import { afterEach, describe, expect, test } from "bun:test";
import type { Context } from "@wrnexus/core";
import { signJwt } from "@wrnexus/jwt";
import { exportSubjectContext, importSubjectContext } from "../src/identity.ts";

const SECRET = "test-rpc-secret-at-least-32-chars-long";
const originalRpcSecret = process.env.WRNEXUS_RPC_SECRET;
const originalAppName = process.env.WRNEXUS_APP_NAME;

afterEach(() => {
  if (originalRpcSecret === undefined) delete process.env.WRNEXUS_RPC_SECRET;
  else process.env.WRNEXUS_RPC_SECRET = originalRpcSecret;
  if (originalAppName === undefined) delete process.env.WRNEXUS_APP_NAME;
  else process.env.WRNEXUS_APP_NAME = originalAppName;
});

function ctxFor(user: unknown, tenantId?: string): Context {
  return {
    user,
    tenant: tenantId ? { id: tenantId } : undefined,
    locals: {},
  } as unknown as Context;
}

function configure(appName = "web") {
  process.env.WRNEXUS_RPC_SECRET = SECRET;
  process.env.WRNEXUS_APP_NAME = appName;
}

describe("subject context token", () => {
  test("round-trips subject and tenant", async () => {
    configure("web");
    const token = await exportSubjectContext(ctxFor({ id: "u1" }, "acme"), "billing");
    const imported = await importSubjectContext(token!, "billing");
    expect(imported.subjectId).toBe("u1");
    expect(imported.tenantId).toBe("acme");
    expect(imported.callerApp).toBe("web");
  });

  test("carries NO roles or permissions", async () => {
    configure();
    const token = await exportSubjectContext(
      ctxFor({ id: "u1", roles: ["admin"], permissions: ["*"] }),
      "billing",
    );
    // Decode the payload directly: the claim set must not include privileges.
    const payload = JSON.parse(atob(token!.split(".")[1]!.replace(/-/g, "+").replace(/_/g, "/")));
    expect(payload.roles).toBeUndefined();
    expect(payload.permissions).toBeUndefined();
    expect(payload.sub).toBe("u1");
  });

  test("an anonymous context produces no token", async () => {
    configure();
    expect(await exportSubjectContext(ctxFor(null), "billing")).toBeUndefined();
    expect(await exportSubjectContext(ctxFor({}), "billing")).toBeUndefined();
  });

  test("a non-string subject id is refused", async () => {
    configure();
    // Matches the permissions system: only a non-empty string identifies a subject.
    for (const id of [0, "", 123, {}]) {
      await expect(exportSubjectContext(ctxFor({ id }), "billing")).rejects.toThrow(/subject/i);
    }
  });

  test("a token minted for one app is rejected by another", async () => {
    configure();
    const token = await exportSubjectContext(ctxFor({ id: "u1" }), "billing");
    await expect(importSubjectContext(token!, "reports")).rejects.toThrow();
  });

  test("an expired token is rejected", async () => {
    configure();
    const token = await exportSubjectContext(ctxFor({ id: "u1" }), "billing", { ttlSeconds: -1 });
    await expect(importSubjectContext(token!, "billing")).rejects.toThrow();
  });

  test("a forged token with no exp is refused", async () => {
    configure();
    // verifyJwt only checks exp when present, so a token minted without one
    // never expires unless importSubjectContext requires it explicitly.
    const token = await signJwt({ sub: "u1" }, SECRET, { issuer: "web", audience: "billing" });
    await expect(importSubjectContext(token, "billing")).rejects.toThrow(/expiry/i);
  });

  test("a forged token with no iat is refused", async () => {
    configure();
    // signJwt always sets iat unless the payload explicitly overrides it with
    // undefined (JSON.stringify then drops the key). verifyJwt's maxAge check
    // is gated on iat being a number, so this would otherwise defeat the age
    // bound at ANY maxAgeSeconds.
    const token = await signJwt({ sub: "u1", iat: undefined }, SECRET, {
      issuer: "web",
      audience: "billing",
      expiresIn: 60,
    });
    await expect(importSubjectContext(token, "billing")).rejects.toThrow(/issued-at/i);
  });

  test("a token signed with a different secret is rejected", async () => {
    configure();
    const token = await exportSubjectContext(ctxFor({ id: "u1" }), "billing");
    process.env.WRNEXUS_RPC_SECRET = "a-completely-different-secret-32-chars";
    await expect(importSubjectContext(token!, "billing")).rejects.toThrow();
  });

  test("a tampered payload is rejected", async () => {
    configure();
    const token = await exportSubjectContext(ctxFor({ id: "u1" }), "billing");
    const [header, , signature] = token!.split(".");
    const forged = btoa(JSON.stringify({ sub: "admin", aud: "billing", iss: "web" }))
      .replace(/\+/g, "-")
      .replace(/\//g, "_")
      .replace(/=+$/, "");
    await expect(
      importSubjectContext(`${header}.${forged}.${signature}`, "billing"),
    ).rejects.toThrow();
  });

  test("an empty selfApp is refused rather than disabling the audience check", async () => {
    configure();
    const token = await exportSubjectContext(ctxFor({ id: "u1" }), "billing");
    // verifyJwt skips the audience check when audience is undefined, so this
    // would otherwise accept every token from every app.
    for (const bad of [undefined, "", null]) {
      await expect(importSubjectContext(token!, bad as never)).rejects.toThrow(/selfApp/);
    }
  });

  test("a token with a huge ttl is still rejected once it exceeds maxAge", async () => {
    configure();
    const token = await exportSubjectContext(ctxFor({ id: "u1" }), "billing", {
      ttlSeconds: 31_536_000,
    });
    await expect(importSubjectContext(token!, "billing", { maxAgeSeconds: -1 })).rejects.toThrow();
  });

  test("a backdated iat is refused under the default max age, and accepted once maxAgeSeconds is raised", async () => {
    configure();
    // Age 400s, older than DEFAULT_MAX_AGE_SECONDS (300s). Calling with NO
    // options (the real default) must reject -- unlike the huge-ttl test
    // above, which always passes an explicit maxAgeSeconds: -1 and so never
    // actually exercises the 300s constant itself.
    const now = Math.floor(Date.now() / 1000);
    const token = await signJwt({ sub: "u1" }, SECRET, {
      issuer: "web",
      audience: "billing",
      expiresIn: 1000,
      now: now - 400,
    });
    await expect(importSubjectContext(token, "billing")).rejects.toThrow();
    // Same token, wider explicit bound: proves maxAgeSeconds is actually
    // connected through rather than the guard being a hardcoded rejection.
    await expect(
      importSubjectContext(token, "billing", { maxAgeSeconds: 1000 }),
    ).resolves.toBeDefined();
  });

  test("an array targetApp is refused, so no token is valid at two apps", async () => {
    configure();
    await expect(
      exportSubjectContext(ctxFor({ id: "u1" }), ["billing", "reports"] as never),
    ).rejects.toThrow(/targetApp/);
  });

  test("a token signed with an array audience is refused on import", async () => {
    configure();
    // verifyJwt compares audience with includes(), so a token signed with
    // audience: ["billing", "reports"] would verify at BOTH apps -- exactly
    // what the audience binding exists to prevent -- unless importSubjectContext
    // requires an exact single-audience match itself.
    const token = await signJwt({ sub: "u1" }, SECRET, {
      issuer: "web",
      audience: ["billing", "reports"],
      expiresIn: 60,
    });
    await expect(importSubjectContext(token, "billing")).rejects.toThrow();
  });

  test("a non-string tenant id is refused rather than silently dropped", async () => {
    configure();
    // Silently dropping it leaves the callee reading "no tenant" as "global".
    for (const tenant of [42, {}, ""]) {
      await expect(
        exportSubjectContext(
          { user: { id: "u1" }, tenant: { id: tenant }, locals: {} } as unknown as Context,
          "billing",
        ),
      ).rejects.toThrow(/tenant/i);
    }
  });

  test("ctx.tenant = { id: null } is refused at mint rather than minting untenanted", async () => {
    configure();
    // Unlike rawId === null (mints no token at all), a present tenant with an
    // unusable id must not silently issue an authenticated credential with
    // widened (untenanted/global) scope.
    await expect(
      exportSubjectContext(
        { user: { id: "u1" }, tenant: { id: null }, locals: {} } as unknown as Context,
        "billing",
      ),
    ).rejects.toThrow(/tenant/i);
  });

  test("a forged token whose tenant claim is a number is refused on import", async () => {
    configure();
    const token = await signJwt({ sub: "u1", tenant: 42 }, SECRET, {
      issuer: "web",
      audience: "billing",
      expiresIn: 60,
    });
    await expect(importSubjectContext(token, "billing")).rejects.toThrow(/tenant/i);
  });

  test("a missing secret is a setup error, not a silent pass", async () => {
    process.env.WRNEXUS_APP_NAME = "web";
    delete process.env.WRNEXUS_RPC_SECRET;
    await expect(exportSubjectContext(ctxFor({ id: "u1" }), "billing")).rejects.toThrow(
      /WRNEXUS_RPC_SECRET/,
    );
  });

  test("a short secret is refused", async () => {
    process.env.WRNEXUS_APP_NAME = "web";
    process.env.WRNEXUS_RPC_SECRET = "too-short";
    await expect(exportSubjectContext(ctxFor({ id: "u1" }), "billing")).rejects.toThrow(/32/);
  });
});