import { beforeEach, describe, expect, it, vi } from "vitest";

const betterAuthMock = vi.hoisted(() => vi.fn());
const drizzleAdapterMock = vi.hoisted(() =>
  vi.fn((db: unknown, options: unknown) => ({ __adapterOptions: options, db })),
);

vi.mock("better-auth", () => ({ betterAuth: betterAuthMock }));
vi.mock("better-auth/adapters/drizzle", () => ({ drizzleAdapter: drizzleAdapterMock }));

import type { IdentityConfig } from "../src/identity/config.js";
import { createIdentityRuntime, IdentityRuntimeError } from "../src/identity/runtime.js";
import { identityAdapterSchema } from "../src/identity/schema.js";

function validConfig(): IdentityConfig {
  return Object.freeze({
    baseUrl: "https://identity.example.test",
    secret: "correct-horse-battery-staple-0123456789",
    trustedOrigins: Object.freeze(["https://identity.example.test"]),
  });
}

function fakeDb(overrides: Partial<{ execute: ReturnType<typeof vi.fn> }> = {}) {
  return { __fakeDb: true, execute: vi.fn().mockResolvedValue(undefined), ...overrides } as never;
}

describe("Core identity runtime construction boundary", () => {
  beforeEach(() => {
    betterAuthMock.mockReset();
    drizzleAdapterMock.mockClear();
  });

  it("does not construct Better Auth or the Drizzle adapter merely because the module is imported", () => {
    expect(betterAuthMock).not.toHaveBeenCalled();
    expect(drizzleAdapterMock).not.toHaveBeenCalled();
  });

  it("constructs explicitly and returns only the two narrow transport capabilities", () => {
    betterAuthMock.mockReturnValue({ api: { getSession: vi.fn() }, handler: vi.fn() });

    const runtime = createIdentityRuntime({ config: validConfig(), db: fakeDb() });

    expect(Object.keys(runtime).sort()).toEqual(["handleAuthRequest", "resolvePrincipal"]);
    expect(typeof runtime.handleAuthRequest).toBe("function");
    expect(typeof runtime.resolvePrincipal).toBe("function");
    expect(Object.isFrozen(runtime)).toBe(true);
  });

  it("does not expose the raw database, adapter, or Better Auth instance on the returned value", () => {
    betterAuthMock.mockReturnValue({ api: { getSession: vi.fn() }, handler: vi.fn() });
    const db = fakeDb();

    const runtime = createIdentityRuntime({ config: validConfig(), db });

    expect(JSON.stringify(runtime)).toBe("{}");
  });

  it("passes the explicit ekklesia_core_* schema mapping to the Drizzle adapter", () => {
    betterAuthMock.mockReturnValue({ api: { getSession: vi.fn() }, handler: vi.fn() });
    const db = fakeDb();

    createIdentityRuntime({ config: validConfig(), db });

    expect(drizzleAdapterMock).toHaveBeenCalledTimes(1);
    const [passedDb, options] = drizzleAdapterMock.mock.calls[0] as [unknown, unknown];
    expect(passedDb).toBe(db);
    expect(options).toEqual({ provider: "pg", schema: identityAdapterSchema });
  });

  it("enables exactly email/password (autoSignIn disabled) and rate limiting, nothing else", () => {
    betterAuthMock.mockReturnValue({ api: { getSession: vi.fn() }, handler: vi.fn() });

    createIdentityRuntime({ config: validConfig(), db: fakeDb() });

    expect(betterAuthMock).toHaveBeenCalledTimes(1);
    const [options] = betterAuthMock.mock.calls[0] as [Record<string, unknown>];
    expect(Object.keys(options).sort()).toEqual([
      "advanced",
      "baseURL",
      "database",
      "emailAndPassword",
      "logger",
      "onAPIError",
      "rateLimit",
      "secret",
      "trustedOrigins",
    ]);
    expect(options.emailAndPassword).toEqual({
      autoSignIn: false,
      disableSignUp: false,
      enabled: true,
      maxPasswordLength: 128,
      minPasswordLength: 8,
    });
    expect(options.rateLimit).toEqual({ enabled: true, max: 100, window: 10 });
    expect(options.baseURL).toBe(validConfig().baseUrl);
    expect(options.secret).toBe(validConfig().secret);
    expect(options.trustedOrigins).toEqual([...validConfig().trustedOrigins]);
  });

  it("explicitly disables Better Auth's default test-environment origin/CSRF skip", () => {
    betterAuthMock.mockReturnValue({ api: { getSession: vi.fn() }, handler: vi.fn() });

    createIdentityRuntime({ config: validConfig(), db: fakeDb() });

    const [options] = betterAuthMock.mock.calls[0] as [Record<string, unknown>];
    expect(options.advanced).toEqual({ disableCSRFCheck: false, disableOriginCheck: false });
  });

  it("configures onAPIError.throw so an unexpected failure escapes Better Auth's own unsanitized fallback logger instead of being swallowed internally", () => {
    betterAuthMock.mockReturnValue({ api: { getSession: vi.fn() }, handler: vi.fn() });

    createIdentityRuntime({ config: validConfig(), db: fakeDb() });

    const [options] = betterAuthMock.mock.calls[0] as [Record<string, unknown>];
    expect(options.onAPIError).toEqual({ throw: true });
  });

  it("configures an explicit, error-only Better Auth logger that never forwards Better Auth's own message or arguments", () => {
    betterAuthMock.mockReturnValue({ api: { getSession: vi.fn() }, handler: vi.fn() });

    createIdentityRuntime({ config: validConfig(), db: fakeDb() });

    const [options] = betterAuthMock.mock.calls[0] as [Record<string, unknown>];
    const loggerOption = options.logger as {
      disabled?: boolean;
      level?: string;
      log?: (...args: unknown[]) => void;
    };
    expect(loggerOption.disabled).toBe(false);
    expect(loggerOption.level).toBe("error");
    expect(typeof loggerOption.log).toBe("function");

    const errorSpy = vi.spyOn(console, "error").mockImplementation(() => undefined);
    try {
      const hostileException = new Error(
        "password=hunter2 host=db.internal.example port=5432 statement_timeout at /var/app/src/secret.ts:10:5",
      );
      loggerOption.log?.(
        "error",
        "Invalid origin: https://evil.example.test",
        hostileException,
        "select * from ekklesia_core_session",
      );

      expect(errorSpy).toHaveBeenCalledTimes(1);
      const emitted = errorSpy.mock.calls
        .flat()
        .map((value) =>
          value instanceof Error ? `${value.message}\n${value.stack ?? ""}` : String(value),
        )
        .join("\n");
      expect(emitted).not.toContain("hunter2");
      expect(emitted).not.toContain("db.internal.example");
      expect(emitted).not.toContain("5432");
      expect(emitted).not.toContain("/var/app");
      expect(emitted).not.toContain("evil.example.test");
      expect(emitted.toLowerCase()).not.toContain("select");
      expect(emitted.toLowerCase()).not.toContain("stack");
    } finally {
      errorSpy.mockRestore();
    }
  });

  it("never publishes a Better Auth log at or below warn level", () => {
    betterAuthMock.mockReturnValue({ api: { getSession: vi.fn() }, handler: vi.fn() });

    createIdentityRuntime({ config: validConfig(), db: fakeDb() });

    const [options] = betterAuthMock.mock.calls[0] as [Record<string, unknown>];
    const loggerOption = options.logger as { log?: (...args: unknown[]) => void };

    const errorSpy = vi.spyOn(console, "error").mockImplementation(() => undefined);
    const warnSpy = vi.spyOn(console, "warn").mockImplementation(() => undefined);
    const logSpy = vi.spyOn(console, "log").mockImplementation(() => undefined);
    try {
      loggerOption.log?.("warn", "a warning", "detail");
      loggerOption.log?.("info", "some info", "detail");
      loggerOption.log?.("debug", "some debug", "detail");

      expect(errorSpy).not.toHaveBeenCalled();
      expect(warnSpy).not.toHaveBeenCalled();
      expect(logSpy).not.toHaveBeenCalled();
    } finally {
      errorSpy.mockRestore();
      warnSpy.mockRestore();
      logSpy.mockRestore();
    }
  });

  it("only widens the sign-in/sign-up rate-limit window when a narrow override is explicitly injected", () => {
    betterAuthMock.mockReturnValue({ api: { getSession: vi.fn() }, handler: vi.fn() });

    createIdentityRuntime({
      config: validConfig(),
      db: fakeDb(),
      rateLimitOverride: { max: 1000, window: 1 },
    });

    const [options] = betterAuthMock.mock.calls[0] as [Record<string, unknown>];
    expect(options.rateLimit).toEqual({
      customRules: {
        "/sign-in/email": { max: 1000, window: 1 },
        "/sign-up/email": { max: 1000, window: 1 },
      },
      enabled: true,
      max: 100,
      window: 10,
    });
  });

  it("sanitizes a construction failure without leaking the underlying error, secret, or URL", () => {
    const hostileSecret = validConfig().secret;
    betterAuthMock.mockImplementation(() => {
      throw new Error(
        `Better Auth failed for secret ${hostileSecret} at https://internal.example.test`,
      );
    });

    let captured: unknown;
    try {
      createIdentityRuntime({ config: validConfig(), db: fakeDb() });
    } catch (error) {
      captured = error;
    }

    expect(captured).toBeInstanceOf(IdentityRuntimeError);
    expect(captured).toMatchObject({ code: "IDENTITY_CONSTRUCTION_FAILED" });
    const publicText = `${String(captured)}\n${
      captured instanceof Error ? (captured.stack ?? "") : ""
    }`;
    expect(publicText).not.toContain(hostileSecret);
    expect(publicText).not.toContain("internal.example.test");
  });
});

describe("Core identity runtime — handleAuthRequest", () => {
  beforeEach(() => {
    betterAuthMock.mockReset();
    drizzleAdapterMock.mockClear();
  });

  it("delegates directly to Better Auth's Fetch handler and passes the response through unmodified", async () => {
    const expectedResponse = new Response("ok", { status: 200 });
    const handler = vi.fn().mockResolvedValue(expectedResponse);
    betterAuthMock.mockReturnValue({ api: { getSession: vi.fn() }, handler });

    const runtime = createIdentityRuntime({ config: validConfig(), db: fakeDb() });
    const request = new Request("https://identity.example.test/api/auth/sign-in/email");
    const response = await runtime.handleAuthRequest(request);

    expect(handler).toHaveBeenCalledWith(request);
    expect(response).toBe(expectedResponse);
  });

  it("passes through Better Auth's own error responses (e.g. 401, 403, 422) unmodified", async () => {
    const errorResponse = new Response(JSON.stringify({ code: "INVALID_EMAIL_OR_PASSWORD" }), {
      status: 401,
    });
    const handler = vi.fn().mockResolvedValue(errorResponse);
    betterAuthMock.mockReturnValue({ api: { getSession: vi.fn() }, handler });

    const runtime = createIdentityRuntime({ config: validConfig(), db: fakeDb() });
    const response = await runtime.handleAuthRequest(
      new Request("https://identity.example.test/x"),
    );

    expect(response.status).toBe(401);
  });

  it("sanitizes a genuinely unexpected handler failure", async () => {
    const handler = vi.fn().mockRejectedValue(new Error("postgresql://admin:secret@db.internal/x"));
    betterAuthMock.mockReturnValue({ api: { getSession: vi.fn() }, handler });

    const runtime = createIdentityRuntime({ config: validConfig(), db: fakeDb() });

    let captured: unknown;
    try {
      await runtime.handleAuthRequest(new Request("https://identity.example.test/x"));
    } catch (error) {
      captured = error;
    }

    expect(captured).toBeInstanceOf(IdentityRuntimeError);
    expect(captured).toMatchObject({ code: "AUTH_REQUEST_FAILED" });
    const publicText = `${String(captured)}\n${
      captured instanceof Error ? (captured.stack ?? "") : ""
    }`;
    expect(publicText).not.toContain("db.internal");
    expect(publicText).not.toContain("admin");
  });
});

describe("Core identity runtime — resolvePrincipal", () => {
  beforeEach(() => {
    betterAuthMock.mockReset();
    drizzleAdapterMock.mockClear();
  });

  it("maps a valid session to an authenticated principal containing only the opaque user id", async () => {
    const getSession = vi.fn().mockResolvedValue({
      session: { id: "sess_1", token: "tok" },
      user: { email: "person@example.test", id: "user_123", name: "Person" },
    });
    betterAuthMock.mockReturnValue({ api: { getSession }, handler: vi.fn() });

    const runtime = createIdentityRuntime({ config: validConfig(), db: fakeDb() });
    const principal = await runtime.resolvePrincipal(
      new Headers({ cookie: "better-auth.session_token=tok" }),
    );

    expect(principal).toEqual({ kind: "authenticated", userId: "user_123" });
    expect(Object.keys(principal)).toEqual(["kind", "userId"]);
    expect(Object.isFrozen(principal)).toBe(true);
  });

  it("maps a missing session with no cookie header to anonymous without probing the database", async () => {
    const getSession = vi.fn().mockResolvedValue(null);
    const execute = vi.fn().mockResolvedValue(undefined);
    betterAuthMock.mockReturnValue({ api: { getSession }, handler: vi.fn() });

    const runtime = createIdentityRuntime({ config: validConfig(), db: fakeDb({ execute }) });
    const principal = await runtime.resolvePrincipal(new Headers());

    expect(principal).toEqual({ kind: "anonymous" });
    expect(execute).not.toHaveBeenCalled();
  });

  it("maps an expired/revoked/malformed session (cookie present, null session) to anonymous when the database is reachable", async () => {
    const getSession = vi.fn().mockResolvedValue(null);
    const execute = vi.fn().mockResolvedValue(undefined);
    betterAuthMock.mockReturnValue({ api: { getSession }, handler: vi.fn() });

    const runtime = createIdentityRuntime({ config: validConfig(), db: fakeDb({ execute }) });
    const principal = await runtime.resolvePrincipal(
      new Headers({ cookie: "better-auth.session_token=stale-or-garbage" }),
    );

    expect(principal).toEqual({ kind: "anonymous" });
    expect(execute).toHaveBeenCalledTimes(1);
  });

  it("never downgrades an infrastructure failure to anonymous: throws when the database is unreachable", async () => {
    const getSession = vi.fn().mockResolvedValue(null);
    const execute = vi.fn().mockRejectedValue(new Error("connection terminated unexpectedly"));
    betterAuthMock.mockReturnValue({ api: { getSession }, handler: vi.fn() });

    const runtime = createIdentityRuntime({ config: validConfig(), db: fakeDb({ execute }) });

    let captured: unknown;
    try {
      await runtime.resolvePrincipal(new Headers({ cookie: "better-auth.session_token=x" }));
    } catch (error) {
      captured = error;
    }

    expect(captured).toBeInstanceOf(IdentityRuntimeError);
    expect(captured).toMatchObject({ code: "PRINCIPAL_RESOLUTION_FAILED" });
  });

  it("treats an unexpected throw from getSession itself as a sanitized infrastructure failure", async () => {
    const hostile = "password=hunter2 host=db.internal.example port=5432";
    const getSession = vi.fn().mockRejectedValue(new Error(hostile));
    betterAuthMock.mockReturnValue({ api: { getSession }, handler: vi.fn() });

    const runtime = createIdentityRuntime({ config: validConfig(), db: fakeDb() });

    let captured: unknown;
    try {
      await runtime.resolvePrincipal(new Headers({ cookie: "better-auth.session_token=x" }));
    } catch (error) {
      captured = error;
    }

    expect(captured).toBeInstanceOf(IdentityRuntimeError);
    expect(captured).toMatchObject({ code: "PRINCIPAL_RESOLUTION_FAILED" });
    const publicText = `${String(captured)}\n${
      captured instanceof Error ? (captured.stack ?? "") : ""
    }`;
    expect(publicText).not.toContain("hunter2");
    expect(publicText).not.toContain("db.internal.example");
  });
});