전방 js IOS 장치 모델 식별

(function () {
    var canvas, gl, glRenderer, models,
        devices = {
            "Apple A7 GPU": {
                1136: ["iPhone 5", "iPhone 5s"],
                2048: ["iPad Air", "iPad Mini 2", "iPad Mini 3"]
            },

            "Apple A8 GPU": {
                1334: ["iPhone 6"],
                2208: ["iPhone 6 Plus"],
                2048: ["iPad Air 2", "iPad Mini 4"]
            },

            "Apple A9 GPU": {
                1136: ["iPhone SE"],
                1334: ["iPhone 6s"],
                2208: ["iPhone 6s Plus"],
            },

            "Apple A10 GPU": {
                1334: ["iPhone 7"],
                2208: ["iPhone 7 Plus"]
            },

            "Apple A11 GPU": {
                1334: ["iPhone 8"],
                2208: ["iPhone 8 Plus"],
                2436: ["iPhone X"],
            },

            "Apple A12 GPU": {
                2436: ["iPhone XS"],
                2688: ["iPhone XS MAX"],
                1792: ["iphone XR"]
            },
        };

    function getCanvas() {
        if (canvas == null) {
            canvas = document.createElement('canvas');
        }

        return canvas;
    }

    function getGl() {
        if (gl == null) {
            gl = getCanvas().getContext('experimental-webgl');
        }

        return gl;
    }

    function getScreenWidth() {
        // alert(Math.max(screen.width, screen.height) * (window.devicePixelRatio || 1))
        console.log(Math.max(screen.width, screen.height) * (window.devicePixelRatio || 1))
        return Math.max(screen.width, screen.height) * (window.devicePixelRatio || 1);
    }

    function getGlRenderer() {
        if (glRenderer == null) {
            debugInfo = getGl().getExtension('WEBGL_debug_renderer_info');
            glRenderer = debugInfo == null ? 'unknown' : getGl().getParameter(debugInfo.UNMASKED_RENDERER_WEBGL);
        }
        console.log(glRenderer);
        return glRenderer;
    }

    function getModels() {
        var userAgent = window.navigator.userAgent;
        //  
        if (userAgent.indexOf('iPhone') === -1) {
            // return 'Android';
            models = ['Android'];
            return models;
        }

        var device = devices[getGlRenderer()];
        if (device == undefined) {
            models = ['unknown'];
        } else {
            models = device[getScreenWidth()];
            if (models == undefined) {
                models = ['unknown'];
            }
        }
        return models;
    }

    function getIphoneVersion() {
        var userAgent = window.navigator.userAgent;
        //  
        if (userAgent.indexOf('iPhone') === -1) {
            return ' ！';
        }

        var str = userAgent.toLowerCase(); 
        var version =str.match(/cpu iphone os (.*?) like mac os/);
        return version[1].replace(/_/g,".")
    }

    if (window.MobileDevice == undefined) {
        window.MobileDevice = {};
    }

    window.MobileDevice.getGlRenderer = getGlRenderer;
    window.MobileDevice.getModels = getModels;
    window.MobileDevice.getIphoneVersion = getIphoneVersion;
})();