import time
from datetime import datetime, timezone
from types import SimpleNamespace

import jwt
from fastapi.testclient import TestClient
from cryptography.hazmat.primitives.asymmetric import rsa
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from sqlalchemy.pool import StaticPool

import app.security as security
from app.config import Settings, get_settings
from app.db import Base, get_db
from app.main import app
from app.models import CrawlRun, Employee
from app.security import SESSION_COOKIE, sign_session


def test_health_returns_versions():
    client = TestClient(app)

    response = client.get("/api/health")

    assert response.status_code == 200
    assert response.json()["backend_version"] == "0.3.0"


def test_mcp_requires_token_and_lists_tools():
    engine = create_engine(
        "sqlite:///:memory:",
        connect_args={"check_same_thread": False},
        poolclass=StaticPool,
    )
    Base.metadata.create_all(engine)
    Session = sessionmaker(bind=engine)

    def override_db():
        session = Session()
        try:
            yield session
        finally:
            session.close()

    app.dependency_overrides[get_db] = override_db
    app.dependency_overrides[get_settings] = lambda: Settings(
        mcp_auth_mode="token", mcp_token="secret", session_secret="session-secret"
    )
    client = TestClient(app)

    unauthorized = client.post("/mcp", json={"jsonrpc": "2.0", "id": 1, "method": "tools/list", "params": {}})
    authorized = client.post(
        "/mcp",
        headers={"Authorization": "Bearer secret"},
        json={"jsonrpc": "2.0", "id": 1, "method": "tools/list", "params": {}},
    )

    assert unauthorized.status_code == 401
    assert authorized.status_code == 200
    assert authorized.json()["result"]["tools"][0]["name"] == "search_employees"

    app.dependency_overrides.clear()


def test_mcp_search_employees_returns_matching_employee():
    engine = create_engine(
        "sqlite:///:memory:",
        connect_args={"check_same_thread": False},
        poolclass=StaticPool,
    )
    Base.metadata.create_all(engine)
    Session = sessionmaker(bind=engine)
    session = Session()
    session.add(
        Employee(
            profile_key="staff:avsergeev",
            profile_type="staff",
            profile_id="avsergeev",
            canonical_url="https://www.hse.ru/staff/avsergeev",
            full_name="Сергеев Алексей Викторович",
            status="active",
            first_seen_at=datetime.now(timezone.utc),
            last_seen_at=datetime.now(timezone.utc),
            current_data={"sections": []},
        )
    )
    session.commit()
    session.close()

    def override_db():
        db = Session()
        try:
            yield db
        finally:
            db.close()

    app.dependency_overrides[get_db] = override_db
    app.dependency_overrides[get_settings] = lambda: Settings(
        mcp_auth_mode="token", mcp_token="secret", session_secret="session-secret"
    )
    client = TestClient(app)

    response = client.post(
        "/mcp",
        headers={"Authorization": "Bearer secret"},
        json={
            "jsonrpc": "2.0",
            "id": 1,
            "method": "tools/call",
            "params": {"name": "search_employees", "arguments": {"query": "Сергеев"}},
        },
    )

    assert response.status_code == 200
    assert "Сергеев Алексей Викторович" in response.json()["result"]["content"][0]["text"]

    app.dependency_overrides.clear()


def test_mcp_oauth_rejects_static_token():
    engine = create_engine(
        "sqlite:///:memory:",
        connect_args={"check_same_thread": False},
        poolclass=StaticPool,
    )
    Base.metadata.create_all(engine)
    Session = sessionmaker(bind=engine)

    def override_db():
        session = Session()
        try:
            yield session
        finally:
            session.close()

    settings = Settings(
        mcp_auth_mode="oauth",
        mcp_token="secret",
        session_secret="session-secret",
        mcp_oauth_issuer="https://auth.example.com",
        mcp_oauth_audience="miem-mcp",
        mcp_oauth_jwks_url="https://auth.example.com/.well-known/jwks.json",
    )
    app.dependency_overrides[get_db] = override_db
    app.dependency_overrides[get_settings] = lambda: settings
    client = TestClient(app)

    response = client.post(
        "/mcp",
        headers={"Authorization": "Bearer secret"},
        json={"jsonrpc": "2.0", "id": 1, "method": "tools/list", "params": {}},
    )

    assert response.status_code == 401
    assert response.headers["www-authenticate"] == (
        'Bearer resource_metadata="http://localhost:8001/.well-known/oauth-protected-resource"'
    )

    app.dependency_overrides.clear()


def test_mcp_oauth_missing_auth_returns_metadata_challenge():
    settings = Settings(
        mcp_auth_mode="oauth",
        mcp_resource_url="https://api.example.com/mcp",
        mcp_oauth_issuer="https://auth.example.com",
        mcp_oauth_audience="miem-mcp",
        mcp_oauth_jwks_url="https://auth.example.com/.well-known/jwks.json",
    )
    app.dependency_overrides[get_settings] = lambda: settings
    client = TestClient(app)

    response = client.post("/mcp", json={"jsonrpc": "2.0", "id": 1, "method": "tools/list", "params": {}})

    assert response.status_code == 401
    assert response.headers["www-authenticate"] == (
        'Bearer resource_metadata="https://api.example.com/.well-known/oauth-protected-resource"'
    )

    app.dependency_overrides.clear()


def test_mcp_accepts_valid_oauth_jwt(monkeypatch):
    public_key, token = _oauth_key_and_token()
    monkeypatch.setattr(security, "_get_mcp_oauth_signing_key", lambda _token, _settings: SimpleNamespace(key=public_key))
    app.dependency_overrides[get_settings] = lambda: _oauth_settings()
    client = TestClient(app)

    response = client.post(
        "/mcp",
        headers={"Authorization": f"Bearer {token}"},
        json={"jsonrpc": "2.0", "id": 1, "method": "tools/list", "params": {}},
    )

    assert response.status_code == 200
    assert response.json()["result"]["tools"][0]["name"] == "search_employees"

    app.dependency_overrides.clear()


def test_mcp_rejects_invalid_oauth_jwts(monkeypatch):
    public_key, expired_token = _oauth_key_and_token(exp=int(time.time()) - 60)
    _, wrong_issuer_token = _oauth_key_and_token(issuer="https://other.example.com")
    _, wrong_audience_token = _oauth_key_and_token(audience="other-audience")
    _, bad_signature_token = _oauth_key_and_token(public_key=public_key)
    monkeypatch.setattr(security, "_get_mcp_oauth_signing_key", lambda _token, _settings: SimpleNamespace(key=public_key))
    app.dependency_overrides[get_settings] = lambda: _oauth_settings()
    client = TestClient(app)

    for token in [expired_token, wrong_issuer_token, wrong_audience_token, bad_signature_token]:
        response = client.post(
            "/mcp",
            headers={"Authorization": f"Bearer {token}"},
            json={"jsonrpc": "2.0", "id": 1, "method": "tools/list", "params": {}},
        )

        assert response.status_code == 401

    app.dependency_overrides.clear()


def test_mcp_rejects_oauth_jwt_without_required_scope(monkeypatch):
    public_key, token = _oauth_key_and_token(scope="profile")
    monkeypatch.setattr(security, "_get_mcp_oauth_signing_key", lambda _token, _settings: SimpleNamespace(key=public_key))
    app.dependency_overrides[get_settings] = lambda: _oauth_settings()
    client = TestClient(app)

    response = client.post(
        "/mcp",
        headers={"Authorization": f"Bearer {token}"},
        json={"jsonrpc": "2.0", "id": 1, "method": "tools/list", "params": {}},
    )

    assert response.status_code == 403

    app.dependency_overrides.clear()


def test_mcp_protected_resource_metadata_uses_settings():
    settings = Settings(
        mcp_resource_url="https://api.example.com/mcp",
        mcp_oauth_issuer="https://auth.example.com/",
        mcp_oauth_required_scope="mcp:tools",
    )
    app.dependency_overrides[get_settings] = lambda: settings
    client = TestClient(app)

    response = client.get("/.well-known/oauth-protected-resource")

    assert response.status_code == 200
    assert response.json() == {
        "resource": "https://api.example.com/mcp",
        "authorization_servers": ["https://auth.example.com"],
        "bearer_methods_supported": ["header"],
        "scopes_supported": ["mcp:tools"],
        "resource_documentation": "https://api.example.com/mcp",
    }

    app.dependency_overrides.clear()


def test_api_employees_and_stats_require_admin_session():
    engine = create_engine(
        "sqlite:///:memory:",
        connect_args={"check_same_thread": False},
        poolclass=StaticPool,
    )
    Base.metadata.create_all(engine)
    Session = sessionmaker(bind=engine)
    db = Session()
    db.add(
        Employee(
            profile_key="staff:alpha",
            profile_type="staff",
            profile_id="alpha",
            canonical_url="https://www.hse.ru/staff/alpha",
            full_name="Alpha Person",
            status="active",
            first_seen_at=datetime.now(timezone.utc),
            last_seen_at=datetime.now(timezone.utc),
            current_data={"contacts": {"emails": ["alpha@hse.ru"]}, "sections": []},
        )
    )
    db.add(CrawlRun(source_url="https://miem.hse.ru/persons", status="completed", new_count=1))
    db.commit()
    db.close()

    settings = Settings(admin_username="admin", admin_password="password", session_secret="session-secret")

    def override_db():
        session = Session()
        try:
            yield session
        finally:
            session.close()

    app.dependency_overrides[get_db] = override_db
    app.dependency_overrides[get_settings] = lambda: settings
    client = TestClient(app)
    client.cookies.set(SESSION_COOKIE, sign_session("admin", settings))

    employees = client.get("/api/employees", params={"q": "Alpha", "has_email": True})
    stats = client.get("/api/stats")

    assert employees.status_code == 200
    assert employees.json()["total"] == 1
    assert stats.status_code == 200
    assert stats.json()["new_in_last_run"] == 1

    app.dependency_overrides.clear()


def _oauth_settings() -> Settings:
    return Settings(
        mcp_auth_mode="oauth",
        mcp_resource_url="https://api.example.com/mcp",
        mcp_oauth_issuer="https://auth.example.com",
        mcp_oauth_audience="miem-mcp",
        mcp_oauth_jwks_url="https://auth.example.com/.well-known/jwks.json",
        session_secret="session-secret",
    )


def _oauth_key_and_token(
    *,
    issuer: str = "https://auth.example.com",
    audience: str = "miem-mcp",
    scope: str = "mcp:tools",
    exp: int | None = None,
    public_key=None,
):
    private_key = rsa.generate_private_key(public_exponent=65537, key_size=2048)
    claims = {
        "iss": issuer,
        "aud": audience,
        "scope": scope,
        "sub": "mcp-client",
        "iat": int(time.time()),
        "exp": exp or int(time.time()) + 300,
    }
    token = jwt.encode(claims, private_key, algorithm="RS256", headers={"kid": "test-key"})
    return public_key or private_key.public_key(), token