import { RETINA_PREFIX, DATA_URI, URL_FILE_EXTENSION, SVG_SIZE, VERSION } from '../const';
import EventEmitter from 'eventemitter3';
import pluginTarget from './pluginTarget';

let nextUid = 0;
let saidHello = false;

/**
 * @namespace PIXI.utils
 */
export { EventEmitter, pluginTarget };

/**
 * Gets the next unique identifier
 *
 * @memberof PIXI.utils
 * @return {number} The next unique identifier to use.
 */
export function uid()
{
    return ++nextUid;
}

/**
 * Converts a hex color number to an [R, G, B] array
 *
 * @memberof PIXI.utils
 * @param {number} hex - The number to convert
 * @param  {number[]} [out=[]] If supplied, this array will be used rather than returning a new one
 * @return {number[]} An array representing the [R, G, B] of the color.
 */
export function hex2rgb(hex, out)
{
    out = out || [];

    out[0] = ((hex >> 16) & 0xFF) / 255;
    out[1] = ((hex >> 8) & 0xFF) / 255;
    out[2] = (hex & 0xFF) / 255;

    return out;
}

/**
 * Converts a hex color number to a string.
 *
 * @memberof PIXI.utils
 * @param {number} hex - Number in hex
 * @return {string} The string color.
 */
export function hex2string(hex)
{
    hex = hex.toString(16);
    hex = '000000'.substr(0, 6 - hex.length) + hex;

    return `#${hex}`;
}

/**
 * Converts a color as an [R, G, B] array to a hex number
 *
 * @memberof PIXI.utils
 * @param {number[]} rgb - rgb array
 * @return {number} The color number
 */
export function rgb2hex(rgb)
{
    return (((rgb[0] * 255) << 16) + ((rgb[1] * 255) << 8) + (rgb[2] * 255));
}

/**
 * get the resolution / device pixel ratio of an asset by looking for the prefix
 * used by spritesheets and image urls
 *
 * @memberof PIXI.utils
 * @param {string} url - the image path
 * @return {number} resolution / device pixel ratio of an asset
 */
export function getResolutionOfUrl(url)
{
    const resolution = RETINA_PREFIX.exec(url);

    if (resolution)
    {
        return parseFloat(resolution[1]);
    }

    return 1;
}

/**
 * Typedef for decomposeDataUri return object.
 *
 * @typedef {object} DecomposedDataUri
 * @property {mediaType} Media type, eg. `image`
 * @property {subType} Sub type, eg. `png`
 * @property {encoding} Data encoding, eg. `base64`
 * @property {data} The actual data
 */

/**
 * Split a data URI into components. Returns undefined if
 * parameter `dataUri` is not a valid data URI.
 *
 * @memberof PIXI.utils
 * @param {string} dataUri - the data URI to check
 * @return {DecomposedDataUri|undefined} The decomposed data uri or undefined
 */
export function decomposeDataUri(dataUri)
{
    const dataUriMatch = DATA_URI.exec(dataUri);

    if (dataUriMatch)
    {
        return {
            mediaType: dataUriMatch[1] ? dataUriMatch[1].toLowerCase() : undefined,
            subType: dataUriMatch[2] ? dataUriMatch[2].toLowerCase() : undefined,
            encoding: dataUriMatch[3] ? dataUriMatch[3].toLowerCase() : undefined,
            data: dataUriMatch[4],
        };
    }

    return undefined;
}

/**
 * Get type of the image by regexp for extension. Returns undefined for unknown extensions.
 *
 * @memberof PIXI.utils
 * @param {string} url - the image path
 * @return {string|undefined} image extension
 */
export function getUrlFileExtension(url)
{
    const extension = URL_FILE_EXTENSION.exec(url);

    if (extension)
    {
        return extension[1].toLowerCase();
    }

    return undefined;
}

/**
 * Typedef for Size object.
 *
 * @typedef {object} Size
 * @property {width} Width component
 * @property {height} Height component
 */

/**
 * Get size from an svg string using regexp.
 *
 * @memberof PIXI.utils
 * @param {string} svgString - a serialized svg element
 * @return {Size|undefined} image extension
 */
export function getSvgSize(svgString)
{
    const sizeMatch = SVG_SIZE.exec(svgString);
    const size = {};

    if (sizeMatch)
    {
        size[sizeMatch[1]] = Math.round(parseFloat(sizeMatch[2]));
        size[sizeMatch[3]] = Math.round(parseFloat(sizeMatch[4]));
    }

    return size;
}

/**
 * Skips the hello message of renderers that are created after this is run.
 *
 */
export function skipHello()
{
    saidHello = true;
}

/**
 * Logs out the version and renderer information for this running instance of PIXI.
 * If you don't want to see this message you can run `PIXI.utils.skipHello()` before
 * creating your renderer. Keep in mind that doing that will forever makes you a jerk face.
 *
 * @static
 * @memberof PIXI.utils
 * @param {string} type - The string renderer type to log.
 */
export function sayHello(type)
{
    if (saidHello)
    {
        return;
    }

    if (navigator.userAgent.toLowerCase().indexOf('chrome') > -1)
    {
        const args = [
            `\n %c %c %c Pixi.js ${VERSION} - ✰ ${type} ✰  %c  %c  http://www.pixijs.com/  %c %c ♥%c♥%c♥ \n\n`,
            'background: #ff66a5; padding:5px 0;',
            'background: #ff66a5; padding:5px 0;',
            'color: #ff66a5; background: #030307; padding:5px 0;',
            'background: #ff66a5; padding:5px 0;',
            'background: #ffc3dc; padding:5px 0;',
            'background: #ff66a5; padding:5px 0;',
            'color: #ff2424; background: #fff; padding:5px 0;',
            'color: #ff2424; background: #fff; padding:5px 0;',
            'color: #ff2424; background: #fff; padding:5px 0;',
        ];

        window.console.log.apply(console, args);
    }
    else if (window.console)
    {
        window.console.log(`Pixi.js ${VERSION} - ${type} - http://www.pixijs.com/`);
    }

    saidHello = true;
}

/**
 * Helper for checking for webgl support
 *
 * @memberof PIXI.utils
 * @return {boolean} is webgl supported
 */
export function isWebGLSupported()
{
    const contextOptions = { stencil: true, failIfMajorPerformanceCaveat: true };

    try
    {
        if (!window.WebGLRenderingContext)
        {
            return false;
        }

        const canvas = document.createElement('canvas');
        let gl = canvas.getContext('webgl', contextOptions) || canvas.getContext('experimental-webgl', contextOptions);

        const success = !!(gl && gl.getContextAttributes().stencil);

        if (gl)
        {
            const loseContext = gl.getExtension('WEBGL_lose_context');

            if (loseContext)
            {
                loseContext.loseContext();
            }
        }

        gl = null;

        return success;
    }
    catch (e)
    {
        return false;
    }
}

/**
 * Returns sign of number
 *
 * @memberof PIXI.utils
 * @param {number} n - the number to check the sign of
 * @returns {number} 0 if `n` is 0, -1 if `n` is negative, 1 if `n` is positive
 */
export function sign(n)
{
    if (n === 0) return 0;

    return n < 0 ? -1 : 1;
}

/**
 * Remove a range of items from an array
 *
 * @memberof PIXI.utils
 * @param {Array<*>} arr The target array
 * @param {number} startIdx The index to begin removing from (inclusive)
 * @param {number} removeCount How many items to remove
 */
export function removeItems(arr, startIdx, removeCount)
{
    const length = arr.length;

    if (startIdx >= length || removeCount === 0)
    {
        return;
    }

    removeCount = (startIdx + removeCount > length ? length - startIdx : removeCount);

    const len = length - removeCount;

    for (let i = startIdx; i < len; ++i)
    {
        arr[i] = arr[i + removeCount];
    }

    arr.length = len;
}

/**
 * @todo Describe property usage
 *
 * @memberof PIXI.utils
 * @private
 */
export const TextureCache = {};

/**
 * @todo Describe property usage
 *
 * @memberof PIXI.utils
 * @private
 */
export const BaseTextureCache = {};