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public/js/db.js

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+/*
+ * IndexedDB operations module. Provides typed helpers for reading and writing to
+ * the browser-side database. All functions depend on `state.db` being set during
+ * initialization.
+ *
+ * Changes from the original monolithic app.js:
+ * - A5: `dbTransaction()` wraps multi-store operations in a single IndexedDB
+ *   transaction so related writes (e.g. delete report + delete attachments) are
+ *   atomic and won't leave orphaned records on mid-operation failure.
+ */
+
+import { state } from './state.js';
+import {
+  DB_NAME,
+  DB_VERSION,
+  STORE_TEMPLATES,
+  STORE_LOOKUPS,
+  STORE_CONFIG,
+  STORE_REPORTS,
+  STORE_ATTACHMENTS,
+  STORE_SETTINGS
+} from './constants.js';
+
+/* ── Database bootstrap ─────────────────────────────────────────────────── */
+
+export function openDatabase() {
+  return new Promise((resolve, reject) => {
+    const request = indexedDB.open(DB_NAME, DB_VERSION);
+
+    request.onerror = () => reject(request.error);
+    request.onsuccess = () => resolve(request.result);
+    request.onupgradeneeded = (event) => {
+      const db = request.result;
+
+      if (!db.objectStoreNames.contains(STORE_TEMPLATES)) {
+        db.createObjectStore(STORE_TEMPLATES, { keyPath: 'cacheKey' });
+      }
+
+      if (!db.objectStoreNames.contains(STORE_LOOKUPS)) {
+        db.createObjectStore(STORE_LOOKUPS, { keyPath: 'code' });
+      }
+
+      if (!db.objectStoreNames.contains(STORE_CONFIG)) {
+        db.createObjectStore(STORE_CONFIG, { keyPath: 'key' });
+      }
+
+      if (!db.objectStoreNames.contains(STORE_REPORTS)) {
+        db.createObjectStore(STORE_REPORTS, { keyPath: 'id' });
+      }
+
+      if (!db.objectStoreNames.contains(STORE_ATTACHMENTS)) {
+        const store = db.createObjectStore(STORE_ATTACHMENTS, { keyPath: 'id' });
+        store.createIndex('byReportId', 'reportId', { unique: false });
+      }
+
+      if (!db.objectStoreNames.contains(STORE_SETTINGS)) {
+        db.createObjectStore(STORE_SETTINGS, { keyPath: 'key' });
+      }
+    };
+  });
+}
+
+/* ── Single-store helpers ───────────────────────────────────────────────── */
+
+export function dbGetAll(storeName) {
+  return executeStoreRequest(storeName, 'readonly', (store) => store.getAll());
+}
+
+export function dbGet(storeName, key) {
+  return executeStoreRequest(storeName, 'readonly', (store) => store.get(key));
+}
+
+export function dbPut(storeName, value) {
+  return executeStoreRequest(storeName, 'readwrite', (store) => store.put(value));
+}
+
+export function dbDelete(storeName, key) {
+  return executeStoreRequest(storeName, 'readwrite', (store) => store.delete(key));
+}
+
+export function dbGetAllByIndex(storeName, indexName, key) {
+  return executeStoreRequest(storeName, 'readonly', (store) => {
+    return store.index(indexName).getAll(IDBKeyRange.only(key));
+  });
+}
+
+function executeStoreRequest(storeName, mode, callback) {
+  return new Promise((resolve, reject) => {
+    const transaction = state.db.transaction(storeName, mode);
+    const store = transaction.objectStore(storeName);
+    const request = callback(store);
+
+    request.onsuccess = () => resolve(request.result);
+    request.onerror = () => reject(request.error);
+  });
+}
+
+/* ── Multi-store transaction (A5) ───────────────────────────────────────── */
+
+/*
+ * Wraps multiple writes across different object stores in a single IndexedDB
+ * transaction. The callback receives a helper that returns a store by name.
+ * All writes either commit together or roll back as a unit.
+ *
+ * Example:
+ *   await dbTransaction([STORE_REPORTS, STORE_ATTACHMENTS], 'readwrite', (getStore) => {
+ *     getStore(STORE_REPORTS).delete(reportId);
+ *     getStore(STORE_ATTACHMENTS).delete(attachmentId);
+ *   });
+ */
+export function dbTransaction(storeNames, mode, callback) {
+  return new Promise((resolve, reject) => {
+    const tx = state.db.transaction(storeNames, mode);
+
+    tx.oncomplete = () => resolve();
+    tx.onerror = () => reject(tx.error);
+    tx.onabort = () => reject(tx.error || new Error('Transaction aborted'));
+
+    const getStore = (name) => tx.objectStore(name);
+    callback(getStore);
+  });
+}
+
+/* ── Settings helpers ───────────────────────────────────────────────────── */
+
+export async function saveSetting(key, value) {
+  await dbPut(STORE_SETTINGS, { key, value });
+}
+
+export async function loadSetting(key) {
+  const record = await dbGet(STORE_SETTINGS, key);
+  return record?.value;
+}