"""
Extended tests for session security - Comprehensive session management coverage.

Tests cover:
- Session ID generation and uniqueness
- Session expiry enforcement
- Session tokens and refresh
- Session binding (IP, user agent)
- Hijack detection and replay prevention
- Cookie security settings
- Session storage and cleanup
"""

import secrets
import time


class TestSessionIdGeneration:
    """Tests for session ID generation."""

    def test_session_id_is_cryptographically_secure(self):
        """Session IDs should use cryptographically secure random."""
        session_id = secrets.token_hex(32)
        assert len(session_id) == 64
        assert isinstance(session_id, str)

    def test_session_id_format(self):
        """Session ID should be hex string."""
        session_id = secrets.token_hex(32)
        # All characters should be valid hex
        assert all(c in "0123456789abcdef" for c in session_id)

    def test_session_id_length_sufficient(self):
        """Session ID should be at least 128 bits (32 hex chars)."""
        session_id = secrets.token_hex(16)  # 16 bytes = 128 bits
        assert len(session_id) >= 32


class TestSessionIdUniqueness:
    """Tests for session ID uniqueness."""

    def test_generated_ids_are_unique(self):
        """Generated session IDs should be unique."""
        ids = set()
        for _ in range(10000):
            session_id = secrets.token_hex(32)
            assert session_id not in ids
            ids.add(session_id)

    def test_no_collision_in_large_set(self):
        """Should not have collisions in large sets."""
        ids = [secrets.token_hex(32) for _ in range(10000)]
        assert len(ids) == len(set(ids))


class TestSessionExpiryEnforcement:
    """Tests for session expiry enforcement."""

    def test_session_expires_after_ttl(self):
        """Session should expire after TTL."""
        session = {
            "id": "test_session",
            "created_at": time.time() - 3700,  # Created 1hr 1min ago
            "ttl": 3600,  # 1 hour
        }

        def is_expired(session):
            return time.time() - session["created_at"] > session["ttl"]

        assert is_expired(session) is True

    def test_session_valid_before_expiry(self):
        """Session should be valid before TTL."""
        session = {
            "id": "test_session",
            "created_at": time.time() - 1800,  # Created 30min ago
            "ttl": 3600,  # 1 hour
        }

        def is_expired(session):
            return time.time() - session["created_at"] > session["ttl"]

        assert is_expired(session) is False

    def test_session_expiry_at_boundary(self):
        """Session should expire exactly at TTL boundary."""
        now = time.time()
        session = {
            "id": "test_session",
            "created_at": now - 3600,  # Exactly at TTL
            "ttl": 3600,
        }

        def is_expired(session, current_time):
            return current_time - session["created_at"] >= session["ttl"]

        assert is_expired(session, now) is True


class TestSessionRefreshToken:
    """Tests for session refresh token handling."""

    def test_refresh_token_generation(self):
        """Refresh token should be generated securely."""
        refresh_token = secrets.token_urlsafe(32)
        assert len(refresh_token) >= 32

    def test_refresh_token_rotation(self):
        """Refresh token should be rotated on use."""
        session = {
            "refresh_token": secrets.token_urlsafe(32),
        }

        old_token = session["refresh_token"]

        # Rotate token
        session["refresh_token"] = secrets.token_urlsafe(32)

        assert session["refresh_token"] != old_token

    def test_refresh_extends_session(self):
        """Refresh should extend session expiry."""
        session = {
            "expires_at": time.time() + 100,  # 100 seconds left
            "ttl": 3600,
        }

        def refresh_session(session):
            session["expires_at"] = time.time() + session["ttl"]

        old_expiry = session["expires_at"]
        refresh_session(session)

        assert session["expires_at"] > old_expiry


class TestSlidingExpiry:
    """Tests for sliding session expiry."""

    def test_sliding_expiry_extends_on_activity(self):
        """Session expiry should extend on activity."""
        session = {
            "last_activity": time.time() - 600,  # 10 min ago
            "sliding_window": 1800,  # 30 min
        }

        def update_activity(session):
            session["last_activity"] = time.time()

        update_activity(session)

        # Should not be expired now
        def is_expired(session):
            return (
                time.time() - session["last_activity"]
                > session["sliding_window"]
            )

        assert is_expired(session) is False


class TestAbsoluteExpiry:
    """Tests for absolute session expiry."""

    def test_absolute_expiry_not_extendable(self):
        """Absolute expiry should not be extended."""
        session = {
            "absolute_expiry": time.time() - 1,  # Already expired
            "sliding_expiry": time.time() + 3600,  # Still valid sliding
        }

        def is_absolutely_expired(session):
            return time.time() > session["absolute_expiry"]

        assert is_absolutely_expired(session) is True


class TestSessionInvalidationCascade:
    """Tests for session invalidation cascade."""

    def test_invalidation_clears_related_sessions(self):
        """Invalidating one session should clear related sessions."""
        user_sessions = {
            "user1": ["session1", "session2", "session3"],
        }

        def invalidate_all_sessions(user_id):
            user_sessions[user_id] = []

        invalidate_all_sessions("user1")

        assert len(user_sessions["user1"]) == 0

    def test_single_session_invalidation(self):
        """Should be able to invalidate single session."""
        user_sessions = {
            "user1": ["session1", "session2", "session3"],
        }

        def invalidate_session(user_id, session_id):
            if session_id in user_sessions[user_id]:
                user_sessions[user_id].remove(session_id)

        invalidate_session("user1", "session2")

        assert "session2" not in user_sessions["user1"]
        assert len(user_sessions["user1"]) == 2


class TestConcurrentSessionLimit:
    """Tests for concurrent session limits."""

    def test_concurrent_session_limit_enforced(self):
        """Should enforce maximum concurrent sessions."""
        max_sessions = 3
        user_sessions = {
            "user1": ["s1", "s2", "s3"],
        }

        def can_create_session(user_id):
            return len(user_sessions.get(user_id, [])) < max_sessions

        assert can_create_session("user1") is False
        assert can_create_session("user2") is True

    def test_oldest_session_evicted(self):
        """Oldest session should be evicted when limit reached."""
        max_sessions = 3
        sessions = [
            {"id": "s1", "created": 1},
            {"id": "s2", "created": 2},
            {"id": "s3", "created": 3},
        ]

        def add_session_with_eviction(new_session):
            if len(sessions) >= max_sessions:
                # Remove oldest
                sessions.sort(key=lambda s: s["created"])
                sessions.pop(0)
            sessions.append(new_session)

        add_session_with_eviction({"id": "s4", "created": 4})

        assert len(sessions) == 3
        assert "s1" not in [s["id"] for s in sessions]


class TestSessionDeviceTracking:
    """Tests for session device tracking."""

    def test_device_fingerprint_stored(self):
        """Device fingerprint should be stored with session."""
        session = {
            "id": "session1",
            "device": {
                "user_agent": "Mozilla/5.0...",
                "screen_resolution": "1920x1080",
                "timezone": "America/New_York",
            },
        }

        assert "device" in session
        assert "user_agent" in session["device"]

    def test_device_change_detection(self):
        """Should detect device changes."""
        original_device = {
            "user_agent": "Chrome/100",
        }
        new_device = {
            "user_agent": "Firefox/100",
        }

        def device_changed(original, new):
            return original.get("user_agent") != new.get("user_agent")

        assert device_changed(original_device, new_device) is True


class TestSessionIPBinding:
    """Tests for session IP binding."""

    def test_ip_bound_to_session(self):
        """IP address should be bound to session."""
        session = {
            "id": "session1",
            "ip_address": "192.168.1.100",
        }

        def validate_ip(session, request_ip):
            return session["ip_address"] == request_ip

        assert validate_ip(session, "192.168.1.100") is True
        assert validate_ip(session, "10.0.0.1") is False

    def test_ip_binding_optional(self):
        """IP binding should be configurable."""
        config = {"strict_ip_binding": False}
        session = {"id": "session1", "ip_address": "192.168.1.100"}

        def validate_ip(session, request_ip, config):
            if not config.get("strict_ip_binding", True):
                return True
            return session["ip_address"] == request_ip

        assert validate_ip(session, "10.0.0.1", config) is True


class TestUserAgentCheck:
    """Tests for user agent validation."""

    def test_user_agent_bound_to_session(self):
        """User agent should be bound to session."""
        session = {
            "id": "session1",
            "user_agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64)",
        }

        def validate_user_agent(session, request_ua):
            return session["user_agent"] == request_ua

        assert (
            validate_user_agent(
                session, "Mozilla/5.0 (Windows NT 10.0; Win64; x64)"
            )
            is True
        )

    def test_user_agent_mismatch_detection(self):
        """Should detect user agent mismatch."""
        session = {
            "user_agent": "Chrome/100",
        }

        def user_agent_changed(session, new_ua):
            return session["user_agent"] != new_ua

        assert user_agent_changed(session, "Firefox/100") is True


class TestSessionHijackDetection:
    """Tests for session hijack detection."""

    def test_hijack_detected_on_ip_change(self):
        """Session hijack should be detected on IP change."""
        session = {"ip_address": "192.168.1.100", "user_agent": "Chrome/100"}
        request = {"ip_address": "10.0.0.1", "user_agent": "Chrome/100"}

        def detect_hijack(session, request):
            return session["ip_address"] != request["ip_address"]

        assert detect_hijack(session, request) is True

    def test_hijack_detected_on_multiple_factors(self):
        """Hijack detection should consider multiple factors."""
        session = {"ip_address": "192.168.1.100", "user_agent": "Chrome/100"}
        request = {"ip_address": "10.0.0.1", "user_agent": "Firefox/100"}

        def calculate_risk_score(session, request):
            score = 0
            if session["ip_address"] != request["ip_address"]:
                score += 50
            if session["user_agent"] != request["user_agent"]:
                score += 30
            return score

        assert calculate_risk_score(session, request) == 80


class TestSessionReplayPrevention:
    """Tests for session replay attack prevention."""

    def test_nonce_prevents_replay(self):
        """Nonce should prevent session replay."""
        used_nonces = set()

        def validate_nonce(nonce):
            if nonce in used_nonces:
                return False  # Replay detected
            used_nonces.add(nonce)
            return True

        assert validate_nonce("nonce1") is True
        assert validate_nonce("nonce1") is False  # Replay

    def test_timestamp_validation(self):
        """Request timestamp should be within acceptable window."""
        window = 300  # 5 minutes

        def validate_timestamp(request_time, server_time):
            return abs(server_time - request_time) <= window

        now = time.time()
        assert validate_timestamp(now, now) is True
        assert validate_timestamp(now - 400, now) is False


class TestCookieSecureFlag:
    """Tests for cookie Secure flag."""

    def test_secure_flag_set(self):
        """Secure flag should be set for session cookies."""
        cookie = {"name": "session", "value": "abc123", "secure": True}

        assert cookie["secure"] is True

    def test_secure_flag_required_in_production(self):
        """Secure flag should be required in production."""
        environment = "production"
        secure_required = environment == "production"

        assert secure_required is True


class TestCookieHttpOnlyFlag:
    """Tests for cookie HttpOnly flag."""

    def test_httponly_flag_set(self):
        """HttpOnly flag should be set for session cookies."""
        cookie = {"name": "session", "value": "abc123", "httponly": True}

        assert cookie["httponly"] is True

    def test_httponly_prevents_js_access(self):
        """HttpOnly prevents JavaScript access to cookie."""
        # This is a behavioral test - HttpOnly is enforced by browser
        cookie = {"httponly": True}
        assert cookie["httponly"] is True


class TestCookieSameSiteAttribute:
    """Tests for cookie SameSite attribute."""

    def test_samesite_strict(self):
        """SameSite should be Strict for sensitive cookies."""
        cookie = {"name": "session", "samesite": "Strict"}

        assert cookie["samesite"] in ["Strict", "Lax", "None"]

    def test_samesite_lax_default(self):
        """SameSite Lax is a reasonable default."""
        cookie = {"name": "session", "samesite": "Lax"}

        assert cookie["samesite"] == "Lax"


class TestSessionDatabaseCleanup:
    """Tests for session database cleanup."""

    def test_expired_sessions_cleaned_up(self):
        """Expired sessions should be cleaned up."""
        sessions = {
            "s1": {"expires": time.time() - 100},  # Expired
            "s2": {"expires": time.time() + 100},  # Valid
            "s3": {"expires": time.time() - 50},  # Expired
        }

        def cleanup_expired():
            now = time.time()
            expired = [k for k, v in sessions.items() if v["expires"] < now]
            for k in expired:
                del sessions[k]

        cleanup_expired()

        assert "s1" not in sessions
        assert "s2" in sessions
        assert "s3" not in sessions

    def test_cleanup_runs_periodically(self):
        """Cleanup should run periodically."""
        cleanup_interval = 300  # 5 minutes
        last_cleanup = time.time() - 400  # 6+ minutes ago

        def should_run_cleanup(last_cleanup, interval):
            return time.time() - last_cleanup > interval

        assert should_run_cleanup(last_cleanup, cleanup_interval) is True


class TestSessionRedisStorage:
    """Tests for Redis session storage."""

    def test_session_stored_in_redis(self):
        """Sessions should be storable in Redis."""
        redis_mock = {}

        def store_session(session_id, data, ttl):
            redis_mock[session_id] = {"data": data, "ttl": ttl}

        def get_session(session_id):
            return redis_mock.get(session_id, {}).get("data")

        store_session("session1", {"user_id": "user1"}, 3600)

        assert get_session("session1") == {"user_id": "user1"}

    def test_session_ttl_in_redis(self):
        """Session TTL should be set in Redis."""
        redis_mock = {}

        def store_with_ttl(key, data, ttl):
            redis_mock[key] = {"data": data, "ttl": ttl, "created": time.time()}

        store_with_ttl("session1", {"user": "test"}, 3600)

        assert redis_mock["session1"]["ttl"] == 3600


class TestSessionEncryption:
    """Tests for session data encryption."""

    def test_session_data_encrypted(self):
        """Session data should be encrypted at rest."""
        import base64

        session_data = {"user_id": "user1", "role": "admin"}

        def encrypt_session(data, key="secret"):
            # Simple encoding for test (real impl uses proper encryption)
            return base64.b64encode(str(data).encode()).decode()

        encrypted = encrypt_session(session_data)

        # Should not contain plaintext
        assert "user1" not in encrypted

    def test_session_data_decryptable(self):
        """Encrypted session data should be decryptable."""
        import base64

        original = {"user_id": "user1"}

        def encrypt(data):
            return base64.b64encode(str(data).encode()).decode()

        def decrypt(encrypted):
            return base64.b64decode(encrypted.encode()).decode()

        encrypted = encrypt(original)
        decrypted = decrypt(encrypted)

        assert "user1" in decrypted


class TestSessionRevocationList:
    """Tests for session revocation list."""

    def test_revoked_session_rejected(self):
        """Revoked sessions should be rejected."""
        revocation_list = {"session1", "session3"}

        def is_revoked(session_id):
            return session_id in revocation_list

        assert is_revoked("session1") is True
        assert is_revoked("session2") is False

    def test_revocation_list_cleanup(self):
        """Old entries should be cleaned from revocation list."""
        revocations = {
            "s1": {"revoked_at": time.time() - 86500},  # Old (>24h)
            "s2": {"revoked_at": time.time() - 100},  # Recent
        }

        def cleanup_old_revocations(max_age=86400):
            now = time.time()
            old = [
                k
                for k, v in revocations.items()
                if now - v["revoked_at"] > max_age
            ]
            for k in old:
                del revocations[k]

        cleanup_old_revocations()

        assert "s1" not in revocations
        assert "s2" in revocations
