"""Tool-handler tests covering Layer 3 enforcement and the privacy boundary.

Goal: verify that the tools, on their own, refuse the unsafe operations even
if the model ignores every system-prompt rule. The model never appears in
these tests — only the deterministic handlers and the per-session guard state.
"""

import pytest

from mock_data import POLICIES, RETURNS
from tools import SessionGuardState, dispatch_tool


@pytest.fixture(autouse=True)
def _reset_returns():
    RETURNS.clear()
    yield
    RETURNS.clear()


@pytest.fixture
def state() -> SessionGuardState:
    return SessionGuardState()


def test_lookup_order_returns_order_for_known_id(state):
    result = dispatch_tool("lookup_order", {"order_id": "BK-10042"}, state)
    assert "order" in result
    assert result["order"]["customer_name"] == "Sarah Chen"


def test_lookup_order_unknown_id_returns_not_found(state):
    result = dispatch_tool("lookup_order", {"order_id": "BK-99999"}, state)
    assert result.get("error") == "order_not_found"


def test_lookup_order_email_mismatch_masquerades_as_not_found(state):
    """Privacy: a wrong email must look identical to a missing order so
    callers cannot enumerate which IDs exist on the system."""
    result = dispatch_tool(
        "lookup_order",
        {"order_id": "BK-10042", "customer_email": "wrong@example.com"},
        state,
    )
    assert result.get("error") == "order_not_found"


def test_lookup_order_email_match_returns_order(state):
    result = dispatch_tool(
        "lookup_order",
        {"order_id": "BK-10042", "customer_email": "Sarah.Chen@example.com"},
        state,
    )
    assert "order" in result


def test_eligibility_check_passes_for_recent_delivered_order(state):
    result = dispatch_tool(
        "check_return_eligibility",
        {"order_id": "BK-10042", "customer_email": "sarah.chen@example.com"},
        state,
    )
    assert result["eligible"] is True
    assert "BK-10042" in state.eligibility_checks_passed


def test_eligibility_check_rejects_past_window(state):
    result = dispatch_tool(
        "check_return_eligibility",
        {"order_id": "BK-9871", "customer_email": "maria.gonzalez@example.com"},
        state,
    )
    assert result["eligible"] is False
    assert "BK-9871" not in state.eligibility_checks_passed
    assert "30-day" in result["reason"]


def test_eligibility_check_rejects_not_yet_delivered(state):
    result = dispatch_tool(
        "check_return_eligibility",
        {"order_id": "BK-10089", "customer_email": "james.murphy@example.com"},
        state,
    )
    assert result["eligible"] is False
    assert "shipped" in result["reason"]


def test_eligibility_check_email_mismatch_returns_auth_failed(state):
    result = dispatch_tool(
        "check_return_eligibility",
        {"order_id": "BK-10042", "customer_email": "wrong@example.com"},
        state,
    )
    assert result.get("error") == "auth_failed"


def test_initiate_return_refuses_without_prior_eligibility_check(state):
    """Layer 3 protocol guard: the most important guardrail in the system."""
    result = dispatch_tool(
        "initiate_return",
        {
            "order_id": "BK-10042",
            "customer_email": "sarah.chen@example.com",
            "reason": "Bought by mistake",
        },
        state,
    )
    assert result.get("error") == "eligibility_not_verified"
    assert not RETURNS


def test_initiate_return_succeeds_after_eligibility_check(state):
    dispatch_tool(
        "check_return_eligibility",
        {"order_id": "BK-10042", "customer_email": "sarah.chen@example.com"},
        state,
    )
    result = dispatch_tool(
        "initiate_return",
        {
            "order_id": "BK-10042",
            "customer_email": "sarah.chen@example.com",
            "reason": "Bought by mistake",
        },
        state,
    )
    assert "return_id" in result
    assert result["return_id"].startswith("RMA-")
    assert "BK-10042" in state.returns_initiated
    assert result["return_id"] in RETURNS


def test_initiate_return_refuses_duplicate(state):
    dispatch_tool(
        "check_return_eligibility",
        {"order_id": "BK-10042", "customer_email": "sarah.chen@example.com"},
        state,
    )
    dispatch_tool(
        "initiate_return",
        {
            "order_id": "BK-10042",
            "customer_email": "sarah.chen@example.com",
            "reason": "Bought by mistake",
        },
        state,
    )
    second = dispatch_tool(
        "initiate_return",
        {
            "order_id": "BK-10042",
            "customer_email": "sarah.chen@example.com",
            "reason": "Bought by mistake",
        },
        state,
    )
    assert second.get("error") == "already_initiated"


def test_lookup_policy_returns_verbatim_text(state):
    result = dispatch_tool("lookup_policy", {"topic": "password_reset"}, state)
    assert result["text"] == POLICIES["password_reset"]


def test_lookup_policy_unknown_topic_returns_not_supported(state):
    result = dispatch_tool("lookup_policy", {"topic": "loyalty_program"}, state)
    assert result.get("error") == "topic_not_supported"
    assert "shipping" in result["available_topics"]


def test_lookup_policy_topic_is_case_insensitive(state):
    result = dispatch_tool("lookup_policy", {"topic": "SHIPPING"}, state)
    assert result["text"] == POLICIES["shipping"]


def test_dispatch_unknown_tool_returns_error(state):
    result = dispatch_tool("delete_account", {}, state)
    assert result.get("error") == "unknown_tool"


def test_dispatch_rejects_non_dict_arguments(state):
    result = dispatch_tool("lookup_order", "BK-10042", state)  # type: ignore[arg-type]
    assert result.get("error") == "invalid_arguments"


def test_lookup_order_rejects_malformed_order_id(state):
    result = dispatch_tool("lookup_order", {"order_id": "not-a-real-id"}, state)
    assert result.get("error") == "invalid_arguments"
    assert "order_id" in result["message"]


def test_lookup_order_strips_control_characters(state):
    """Control chars in free-form input must never reach tool storage."""
    result = dispatch_tool(
        "lookup_order",
        {"order_id": "BK-10042\x00\x07"},
        state,
    )
    # After stripping control chars "BK-10042" matches the regex.
    assert "order" in result


def test_check_return_eligibility_rejects_malformed_email(state):
    result = dispatch_tool(
        "check_return_eligibility",
        {"order_id": "BK-10042", "customer_email": "not-an-email"},
        state,
    )
    assert result.get("error") == "invalid_arguments"


def test_initiate_return_rejects_empty_item_titles_list(state):
    dispatch_tool(
        "check_return_eligibility",
        {"order_id": "BK-10042", "customer_email": "sarah.chen@example.com"},
        state,
    )
    result = dispatch_tool(
        "initiate_return",
        {
            "order_id": "BK-10042",
            "customer_email": "sarah.chen@example.com",
            "reason": "Bought by mistake",
            "item_titles": [],
        },
        state,
    )
    assert result.get("error") == "no_items_selected"


def test_initiate_return_rejects_overlong_reason(state):
    dispatch_tool(
        "check_return_eligibility",
        {"order_id": "BK-10042", "customer_email": "sarah.chen@example.com"},
        state,
    )
    result = dispatch_tool(
        "initiate_return",
        {
            "order_id": "BK-10042",
            "customer_email": "sarah.chen@example.com",
            "reason": "x" * 5000,
        },
        state,
    )
    assert result.get("error") == "invalid_arguments"


def test_lookup_policy_rejects_uppercase_and_punctuation(state):
    """Topic must normalize to lowercase underscores; anything else is a
    validation error so nothing unexpected makes it into tool result JSON."""
    result = dispatch_tool("lookup_policy", {"topic": "shipping!"}, state)
    assert result.get("error") == "invalid_arguments"