// ==UserScript==
// @name         Dark++
// @namespace    http://tampermonkey.net/
// @version      0.2
// @description  CSS 实现夜间模式; 代码是从贴吧抄的, 嗯 ... over
// @icon         https://gss0.baidu.com/7Ls0a8Sm2Q5IlBGlnYG/sys/portraith/item/feb81406?t=1435668917
// @author       sven
// @include      https://*
// @include      http://*
// @match        .*
// @grant        GM_getValue
// @grant        GM_setValue
// @downloadURL none
// ==/UserScript==

(function() {
    'use strict';
    const m = document.createElement('div')
    m.style.zIndex = '999999'
    m.style.position = 'absolute'
    m.style.height = '100vh'
    m.style.width = '100vw'
    m.style.position = 'fixed'
    m.style.top = '0'
    m.style.left = '-9999px'
    m.style.id = 'dark-modal'
    let opacity = GM_getValue('dark_mode_opacity') || 0.4
    const step = 0.05
    const setOpacity = ({opa, add, sub} = {}) => {
        let _opa = opa || opacity
        _opa = add
            ? _opa + step
            : (sub ? (_opa - step) : _opa)
        _opa = Math.max(0, _opa)
        _opa = Math.min(1, _opa)
        GM_setValue('dark_mode_opacity', _opa)
        m.style.outline = `rgba(0, 0, 0, ${opacity = _opa}) solid 10000px`
    }
    setOpacity()
    const keyMap = {
        81: () => setOpacity({add: true}),
        87: () => setOpacity({sub: true})
    }
    document.body.append(m)
    document.addEventListener('keydown', evt => {
        keyMap[evt.keyCode] && keyMap[evt.keyCode](evt)
    })
    console.log(m)
    console.dir(m)
})();