"""Tests for B-2.5 — TOTP MFA + recovery codes.

Covers:
  - Encrypt/decrypt round-trip (Fernet derived from SECRET_KEY).
  - Decrypt rejects ciphertext from a different SECRET_KEY.
  - generate_totp_secret produces a valid base32 secret (RFC 6238).
  - verify_totp_code accepts current window, rejects wrong / non-digit codes.
  - generate_recovery_codes returns 10 display + 10 hashes that map 1:1.
  - consume_recovery_code is single-use; rejects unknown.
  - set_user_totp persists encrypted (not raw) secret + flips flag.
  - disable_user_totp clears all 3 fields.
  - Login route gates on totp_enabled; bypasses gate when disabled.
  - /2fa/verify accepts correct TOTP code, rejects wrong, accepts recovery.
  - /2fa/verify redirects to /login when no pending session.
  - /2fa/setup creates pending session on GET, persists on valid POST,
    keeps pending on invalid POST.
  - /2fa/disable requires correct password.

Note: pytest cannot collect this file on Windows native because src/init_db.py
imports `fcntl` (POSIX-only). Use tests/_run_totp_mfa_windows.py.
"""
import os
import sys

sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
os.environ.setdefault('SQLALCHEMY_DATABASE_URI', 'sqlite:///:memory:')
os.environ.setdefault('SECRET_KEY', 'test-secret-key-totp')
os.environ.setdefault('ENABLE_EMAIL_VERIFICATION', 'false')
os.environ.setdefault('REQUIRE_EMAIL_VERIFICATION', 'false')
os.environ.setdefault('RATELIMIT_ENABLED', 'false')

import pyotp  # noqa: E402

from src.app import app, db, bcrypt  # noqa: E402
from src.models.user import User  # noqa: E402
from src.auth import totp as totp_module  # noqa: E402


def _disable_csrf():
    app.config['WTF_CSRF_ENABLED'] = False


def _make_user(email='totp@example.qc.ca', password='Password!123', totp_enabled=False,
                username=None, totp_secret_encrypted=None, totp_recovery_codes=None):
    """Create a User row with bcrypt-hashed password. Returns the User."""
    hashed = bcrypt.generate_password_hash(password).decode('utf-8')
    u = User(
        username=username or email.split('@', 1)[0][:20],
        email=email,
        password=hashed,
        email_verified=True,
        totp_enabled=totp_enabled,
        totp_secret_encrypted=totp_secret_encrypted,
        totp_recovery_codes=totp_recovery_codes,
    )
    db.session.add(u)
    db.session.commit()
    return u


# ----------------------------------------------------------------------
# 1. Service layer — encryption round-trip
# ----------------------------------------------------------------------

def test_encrypt_decrypt_round_trips():
    """encrypt_totp_secret → decrypt_totp_secret returns the original base32."""
    with app.app_context():
        secret = pyotp.random_base32()
        ct = totp_module.encrypt_totp_secret(secret)
        assert ct != secret  # ciphertext is NOT the raw secret
        assert totp_module.decrypt_totp_secret(ct) == secret


def test_decrypt_with_different_secret_key_fails():
    """Fernet rejects a token encrypted with a different SECRET_KEY."""
    with app.app_context():
        secret = pyotp.random_base32()
        ct = totp_module.encrypt_totp_secret(secret)
    # Swap SECRET_KEY and confirm decryption fails
    original_key = app.config['SECRET_KEY']
    try:
        app.config['SECRET_KEY'] = 'totally-different-secret-key'
        with app.app_context():
            try:
                totp_module.decrypt_totp_secret(ct)
                raise AssertionError('Expected ValueError on key mismatch')
            except ValueError:
                pass
    finally:
        app.config['SECRET_KEY'] = original_key


def test_generate_totp_secret_is_valid_base32_160_bit():
    """generate_totp_secret returns a base32 string accepted by pyotp.TOTP."""
    secret = totp_module.generate_totp_secret()
    assert isinstance(secret, str)
    assert len(secret) >= 16  # pyotp default is 32 chars (160 bits)
    # If invalid, .now() would raise
    code = pyotp.TOTP(secret).now()
    assert len(code) == 6
    assert code.isdigit()


# ----------------------------------------------------------------------
# 2. Service layer — verify_totp_code
# ----------------------------------------------------------------------

def test_verify_totp_code_accepts_current_window():
    """A code generated by pyotp.TOTP(secret).now() is accepted."""
    with app.app_context():
        secret = totp_module.generate_totp_secret()
        code = pyotp.TOTP(secret).now()
        assert totp_module.verify_totp_code(secret, code) is True


def test_verify_totp_code_rejects_wrong_code():
    """The literal '000000' is (almost certainly) not the current code."""
    with app.app_context():
        secret = totp_module.generate_totp_secret()
        current = pyotp.TOTP(secret).now()
        wrong = '000000' if current != '000000' else '111111'
        assert totp_module.verify_totp_code(secret, wrong) is False


def test_verify_totp_code_rejects_non_digit():
    """Non-digit input is rejected before reaching pyotp."""
    secret = totp_module.generate_totp_secret()
    assert totp_module.verify_totp_code(secret, 'abcdef') is False
    assert totp_module.verify_totp_code(secret, '') is False
    assert totp_module.verify_totp_code(secret, '12345') is False  # too short
    assert totp_module.verify_totp_code(secret, '1234567') is False  # too long


# ----------------------------------------------------------------------
# 3. Service layer — recovery codes
# ----------------------------------------------------------------------

def test_generate_recovery_codes_returns_10_pairs():
    """generate_recovery_codes returns 10 displays + 10 hashes that map 1:1."""
    with app.app_context():
        display, hashed = totp_module.generate_recovery_codes()
        assert len(display) == 10
        assert len(hashed) == 10
        # Each display follows XXXXX-XXXXX
        for d in display:
            assert len(d) == 11
            assert d[5] == '-'
        # Each display matches its hash; mismatches don't match
        for d, h in zip(display, hashed):
            assert bcrypt.check_password_hash(h, d) is True
        # And a wrong code never matches
        assert bcrypt.check_password_hash(hashed[0], 'WRONG-CODE0') is False


def test_consume_recovery_code_succeeds_once():
    """Consuming a code twice: 2nd attempt fails; list shrinks by 1."""
    with app.app_context():
        db.create_all()
        try:
            user = _make_user(email='consume1@example.qc.ca')
            display, hashed = totp_module.generate_recovery_codes()
            user.totp_recovery_codes = hashed
            user.totp_enabled = True
            db.session.commit()

            assert len(user.totp_recovery_codes) == 10
            assert totp_module.consume_recovery_code(user, display[0]) is True
            assert len(user.totp_recovery_codes) == 9
            # Second attempt with the same code: rejected (single-use)
            assert totp_module.consume_recovery_code(user, display[0]) is False
            assert len(user.totp_recovery_codes) == 9
        finally:
            db.session.rollback()
            db.drop_all()


def test_consume_recovery_code_rejects_unknown():
    """Submitting a code that isn't in the list returns False; no DB write."""
    with app.app_context():
        db.create_all()
        try:
            user = _make_user(email='consume2@example.qc.ca')
            _, hashed = totp_module.generate_recovery_codes()
            user.totp_recovery_codes = hashed
            user.totp_enabled = True
            db.session.commit()

            assert totp_module.consume_recovery_code(user, 'NOPE1-NOPE2') is False
            assert len(user.totp_recovery_codes) == 10
        finally:
            db.session.rollback()
            db.drop_all()


# ----------------------------------------------------------------------
# 4. Service layer — set / disable user TOTP
# ----------------------------------------------------------------------

def test_set_user_totp_persists_encrypted_not_raw():
    """set_user_totp encrypts secret, stores hashes, flips totp_enabled True."""
    with app.app_context():
        db.create_all()
        try:
            user = _make_user(email='setuser@example.qc.ca')
            secret = totp_module.generate_totp_secret()
            display, hashed = totp_module.generate_recovery_codes()
            totp_module.set_user_totp(user, secret, hashed)

            db.session.refresh(user)
            assert user.totp_enabled is True
            assert user.totp_secret_encrypted is not None
            assert user.totp_secret_encrypted != secret  # encrypted, not raw
            assert totp_module.decrypt_totp_secret(user.totp_secret_encrypted) == secret
            assert len(user.totp_recovery_codes) == 10
        finally:
            db.session.rollback()
            db.drop_all()


def test_disable_user_totp_clears_all_fields():
    """disable_user_totp nullifies the 3 TOTP-related fields."""
    with app.app_context():
        db.create_all()
        try:
            user = _make_user(email='disable@example.qc.ca')
            secret = totp_module.generate_totp_secret()
            _, hashed = totp_module.generate_recovery_codes()
            totp_module.set_user_totp(user, secret, hashed)
            assert user.totp_enabled is True

            totp_module.disable_user_totp(user)
            db.session.refresh(user)
            assert user.totp_enabled is False
            assert user.totp_secret_encrypted is None
            assert user.totp_recovery_codes is None
        finally:
            db.session.rollback()
            db.drop_all()


# ----------------------------------------------------------------------
# 5. Login route — TOTP gate
# ----------------------------------------------------------------------

def test_login_redirects_to_totp_verify_when_mfa_enabled():
    """Password OK + totp_enabled → 302 to /2fa/verify; pending_totp_user_id set."""
    with app.app_context():
        _disable_csrf()
        db.create_all()
        try:
            password = 'CorrectHorseBattery!42'
            secret = totp_module.generate_totp_secret()
            user = _make_user(
                email='gate@example.qc.ca', password=password,
                totp_enabled=True,
                totp_secret_encrypted=totp_module.encrypt_totp_secret(secret),
                totp_recovery_codes=[],
            )
            with app.test_client() as client:
                resp = client.post('/login', data={
                    'email': 'gate@example.qc.ca',
                    'password': password,
                    'remember': 'y',
                })
                assert resp.status_code == 302
                assert '/2fa/verify' in resp.headers['Location']
                with client.session_transaction() as sess:
                    assert sess.get('pending_totp_user_id') == user.id
                    assert sess.get('pending_totp_remember') is True
                    # NOT yet logged in
                    assert '_user_id' not in sess
        finally:
            db.session.rollback()
            db.drop_all()


def test_login_logs_in_directly_when_mfa_disabled():
    """Password OK + totp_enabled=False → 302 to /; no pending_totp_user_id."""
    with app.app_context():
        _disable_csrf()
        db.create_all()
        try:
            password = 'CorrectHorseBattery!42'
            user = _make_user(
                email='nomfa@example.qc.ca', password=password, totp_enabled=False,
            )
            with app.test_client() as client:
                resp = client.post('/login', data={
                    'email': 'nomfa@example.qc.ca',
                    'password': password,
                })
                assert resp.status_code == 302
                # Logged in directly
                with client.session_transaction() as sess:
                    assert 'pending_totp_user_id' not in sess
                    assert sess.get('_user_id') == str(user.id)
        finally:
            db.session.rollback()
            db.drop_all()


# ----------------------------------------------------------------------
# 6. /2fa/verify — second factor route
# ----------------------------------------------------------------------

def test_totp_verify_login_logs_in_with_correct_code():
    """POST /2fa/verify with correct TOTP code logs the user in."""
    with app.app_context():
        _disable_csrf()
        db.create_all()
        try:
            secret = totp_module.generate_totp_secret()
            user = _make_user(
                email='verifyok@example.qc.ca',
                totp_enabled=True,
                totp_secret_encrypted=totp_module.encrypt_totp_secret(secret),
                totp_recovery_codes=[],
            )
            code = pyotp.TOTP(secret).now()
            with app.test_client() as client:
                with client.session_transaction() as sess:
                    sess['pending_totp_user_id'] = user.id
                    sess['pending_totp_remember'] = False
                resp = client.post('/2fa/verify', data={'code': code})
                assert resp.status_code == 302
                # Cleared pending + logged in
                with client.session_transaction() as sess:
                    assert 'pending_totp_user_id' not in sess
                    assert 'pending_totp_remember' not in sess
                    assert sess.get('_user_id') == str(user.id)
        finally:
            db.session.rollback()
            db.drop_all()


def test_totp_verify_login_rejects_wrong_code():
    """POST /2fa/verify with '000000' → 400; not logged in."""
    with app.app_context():
        _disable_csrf()
        db.create_all()
        try:
            secret = totp_module.generate_totp_secret()
            user = _make_user(
                email='verifybad@example.qc.ca',
                totp_enabled=True,
                totp_secret_encrypted=totp_module.encrypt_totp_secret(secret),
                totp_recovery_codes=[],
            )
            current = pyotp.TOTP(secret).now()
            wrong = '000000' if current != '000000' else '111111'
            with app.test_client() as client:
                with client.session_transaction() as sess:
                    sess['pending_totp_user_id'] = user.id
                resp = client.post('/2fa/verify', data={'code': wrong})
                assert resp.status_code == 400
                with client.session_transaction() as sess:
                    assert '_user_id' not in sess
                    # Pending session preserved so user can retry
                    assert sess.get('pending_totp_user_id') == user.id
        finally:
            db.session.rollback()
            db.drop_all()


def test_totp_verify_login_accepts_recovery_code():
    """POST /2fa/verify with a recovery code logs in + consumes the code."""
    with app.app_context():
        _disable_csrf()
        db.create_all()
        try:
            secret = totp_module.generate_totp_secret()
            display, hashed = totp_module.generate_recovery_codes()
            user = _make_user(
                email='recovery@example.qc.ca',
                totp_enabled=True,
                totp_secret_encrypted=totp_module.encrypt_totp_secret(secret),
                totp_recovery_codes=hashed,
            )
            with app.test_client() as client:
                with client.session_transaction() as sess:
                    sess['pending_totp_user_id'] = user.id
                resp = client.post('/2fa/verify', data={'recovery_code': display[0]})
                assert resp.status_code == 302
                with client.session_transaction() as sess:
                    assert sess.get('_user_id') == str(user.id)
                # Recovery code consumed
                db.session.refresh(user)
                assert len(user.totp_recovery_codes) == 9
        finally:
            db.session.rollback()
            db.drop_all()


def test_totp_verify_login_redirects_to_login_without_pending_session():
    """GET /2fa/verify with no pending session → 302 to /login."""
    with app.app_context():
        _disable_csrf()
        db.create_all()
        try:
            with app.test_client() as client:
                resp = client.get('/2fa/verify')
                assert resp.status_code == 302
                assert '/login' in resp.headers['Location']
        finally:
            db.session.rollback()
            db.drop_all()


# ----------------------------------------------------------------------
# 7. /2fa/setup — enrollment route
# ----------------------------------------------------------------------

def test_totp_setup_get_creates_pending_session():
    """GET /2fa/setup as logged-in user shows QR and primes session."""
    with app.app_context():
        _disable_csrf()
        db.create_all()
        try:
            user = _make_user(email='setupget@example.qc.ca')
            with app.test_client() as client:
                with client.session_transaction() as sess:
                    sess['_user_id'] = str(user.id)
                    sess['_fresh'] = True
                resp = client.get('/2fa/setup')
                assert resp.status_code == 200
                body = resp.data.decode('utf-8')
                assert 'data:image/png;base64,' in body
                with client.session_transaction() as sess:
                    assert sess.get('totp_pending_secret') is not None
                    assert len(sess.get('totp_pending_recovery_hashes')) == 10
                    assert len(sess.get('totp_pending_display_codes')) == 10
        finally:
            db.session.rollback()
            db.drop_all()


def test_totp_setup_post_with_valid_code_enables_mfa():
    """POST with a code matching the pending secret enables MFA + clears session."""
    with app.app_context():
        _disable_csrf()
        db.create_all()
        try:
            user = _make_user(email='setupok@example.qc.ca')
            secret = totp_module.generate_totp_secret()
            display, hashed = totp_module.generate_recovery_codes()
            with app.test_client() as client:
                with client.session_transaction() as sess:
                    sess['_user_id'] = str(user.id)
                    sess['_fresh'] = True
                    sess['totp_pending_secret'] = secret
                    sess['totp_pending_recovery_hashes'] = hashed
                    sess['totp_pending_display_codes'] = display
                code = pyotp.TOTP(secret).now()
                resp = client.post('/2fa/setup', data={'code': code})
                assert resp.status_code == 302
                # User enrolled
                db.session.refresh(user)
                assert user.totp_enabled is True
                assert user.totp_secret_encrypted is not None
                assert totp_module.decrypt_totp_secret(user.totp_secret_encrypted) == secret
                # Pending session cleared
                with client.session_transaction() as sess:
                    assert 'totp_pending_secret' not in sess
                    assert 'totp_pending_recovery_hashes' not in sess
                    assert 'totp_pending_display_codes' not in sess
        finally:
            db.session.rollback()
            db.drop_all()


def test_totp_setup_post_with_invalid_code_returns_400_keeps_pending():
    """POST with wrong code → 400; user not yet enabled; pending preserved."""
    with app.app_context():
        _disable_csrf()
        db.create_all()
        try:
            user = _make_user(email='setupbad@example.qc.ca')
            secret = totp_module.generate_totp_secret()
            display, hashed = totp_module.generate_recovery_codes()
            with app.test_client() as client:
                with client.session_transaction() as sess:
                    sess['_user_id'] = str(user.id)
                    sess['_fresh'] = True
                    sess['totp_pending_secret'] = secret
                    sess['totp_pending_recovery_hashes'] = hashed
                    sess['totp_pending_display_codes'] = display
                current = pyotp.TOTP(secret).now()
                wrong = '000000' if current != '000000' else '111111'
                resp = client.post('/2fa/setup', data={'code': wrong})
                assert resp.status_code == 400
                db.session.refresh(user)
                assert user.totp_enabled is False
                assert user.totp_secret_encrypted is None
                # Pending session preserved so user can retry without scanning a new QR
                with client.session_transaction() as sess:
                    assert sess.get('totp_pending_secret') == secret
        finally:
            db.session.rollback()
            db.drop_all()


# ----------------------------------------------------------------------
# 8. /2fa/disable — password re-auth required
# ----------------------------------------------------------------------

def test_totp_disable_requires_password():
    """Wrong password → flash + still enabled. Correct password → disabled."""
    with app.app_context():
        _disable_csrf()
        db.create_all()
        try:
            password = 'CorrectHorseBattery!42'
            secret = totp_module.generate_totp_secret()
            _, hashed = totp_module.generate_recovery_codes()
            user = _make_user(
                email='disable@example.qc.ca', password=password,
                totp_enabled=True,
                totp_secret_encrypted=totp_module.encrypt_totp_secret(secret),
                totp_recovery_codes=hashed,
            )
            with app.test_client() as client:
                with client.session_transaction() as sess:
                    sess['_user_id'] = str(user.id)
                    sess['_fresh'] = True

                # Wrong password → still enabled
                resp = client.post('/2fa/disable', data={'password': 'wrong-password'})
                assert resp.status_code == 302  # redirect to /account
                db.session.refresh(user)
                assert user.totp_enabled is True
                assert user.totp_secret_encrypted is not None

                # Correct password → disabled
                resp = client.post('/2fa/disable', data={'password': password})
                assert resp.status_code == 302
                db.session.refresh(user)
                assert user.totp_enabled is False
                assert user.totp_secret_encrypted is None
                assert user.totp_recovery_codes is None
        finally:
            db.session.rollback()
            db.drop_all()