Store calculation history on server with bazi input and chart snapshots.

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

lib/history/server-store.ts

@@ -0,0 +1,90 @@
+import fs from "fs/promises";
+import path from "path";
+import { randomUUID } from "crypto";
+import {
+  HISTORY_MAX_ITEMS,
+  type CalcHistoryCreate,
+  type CalcHistoryEntry,
+} from "@/lib/history/types";
+
+function getDataDir(): string {
+  const configured = process.env.HISTORY_DATA_DIR?.trim();
+  if (configured) {
+    return configured;
+  }
+  return path.join(process.cwd(), "data", "history");
+}
+
+function sanitizeUsername(username: string): string {
+  const safe = username.replace(/[^a-zA-Z0-9_-]/g, "_");
+  return safe || "guest";
+}
+
+function userFile(username: string): string {
+  return path.join(getDataDir(), `${sanitizeUsername(username)}.json`);
+}
+
+async function ensureDir(): Promise<void> {
+  await fs.mkdir(getDataDir(), { recursive: true });
+}
+
+async function readUserHistory(username: string): Promise<CalcHistoryEntry[]> {
+  await ensureDir();
+  try {
+    const raw = await fs.readFile(userFile(username), "utf-8");
+    const parsed = JSON.parse(raw) as CalcHistoryEntry[];
+    return Array.isArray(parsed) ? parsed : [];
+  } catch (error) {
+    if ((error as NodeJS.ErrnoException).code === "ENOENT") {
+      return [];
+    }
+    throw error;
+  }
+}
+
+async function writeUserHistory(
+  username: string,
+  entries: CalcHistoryEntry[],
+): Promise<void> {
+  await ensureDir();
+  const file = userFile(username);
+  const tmp = `${file}.tmp`;
+  await fs.writeFile(tmp, JSON.stringify(entries, null, 2), "utf-8");
+  await fs.rename(tmp, file);
+}
+
+export async function listHistoryEntries(
+  username: string,
+): Promise<CalcHistoryEntry[]> {
+  return readUserHistory(username);
+}
+
+export async function addHistoryEntry(
+  username: string,
+  entry: CalcHistoryCreate,
+): Promise<CalcHistoryEntry> {
+  const full: CalcHistoryEntry = {
+    ...entry,
+    id: randomUUID(),
+    createdAt: new Date().toISOString(),
+  };
+  const list = [full, ...(await readUserHistory(username))].slice(
+    0,
+    HISTORY_MAX_ITEMS,
+  );
+  await writeUserHistory(username, list);
+  return full;
+}
+
+export async function deleteHistoryEntry(
+  username: string,
+  id: string,
+): Promise<boolean> {
+  const current = await readUserHistory(username);
+  const next = current.filter((entry) => entry.id !== id);
+  if (next.length === current.length) {
+    return false;
+  }
+  await writeUserHistory(username, next);
+  return true;
+}