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

const FLAG_KEYS = [
  "FEATURE_ASSISTANT_INVESTIGATION_STATE_V1",
  "FEATURE_ASSISTANT_STATE_FOLLOWUP_BINDING_V1",
  "FEATURE_ASSISTANT_CONTRACTS_V11"
] as const;

const ORIGINAL_FLAGS: Record<string, string | undefined> = Object.fromEntries(
  FLAG_KEYS.map((key) => [key, process.env[key]])
);

function restoreFlags(): void {
  for (const key of FLAG_KEYS) {
    const original = ORIGINAL_FLAGS[key];
    if (original === undefined) {
      delete process.env[key];
    } else {
      process.env[key] = original;
    }
  }
}

async function createAppWithFlags(flags: {
  state: "0" | "1";
  binding: "0" | "1";
  contracts?: "0" | "1";
}) {
  process.env.FEATURE_ASSISTANT_INVESTIGATION_STATE_V1 = flags.state;
  process.env.FEATURE_ASSISTANT_STATE_FOLLOWUP_BINDING_V1 = flags.binding;
  process.env.FEATURE_ASSISTANT_CONTRACTS_V11 = flags.contracts ?? "1";
  vi.resetModules();
  const { createApp } = await import("../src/server");
  return createApp();
}

describe.sequential("assistant follow-up state binding", () => {
  afterEach(() => {
    restoreFlags();
    vi.resetModules();
  });

  it("applies investigation_state binding in follow-up flow when flags are ON", async () => {
    const app = await createAppWithFlags({
      state: "1",
      binding: "1"
    });
    const sessionId = `asst-wave2-on-${Date.now()}`;

    const first = await request(app).post("/api/assistant/message").send({
      session_id: sessionId,
      useMock: true,
      promptVersion: "normalizer_v2_0_2",
      user_message: "Разложи цепочку документов по контрагентам."
    });

    expect(first.status).toBe(200);
    expect(first.body.debug?.followup_state_usage).toBeUndefined();
    expect(first.body.debug?.investigation_state_snapshot?.turn_index).toBe(1);

    const second = await request(app).post("/api/assistant/message").send({
      session_id: sessionId,
      useMock: true,
      promptVersion: "normalizer_v2_0_2",
      user_message: "И по периоду 2020-06."
    });

    expect(second.status).toBe(200);
    expect(second.body.debug?.followup_state_usage?.applied).toBe(true);
    expect(second.body.debug?.followup_state_usage?.context_patch?.business_context_from_state).toBe(true);
    expect(second.body.debug?.followup_state_usage?.state_turn_index).toBe(1);
    expect(
      (second.body.debug?.routes ?? []).some((item: { route?: string }) => item.route && item.route !== "no_route")
    ).toBe(true);
    expect(second.body.debug?.investigation_state_snapshot?.turn_index).toBe(2);
  });

  it("does not apply follow-up binding when binding flag is OFF", async () => {
    const app = await createAppWithFlags({
      state: "1",
      binding: "0"
    });
    const sessionId = `asst-wave2-off-${Date.now()}`;

    const first = await request(app).post("/api/assistant/message").send({
      session_id: sessionId,
      useMock: true,
      promptVersion: "normalizer_v2_0_2",
      user_message: "Разложи цепочку документов по контрагентам."
    });
    expect(first.status).toBe(200);

    const second = await request(app).post("/api/assistant/message").send({
      session_id: sessionId,
      useMock: true,
      promptVersion: "normalizer_v2_0_2",
      user_message: "И по периоду 2020-06."
    });

    expect(second.status).toBe(200);
    expect(second.body.debug?.followup_state_usage).toBeUndefined();
    expect((second.body.debug?.routes ?? []).every((item: { route?: string }) => item.route === "no_route")).toBe(true);
  });

  it("keeps legacy-like behavior when investigation state flag is OFF", async () => {
    const app = await createAppWithFlags({
      state: "0",
      binding: "1"
    });

    const response = await request(app).post("/api/assistant/message").send({
      useMock: true,
      promptVersion: "normalizer_v2_0_2",
      user_message: "И по периоду 2020-06."
    });

    expect(response.status).toBe(200);
    expect(response.body.debug?.investigation_state_snapshot).toBeNull();
    expect(response.body.debug?.followup_state_usage).toBeUndefined();
  });
});