import { describe, expect, test } from "vitest";
import { parseHost } from "./host";

describe("parseHost", () => {
  test("null host → unknown", () => {
    expect(parseHost(null)).toEqual({ kind: "unknown" });
    expect(parseHost(undefined)).toEqual({ kind: "unknown" });
    expect(parseHost("")).toEqual({ kind: "unknown" });
  });

  test("apex hosts return apex", () => {
    expect(parseHost("localhost")).toEqual({ kind: "apex" });
    expect(parseHost("localhost:3000")).toEqual({ kind: "apex" });
    expect(parseHost("breakpilot.com")).toEqual({ kind: "apex" });
    expect(parseHost("stage.breakpilot.com")).toEqual({ kind: "apex" });
  });

  test("tenant subdomain returns slug", () => {
    expect(parseHost("acme.localhost:3000")).toEqual({ kind: "tenant", slug: "acme" });
    expect(parseHost("acme.breakpilot.com")).toEqual({ kind: "tenant", slug: "acme" });
    expect(parseHost("acme.stage.breakpilot.com")).toEqual({ kind: "tenant", slug: "acme" });
  });

  test("backstage subdomain is reserved", () => {
    expect(parseHost("backstage.localhost:3000")).toEqual({ kind: "backstage" });
    expect(parseHost("backstage.breakpilot.com")).toEqual({ kind: "backstage" });
  });

  test("invalid slugs return unknown", () => {
    expect(parseHost("a.localhost")).toEqual({ kind: "unknown" }); // too short (1 char)
    expect(parseHost("foo_bar.localhost")).toEqual({ kind: "unknown" }); // underscore not allowed
    expect(parseHost("FOO!.localhost")).toEqual({ kind: "unknown" }); // exclamation invalid
  });

  test("empty subdomain falls back to apex", () => {
    expect(parseHost(".localhost")).toEqual({ kind: "apex" });
  });

  test("uppercase host is lowercased", () => {
    expect(parseHost("ACME.LOCALHOST")).toEqual({ kind: "tenant", slug: "acme" });
  });

  test("unknown apex returns unknown", () => {
    expect(parseHost("acme.example.com")).toEqual({ kind: "unknown" });
  });
});