import { afterEach, describe, expect, it, vi } from "vitest";
import { NextRequest } from "next/server";
import { GET, POST } from "@/app/api/session/route";
import { SESSION_COOKIE } from "@/lib/cookie";
import { getSession } from "@/lib/session-store";

// A fetch stub that walks the three Minnect calls. `overrides` lets a test
// force a non-200 or a weird body at any step.
function makeFetchStub(overrides: Partial<Record<"login" | "me" | "feed", Response>> = {}) {
  return vi.fn(async (input: RequestInfo | URL): Promise<Response> => {
    const url = typeof input === "string" ? input : input.toString();

    if (url.endsWith("/api/v4/auth/login")) {
      return (
        overrides.login ??
        new Response(
          JSON.stringify({
            data: { accessToken: "profile-access", refreshToken: "profile-refresh", expiresIn: 3600 },
          }),
          { status: 200, headers: { "content-type": "application/json" } },
        )
      );
    }
    if (url.endsWith("/api/v4/auth/me")) {
      return (
        overrides.me ??
        new Response(
          JSON.stringify({
            data: {
              userId: "user-123",
              email: "person@example.com",
              firstName: "Pat",
              lastName: "Rivera",
              profilePictureUrl: "https://cdn.example.com/pat.jpg",
              role: "user",
            },
          }),
          { status: 200, headers: { "content-type": "application/json" } },
        )
      );
    }
    if (url.endsWith("/api/v4/auth/external-services/feed")) {
      return (
        overrides.feed ??
        new Response(JSON.stringify({ accessToken: "feed-access" }), {
          status: 200,
          headers: { "content-type": "application/json" },
        })
      );
    }
    throw new Error(`unexpected fetch to ${url}`);
  });
}

function postRequest(body: unknown): NextRequest {
  return new NextRequest("http://localhost/api/session", {
    method: "POST",
    headers: { "content-type": "application/json" },
    body: JSON.stringify(body),
  });
}

afterEach(() => {
  vi.unstubAllGlobals();
  vi.restoreAllMocks();
});

describe("POST /api/session", () => {
  it("wrong password: 401, generic message, no cookie, no session", async () => {
    const serverError = {
      data: null,
      errors: [{ message: "User not found in our records", code: "UnauthorizedException" }],
    };
    vi.stubGlobal(
      "fetch",
      makeFetchStub({
        login: new Response(JSON.stringify(serverError), {
          status: 401,
          headers: { "content-type": "application/json" },
        }),
      }),
    );

    const res = await POST(postRequest({ email: "person@example.com", password: "wrong" }));
    const json = await res.json();

    expect(res.status).toBe(401);
    expect(json).toEqual({ error: "Email or password is incorrect." });
    // The Minnect message must not leak through.
    expect(JSON.stringify(json)).not.toContain("records");
    // No cookie is set.
    expect(res.cookies.get(SESSION_COOKIE)).toBeUndefined();
  });

  it("missing fields: 400, no cookie", async () => {
    vi.stubGlobal("fetch", makeFetchStub());
    const res = await POST(postRequest({ email: "person@example.com" }));
    expect(res.status).toBe(400);
    expect(res.cookies.get(SESSION_COOKIE)).toBeUndefined();
  });

  it("correct login: 200, person body, opaque session cookie, server session created", async () => {
    vi.stubGlobal("fetch", makeFetchStub());

    const res = await POST(postRequest({ email: "person@example.com", password: "right" }));
    const json = await res.json();

    expect(res.status).toBe(200);
    expect(json).toEqual({
      name: "Pat Rivera",
      email: "person@example.com",
      pictureUrl: "https://cdn.example.com/pat.jpg",
    });

    const cookie = res.cookies.get(SESSION_COOKIE);
    expect(cookie).toBeDefined();
    expect(cookie?.httpOnly).toBe(true);
    expect(cookie?.sameSite).toBe("lax");
    // The cookie is an opaque id, not a Minnect token.
    const id = cookie!.value;
    expect(id).not.toContain("profile-access");
    expect(id).not.toContain("feed-access");

    // The tokens live server-side only.
    const session = getSession(id);
    expect(session?.profileAccessToken).toBe("profile-access");
    expect(session?.profileRefreshToken).toBe("profile-refresh");
    expect(session?.feedAccessToken).toBe("feed-access");
  });

  it("feed-token exchange fails: 502, feed message, no cookie", async () => {
    vi.stubGlobal(
      "fetch",
      makeFetchStub({
        feed: new Response(JSON.stringify({ data: null }), {
          status: 500,
          headers: { "content-type": "application/json" },
        }),
      }),
    );
    const res = await POST(postRequest({ email: "person@example.com", password: "right" }));
    const json = await res.json();
    expect(res.status).toBe(502);
    expect(json).toEqual({ error: "Could not open the feed." });
    expect(res.cookies.get(SESSION_COOKIE)).toBeUndefined();
  });
});

describe("GET /api/session", () => {
  it("no cookie: 401 sign_in", async () => {
    const res = await GET(new NextRequest("http://localhost/api/session"));
    const json = await res.json();
    expect(res.status).toBe(401);
    expect(json).toEqual({ error: "sign_in" });
  });

  it("unknown session id: 401 sign_in", async () => {
    const res = await GET(
      new NextRequest("http://localhost/api/session", {
        headers: { cookie: `${SESSION_COOKIE}=does-not-exist` },
      }),
    );
    const json = await res.json();
    expect(res.status).toBe(401);
    expect(json).toEqual({ error: "sign_in" });
  });

  it("valid session: returns the person's name and email", async () => {
    vi.stubGlobal("fetch", makeFetchStub());
    const postRes = await POST(postRequest({ email: "person@example.com", password: "right" }));
    const id = postRes.cookies.get(SESSION_COOKIE)!.value;

    const res = await GET(
      new NextRequest("http://localhost/api/session", {
        headers: { cookie: `${SESSION_COOKIE}=${id}` },
      }),
    );
    const json = await res.json();
    expect(res.status).toBe(200);
    expect(json.name).toBe("Pat Rivera");
    expect(json.email).toBe("person@example.com");
  });
});