Kick off (#1)

* Kick off
* Update LICENSE copyright

src/db.ts

@@ -0,0 +1,90 @@
+import type { MonitorState, DbWrite, StateUpdate } from './types.js';
+
+const batchLimit = 100;
+
+function chunkArray<T>(array: T[], chunkSize: number): T[][] {
+  const chunks: T[][] = [];
+  for (let i = 0; i < array.length; i += chunkSize) {
+    chunks.push(array.slice(i, i + chunkSize));
+  }
+
+  return chunks;
+}
+
+export async function getMonitorStates(database: D1Database): Promise<MonitorState[]> {
+  const result = await database
+    .prepare(
+      'SELECT monitor_name, current_status, consecutive_failures, last_status_change, last_checked FROM monitor_state WHERE 1=?'
+    )
+    .bind(1)
+    .all<MonitorState>();
+
+  return result.results || [];
+}
+
+export async function writeCheckResults(database: D1Database, writes: DbWrite[]): Promise<void> {
+  if (writes.length === 0) {
+    return;
+  }
+
+  const stmt = database.prepare(
+    'INSERT INTO check_results (monitor_name, checked_at, status, response_time_ms, error_message, attempts) VALUES (?, ?, ?, ?, ?, ?)'
+  );
+
+  const batch = writes.map(w =>
+    stmt.bind(w.monitorName, w.checkedAt, w.status, w.responseTimeMs, w.errorMessage, w.attempts)
+  );
+
+  const chunks = chunkArray(batch, batchLimit);
+  for (const chunk of chunks) {
+    await database.batch(chunk);
+  }
+}
+
+export async function updateMonitorStates(
+  database: D1Database,
+  updates: StateUpdate[]
+): Promise<void> {
+  if (updates.length === 0) {
+    return;
+  }
+
+  const stmt =
+    database.prepare(`INSERT INTO monitor_state (monitor_name, current_status, consecutive_failures, last_status_change, last_checked)
+     VALUES (?, ?, ?, ?, ?)
+     ON CONFLICT(monitor_name) DO UPDATE SET
+       current_status = excluded.current_status,
+       consecutive_failures = excluded.consecutive_failures,
+       last_status_change = excluded.last_status_change,
+       last_checked = excluded.last_checked`);
+
+  const batch = updates.map(u =>
+    stmt.bind(
+      u.monitorName,
+      u.currentStatus,
+      u.consecutiveFailures,
+      u.lastStatusChange,
+      u.lastChecked
+    )
+  );
+
+  const chunks = chunkArray(batch, batchLimit);
+  for (const chunk of chunks) {
+    await database.batch(chunk);
+  }
+}
+
+export async function recordAlert(
+  database: D1Database,
+  monitorName: string,
+  alertType: string,
+  alertName: string,
+  success: boolean
+): Promise<void> {
+  await database
+    .prepare(
+      'INSERT INTO alerts (monitor_name, alert_type, sent_at, alert_name, success) VALUES (?, ?, ?, ?, ?)'
+    )
+    .bind(monitorName, alertType, Math.floor(Date.now() / 1000), alertName, success ? 1 : 0)
+    .run();
+}