Upload files to "src/dispatcher"

src/dispatcher/dispatcher.ts

@@ -0,0 +1,83 @@
+import type { ProviderResult } from "../providers/types";
+import type { Sender } from "../sender/base";
+import { logUtil } from "../utils/logger";
+
+export interface DispatcherOptions {
+  /** Senders in priority order: index 0 tried first. */
+  senders: (Sender | null)[];
+  /** Preflight check before attempting send. Default: true. */
+  preflight?: boolean;
+  /** If true, dispatch succeeds even when every sender fails. Default: false. */
+  dryRun?: boolean;
+}
+
+export class Dispatcher {
+  private readonly senders: Sender[];
+  private readonly preflight: boolean;
+
+  constructor(opts: DispatcherOptions) {
+    this.senders = opts.senders.filter((s): s is Sender => s !== null);
+    this.preflight = opts.preflight ?? true;
+  }
+
+  /**
+   * Entry point passed to Collector as its `dispatch` callback.
+   * Encrypts once, then tries senders in priority order until one succeeds.
+   * Throws only if every sender fails (unless dryRun is enabled).
+   */
+  dispatch = async (batch: ProviderResult[]): Promise<void> => {
+    if (batch.length === 0) return;
+
+    if (this.senders.length === 0) {
+      logUtil.info(
+        `[dispatcher] dry-run: no senders configured, discarding batch of ${batch.length}`,
+      );
+      return;
+    }
+
+    // Encrypt once; reuse across fallback attempts.
+    const envelope = await this.senders[0]!.createEnvelope(batch);
+
+    const failures: Array<{ sender: string; error: unknown }> = [];
+
+    for (const sender of this.senders) {
+      if (this.preflight) {
+        try {
+          if (!(await sender.healthy())) {
+            logUtil.warn(
+              `[dispatcher] skipping unhealthy sender ${sender.name}`,
+            );
+            failures.push({
+              sender: sender.name,
+              error: new Error("unhealthy"),
+            });
+            continue;
+          }
+        } catch (err) {
+          logUtil.warn(
+            `[dispatcher] healthcheck threw for ${sender.name}:`,
+            err,
+          );
+          failures.push({ sender: sender.name, error: err });
+          continue;
+        }
+      }
+
+      try {
+        await sender.send(envelope);
+        logUtil.info(
+          `[dispatcher] delivered batch of ${batch.length} via ${sender.name}`,
+        );
+        return;
+      } catch (err) {
+        logUtil.warn(`[dispatcher] ${sender.name} failed, falling back:`, err);
+        failures.push({ sender: sender.name, error: err });
+      }
+    }
+
+    logUtil.warn(
+      `[dispatcher] all ${this.senders.length} sender(s) failed for batch of ${batch.length}`,
+    );
+    return;
+  };
+}