import { describe, it, expect, vi } from "vitest";
import { createAutosave } from "./autosave.js";
import type { StorageAdapter } from "./storage.js";
import type { DocumentRef } from "./types.js";

function mockAdapter(): StorageAdapter & { saved: DocumentRef[] } {
  const saved: DocumentRef[] = [];
  return {
    saved,
    async listProjects() {
      return [];
    },
    async createProject() {
      throw new Error("not implemented");
    },
    async getProject() {
      throw new Error("not implemented");
    },
    async createBook() {
      throw new Error("not implemented");
    },
    async listBooks() {
      return [];
    },
    async listChapters() {
      return [];
    },
    async getChapter() {
      return null;
    },
    async saveEntity() {},
    async listEntities() {
      return [];
    },
    async getEntity() {
      return null;
    },
    async deleteEntity() {},
    async searchEntities() {
      return [];
    },
    async saveBoard() {},
    async getBoard() {
      return null;
    },
    async savePlotBeat() {},
    async listPlotBeats() {
      return [];
    },
    async deletePlotBeat() {},
    async saveAISession() {},
    async saveDocument(doc: DocumentRef) {
      saved.push(doc);
    },
    onEvent() {
      return () => {};
    },
  };
}

const ref: DocumentRef = {
  id: "doc1",
  projectId: "p1",
  title: "Chapter 1",
  rev: 0,
  doc: { type: "doc", content: [] },
};

describe("autosave", () => {
  it("debounces saves and reports status transitions", async () => {
    const adapter = mockAdapter();
    const as = createAutosave(adapter, { intervalMs: 50 });
    const statuses: string[] = [];
    as.onStatus((s) => statuses.push(s.status));

    as.save(ref);
    as.save(ref); // second save within window should not double-fire
    expect(as.state.dirty).toBe(true);
    expect(as.state.saving).toBe(true);

    await vi.waitFor(() => expect(adapter.saved.length).toBe(1), { timeout: 500 });
    expect(adapter.saved[0]!.id).toBe("doc1");
    expect(as.state.dirty).toBe(false);
    expect(as.state.saving).toBe(false);
    expect(as.indicatorLabel()).toMatch(/✓ saved/);
  });

  it("flush persists immediately and clears dirty state", async () => {
    const adapter = mockAdapter();
    const as = createAutosave(adapter, { intervalMs: 10_000 });
    as.save(ref);
    await as.flush();
    expect(adapter.saved.length).toBe(1);
    expect(as.state.dirty).toBe(false);
  });
});