, color.green, color.blue);
        }
    }
}

function isRGBValue(value) {
    return value !== undefined && !isNaN(value) && value >= 0 && value <= 255;
}

function convertRGBToHex(red, green, blue) {
    return '#' + ((1 << 24) + (red << 16) + (green << 8) + blue).toString(16).slice(1);
}

function parseHexColor(value) {
    if (value[0] !== '#') {
        value = '#' + value;
    }
    if (value.length === 4) {
        value = (value[0] + value[1] + value[1] + value[2] + value[2] + value[3] + value[3]);
    }
    if (hexcolor({strict: true}).test(value)) {
        return value;
    }
}

// exports
module.exports = {
    parseColor,
    illuminate,
    powerOff,
    LEDS_ALL
};