const hexcolor = require('hex-color-regex');

const LEDS_ALL = require('./blinkstick.js').ALL;
const MODE_SET = require('./blinkstick.js').MODE_SET;
const MODE_MORPH = require('./blinkstick.js').MODE_MORPH;
const MODE_BLINK = require('./blinkstick.js').MODE_BLINK;
const MODE_PULSE = require('./blinkstick.js').MODE_PULSE;
const MODE_POWEROFF = require('./blinkstick.js').MODE_POWEROFF;

const DURATION_DEFAULT = require('../config.json').api.post.duration.default || 1000;
const DELAY_DEFAULT = require('../config.json').api.post.delay.default || 500;

const COLOR_RANDOM = 'random';

// parse a http post and return an object with sane defaults
function parseRequest(requestBody, mode) {
    if (mode === undefined) {
        mode = MODE_SET;
    }
    let config = {
        'id': Math.random(),
        'mode': mode,
        'options': {
            'index': parseIndex(requestBody.index),
        }
    };
    if (config.mode === MODE_POWEROFF) {
        config.color = '#000000';
        return config;
    } else {
        config.color = parseColor(requestBody.color);
    }
    switch (config.mode) {
        case MODE_MORPH:
            config.options.duration = parseDuration(requestBody.duration, config.options.index);
            config.options.steps = parseSteps(requestBody.steps, config.options.duration);
            break;
        case MODE_BLINK:
            config.options.repeats = 1;
            config.repetitions = parseRepetitions(requestBody.repeats, config.options.index);
            config.options.delay = parseDelay(requestBody.delay);
            break;
        case MODE_PULSE:
            config.options.repeats = 1;
            config.repetitions = parseRepetitions(requestBody.repeats, config.options.index);
            config.options.duration = parseDuration(requestBody.duration, config.options.index, MODE_PULSE);
            config.options.steps = parseSteps(requestBody.steps, config.options.duration);
            break;
    }
    return config;
}

// parse the index
function parseIndex(index) {
    if (index === undefined) {
        return LEDS_ALL;
    }
    index = parseInt(index);
    if (index !== index) {
        return LEDS_ALL;
    }
    if (index < 0) {
        index = 0;
    } else if (index > 7) {
        index = 7;
    }
    return index;
}

// parse the duration
function parseDuration(duration, index, mode) {
    if (duration === undefined) {
        duration = DURATION_DEFAULT;
    }
    if (index === LEDS_ALL && mode !== MODE_PULSE) {
        duration = duration / 8;
    }
    if (duration < 100) {
        duration = 100;
    }
    return duration;
}

// parse the steps
function parseSteps(steps, duration) {
    if (duration === undefined) {
        duration = DURATION_DEFAULT;
    }
    if (steps === undefined || steps === 0) {
        steps = duration / 10;
    }
    return steps;
}

// parse the repetitions
function parseRepetitions(repeats, index) {
    repeats = parseInt(repeats);
    if (repeats !== repeats) {
        repeats = 0;
    }
    return {done: 0, max: repeats};
}

// parse the delay
function parseDelay(delay) {
    if (delay === undefined) {
        delay = DELAY_DEFAULT;
    }
    return delay;
}

// color / parser functions
function parseColor(value) {
    if (value === undefined || value === COLOR_RANDOM) {
        return COLOR_RANDOM;
    }
    let parsedColor = parseHexColor(value);
    if (parsedColor !== undefined) {
        return parsedColor;
    }
    return parseRGBColor(value) || COLOR_RANDOM;
}

function parseRGBColor(value) {
    if (value.indexOf(',') === -1 && isRGBValue(value)) {
        value = parseInt(value);
        return convertRGBToHex(value, value, value);
    }
    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 !== 7) {
        return;
    }
    if (!hexcolor({strict: true}).test(value)) {
        return;
    }
    return value;
}

// exports
module.exports = {
    parseRequest,
};