"""
Tests for authentication module (starpunk/auth.py)
"""

import hashlib
import secrets
from datetime import datetime, timedelta
from unittest.mock import MagicMock, patch

import httpx
import pytest
from flask import g

from starpunk.auth import (
    AuthError,
    IndieLoginError,
    InvalidStateError,
    UnauthorizedError,
    _cleanup_expired_sessions,
    _generate_state_token,
    _hash_token,
    _verify_state_token,
    create_session,
    destroy_session,
    handle_callback,
    initiate_login,
    require_auth,
    verify_session,
)


@pytest.fixture
def app(tmp_path):
    """Create Flask app for testing"""
    from starpunk import create_app

    # Create test-specific data directory
    test_data_dir = tmp_path / "data"
    test_data_dir.mkdir(parents=True, exist_ok=True)

    app = create_app(
        {
            "TESTING": True,
            "SITE_URL": "http://localhost:5000",
            "ADMIN_ME": "https://example.com",
            "SESSION_SECRET": secrets.token_hex(32),
            "SESSION_LIFETIME": 30,
            "INDIELOGIN_URL": "https://indielogin.com",
            "DATA_PATH": test_data_dir,
            "NOTES_PATH": test_data_dir / "notes",
            "DATABASE_PATH": test_data_dir / "starpunk.db",
        }
    )
    return app


@pytest.fixture
def db(app):
    """Get database connection"""
    from starpunk.database import get_db

    with app.app_context():
        yield get_db(app)


@pytest.fixture
def client(app):
    """Get Flask test client"""
    return app.test_client()


# Test helper functions
class TestHelpers:
    def test_hash_token(self):
        """Test token hashing"""
        token = "test-token-123"
        expected = hashlib.sha256(token.encode()).hexdigest()
        assert _hash_token(token) == expected

    def test_hash_token_consistent(self):
        """Test that hashing is consistent"""
        token = "test-token"
        hash1 = _hash_token(token)
        hash2 = _hash_token(token)
        assert hash1 == hash2

    def test_hash_token_different_inputs(self):
        """Test that different tokens produce different hashes"""
        token1 = "token1"
        token2 = "token2"
        assert _hash_token(token1) != _hash_token(token2)

    def test_generate_state_token(self):
        """Test state token generation"""
        token = _generate_state_token()
        assert isinstance(token, str)
        assert len(token) > 0

    def test_generate_state_token_unique(self):
        """Test that generated tokens are unique"""
        tokens = [_generate_state_token() for _ in range(10)]
        assert len(set(tokens)) == 10


class TestStateTokenVerification:
    def test_verify_valid_state_token(self, app, db):
        """Test verifying a valid state token"""
        with app.app_context():
            state = secrets.token_urlsafe(32)
            expires_at = datetime.utcnow() + timedelta(minutes=5)

            db.execute(
                "INSERT INTO auth_state (state, expires_at) VALUES (?, ?)",
                (state, expires_at),
            )
            db.commit()

            assert _verify_state_token(state) is True

            # Token should be deleted after verification
            result = db.execute(
                "SELECT 1 FROM auth_state WHERE state = ?", (state,)
            ).fetchone()
            assert result is None

    def test_verify_invalid_state_token(self, app):
        """Test verifying an invalid state token"""
        with app.app_context():
            assert _verify_state_token("invalid-token") is False

    def test_verify_expired_state_token(self, app, db):
        """Test verifying an expired state token"""
        with app.app_context():
            state = secrets.token_urlsafe(32)
            expires_at = datetime.utcnow() - timedelta(minutes=5)

            db.execute(
                "INSERT INTO auth_state (state, expires_at) VALUES (?, ?)",
                (state, expires_at),
            )
            db.commit()

            assert _verify_state_token(state) is False


class TestCleanup:
    def test_cleanup_expired_sessions(self, app, db):
        """Test cleanup of expired sessions"""
        with app.app_context():
            # Create expired session
            token_hash = _hash_token("expired-token")
            expires_at = datetime.utcnow() - timedelta(days=1)

            db.execute(
                """
                INSERT INTO sessions (session_token_hash, me, expires_at)
                VALUES (?, ?, ?)
            """,
                (token_hash, "https://example.com", expires_at),
            )
            db.commit()

            _cleanup_expired_sessions()

            # Expired session should be deleted
            result = db.execute(
                "SELECT 1 FROM sessions WHERE session_token_hash = ?", (token_hash,)
            ).fetchone()
            assert result is None

    def test_cleanup_expired_auth_state(self, app, db):
        """Test cleanup of expired auth state"""
        with app.app_context():
            state = secrets.token_urlsafe(32)
            expires_at = datetime.utcnow() - timedelta(minutes=10)

            db.execute(
                "INSERT INTO auth_state (state, expires_at) VALUES (?, ?)",
                (state, expires_at),
            )
            db.commit()

            _cleanup_expired_sessions()

            # Expired state should be deleted
            result = db.execute(
                "SELECT 1 FROM auth_state WHERE state = ?", (state,)
            ).fetchone()
            assert result is None

    def test_cleanup_keeps_valid_sessions(self, app, db):
        """Test that cleanup keeps valid sessions"""
        with app.app_context():
            token_hash = _hash_token("valid-token")
            expires_at = datetime.utcnow() + timedelta(days=30)

            db.execute(
                """
                INSERT INTO sessions (session_token_hash, me, expires_at)
                VALUES (?, ?, ?)
            """,
                (token_hash, "https://example.com", expires_at),
            )
            db.commit()

            _cleanup_expired_sessions()

            # Valid session should still exist
            result = db.execute(
                "SELECT 1 FROM sessions WHERE session_token_hash = ?", (token_hash,)
            ).fetchone()
            assert result is not None


class TestInitiateLogin:
    def test_initiate_login_success(self, app, db):
        """Test successful login initiation"""
        with app.app_context():
            me_url = "https://example.com"
            auth_url = initiate_login(me_url)

            assert "indielogin.com/auth" in auth_url
            assert "me=https%3A%2F%2Fexample.com" in auth_url
            assert "client_id=" in auth_url
            assert "redirect_uri=" in auth_url
            assert "state=" in auth_url
            assert "response_type=code" in auth_url

            # State should be stored in database
            result = db.execute("SELECT COUNT(*) as count FROM auth_state").fetchone()
            assert result["count"] > 0

    def test_initiate_login_invalid_url(self, app):
        """Test login initiation with invalid URL"""
        with app.app_context():
            with pytest.raises(ValueError, match="Invalid URL format"):
                initiate_login("not-a-url")

    def test_initiate_login_stores_state(self, app, db):
        """Test that state token is stored"""
        with app.app_context():
            me_url = "https://example.com"
            auth_url = initiate_login(me_url)

            # Extract state from URL
            state_param = [p for p in auth_url.split("&") if p.startswith("state=")][0]
            state = state_param.split("=")[1]

            # State should exist in database
            result = db.execute(
                "SELECT expires_at FROM auth_state WHERE state = ?", (state,)
            ).fetchone()
            assert result is not None


class TestHandleCallback:
    @patch("starpunk.auth.httpx.post")
    def test_handle_callback_success(self, mock_post, app, db, client):
        """Test successful callback handling"""
        with app.test_request_context():
            # Setup state token
            state = secrets.token_urlsafe(32)
            expires_at = datetime.utcnow() + timedelta(minutes=5)
            db.execute(
                "INSERT INTO auth_state (state, expires_at) VALUES (?, ?)",
                (state, expires_at),
            )
            db.commit()

            # Mock IndieLogin response
            mock_response = MagicMock()
            mock_response.json.return_value = {"me": "https://example.com"}
            mock_post.return_value = mock_response

            # Handle callback
            code = "test-code"
            session_token = handle_callback(code, state)

            assert session_token is not None
            assert isinstance(session_token, str)

            # Session should be created
            token_hash = _hash_token(session_token)
            result = db.execute(
                "SELECT me FROM sessions WHERE session_token_hash = ?", (token_hash,)
            ).fetchone()
            assert result is not None
            assert result["me"] == "https://example.com"

    def test_handle_callback_invalid_state(self, app):
        """Test callback with invalid state"""
        with app.app_context():
            with pytest.raises(InvalidStateError):
                handle_callback("code", "invalid-state")

    @patch("starpunk.auth.httpx.post")
    def test_handle_callback_unauthorized_user(self, mock_post, app, db):
        """Test callback with unauthorized user"""
        with app.app_context():
            # Setup state token
            state = secrets.token_urlsafe(32)
            expires_at = datetime.utcnow() + timedelta(minutes=5)
            db.execute(
                "INSERT INTO auth_state (state, expires_at) VALUES (?, ?)",
                (state, expires_at),
            )
            db.commit()

            # Mock IndieLogin response with different user
            mock_response = MagicMock()
            mock_response.json.return_value = {"me": "https://attacker.com"}
            mock_post.return_value = mock_response

            with pytest.raises(UnauthorizedError):
                handle_callback("code", state)

    @patch("starpunk.auth.httpx.post")
    def test_handle_callback_indielogin_error(self, mock_post, app, db):
        """Test callback with IndieLogin error"""
        with app.app_context():
            # Setup state token
            state = secrets.token_urlsafe(32)
            expires_at = datetime.utcnow() + timedelta(minutes=5)
            db.execute(
                "INSERT INTO auth_state (state, expires_at) VALUES (?, ?)",
                (state, expires_at),
            )
            db.commit()

            # Mock IndieLogin error
            mock_post.side_effect = httpx.RequestError("Connection failed")

            with pytest.raises(IndieLoginError):
                handle_callback("code", state)

    @patch("starpunk.auth.httpx.post")
    def test_handle_callback_no_identity(self, mock_post, app, db):
        """Test callback with no identity in response"""
        with app.app_context():
            # Setup state token
            state = secrets.token_urlsafe(32)
            expires_at = datetime.utcnow() + timedelta(minutes=5)
            db.execute(
                "INSERT INTO auth_state (state, expires_at) VALUES (?, ?)",
                (state, expires_at),
            )
            db.commit()

            # Mock IndieLogin response without 'me' field
            mock_response = MagicMock()
            mock_response.json.return_value = {}
            mock_post.return_value = mock_response

            with pytest.raises(IndieLoginError, match="No identity returned"):
                handle_callback("code", state)


class TestCreateSession:
    def test_create_session_success(self, app, db, client):
        """Test successful session creation"""
        with app.test_request_context():
            me = "https://example.com"
            session_token = create_session(me)

            assert session_token is not None
            assert isinstance(session_token, str)

            # Session should exist in database
            token_hash = _hash_token(session_token)
            result = db.execute(
                """
                SELECT me, expires_at, created_at
                FROM sessions
                WHERE session_token_hash = ?
            """,
                (token_hash,),
            ).fetchone()

            assert result is not None
            assert result["me"] == me
            assert result["expires_at"] is not None

    def test_create_session_metadata(self, app, db, client):
        """Test that session stores metadata"""
        with app.test_request_context(
            headers={"User-Agent": "Test Browser"},
            environ_base={"REMOTE_ADDR": "127.0.0.1"},
        ):
            me = "https://example.com"
            session_token = create_session(me)

            token_hash = _hash_token(session_token)
            result = db.execute(
                """
                SELECT user_agent, ip_address
                FROM sessions
                WHERE session_token_hash = ?
            """,
                (token_hash,),
            ).fetchone()

            assert result["user_agent"] == "Test Browser"
            assert result["ip_address"] == "127.0.0.1"


class TestVerifySession:
    def test_verify_valid_session(self, app, db, client):
        """Test verifying a valid session"""
        with app.test_request_context():
            # Create session
            me = "https://example.com"
            session_token = create_session(me)

            # Verify session
            session_info = verify_session(session_token)

            assert session_info is not None
            assert session_info["me"] == me
            assert "created_at" in session_info
            assert "expires_at" in session_info

    def test_verify_invalid_session(self, app):
        """Test verifying an invalid session"""
        with app.app_context():
            session_info = verify_session("invalid-token")
            assert session_info is None

    def test_verify_expired_session(self, app, db):
        """Test verifying an expired session"""
        with app.app_context():
            # Create expired session
            token = secrets.token_urlsafe(32)
            token_hash = _hash_token(token)
            expires_at = datetime.utcnow() - timedelta(days=1)

            db.execute(
                """
                INSERT INTO sessions (session_token_hash, me, expires_at)
                VALUES (?, ?, ?)
            """,
                (token_hash, "https://example.com", expires_at),
            )
            db.commit()

            session_info = verify_session(token)
            assert session_info is None

    def test_verify_session_updates_last_used(self, app, db, client):
        """Test that verification updates last_used_at"""
        with app.test_request_context():
            # Create session
            me = "https://example.com"
            session_token = create_session(me)

            # Verify session
            verify_session(session_token)

            # Check last_used_at is set
            token_hash = _hash_token(session_token)
            result = db.execute(
                "SELECT last_used_at FROM sessions WHERE session_token_hash = ?",
                (token_hash,),
            ).fetchone()

            assert result["last_used_at"] is not None

    def test_verify_empty_token(self, app):
        """Test verifying empty token"""
        with app.app_context():
            assert verify_session("") is None
            assert verify_session(None) is None


class TestDestroySession:
    def test_destroy_session_success(self, app, db, client):
        """Test successful session destruction"""
        with app.test_request_context():
            # Create session
            me = "https://example.com"
            session_token = create_session(me)

            # Destroy session
            destroy_session(session_token)

            # Session should no longer exist
            token_hash = _hash_token(session_token)
            result = db.execute(
                "SELECT 1 FROM sessions WHERE session_token_hash = ?", (token_hash,)
            ).fetchone()
            assert result is None

    def test_destroy_invalid_session(self, app):
        """Test destroying an invalid session (should not raise error)"""
        with app.app_context():
            destroy_session("invalid-token")  # Should not raise

    def test_destroy_empty_token(self, app):
        """Test destroying empty token"""
        with app.app_context():
            destroy_session("")  # Should not raise
            destroy_session(None)  # Should not raise


class TestRequireAuthDecorator:
    def test_require_auth_with_valid_session(self, app, db, client):
        """Test require_auth decorator with valid session"""
        with app.test_request_context():
            # Create session
            me = "https://example.com"
            session_token = create_session(me)

            # Create test route
            @require_auth
            def protected_route():
                return "Protected content"

            # Manually set cookie header
            environ = {"HTTP_COOKIE": f"session={session_token}"}

            with app.test_request_context(environ_base=environ):
                result = protected_route()
                assert result == "Protected content"
                assert hasattr(g, "user")
                assert g.user["me"] == me

    def test_require_auth_without_session(self, app, client):
        """Test require_auth decorator without session"""

        # Create test route
        @require_auth
        def protected_route():
            return "Protected content"

        # Call protected route without session
        with app.test_request_context():
            with patch("starpunk.auth.redirect") as mock_redirect:
                with patch("starpunk.auth.url_for") as mock_url_for:
                    mock_url_for.return_value = "/auth/login"
                    protected_route()
                    mock_redirect.assert_called_once()

    def test_require_auth_with_expired_session(self, app, db, client):
        """Test require_auth decorator with expired session"""
        # Create expired session
        with app.app_context():
            token = secrets.token_urlsafe(32)
            token_hash = _hash_token(token)
            expires_at = datetime.utcnow() - timedelta(days=1)

            db.execute(
                """
                INSERT INTO sessions (session_token_hash, me, expires_at)
                VALUES (?, ?, ?)
            """,
                (token_hash, "https://example.com", expires_at),
            )
            db.commit()

            # Create test route
            @require_auth
            def protected_route():
                return "Protected content"

            # Call protected route with expired session
            environ = {"HTTP_COOKIE": f"session={token}"}

            with app.test_request_context(environ_base=environ):
                with patch("starpunk.auth.redirect") as mock_redirect:
                    with patch("starpunk.auth.url_for") as mock_url_for:
                        mock_url_for.return_value = "/auth/login"
                        protected_route()
                        mock_redirect.assert_called_once()


class TestSecurityFeatures:
    def test_token_hashing_prevents_plaintext_storage(self, app, db, client):
        """Test that tokens are hashed, not stored in plaintext"""
        with app.test_request_context():
            me = "https://example.com"
            session_token = create_session(me)

            # Database should not contain plaintext token
            result = db.execute("SELECT session_token_hash FROM sessions").fetchone()

            assert result["session_token_hash"] != session_token
            assert len(result["session_token_hash"]) == 64  # SHA-256 hex length

    def test_state_tokens_are_single_use(self, app, db):
        """Test that state tokens can only be used once"""
        with app.app_context():
            state = secrets.token_urlsafe(32)
            expires_at = datetime.utcnow() + timedelta(minutes=5)

            db.execute(
                "INSERT INTO auth_state (state, expires_at) VALUES (?, ?)",
                (state, expires_at),
            )
            db.commit()

            # First verification should succeed
            assert _verify_state_token(state) is True

            # Second verification should fail (token deleted)
            assert _verify_state_token(state) is False

    def test_session_expiry(self, app, db, client):
        """Test that sessions expire correctly"""
        with app.test_request_context():
            # Create session with custom lifetime
            app.config["SESSION_LIFETIME"] = 1  # 1 day

            me = "https://example.com"
            session_token = create_session(me)

            token_hash = _hash_token(session_token)
            result = db.execute(
                "SELECT expires_at FROM sessions WHERE session_token_hash = ?",
                (token_hash,),
            ).fetchone()

            expires_at = datetime.fromisoformat(result["expires_at"])
            created_at = datetime.utcnow()

            # Should expire approximately 1 day from now
            # (allow for minor timing differences)
            delta = expires_at - created_at
            assert delta.total_seconds() >= 86000  # At least 23.8 hours
            assert delta.total_seconds() <= 86401  # At most 1 day + 1 second


class TestExceptionHierarchy:
    def test_exception_inheritance(self):
        """Test that custom exceptions inherit correctly"""
        assert issubclass(InvalidStateError, AuthError)
        assert issubclass(UnauthorizedError, AuthError)
        assert issubclass(IndieLoginError, AuthError)
        assert issubclass(AuthError, Exception)

    def test_exception_messages(self):
        """Test that exceptions can carry messages"""
        error = InvalidStateError("Test message")
        assert str(error) == "Test message"

        error = UnauthorizedError("Unauthorized")
        assert str(error) == "Unauthorized"

        error = IndieLoginError("Service error")
        assert str(error) == "Service error"