import { describe, expect, it } from "vitest";
import {
  DEFAULT_DEV_EMAIL,
  DEV_IDENTITY_COOKIE,
  DEV_IDENTITY_HEADER,
  getServerIdentity,
} from "./dev-identity";
import type { NextRequest } from "next/server";

/**
 * Minimal NextRequest stub — only the bits getServerIdentity reads.
 * Avoids pulling in Next's actual class for unit tests.
 */
function makeReq(opts: {
  header?: string;
  cookie?: string;
  envEmail?: string;
}): NextRequest {
  const headers = new Headers();
  if (opts.header) headers.set(DEV_IDENTITY_HEADER, opts.header);

  // Build a minimal cookie jar NextRequest understands.
  const cookieValue = opts.cookie
    ? `${DEV_IDENTITY_COOKIE}=${opts.cookie}`
    : "";

  const req = {
    headers,
    cookies: {
      get(name: string) {
        if (name !== DEV_IDENTITY_COOKIE) return undefined;
        if (!cookieValue) return undefined;
        // mimic NextRequest's behavior: returns the raw value
        const eq = cookieValue.indexOf("=");
        return { name, value: cookieValue.slice(eq + 1) };
      },
    },
  } as unknown as NextRequest;

  if (opts.envEmail !== undefined) {
    process.env.DEV_USER_EMAIL = opts.envEmail;
  } else {
    delete process.env.DEV_USER_EMAIL;
  }

  return req;
}

describe("getServerIdentity", () => {
  it("returns the X-User-Email header when present", () => {
    const req = makeReq({ header: "alice@example.com" });
    expect(getServerIdentity(req)).toBe("alice@example.com");
  });

  it("falls back to the cookie when the header is missing", () => {
    const req = makeReq({
      cookie: encodeURIComponent("bob@example.com"),
    });
    expect(getServerIdentity(req)).toBe("bob@example.com");
  });

  it("falls back to DEV_USER_EMAIL when header and cookie are missing", () => {
    const req = makeReq({ envEmail: "ci@example.com" });
    expect(getServerIdentity(req)).toBe("ci@example.com");
  });

  it("falls back to the default when nothing is set", () => {
    const req = makeReq({});
    expect(getServerIdentity(req)).toBe(DEFAULT_DEV_EMAIL);
  });

  it("prefers the header over the cookie", () => {
    const req = makeReq({
      header: "header@example.com",
      cookie: encodeURIComponent("cookie@example.com"),
    });
    expect(getServerIdentity(req)).toBe("header@example.com");
  });

  it("prefers the cookie over the env default", () => {
    const req = makeReq({
      cookie: encodeURIComponent("cookie@example.com"),
      envEmail: "env@example.com",
    });
    expect(getServerIdentity(req)).toBe("cookie@example.com");
  });

  it("trims whitespace from all sources", () => {
    const req = makeReq({ header: "  spaced@example.com  " });
    expect(getServerIdentity(req)).toBe("spaced@example.com");
  });

  it("ignores empty values and falls through to the next source", () => {
    const req = makeReq({
      header: "   ",
      cookie: encodeURIComponent("   "),
      envEmail: "env@example.com",
    });
    expect(getServerIdentity(req)).toBe("env@example.com");
  });
});