# Common imports used across patterns in this skill
import base64, hashlib, hmac, struct, time
import pyotp          # pyauth.github.io/pyotp

import pyotp

def make_totp_fixture(digits=6, interval=30):
    """Return a base32 secret and the matching pyotp.TOTP instance."""
    secret = pyotp.random_base32()     # 32-char base32 per pyotp docs
    totp = pyotp.TOTP(secret, digits=digits, interval=interval)
    return secret, totp

def test_totp_happy_path(client, db):
    secret, totp = make_totp_fixture()
    # Seed the user's MFA secret in the test fixture (not production DB)
    db.set_totp_secret(user_id="alice", secret=secret)

    fixed_time = 1_234_567_890        # deterministic: RFC 6238 Appendix B
    expected_code = totp.at(for_time=fixed_time)   # "89005924" for SHA-1

    response = client.post(
        "/auth/mfa/verify",
        json={"otp": expected_code},
        headers={"X-Test-Time": str(fixed_time)},  # server must accept clock injection
    )
    assert response.status_code == 200

def test_totp_wrong_code_rejected(client, db):
    secret, totp = make_totp_fixture()
    db.set_totp_secret(user_id="alice", secret=secret)

    wrong_code = "000000"
    response = client.post("/auth/mfa/verify", json={"otp": wrong_code})
    assert response.status_code in [400, 401]
    assert "invalid" in response.json().get("error", "").lower()

def test_totp_expired_step_rejected(client, db):
    """A code more than valid_window steps old must be rejected."""
    secret, totp = make_totp_fixture()
    db.set_totp_secret(user_id="alice", secret=secret)

    old_time = time.time() - 120      # 4 steps ago; outside the grace window
    stale_code = totp.at(for_time=old_time)
    response = client.post("/auth/mfa/verify", json={"otp": stale_code})
    assert response.status_code in [400, 401]

def test_hotp_sequential_codes(client, db):
    secret = pyotp.random_base32()
    hotp = pyotp.HOTP(secret)           # pyotp.HOTP(s, digits=6, initial_count=0)
    db.set_hotp_secret(user_id="bob", secret=secret, counter=0)

    # Each code is valid exactly once; server increments counter on success
    for counter in range(3):
        code = hotp.at(counter)
        response = client.post("/auth/mfa/verify", json={"otp": code})
        assert response.status_code == 200, f"counter {counter} rejected"

def test_hotp_replay_rejected(client, db):
    """Replaying a used counter code must be rejected (counter advanced)."""
    secret = pyotp.random_base32()
    hotp = pyotp.HOTP(secret)
    db.set_hotp_secret(user_id="bob", secret=secret, counter=0)

    code = hotp.at(0)
    client.post("/auth/mfa/verify", json={"otp": code})   # consume counter 0
    replay = client.post("/auth/mfa/verify", json={"otp": code})
    assert replay.status_code in [400, 401]

def test_hotp_look_ahead_resync(client, db):
    """Server must accept a code within the resync window (RFC 4226 §7.4)."""
    secret = pyotp.random_base32()
    hotp = pyotp.HOTP(secret)
    db.set_hotp_secret(user_id="bob", secret=secret, counter=0)
    # Client is 2 steps ahead (simulates missed increments)
    ahead_code = hotp.at(2)
    response = client.post("/auth/mfa/verify", json={"otp": ahead_code})
    assert response.status_code == 200

def test_sms_otp_happy_path(client, sms_stub):
    """sms_stub is a test double that captures outbound OTPs."""
    client.post("/auth/mfa/send-otp", json={"channel": "sms"})
    captured_otp = sms_stub.last_otp()          # read from the stub

    response = client.post("/auth/mfa/verify", json={"otp": captured_otp})
    assert response.status_code == 200

def test_sms_otp_single_use(client, sms_stub):
    client.post("/auth/mfa/send-otp", json={"channel": "sms"})
    captured_otp = sms_stub.last_otp()
    client.post("/auth/mfa/verify", json={"otp": captured_otp})   # consume
    replay = client.post("/auth/mfa/verify", json={"otp": captured_otp})
    assert replay.status_code in [400, 401]

def test_sms_otp_expired(client, sms_stub, freeze_clock):
    client.post("/auth/mfa/send-otp", json={"channel": "sms"})
    captured_otp = sms_stub.last_otp()
    freeze_clock.advance(seconds=600)           # advance past TTL
    response = client.post("/auth/mfa/verify", json={"otp": captured_otp})
    assert response.status_code in [400, 401]

# Playwright + CDP virtual authenticator pattern (Python)
import pytest
from playwright.sync_api import sync_playwright

@pytest.fixture
def virtual_auth_page():
    with sync_playwright() as p:
        browser = p.chromium.launch()          # CDP only on Chromium
        context = browser.new_context()
        page = context.new_page()

        cdp = context.new_cdp_session(page)
        cdp.send("WebAuthn.enable", {"enableUI": False})

        result = cdp.send("WebAuthn.addVirtualAuthenticator", {
            "options": {
                "protocol": "ctap2",
                "transport": "internal",
                "hasResidentKey": True,
                "hasUserVerification": True,
                "isUserVerified": True,
                "automaticPresenceSimulation": True,   # auto-approve gestures
            }
        })
        authenticator_id = result["authenticatorId"]

        yield page, cdp, authenticator_id

        cdp.send("WebAuthn.removeVirtualAuthenticator",
                 {"authenticatorId": authenticator_id})
        browser.close()


def test_webauthn_registration(virtual_auth_page, app_url):
    """Happy path: register a passkey with the virtual authenticator."""
    page, cdp, auth_id = virtual_auth_page
    page.goto(f"{app_url}/settings/passkeys")
    page.click("#register-passkey")
    page.wait_for_selector("#passkey-registered-confirmation")
    assert page.is_visible("#passkey-registered-confirmation")

    creds = cdp.send("WebAuthn.getCredentials", {"authenticatorId": auth_id})
    assert len(creds["credentials"]) == 1

def test_recovery_code_single_use(client, db):
    codes = db.generate_recovery_codes(user_id="alice", count=8)
    first_code = codes[0]

    r1 = client.post("/auth/mfa/verify", json={"recovery_code": first_code})
    assert r1.status_code == 200

    r2 = client.post("/auth/mfa/verify", json={"recovery_code": first_code})
    assert r2.status_code in [400, 401]     # consumed

def test_invalid_recovery_code_rejected(client, db):
    db.generate_recovery_codes(user_id="alice", count=8)
    r = client.post("/auth/mfa/verify", json={"recovery_code": "XXXX-XXXX"})
    assert r.status_code in [400, 401]

def test_totp_enrollment_requires_valid_session(client):
    # Unauthenticated request to the enroll endpoint must be rejected
    r = client.post("/auth/mfa/enroll/totp")
    assert r.status_code in [401, 403]

def test_totp_enrollment_verify_confirms_factor(client, db, authenticated_session):
    r = client.post("/auth/mfa/enroll/totp",
                    headers=authenticated_session.headers)
    assert r.status_code == 200
    provisioned_secret = r.json()["secret"]   # server-generated, base32

    totp = pyotp.TOTP(provisioned_secret)
    confirm_code = totp.now()

    r2 = client.post("/auth/mfa/enroll/totp/confirm",
                     json={"otp": confirm_code},
                     headers=authenticated_session.headers)
    assert r2.status_code == 200
    assert db.user_has_totp(user_id=authenticated_session.user_id)

def test_step_up_triggers_mfa_challenge(client, authenticated_session_no_mfa):
    """Accessing a privileged endpoint without MFA should return 403/step-up."""
    r = client.delete("/account/delete",
                      headers=authenticated_session_no_mfa.headers)
    assert r.status_code in [403, 401]
    data = r.json()
    assert data.get("mfa_required") is True

def test_step_up_grants_access_after_mfa(client, db, authenticated_session_no_mfa):
    """After completing MFA the privileged operation is permitted."""
    secret, totp = make_totp_fixture()
    db.set_totp_secret(user_id=authenticated_session_no_mfa.user_id,
                       secret=secret)

    fixed_time = 1_234_567_890
    code = totp.at(for_time=fixed_time)

    # Step-up: verify MFA
    step_up = client.post(
        "/auth/step-up",
        json={"otp": code},
        headers={**authenticated_session_no_mfa.headers,
                 "X-Test-Time": str(fixed_time)},
    )
    assert step_up.status_code == 200
    elevated_token = step_up.json()["elevated_token"]

    # Use elevated token on the privileged endpoint
    r = client.delete("/account/delete",
                      headers={"Authorization": f"Bearer {elevated_token}"})
    assert r.status_code == 200