import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";

import { AgentController, NoteBuilder } from "./index.js";
import type { ResolvedProvider } from "./index.js";

const config: ResolvedProvider = {
  id: "test-openai",
  kind: "openai-compatible",
  baseUrl: "https://api.openai.com/v1",
  apiKey: "sk-test",
  model: "gpt-4o",
  contextWindow: 128_000,
};

let savedFetch: typeof fetch;

/** Build an SSE Response streaming a single text delta. */
function sseResponse(events: string[]): Response {
  const encoder = new TextEncoder();
  const body = new ReadableStream<Uint8Array<ArrayBuffer>>({
    start(controller) {
      for (const event of events) controller.enqueue(encoder.encode(`data: ${event}\n\n`));
      controller.enqueue(encoder.encode("data: [DONE]\n\n"));
      controller.close();
    },
  });
  return new Response(body, { status: 200, headers: { "content-type": "text/event-stream" } });
}

describe("NoteBuilder", () => {
  let builder: NoteBuilder;

  beforeEach(() => {
    savedFetch = globalThis.fetch;
  });

  afterEach(() => {
    globalThis.fetch = savedFetch;
    vi.restoreAllMocks();
  });

  it("streams a prompt and builds a draft note", async () => {
    globalThis.fetch = (() =>
      sseResponse([JSON.stringify({ choices: [{ delta: { content: "Aria is the protagonist. She is a young mage with a mysterious past. #protagonist #mage" } }] })])) as unknown as typeof fetch;

    const agent = new AgentController(config);
    builder = new NoteBuilder(agent);

    const result = await builder.build(
      { kind: "character", prompt: "Summarize Aria", context: { title: "Aria" } },
      "sess-1",
    );

    expect(result.id).toBeTruthy();
    expect(result.sessionId).toBe("sess-1");
    expect(result.kind).toBe("character");
    expect(result.status).toBe("draft");
    expect(result.body).toContain("Aria");
    expect(result.tags).toContain("protagonist");
    expect(result.tags).toContain("mage");
    expect(result.createdAt).toBeTruthy();
    expect(result.updatedAt).toBeTruthy();
  });

  it("extracts tags from a #tag list in the response", async () => {
    globalThis.fetch = (() =>
      sseResponse([JSON.stringify({ choices: [{ delta: { content: "The Sunspire Mountains. #location #magic #north" } }] })])) as unknown as typeof fetch;

    const agent = new AgentController(config);
    builder = new NoteBuilder(agent);

    const result = await builder.build(
      { kind: "setting", prompt: "Describe the setting" },
      "sess-1",
    );

    expect(result.kind).toBe("setting");
    expect(result.tags.sort()).toEqual(["location", "magic", "north"]);
  });

  it("includes the note title in the system prompt", async () => {
    const calls: Array<RequestInit> = [];
    globalThis.fetch = ((_url: string, init: RequestInit) => {
      calls.push(init);
      return Promise.resolve(
        sseResponse([JSON.stringify({ choices: [{ delta: { content: "ok" } }] })]),
      );
    }) as unknown as typeof fetch;

    const agent = new AgentController(config);
    builder = new NoteBuilder(agent);

    await builder.build(
      { kind: "plot", prompt: "Summarize the plot thread", context: { title: "The Stolen Relic" } },
      "sess-1",
    );

    const init = calls[0] as RequestInit;
    const body = JSON.parse(init.body as string) as Record<string, unknown>;
    const messages = body.messages as Array<{ content: string; role?: string }>;
    const system = messages.find((m) => m.role === "system")?.content ?? "";
    expect(system).toContain("The Stolen Relic");
  });
});