/**
 * Round-trip test for state-replay (per change: fix-per-message-fork):
 * for every persisted entry, the reducer-equivalent message_start /
 * message_end carries entryId === entry.id. Replay does NOT need
 * entry_persisted back-fill because it reads from the persisted JSONL.
 */
import { describe, it, expect } from "vitest";
import { replayEntriesAsEvents } from "../state-replay.js";

describe("replayEntriesAsEvents — entryId fidelity", () => {
  it("stamps entryId on user message_start matching the source entry id", () => {
    const sessionId = "sess-1";
    const entries = [
      {
        type: "message",
        id: "u1",
        parentId: "root",
        timestamp: "2026-04-27T07:26:25.000Z",
        message: { role: "user", content: [{ type: "text", text: "Hello" }] },
      },
    ];

    const events = replayEntriesAsEvents(sessionId, entries);
    const start = events.find((e) => e.event.eventType === "message_start");
    expect(start).toBeDefined();
    expect((start!.event.data as any).entryId).toBe("u1");
  });

  it("stamps entryId on assistant message_end matching the source entry id", () => {
    const sessionId = "sess-1";
    const entries = [
      {
        type: "message",
        id: "a1",
        parentId: "u1",
        timestamp: "2026-04-27T07:26:30.000Z",
        message: { role: "assistant", content: [{ type: "text", text: "Hi!" }] },
      },
    ];

    const events = replayEntriesAsEvents(sessionId, entries);
    const end = events.find((e) => e.event.eventType === "message_end");
    expect(end).toBeDefined();
    expect((end!.event.data as any).entryId).toBe("a1");
  });

  it("emits no entry_persisted events during replay", () => {
    const sessionId = "sess-1";
    const entries = [
      {
        type: "message",
        id: "u1",
        timestamp: "2026-04-27T07:26:25.000Z",
        message: { role: "user", content: [{ type: "text", text: "Hi" }] },
      },
      {
        type: "message",
        id: "a1",
        parentId: "u1",
        timestamp: "2026-04-27T07:26:30.000Z",
        message: { role: "assistant", content: [{ type: "text", text: "Hello!" }] },
      },
    ];

    const events = replayEntriesAsEvents(sessionId, entries);
    const persisted = events.filter((e) => e.event.eventType === "entry_persisted");
    expect(persisted).toHaveLength(0);
  });
});