// ==UserScript==
// @name         调整网页亮度
// @namespace    http://tampermonkey.net/
// @version      0.3
// @description  调整网页亮度,护眼
// @description:en  Adjust page brightness,eyeshield
// @author       wodexianghua
// @match        http://*/*
// @match        https://*/*
// @match        file:///*
// @grant        GM_setValue
// @grant        GM_getValue
// @downloadURL none
// ==/UserScript==

(function() {
    'use strict';
    //保证iframe不起作用
    if (self == top) {
        function insertHTML(lv) {
            if (self == top) {
                document.body.insertAdjacentHTML("beforebegin",
                    '<div id="__nightingale_view_cover" style="width: 100%; height: 100%; transition: -webkit-transform 10s ease-in-out 0s; position: fixed !important; left: 0px !important; bottom: 0px !important; overflow: hidden !important; background: rgb(0, 0, 0) !important; pointer-events: none !important; z-index: 2147483647; opacity: ' +
                    lv + ';"></div>');
            }
        }

        if (GM_getValue("lv") == undefined) {
            GM_setValue("lv", '0.35');
        }

        document.addEventListener('keydown', function (event) {
            if (event.altKey && event.which == 40) {
                var lv = parseFloat(GM_getValue("lv"));
                lv += 0.1;
                GM_setValue('lv', lv);
                document.querySelector("#__nightingale_view_cover").style.opacity = lv;
            } else if (event.altKey && event.which == 38) {
                var lv = parseFloat(GM_getValue("lv"));
                lv -= 0.1;
                GM_setValue("lv", lv);
                document.querySelector("#__nightingale_view_cover").style.opacity = lv;
            }
        });

        document.addEventListener('visibilitychange', function() {
            if (document.visibilityState == 'hidden') { //状态判断

            } else {
                var lv = parseFloat(GM_getValue("lv"));
                if (document.querySelector("#__nightingale_view_cover") == null) {
                    insertHTML(GM_getValue("lv"));
                }
                GM_setValue("lv", lv);
                document.querySelector("#__nightingale_view_cover").style.opacity = lv
            }
        });

        // window.addEventListener("storage", function(event) {
        //     console.log(event.key + '=' +event.newValue);
        // });

        setTimeout(insertHTML(GM_getValue("lv")), 300);
    }

    // Your code here...
})();