feat: use a local database per user

apps/web/src/data/db.ts

@@ -18,7 +18,7 @@ export type LocalExchangeRate = {
   updatedAt: string;
 };
 
-export const db = new Dexie("cents") as Dexie & {
+export type CentsDatabase = Dexie & {
   entries: EntityTable<LedgerEntry, "id">;
   syncOperations: EntityTable<SyncOperation, "id">;
   ledgers: EntityTable<LedgerRecord, "id">;
@@ -27,6 +27,7 @@ export const db = new Dexie("cents") as Dexie & {
   exchangeRates: EntityTable<LocalExchangeRate, "id">;
 };
 
+function configureDatabase(db: CentsDatabase) {
 db.version(1).stores({
   entries: "id, ledgerId, occurredAt, updatedAt, deletedAt",
   syncOperations: "id, ledgerId, createdAt, syncedAt",
@@ -107,6 +108,77 @@ db.version(5).stores({
     normalizeEntry(operation.payload);
   });
 });
+}
+
+const databaseCache = new Map<string, CentsDatabase>();
+const databaseOpeners = new Map<string, Promise<CentsDatabase>>();
+
+export async function getUserDb(userId: string) {
+  const name = `cents-user-${userId}`;
+  const cached = databaseCache.get(name);
+  if (cached) return cached;
+  const opening = databaseOpeners.get(name);
+  if (opening) return opening;
+  const promise = (async () => {
+    const database = new Dexie(name) as CentsDatabase;
+    configureDatabase(database);
+    await database.open();
+    await migrateLegacyUserData(database, userId);
+    databaseCache.set(name, database);
+    return database;
+  })();
+  databaseOpeners.set(name, promise);
+  try {
+    return await promise;
+  } finally {
+    databaseOpeners.delete(name);
+  }
+}
+
+export function closeUserDb(userId: string) {
+  const name = `cents-user-${userId}`;
+  const database = databaseCache.get(name);
+  database?.close();
+  databaseCache.delete(name);
+}
+
+async function migrateLegacyUserData(database: CentsDatabase, userId: string) {
+  const markerId = `${userId}:legacy-migration-v1`;
+  if (await database.userPreferences.get(markerId)) return;
+  const legacy = new Dexie("cents") as CentsDatabase;
+  configureDatabase(legacy);
+  try {
+    await legacy.open();
+    const [entries, operations, preferences, exchangeRates] = await Promise.all([
+      legacy.entries.filter((entry) => entry.ownerId === userId).toArray(),
+      legacy.syncOperations.filter((operation) => (operation.userId ?? operation.payload.updatedBy) === userId).toArray(),
+      legacy.userPreferences.filter((preference) => preference.userId === userId).toArray(),
+      legacy.exchangeRates.toArray(),
+    ]);
+    const operationEntries = await Promise.all(
+      operations.map((operation) => legacy.entries.get(operation.entityId)),
+    );
+    const mergedEntries = new Map(entries.map((entry) => [entry.id, entry]));
+    for (const entry of operationEntries) {
+      if (entry) mergedEntries.set(entry.id, entry);
+    }
+    await database.transaction("rw", database.entries, database.syncOperations, database.userPreferences, database.exchangeRates, async () => {
+      if (mergedEntries.size) await database.entries.bulkPut([...mergedEntries.values()]);
+      if (operations.length) await database.syncOperations.bulkPut(operations);
+      if (preferences.length) await database.userPreferences.bulkPut(preferences);
+      if (exchangeRates.length) await database.exchangeRates.bulkPut(exchangeRates);
+      await database.userPreferences.put({
+        id: markerId,
+        userId,
+        key: "legacyMigration",
+        value: "v1",
+        updatedAt: new Date().toISOString(),
+      });
+    });
+  } finally {
+    legacy.close();
+  }
+}
 
 function localDate(value: string) {
   const date = new Date(value);

apps/web/src/data/ledgers.ts

@@ -41,7 +41,7 @@ export type LedgerRecord = {
 export type UserPreference = {
   id: string;
   userId: string;
-  key: "currentLedgerId" | "ledgerAmountDisplay";
+  key: "currentLedgerId" | "ledgerAmountDisplay" | "legacyMigration";
   value: string;
   updatedAt: string;
 };

apps/web/src/stores/auth.ts

@@ -1,5 +1,6 @@
 import { defineStore } from "pinia";
 import { apiRequest } from "../data/api";
+import { closeUserDb } from "../data/db";
 
 export type SessionUser = { id: string; name: string };
 
@@ -50,7 +51,9 @@ export const useAuthStore = defineStore("auth", {
       this.unavailable = false;
     },
     async logout() {
+      const userId = this.user?.id;
       await apiRequest("/api/auth/logout", { method: "POST" });
+      if (userId) closeUserDb(userId);
       this.user = null;
       this.loaded = true;
     },

apps/web/src/stores/entries.ts

@@ -1,7 +1,7 @@
 import { defineStore } from "pinia";
 import { calculateCnyAmount, type CurrencyCode, type LedgerEntry, type SyncOperation } from "@cents/domain";
 import { apiRequest } from "../data/api";
-import { db } from "../data/db";
+import { getUserDb } from "../data/db";
 import { localDate } from "../data/entries";
 import { createId } from "../data/ids";
 import { useAuthStore } from "./auth";
@@ -76,6 +76,7 @@ export const useEntryStore = defineStore("entries", {
         this.loadedForUserId = "";
         return;
       }
+      const db = await getUserDb(auth.user.id);
       const allowedLedgerIds = new Set(useLedgerStore().ledgers.map((ledger) => ledger.id));
       const canAccessEntry = (entry: LedgerEntry) =>
         entry.ownerId === auth.user!.id || entry.ledgerIds.some((ledgerId) => allowedLedgerIds.has(ledgerId));
@@ -113,6 +114,7 @@ export const useEntryStore = defineStore("entries", {
         return;
       }
       const userId = auth.user.id;
+      const db = await getUserDb(userId);
       if (syncPromise) return syncPromise;
 
       syncPromise = (async () => {
@@ -184,6 +186,7 @@ export const useEntryStore = defineStore("entries", {
     },
     async addEntry(entry: LedgerEntry) {
       const auth = useAuthStore();
+      const db = await getUserDb(auth.user?.id ?? entry.ownerId);
       const operation: SyncOperation = {
         id: createId(),
         userId: auth.user?.id,
@@ -207,6 +210,7 @@ export const useEntryStore = defineStore("entries", {
     },
     async updateEntry(entry: LedgerEntry) {
       const auth = useAuthStore();
+      const db = await getUserDb(auth.user?.id ?? entry.ownerId);
       const existing = await db.entries.get(entry.id);
       if (!existing || existing.deletedAt) throw new Error("Entry not found");
 
@@ -256,6 +260,9 @@ export const useEntryStore = defineStore("entries", {
       return updated;
     },
     async resolveLocalConversion(entryId: string) {
+      const auth = useAuthStore();
+      if (!auth.user) return;
+      const db = await getUserDb(auth.user.id);
       const entry = await db.entries.get(entryId);
       if (!entry || entry.deletedAt || entry.currency === "CNY") return;
       const cacheId = `${entry.currency}:${entry.exchangeRateDate}`;
@@ -322,6 +329,8 @@ export const useEntryStore = defineStore("entries", {
     },
     async deleteEntry(entryId: string) {
       const auth = useAuthStore();
+      if (!auth.user) return;
+      const db = await getUserDb(auth.user.id);
       const existing = await db.entries.get(entryId);
       if (!existing || existing.deletedAt) return;
 

apps/web/src/stores/ledgers.ts

@@ -1,6 +1,6 @@
 import { defineStore } from "pinia";
 import { apiRequest } from "../data/api";
-import { db } from "../data/db";
+import { getUserDb } from "../data/db";
 import { currentLedgerPreferenceId, ledgerAmountDisplayPreferenceId, type LedgerRecord, type UserPreference } from "../data/ledgers";
 import type { LedgerAmountDisplayMode } from "@cents/domain";
 import { useAuthStore } from "./auth";
@@ -39,6 +39,7 @@ export const useLedgerStore = defineStore("ledgers", {
       ledgerLoadPromise = (async () => {
         const auth = useAuthStore();
         if (!auth.user) return;
+        const db = await getUserDb(auth.user.id);
         const result = await apiRequest<{ ledgers: LedgerRecord[] }>("/api/ledgers");
         const displayPreferences = await db.userPreferences
           .where("userId")
@@ -91,6 +92,7 @@ export const useLedgerStore = defineStore("ledgers", {
     async persistCurrentLedger() {
       const auth = useAuthStore();
       if (!this.currentLedgerId || !auth.user) return;
+      const db = await getUserDb(auth.user.id);
       const preference: UserPreference = {
         id: currentLedgerPreferenceId(auth.user.id),
         userId: auth.user.id,
@@ -125,6 +127,7 @@ export const useLedgerStore = defineStore("ledgers", {
       if (amountDisplay) {
         const auth = useAuthStore();
         if (auth.user) {
+          const db = await getUserDb(auth.user.id);
           const preference: UserPreference = {
             id: ledgerAmountDisplayPreferenceId(auth.user.id, input.id),
             userId: auth.user.id,