refactor(ui): extract message-render-limit module, migrate test off index.js slicing

ui/message-render-limit.js

@@ -0,0 +1,208 @@
+// ST-BME message render-limit policy.
+//
+// Extracted from index.js so it can be unit-tested by direct import instead of
+// slicing index.js into a temp module. Pure decisions take plain arguments;
+// the one side-effecting entry (applyMessageRenderLimit) receives an explicit
+// host adapter, so this module owns no module-level mutable state and never
+// reaches for globals on its own.
+
+/**
+ * Normalizes render-limit settings into {enabled, render_last_n}.
+ * @param {object|null} settings
+ * @param {() => object} [resolveSettings] fallback settings source when none passed
+ */
+export function getMessageRenderLimitSettings(settings = null, resolveSettings = null) {
+  let sourceSettings = settings;
+  if (!sourceSettings || typeof sourceSettings !== "object") {
+    try {
+      sourceSettings =
+        typeof resolveSettings === "function" ? resolveSettings() : {};
+    } catch {
+      sourceSettings = {};
+    }
+  }
+  return {
+    enabled:
+      sourceSettings.enabled !== false &&
+      Boolean(sourceSettings.hideOldMessagesRenderLimitEnabled),
+    render_last_n: Math.max(
+      0,
+      Math.trunc(Number(sourceSettings.hideOldMessagesRenderLimit ?? 0) || 0),
+    ),
+  };
+}
+
+/**
+ * Applies the render limit to the host (power_user.chat_truncation + jQuery
+ * truncation inputs), optionally reloading the chat.
+ *
+ * @param {object|null} settings
+ * @param {object} [options] {clearWhenDisabled, reloadCurrentChat}
+ * @param {object} [host] injected host adapter
+ * @param {() => object|null} [host.getPowerUser]
+ * @param {(selector: string) => any} [host.jq] jQuery-like selector
+ * @param {() => void} [host.reloadCurrentChat]
+ * @param {() => object|null} [host.resolveSettings]
+ * @param {Console} [host.console]
+ */
+export function applyMessageRenderLimit(settings = null, options = {}, host = {}) {
+  const logger = host.console || console;
+  const normalized = getMessageRenderLimitSettings(settings, host.resolveSettings);
+  const shouldClear = options.clearWhenDisabled === true;
+  if (!normalized.enabled && !shouldClear) {
+    return {
+      active: false,
+      renderLimit: 0,
+      applied: false,
+      skipped: true,
+    };
+  }
+
+  const renderLimit =
+    normalized.enabled && normalized.render_last_n > 0
+      ? normalized.render_last_n
+      : 0;
+  let applied = false;
+  const powerUserSettings =
+    typeof host.getPowerUser === "function" ? host.getPowerUser() : null;
+  if (powerUserSettings && typeof powerUserSettings === "object") {
+    powerUserSettings.chat_truncation = renderLimit;
+    applied = true;
+  }
+
+  try {
+    const jq = typeof host.jq === "function" ? host.jq : null;
+    if (jq) {
+      const value = String(renderLimit);
+      const truncationInput = jq("#chat_truncation");
+      if (
+        truncationInput &&
+        Number(truncationInput.length || 0) > 0 &&
+        typeof truncationInput.val === "function"
+      ) {
+        truncationInput.val(value);
+        if (typeof truncationInput.trigger === "function") {
+          truncationInput.trigger("change");
+        }
+        applied = true;
+      }
+      const truncationCounter = jq("#chat_truncation_counter");
+      if (
+        truncationCounter &&
+        Number(truncationCounter.length || 0) > 0 &&
+        typeof truncationCounter.val === "function"
+      ) {
+        truncationCounter.val(value);
+        applied = true;
+      }
+    }
+  } catch (error) {
+    logger.warn("[ST-BME] 同步聊天区渲染楼层限制失败:", error);
+  }
+
+  if (options.reloadCurrentChat === true) {
+    try {
+      if (typeof host.reloadCurrentChat === "function") {
+        host.reloadCurrentChat();
+      }
+    } catch (error) {
+      logger.warn("[ST-BME] 重新加载聊天区渲染楼层失败:", error);
+    }
+  }
+
+  return {
+    active: renderLimit > 0,
+    renderLimit,
+    applied,
+    skipped: false,
+  };
+}
+
+/**
+ * Returns the effective render limit used for the history-recovery guard,
+ * combining configured settings with the host power_user truncation.
+ */
+export function getActiveMessageRenderLimitForHistoryGuard(
+  settings = null,
+  host = {},
+) {
+  const normalized = getMessageRenderLimitSettings(settings, host.resolveSettings);
+  const configuredLimit =
+    normalized.enabled && normalized.render_last_n > 0
+      ? normalized.render_last_n
+      : 0;
+  let hostLimit = 0;
+  try {
+    const powerUserSettings =
+      typeof host.getPowerUser === "function" ? host.getPowerUser() : null;
+    hostLimit = Math.max(
+      0,
+      Math.trunc(Number(powerUserSettings?.chat_truncation ?? 0) || 0),
+    );
+  } catch {
+    hostLimit = 0;
+  }
+
+  if (configuredLimit > 0 && hostLimit > 0) {
+    return Math.min(configuredLimit, hostLimit);
+  }
+  return Math.max(configuredLimit, hostLimit);
+}
+
+/** Highest floor index tracked in processed-history state. Pure. */
+export function getHighestTrackedProcessedHistoryFloor(historyState = {}) {
+  const lastProcessed = Number.isFinite(
+    Number(historyState?.lastProcessedAssistantFloor),
+  )
+    ? Math.floor(Number(historyState.lastProcessedAssistantFloor))
+    : -1;
+  const hashes =
+    historyState?.processedMessageHashes &&
+    typeof historyState.processedMessageHashes === "object" &&
+    !Array.isArray(historyState.processedMessageHashes)
+      ? historyState.processedMessageHashes
+      : {};
+  const maxHashFloor = Object.keys(hashes).reduce((maxFloor, key) => {
+    const floor = Number.parseInt(key, 10);
+    return Number.isFinite(floor) ? Math.max(maxFloor, floor) : maxFloor;
+  }, -1);
+
+  return Math.max(lastProcessed, maxHashFloor);
+}
+
+/**
+ * Decides whether history recovery must be blocked because the chat view is
+ * render-limited (a truncated view must not be mistaken for deleted history).
+ *
+ * @param {Array} chat
+ * @param {object} [opts] {settings, historyState, host}
+ */
+export function getRenderLimitedHistoryRecoveryGuard(
+  chat,
+  { settings = null, historyState = {}, host = {} } = {},
+) {
+  const renderLimit = getActiveMessageRenderLimitForHistoryGuard(settings, host);
+  if (!Array.isArray(chat) || renderLimit <= 0) {
+    return { blocked: false };
+  }
+
+  const chatLength = chat.length;
+  const highestProcessedFloor =
+    getHighestTrackedProcessedHistoryFloor(historyState);
+  const renderWindowTolerance = renderLimit + 1;
+  if (chatLength > renderWindowTolerance || highestProcessedFloor < chatLength) {
+    return { blocked: false };
+  }
+
+  return {
+    blocked: true,
+    chatLength,
+    highestProcessedFloor,
+    renderLimit,
+    reason: "render-limited-chat-slice",
+    message:
+      `当前聊天区最多只渲染最近 ${renderLimit} 条消息，当前可见 ${chatLength} 条；` +
+      `图谱已处理到楼层 ${highestProcessedFloor}。为避免把截断视图误判为历史删除并清空运行时图谱，已暂停历史恢复。` +
+      "请临时关闭“限制聊天区渲染楼层”或调大渲染数量并刷新后再提取。",
+  };
+}