// ==UserScript==
// @name         豆瓣小组话题快速预览-douban group topic fast preview
// @namespace    https://github.com/DragonCat1
// @version      0.6.0
// @license      MIT
// @description  可以在豆瓣小组列表页面快速预览帖子内容，无须再打开新窗口
// @author       铛铛铛铛铛/https://www.douban.com/people/48915223
// @copyright    1991-2018,铛铛铛铛铛-Dragoncat
// @match        https://www.douban.com/group/*
// @exclude      https://www.douban.com/group/*/new_topic
// @exclude      https://www.douban.com/group/people/*/
// @exclude      https://www.douban.com/group/people/*/joins
// @exclude      https://www.douban.com/group/explore*
// @exclude      https://www.douban.com/group/search*
// @grant        none
// @downloadURL https://update.greasyfork.icu/scripts/369414/%E8%B1%86%E7%93%A3%E5%B0%8F%E7%BB%84%E8%AF%9D%E9%A2%98%E5%BF%AB%E9%80%9F%E9%A2%84%E8%A7%88-douban%20group%20topic%20fast%20preview.user.js
// @updateURL https://update.greasyfork.icu/scripts/369414/%E8%B1%86%E7%93%A3%E5%B0%8F%E7%BB%84%E8%AF%9D%E9%A2%98%E5%BF%AB%E9%80%9F%E9%A2%84%E8%A7%88-douban%20group%20topic%20fast%20preview.meta.js
// ==/UserScript==

;(function () {
  'use strict'
  const isTopicPage = location.pathname.match(/\/group\/topic/)
  const style = document.createElement('style')
  style.type = 'text/css'
  if (!isTopicPage) {
    style.innerHTML = `
::-webkit-scrollbar {
width: 10px;
height: 10px;
}
::-webkit-scrollbar-thumb {
background: #656565;
box-shadow: inset 0 0 5px rgba(0,0,0,.1);
}
::-webkit-scrollbar-thumb:hover {
background: #323232;
}
::-webkit-scrollbar-track {
background: #ededed;
box-shadow: inset 0 0 5px rgba(0,0,0,.1);
}
a:visited {
    color: #666;
}
a:hover {
    color: #fff;
}
#wrapper{
margin:0;
width: 100%;
box-sizing: border-box;
}
#group-info .group-desc {
    width: auto;
}
table.olt tr:not(.th):hover,table.olt tr:not(.th).active{
cursor: pointer;
background: #ffe2cd;
}
.grid-16-8 .article{
padding-right: 10px;

}
#iframe-wrapper{
width: -webkit-fill-available;
margin:0 305px 0 686px;
top:0;
}
#iframe-wrapper a{
  position:absolute;
  top:-1.8em;
  left:0;
}
#priview{
  width: -webkit-fill-available;
  height: -webkit-fill-available;
  background: #fefefe;
  border: none;
  box-shadow: 0 0 2px #00000038;
}
.l-preview-l #iframe-wrapper{
margin-right:0;
}
.l-preview-l .aside{
    display:none;
}
`
    document.head.appendChild(style)
    const grid = document.querySelector('.grid-16-8')
    const article = document.querySelector('.article')
    const iframe = document.createElement('iframe')
    const iframeWrapper = document.createElement('div')
    const trs = document.querySelectorAll('table.olt tr:not(.th)')
    let timer
    let prevTr
    iframeWrapper.id = 'iframe-wrapper'
    iframe.srcdoc =
      '<style>p{color:#bbb;font-style:italic;font-size:12px;}a{color: #0f959d;text-decoration: none;}a:hover{color:red;}</style><p>/*话题快速预览 © <a href="https://www.douban.com/people/48915223/">铛铛铛铛铛</a>*/</p>'
    iframe.id = 'priview'
    iframe.sandbox =
      'allow-scripts allow-forms allow-same-origin allow-popups allow-modals'
    iframeWrapper.appendChild(iframe)
    const trigger = document.createElement('a')
    trigger.onclick = function () {
      document.documentElement.classList.toggle('l-preview-l')
    }
    if (innerWidth <= 1440)
      document.documentElement.classList.add('l-preview-l')
    trigger.innerText = '切换'
    iframeWrapper.appendChild(trigger)
    grid.insertBefore(iframeWrapper, document.querySelector('.extra'))
    trs.forEach((tr) => {
      //tr.onmouseenter = function () {
      //   changeClass(tr)
      //    if(timer) clearTimeout(timer)
      //    timer = setTimeout(()=>{
      //       loadContent(tr)
      //     },100)
      // }
      tr.onclick = function () {
        changeClass(tr)
        loadContent(tr)
      }
    })
    article.tabIndex = 1
    article.addEventListener('keydown', (e) => {
      if ([38, 40].includes(e.keyCode)) {
        e.preventDefault()
        const curTr =
          document.querySelector('table.olt tr:not(.th).active') ||
          document.querySelector('table.olt tr:not(.th)')
        let nextTr
        if (e.keyCode === 38) {
          nextTr = curTr.previousElementSibling || curTr
        } else if (e.keyCode === 40) {
          nextTr = curTr.nextElementSibling || curTr
        }
        changeClass(nextTr)
        loadContent(nextTr)
      }
    })
    window.addEventListener('scroll', function () {
      changepos()
    })
    changepos()
    function changeClass(tr) {
      if (prevTr) prevTr.classList.remove('active')
      prevTr = tr
      tr.classList.add('active')
    }
    function loadContent(tr) {
      iframe.removeAttribute('srcdoc')
      iframe.src = tr.querySelector('a').href
    }
    function changepos() {
      if (
        document.documentElement.scrollTop >
        document.querySelector('.article').offsetTop
      ) {
        iframeWrapper.style.position = 'fixed'
        iframeWrapper.style.height = window.innerHeight + 'px'
      } else {
        iframeWrapper.style.position = 'relative'
        iframeWrapper.style.height = window.innerHeight - 195 + 'px'
      }
    }
  } else {
    style.innerHTML = `
::-webkit-scrollbar {
width: 10px;
height: 10px;
}
::-webkit-scrollbar-thumb {
background: #656565;
box-shadow: inset 0 0 5px rgba(0,0,0,.1);
}
::-webkit-scrollbar-thumb:hover {
background: #323232;
}
::-webkit-scrollbar-track {
background: #ededed;
box-shadow: inset 0 0 5px rgba(0,0,0,.1);
}
`
    document.head.appendChild(style)
  }
})()