Add login gate, calculation history, and AI markdown download.

Co-authored-by: Cursor <cursoragent@cursor.com>

lib/history/storage.ts

@@ -0,0 +1,66 @@
+import {
+  HISTORY_MAX_ITEMS,
+  HISTORY_STORAGE_KEY,
+  type CalcHistoryEntry,
+} from "@/lib/history/types";
+
+export function loadHistory(): CalcHistoryEntry[] {
+  if (typeof window === "undefined") {
+    return [];
+  }
+  try {
+    const raw = localStorage.getItem(HISTORY_STORAGE_KEY);
+    if (!raw) {
+      return [];
+    }
+    const parsed = JSON.parse(raw) as CalcHistoryEntry[];
+    return Array.isArray(parsed) ? parsed : [];
+  } catch {
+    return [];
+  }
+}
+
+export function saveHistoryEntry(
+  entry: Omit<CalcHistoryEntry, "id" | "createdAt">,
+): CalcHistoryEntry {
+  const full: CalcHistoryEntry = {
+    ...entry,
+    id: crypto.randomUUID(),
+    createdAt: new Date().toISOString(),
+  };
+  const list = [full, ...loadHistory()].slice(0, HISTORY_MAX_ITEMS);
+  localStorage.setItem(HISTORY_STORAGE_KEY, JSON.stringify(list));
+  return full;
+}
+
+export function deleteHistoryEntry(id: string): void {
+  const list = loadHistory().filter((e) => e.id !== id);
+  localStorage.setItem(HISTORY_STORAGE_KEY, JSON.stringify(list));
+}
+
+export function downloadMarkdown(content: string, filename: string) {
+  const blob = new Blob([content], { type: "text/markdown;charset=utf-8" });
+  const url = URL.createObjectURL(blob);
+  const a = document.createElement("a");
+  a.href = url;
+  a.download = filename.endsWith(".md") ? filename : `${filename}.md`;
+  a.click();
+  URL.revokeObjectURL(url);
+}
+
+export function buildHistoryMarkdown(entry: CalcHistoryEntry): string {
+  const lines = [
+    `# ${entry.title}`,
+    "",
+    `- 类型：${entry.mode}`,
+    `- 时间：${new Date(entry.createdAt).toLocaleString("zh-CN")}`,
+    `- 问事：${entry.question}`,
+    "",
+    ...Object.entries(entry.meta).map(([k, v]) => `- ${k}：${v}`),
+    "",
+    "---",
+    "",
+    entry.completion,
+  ];
+  return lines.join("\n");
+}

lib/history/types.ts

@@ -0,0 +1,21 @@
+export type CalcMode = "liuyao" | "bazi" | "combined";
+
+export interface CalcHistoryEntry {
+  id: string;
+  mode: CalcMode;
+  title: string;
+  question: string;
+  summary: string;
+  completion: string;
+  meta: Record<string, string>;
+  createdAt: string;
+}
+
+export const HISTORY_STORAGE_KEY = "zhimingge-calc-history";
+export const HISTORY_MAX_ITEMS = 100;
+
+export const MODE_LABELS: Record<CalcMode, string> = {
+  liuyao: "六爻算卦",
+  bazi: "生辰八字",
+  combined: "综合测算",
+};