// ==UserScript==
// @name         Nexus Mods 自动慢速下载
// @namespace    https://github.com/yg/nexus-auto-slow
// @version      1.2.1
// @description  按完两次 Manual download 后，自动点击 Slow download，省去多点一步
// @author       YG
// @match        *://*.nexusmods.com/*
// @match        *://nexusmods.com/*
// @run-at       document-idle
// @grant        none
// @license MIT
// ==/UserScript==

(function () {
  "use strict";

  var TAG = "[Nexus Auto Slow]";
  var CLICK_COOLDOWN = 2000;
  var lastClick = 0;
  var clickedEls = new WeakSet();
  var clickedFlag = false;
  var injected = false;
  var pollTimer = null;

  function norm(t) { return (t || "").replace(/\s+/g, " ").trim().toLowerCase(); }

  function isVisible(el) {
    if (!el || !el.getBoundingClientRect) return false;
    var r = el.getBoundingClientRect();
    if (r.width <= 0 && r.height <= 0) return false;
    var s = el.ownerDocument.defaultView.getComputedStyle(el);
    return s.visibility !== "hidden" && s.display !== "none" && s.opacity !== "0";
  }

  function isSlowText(el) {
    var t = norm(el.textContent);
    return t === "slow download" || (t.indexOf("slow download") !== -1 && t.length <= 25);
  }

  function collectDocs() {
    var docs = [document];
    var frames = document.querySelectorAll("iframe");
    for (var i = 0; i < frames.length; i++) {
      try { if (frames[i].contentDocument) docs.push(frames[i].contentDocument); } catch (e) {}
    }
    return docs;
  }

  function allRoots() {
    var roots = [];
    function walk(root) {
      roots.push(root);
      var els = root.querySelectorAll("*");
      for (var i = 0; i < els.length; i++) { if (els[i].shadowRoot) walk(els[i].shadowRoot); }
    }
    var docs = collectDocs();
    for (var j = 0; j < docs.length; j++) walk(docs[j]);
    return roots;
  }

  function findSlow() {
    var roots = allRoots();
    for (var i = 0; i < roots.length; i++) {
      var btns = roots[i].querySelectorAll("button, a, [role='button']");
      for (var b = 0; b < btns.length; b++) { if (isSlowText(btns[b]) && isVisible(btns[b])) return btns[b]; }
      var spans = roots[i].querySelectorAll("span");
      for (var s = 0; s < spans.length; s++) {
        if (norm(spans[s].textContent) === "slow download") {
          var c = spans[s].closest("button, a, [role='button']");
          if (c && isVisible(c)) return c;
        }
      }
    }
    return null;
  }

  function fireClick(el) {
    var opts = { bubbles: true, cancelable: true, composed: true, view: el.ownerDocument.defaultView, button: 0 };
    try { el.dispatchEvent(new PointerEvent("pointerdown", opts)); } catch (e) {}
    try { el.dispatchEvent(new MouseEvent("mousedown", opts)); } catch (e) {}
    try { el.dispatchEvent(new PointerEvent("pointerup", opts)); } catch (e) {}
    try { el.dispatchEvent(new MouseEvent("mouseup", opts)); } catch (e) {}
    try { el.dispatchEvent(new MouseEvent("click", opts)); } catch (e) {}
    try { el.click(); } catch (e) {}
  }

  function buildToast() {
    var t = document.createElement("div");
    t.id = "__nexusSlowToast";
    t.style.cssText = "display:flex;align-items:center;gap:8px;" +
      "background:#1b1b20;color:#e7e7ea;border:1px solid rgba(218,142,53,.55);border-left:3px solid #da8e35;" +
      "border-radius:8px;padding:8px 12px;box-shadow:0 8px 24px rgba(0,0,0,.45);" +
      "font:600 13px/1.4 'Segoe UI',Roboto,-apple-system,sans-serif;letter-spacing:.2px;white-space:nowrap;" +
      "opacity:0;transform:translateY(-4px);transition:opacity .25s ease,transform .25s ease;";
    t.innerHTML = '<span style="display:inline-flex;width:18px;height:18px;border-radius:50%;background:#da8e35;align-items:center;justify-content:center;flex:0 0 auto">' +
      '<svg width="11" height="11" viewBox="0 0 24 24" fill="none" stroke="#1b1b20" stroke-width="3.5" stroke-linecap="round" stroke-linejoin="round"><polyline points="20 6 9 17 4 12"></polyline></svg></span>' +
      '<span>Nexusmods 自动下载已触发</span>';
    return t;
  }

  function showToast() {
    if (injected) return;
    if (document.getElementById("__nexusSlowToast") || document.querySelectorAll("#__nexusSlowToast").length) { injected = true; return; }

    var anchor = null;
    var roots = allRoots();
    for (var i = 0; i < roots.length && !anchor; i++) {
      var els = roots[i].querySelectorAll("div, section, span, strong, h1, h2, h3, p");
      for (var e = 0; e < els.length; e++) {
        var txt = norm(els[e].textContent);
        if (/your download is starting|download didn.t start|start download manually/.test(txt) && txt.length <= 160) {
          var node = els[e];
          for (var up = 0; up < 5 && node.parentElement; up++) {
            var r = node.getBoundingClientRect();
            if (r.width > 220 && r.height > 44) break;
            node = node.parentElement;
          }
          anchor = node;
          break;
        }
      }
    }

    var toast = buildToast();
    if (anchor && anchor.appendChild && anchor.ownerDocument) {
      var cs = anchor.ownerDocument.defaultView.getComputedStyle(anchor);
      if (cs.position === "static") anchor.style.position = "relative";
      toast.style.position = "absolute";
      toast.style.top = "10px";
      toast.style.right = "10px";
      toast.style.zIndex = "2147483647";
      anchor.appendChild(toast);
    } else {
      toast.style.position = "fixed";
      toast.style.top = "16px";
      toast.style.right = "16px";
      toast.style.zIndex = "2147483647";
      (document.body || document.documentElement).appendChild(toast);
    }
    injected = true;
    requestAnimationFrame(function () { toast.style.opacity = "1"; toast.style.transform = "translateY(0)"; });
    setTimeout(function () {
      toast.style.opacity = "0";
      toast.style.transform = "translateY(-4px)";
      setTimeout(function () { if (toast.parentNode) toast.parentNode.removeChild(toast); }, 300);
    }, 3000);
    console.info(TAG, "已显示成功提示（3 秒后自动关闭）");
  }

  function startPollSuccess() {
    if (pollTimer) return;
    var tries = 0;
    pollTimer = setInterval(function () {
      tries++;
      showToast();
      if (injected || tries > 40) { clearInterval(pollTimer); pollTimer = null; }
    }, 500);
    showToast();
  }

  function tryClick() {
    if (clickedFlag) { return false; }
    var btn = findSlow();
    if (!btn) { return false; }
    if (clickedEls.has(btn)) return false;
    var now = Date.now();
    if (now - lastClick < CLICK_COOLDOWN) return false;
    clickedEls.add(btn);
    lastClick = now;
    try { btn.scrollIntoView({ block: "center", inline: "center" }); } catch (e) {}
    fireClick(btn);
    clickedFlag = true;
    console.info(TAG, "已触发点击 Slow download");
    startPollSuccess();
    return true;
  }

  var pending = null;
  function schedule() { if (pending) return; pending = setTimeout(function () { pending = null; tryClick(); }, 200); }

  function start() {
    console.info(TAG, "脚本已启动，监听 Slow download");
    try { window.__nexusSlowDebug = function () { var b = findSlow(); return b ? (b.tagName + "|" + b.textContent) : "none"; }; } catch (e) {}
    try { new MutationObserver(schedule).observe(document.documentElement, { childList: true, subtree: true }); } catch (e) {}
    setInterval(tryClick, 700);
    tryClick();
  }

  if (document.readyState === "loading") document.addEventListener("DOMContentLoaded", start);
  else start();
})();