// ==UserScript==
// @name      NGA Filter
// @namespace https://greasyfork.org/users/263018
// @version    0.6.2
// @author     snyssss
// @description troll must die
// @match        *bbs.nga.cn/thread.php?fid=*
// @match        *bbs.nga.cn/read.php?tid=*
// @match        *ngabbs.com/thread.php?fid=*
// @match        *ngabbs.com/read.php?tid=*
// @grant       GM_registerMenuCommand
// @noframes
// @downloadURL none
// ==/UserScript==

(function() {
  "use strict";

  const dataKey = "troll_data";
  const modeKey = "troll_mode";
  const keywordKey = "troll_keyword";

  let trollMap = (function() {
    try {
      return JSON.parse(localStorage.getItem(dataKey)) || {};
    } catch (e) {
      localStorage.setItem(dataKey, "{}");
    }
    return {};
  })();

  let filterMode = ~~localStorage.getItem(modeKey);

  let filterKeyword = localStorage.getItem(keywordKey) || "";

  const isTroll = function(uid) {
    uid = ~~uid;
    if (uid) {
      return trollMap[uid];
    }
    return false;
  };

  const isMatch = function(text) {
    if (!!filterKeyword && text.search(filterKeyword) >= 0) {
      return true;
    }
    return false;
  };

  const toggleTroll = function(uid, tag) {
    uid = ~~uid;
    if (uid) {
      if (trollMap[uid] && tag === null) {
        delete trollMap[uid];
      } else {
        trollMap[uid] = tag ? [tag] : [];
      }
      localStorage.setItem(dataKey, JSON.stringify(trollMap));
    }
  };

  const getUID = function(e) {
    let ele = e.getElementsByClassName("author")[0];
    if (ele) {
      return ele.search.match(/uid=(\S*)/)[1];
    }
  };

  const getLink = function(e) {
    let ele = e.getElementsByClassName("topic")[0];
    ele.hide = function() {
      if (filterMode) {
        e.remove();
      } else {
        ele.style.textDecoration = "line-through";
      }
    };
    return ele;
  };

  const getToggleButton = function(e) {
    let ele = e.getElementsByClassName("author")[0].nextElementSibling;
    if (ele.nextElementSibling) {
      ele = ele.nextElementSibling;
    }
    let uid = ~~ele.text;
    if (uid) {
      if (isTroll(uid)) {
        ele.style.background = "#CB4042";
      } else {
        ele.style.background = "#AAA";
      }
      return ele;
    } else {
      ele.onclick = null;
    }
  };

  const getAvatar = function(e) {
    let ele = e.getElementsByClassName("avatar")[0] || {
      style: { display: "" }
    };
    ele.show =
      ele.show ||
      function() {
        ele.style.display = "";
      };
    ele.hide =
      ele.hide ||
      function() {
        ele.style.display = "none";
      };
    return ele;
  };

  const getContent = function(e) {
    let uid = getUID(e);
    let name = "$troll_" + uid;
    let ele = e.getElementsByClassName("postcontent")[0] || { innerHTML: "" };
    ele.content = ele.content || ele.innerHTML;
    ele.show =
      ele.show ||
      function() {
        if (filterMode) {
          e.style.display = "";
        } else {
          ele.innerHTML = ele.content;
        }
      };
    ele.hide =
      ele.hide ||
      function() {
        if (filterMode) {
          e.style.display = "none";
        } else {
          ele.innerHTML =
            '<div class="lessernuke" style="background: #81C7D4; border-color: #66BAB7;">' +
            '<span class="crimson">Troll must die.</span> ' +
            '<a href="javascript:void(0)" onclick="var x = document.getElementsByName(&quot;' +
            name +
            '&quot;);for(var i=0;i<x.length;i++){x[i].style.display=&quot;&quot;}">点击查看</a>' +
            '<div style="display:none" name="' +
            name +
            '">' +
            ele.content +
            "</div>" +
            "</div>";
        }
      };
    return ele;
  };

  const getTag = function(e) {
    let container = e.getElementsByClassName("posterinfo")[0];
    let ele = container.children[1];
    if (ele.tagName === "IMG") {
      ele = container.children[2];
    }
    if (ele.className !== "crimson") {
      let t = document.createElement("div");
      t.className = "crimson";
      t.style = "display: none;";
      if (ele.getAttribute("name") === "honor") {
        t.honor = ele;
      }
      ele.before(t);
      ele = t;
    }
    let uid = getUID(e);
    if (isTroll(uid)) {
      if (typeof trollMap[uid] === "object" && trollMap[uid].length) {
        ele.innerHTML = trollMap[uid][0];
      } else {
        ele.innerHTML = "";
      }
    }
    ele.show =
      ele.show ||
      function() {
        if (ele.innerHTML) {
          ele.style.display = "";
        }
        if (ele.honor) {
          ele.honor.style.display = "none";
        }
      };
    ele.hide =
      ele.hide ||
      function() {
        ele.style.display = "none";
        if (ele.honor) {
          ele.honor.style.display = "";
        }
      };
    return ele;
  };

  const observerElements = [
    (function() {
      let container = document.getElementById("topicrows");
      let func = function(e) {
        if (e.tagName == "SCRIPT") return;
        let uid = getUID(e);
        let link = getLink(e);
        if (isTroll(uid) || isMatch(link.innerHTML)) {
          link.hide();
        }
      };
      return [container, func];
    })(),
    (function() {
      let container = document.getElementById("m_posts_c");
      let func = function(e) {
        if (e.tagName == "SCRIPT") return;
        let uid = getUID(e);
        let toggle = getToggleButton(e);
        if (toggle) {
          toggle.onclick = function(e) {
            let tag = null;
            if (e.ctrlKey) {
              tag = window.prompt("标签", (trollMap[uid] || {})[0]);
              if (tag === null) {
                return;
              }
            }
            toggleTroll(uid, tag);
            container.refilter();
          };
        } else {
          return;
        }
        let avatar = getAvatar(e);
        let content = getContent(e);
        let tag = getTag(e);
        if (isTroll(uid)) {
          avatar.hide();
          content.hide();
          tag.show();
        } else {
          avatar.show();
          content.show();
          tag.hide();
        }
      };
      return [container, func];
    })()
  ];

  [].slice.call(observerElements).forEach(function(e) {
    if (!e[0]) return;

    e[0].refilter = function() {
      [].slice.call(e[0].children).forEach(function(c) {
        e[1](c);
      });
    };

    e[0].refilter();

    let observer = new MutationObserver(function(mutations) {
      mutations.forEach(function(mutation) {
        if (mutation.addedNodes.length) {
          e[1](mutation.addedNodes[0]);
        }
      });
    });

    observer.observe(e[0], {
      childList: true
    });
  });

  if (filterMode) {
    GM_registerMenuCommand("过滤模式：删除", () => {
      localStorage.setItem(modeKey, 0);
      location.reload();
    });
  } else {
    GM_registerMenuCommand("过滤模式：标记", () => {
      localStorage.setItem(modeKey, 1);
      location.reload();
    });
  }

  GM_registerMenuCommand("修改过滤关键词", () => {
    let result = window.prompt('过滤关键词，用"|"隔开', filterKeyword);
    if (result === null || result === filterKeyword) {
      return;
    }
    localStorage.setItem(keywordKey, result);
    location.reload();
  });
})();