feat: integrate host bridge prompt pipeline

st-context.js

@@ -3,6 +3,165 @@
 
 import { getContext } from "../../../extensions.js";
 
+function safeClone(value, fallback) {
+  if (value == null) {
+    return fallback;
+  }
+
+  try {
+    if (typeof structuredClone === "function") {
+      return structuredClone(value);
+    }
+  } catch {
+    // ignore and fall back to JSON clone
+  }
+
+  try {
+    return JSON.parse(JSON.stringify(value));
+  } catch {
+    return fallback ?? value;
+  }
+}
+
+function resolveCharacter(ctx) {
+  const charId = ctx?.characterId;
+  return (
+    ctx?.character ||
+    ctx?.characters?.[Number(charId)] ||
+    ctx?.characters?.[charId] ||
+    null
+  );
+}
+
+function resolvePersona(ctx) {
+  return (
+    ctx?.powerUserSettings?.persona_description ||
+    ctx?.extensionSettings?.persona_description ||
+    ctx?.name1_description ||
+    ctx?.persona ||
+    ""
+  );
+}
+
+function resolveCharacterDescription(char) {
+  return (
+    char?.description ||
+    char?.data?.description ||
+    char?.data?.personality ||
+    ""
+  );
+}
+
+function resolveLastUserMessage(chat = []) {
+  return (
+    chat.findLast?.((message) => message?.is_user)?.mes ||
+    [...chat].reverse().find((message) => message?.is_user)?.mes ||
+    ""
+  );
+}
+
+function buildStructuredSnapshot(ctx = {}) {
+  const char = resolveCharacter(ctx);
+  const chat = Array.isArray(ctx.chat) ? safeClone(ctx.chat, []) : [];
+  const currentTime = new Date().toLocaleString("zh-CN");
+  const globalVars = safeClone(
+    ctx.extensionSettings?.variables?.global || {},
+    {},
+  );
+  const localVars = safeClone(ctx.chatMetadata?.variables || {}, {});
+
+  return {
+    persona: {
+      text: resolvePersona(ctx),
+      lorebook:
+        ctx.extensionSettings?.persona_description_lorebook ||
+        ctx.powerUserSettings?.persona_description_lorebook ||
+        ctx.power_user?.persona_description_lorebook ||
+        "",
+    },
+    character: {
+      id: ctx.characterId ?? null,
+      name: ctx.name2 || char?.name || "",
+      description: resolveCharacterDescription(char),
+      avatar: char?.avatar ? `/characters/${char.avatar}` : "",
+      worldbook: char?.data?.extensions?.world || char?.extensions?.world || "",
+      raw: safeClone(char, null),
+    },
+    user: {
+      name: ctx.name1 || "",
+      avatar: "",
+      raw: safeClone(ctx.user || null, null),
+    },
+    chat: {
+      id: ctx.chatId || globalThis.getCurrentChatId?.() || "",
+      messages: chat,
+      lastUserMessage: resolveLastUserMessage(chat),
+    },
+    worldbook: {
+      character: char?.data?.extensions?.world || char?.extensions?.world || "",
+      persona:
+        ctx.extensionSettings?.persona_description_lorebook ||
+        ctx.powerUserSettings?.persona_description_lorebook ||
+        ctx.power_user?.persona_description_lorebook ||
+        "",
+      chat: ctx.chatMetadata?.world || "",
+    },
+    variables: {
+      global: globalVars,
+      local: localVars,
+      merged: {
+        ...globalVars,
+        ...localVars,
+      },
+    },
+    time: {
+      current: currentTime,
+      locale: "zh-CN",
+    },
+    host: {
+      meta: {
+        onlineStatus: ctx.onlineStatus || "",
+        selectedGroupId: ctx.selectedGroupId ?? null,
+      },
+      capabilities: {
+        hasGetContext: typeof getContext === "function",
+        hasGlobalGetContext:
+          typeof globalThis.SillyTavern?.getContext === "function",
+        hasCurrentChatId: typeof globalThis.getCurrentChatId === "function",
+      },
+    },
+    raw: safeClone(ctx, {}),
+  };
+}
+
+function buildCompatPromptAliases(snapshot) {
+  return {
+    userPersona: snapshot.persona.text,
+    charDescription: snapshot.character.description,
+    charName: snapshot.character.name,
+    userName: snapshot.user.name,
+    currentTime: snapshot.time.current,
+  };
+}
+
+export function getSTContextSnapshot() {
+  try {
+    const ctx = getContext?.() || {};
+    const snapshot = buildStructuredSnapshot(ctx);
+    return {
+      snapshot,
+      prompt: buildCompatPromptAliases(snapshot),
+    };
+  } catch (e) {
+    console.warn("[ST-BME] getSTContextSnapshot 失败:", e);
+    const snapshot = buildStructuredSnapshot({});
+    return {
+      snapshot,
+      prompt: buildCompatPromptAliases(snapshot),
+    };
+  }
+}
+
 /**
  * 从 SillyTavern 的 getContext() 提取当前上下文数据，
  * 返回的字段可直接展开传入 buildTaskPrompt 的 context 参数，
@@ -11,37 +170,5 @@ import { getContext } from "../../../extensions.js";
  * @returns {object} 上下文字段映射
  */
 export function getSTContextForPrompt() {
-  try {
-    const ctx = getContext?.() || {};
-    const charId = ctx.characterId;
-    const char =
-      ctx.characters?.[Number(charId)] ||
-      ctx.characters?.[charId] ||
-      null;
-
-    return {
-      userPersona:
-        ctx.powerUserSettings?.persona_description ||
-        ctx.extensionSettings?.persona_description ||
-        ctx.name1_description ||
-        ctx.persona ||
-        "",
-      charDescription:
-        char?.description ||
-        char?.data?.description ||
-        "",
-      charName: ctx.name2 || "",
-      userName: ctx.name1 || "",
-      currentTime: new Date().toLocaleString("zh-CN"),
-    };
-  } catch (e) {
-    console.warn("[ST-BME] getSTContextForPrompt 失败:", e);
-    return {
-      userPersona: "",
-      charDescription: "",
-      charName: "",
-      userName: "",
-      currentTime: new Date().toLocaleString("zh-CN"),
-    };
-  }
+  return getSTContextSnapshot().prompt;
 }