"""Unit tests for the MCP structured-error projection.

``mcp/_errors.py`` translates a :class:`~notebooklm.exceptions.NotebookLMError`
into a FastMCP :class:`~fastmcp.exceptions.ToolError` carrying a structured
payload ``{code, message, retriable, hint?}``. The ``code``/``retriable``/
``hint`` are derived from ``_app.errors.classify`` via a
``category -> (code, hint)`` table; ``message`` is redaction-capped but the
``code`` + ``retriable`` are always preserved.

These tests pin, for an exemplar of EVERY ``ErrorCategory``, the projected
code + retriable + hint. The exemplar list mirrors
``tests/_guardrails/test_classify_error_handler_consistency.py`` so the two
ladders stay aligned.
"""

from __future__ import annotations

import pytest

# Skip cleanly when the `mcp` extra (fastmcp) is absent; see conftest.py.
pytest.importorskip("fastmcp")

from fastmcp.exceptions import ToolError  # noqa: E402 - after importorskip guard

from notebooklm import exceptions as exc  # noqa: E402 - after importorskip guard
from notebooklm._app import SourceMutationError  # noqa: E402 - after importorskip guard
from notebooklm._app.errors import (  # noqa: E402 - after importorskip guard
    ErrorCategory,
    classify,
)
from notebooklm.mcp._errors import (  # noqa: E402 - after importorskip guard
    CATEGORY_TABLE,
    ERROR_CODES,
    mcp_errors,
    redact,
    to_tool_error,
    tool_error_payload,
)

# One exemplar per category — same exemplars the CLI consistency gate uses.
_EXEMPLARS: list[tuple[ErrorCategory, BaseException]] = [
    (ErrorCategory.NOT_FOUND, exc.SourceNotFoundError("src_456")),
    (ErrorCategory.AUTH, exc.AuthError("auth failed")),
    (ErrorCategory.RATE_LIMITED, exc.RateLimitError("slow down", retry_after=5)),
    (ErrorCategory.VALIDATION, exc.ValidationError("bad input")),
    (ErrorCategory.CONFIG, exc.ConfigurationError("missing config")),
    (ErrorCategory.NETWORK, exc.NetworkError("connection refused")),
    (ErrorCategory.NOTEBOOK_LIMIT, exc.NotebookLimitError(499, limit=500)),
    (ErrorCategory.ARTIFACT_TIMEOUT, exc.ArtifactTimeoutError("nb-1", "task-1", 30.0)),
    (ErrorCategory.TIMEOUT, exc.WaitTimeoutError("generic wait timed out")),
    (ErrorCategory.SERVER, exc.ServerError("upstream 503")),
    (ErrorCategory.RPC, exc.RPCError("decode failed", method_id="abc123")),
    (ErrorCategory.SOURCE_MUTATION, SourceMutationError("ambiguous", "AMBIGUOUS_ID")),
    (ErrorCategory.LIBRARY, exc.NotebookLMError("some library error")),
    (ErrorCategory.UNEXPECTED, RuntimeError("boom")),
]

# The MCP code each neutral category projects onto, and whether it is retriable.
# retriable mirrors ``_app.errors`` (rate-limit / server / timeout / network),
# never re-derived here.
# NOTE: this map is duplicated INTENTIONALLY from ``CATEGORY_TABLE`` (and from
# ``test_mcp_classify_consistency.py``) as an INDEPENDENT ORACLE — do NOT "DRY" it
# into a shared import. Hand-writing the expected projection is what lets the test
# catch a wrong edit to the production table; importing the table would make it
# tautological.
_CATEGORY_TO_MCP_CODE: dict[ErrorCategory, str] = {
    ErrorCategory.NOT_FOUND: "NOT_FOUND",
    ErrorCategory.AUTH: "AUTH",
    ErrorCategory.RATE_LIMITED: "RATE_LIMITED",
    ErrorCategory.VALIDATION: "VALIDATION",
    ErrorCategory.CONFIG: "CONFIG",
    ErrorCategory.NETWORK: "NETWORK",
    ErrorCategory.NOTEBOOK_LIMIT: "NOTEBOOK_LIMIT",
    ErrorCategory.ARTIFACT_TIMEOUT: "ARTIFACT_TIMEOUT",
    ErrorCategory.TIMEOUT: "TIMEOUT",
    ErrorCategory.SERVER: "SERVER",
    ErrorCategory.RPC: "RPC",
    ErrorCategory.SOURCE_MUTATION: "SOURCE_MUTATION",
    ErrorCategory.LIBRARY: "ERROR",
    ErrorCategory.UNEXPECTED: "UNEXPECTED",
}


def test_table_covers_every_category() -> None:
    """A new ``ErrorCategory`` with no table entry fails here."""
    assert set(CATEGORY_TABLE) == set(ErrorCategory)


def test_error_codes_is_the_table_code_set() -> None:
    """``ERROR_CODES`` is the pinned set of codes the table can emit."""
    assert frozenset(code for code, _ in CATEGORY_TABLE.values()) == ERROR_CODES


def test_one_exemplar_per_category() -> None:
    """Exactly one exemplar per category — the parametrization is exhaustive."""
    assert {category for category, _ in _EXEMPLARS} == set(ErrorCategory)


@pytest.mark.parametrize(
    ("category", "exception"),
    _EXEMPLARS,
    ids=[category.name for category, _ in _EXEMPLARS],
)
def test_payload_projects_code_retriable_hint(
    category: ErrorCategory, exception: BaseException
) -> None:
    payload = tool_error_payload(exception)
    expected_code, expected_hint = CATEGORY_TABLE[category]
    classified = classify(exception)

    assert payload["code"] == expected_code == _CATEGORY_TO_MCP_CODE[category]
    assert payload["retriable"] is classified.retriable
    assert isinstance(payload["message"], str) and payload["message"]
    if expected_hint is None:
        assert "hint" not in payload
    else:
        assert payload["hint"] == expected_hint


def test_retriable_categories_are_marked_retriable() -> None:
    """The transient categories project retriable=True; deterministic ones False."""
    retriable = {
        ErrorCategory.RATE_LIMITED,
        ErrorCategory.SERVER,
        ErrorCategory.TIMEOUT,
        ErrorCategory.ARTIFACT_TIMEOUT,
        ErrorCategory.NETWORK,
    }
    for category, exception in _EXEMPLARS:
        assert tool_error_payload(exception)["retriable"] is (category in retriable)


def test_message_is_redaction_capped_but_code_preserved() -> None:
    """A very long message is capped; code + retriable still present and correct."""
    long = exc.ValidationError("x" * 2000)
    payload = tool_error_payload(long)
    assert payload["code"] == "VALIDATION"
    assert payload["retriable"] is False
    assert len(payload["message"]) <= 320  # cap + ellipsis slack


def test_to_tool_error_returns_tool_error_with_payload() -> None:
    err = to_tool_error(exc.RateLimitError("slow", retry_after=3))
    assert isinstance(err, ToolError)
    # FastMCP ToolError surfaces the structured payload; the code must be readable.
    assert "RATE_LIMITED" in str(err)


def test_not_found_candidates_surface_in_payload_and_did_you_mean_hint() -> None:
    """Near-miss candidates (issue #1787) appear structurally and swap the hint."""
    err = exc.NotebookNotFoundError("Scientific")
    err.candidates = [{"id": "37fe5c1d", "title": "Scientific PDF Parsing — Landscape"}]
    payload = tool_error_payload(err)

    assert payload["code"] == "NOT_FOUND"
    assert payload["candidates"] == [
        {"id": "37fe5c1d", "title": "Scientific PDF Parsing — Landscape"}
    ]
    # The generic NOT_FOUND hint is replaced by a "Did you mean …" hint that
    # names the title AND id inline (so a flat-string MCP client still sees both).
    assert payload["hint"].startswith("Did you mean:")
    assert "Scientific PDF Parsing — Landscape" in payload["hint"]
    assert "37fe5c1d" in payload["hint"]


def test_candidate_id_reaches_the_flattened_toolerror_wire() -> None:
    """to_tool_error drops the structured list, so the id must ride the hint string.

    Regression for the codex P2: an MCP client only sees the flat ToolError
    message, and must be able to retry by id without another list call.
    """
    err = exc.SourceNotFoundError("Quarterly - Revenue")
    err.candidates = [{"id": "src-abc123-def456", "title": "Quarterly — Revenue Deck"}]
    wire = str(to_tool_error(err))
    assert "Did you mean:" in wire
    assert "src-abc123-def456" in wire
    assert "Quarterly — Revenue Deck" in wire


def test_not_found_without_candidates_keeps_generic_hint() -> None:
    """A miss with no near match carries no candidates and the generic hint."""
    payload = tool_error_payload(exc.NotebookNotFoundError("Nonexistent"))
    assert "candidates" not in payload
    assert payload["hint"] == CATEGORY_TABLE[ErrorCategory.NOT_FOUND][1]


def test_validation_error_with_candidates_is_enriched() -> None:
    """A label near-miss (VALIDATION-coded, candidates on the attr) still enriches.

    ``source_list(label=…)`` resolves labels by name and raises the VALIDATION-
    coded ``LabelResolutionError``; its ``.candidates`` must reach the wire with a
    "Did you mean" hint even though the code is not NOT_FOUND.
    """
    err = exc.ValidationError("No label found matching 'Q3 - Papers'")
    err.candidates = [{"id": "lbl1", "title": "Q3 — Papers"}]  # type: ignore[attr-defined]
    payload = tool_error_payload(err)
    assert payload["code"] == "VALIDATION"
    assert payload["candidates"] == [{"id": "lbl1", "title": "Q3 — Papers"}]
    assert payload["hint"].startswith("Did you mean:")


def test_mcp_errors_translates_notebooklm_error() -> None:
    with pytest.raises(ToolError) as caught, mcp_errors():  # noqa: PT012
        raise exc.NotFoundError("missing")
    assert "NOT_FOUND" in str(caught.value)


def test_mcp_errors_wraps_unexpected_exception() -> None:
    """A plain ``RuntimeError`` is wrapped into a ToolError with code UNEXPECTED.

    Without this the advertised ``UNEXPECTED`` projection is never produced — a
    non-library exception would escape ``mcp_errors()`` unwrapped.
    """
    with pytest.raises(ToolError) as caught, mcp_errors():  # noqa: PT012
        raise RuntimeError("boom")
    assert "UNEXPECTED" in str(caught.value)


def test_mcp_errors_propagates_base_exceptions() -> None:
    """``CancelledError`` (a ``BaseException``) propagates uncaught — never wrapped.

    ``except Exception`` deliberately does not catch ``asyncio.CancelledError`` /
    ``KeyboardInterrupt`` / ``SystemExit`` so cancellation/shutdown is never
    swallowed into a ToolError.
    """
    import asyncio

    with pytest.raises(asyncio.CancelledError), mcp_errors():
        raise asyncio.CancelledError


# --------------------------------------------------------------------------- #
# redact() — secret / path pattern redaction (#1682)
# --------------------------------------------------------------------------- #
def test_redact_strips_bearer_token() -> None:
    """An ``Authorization: Bearer`` header value is masked (via scrub_secrets).

    Uses the header form (which redacts ANY value) rather than a bare token, whose
    shape regex intentionally ignores short non-realistic tokens.
    """
    out = redact("RPC failed: Authorization: Bearer ya29.s3cr3t-Token_VALUE-abc123")
    assert "ya29.s3cr3t-Token_VALUE-abc123" not in out
    assert "Bearer" in out  # the header name survives as a shape hint


def test_redact_strips_session_cookie_values() -> None:
    """A ``Cookie:`` header and a ``__Secure-*`` cookie value are masked."""
    out = redact("boom Cookie: SID=AAAA1111secret; HSID=BBBB2222secret")
    assert "AAAA1111secret" not in out
    assert "BBBB2222secret" not in out
    out2 = redact("__Secure-1PSIDTS=zzzzSECRETvalue")
    assert "zzzzSECRETvalue" not in out2


def test_redact_strips_signed_files_url_token_bare_and_in_url() -> None:
    """The ``/files/(dl|ul)/<token>`` side-channel token is redacted."""
    bare = redact("link is /files/dl/eyJvcCI6ImRsIn0.ZmFrZW1hYw and expired")
    assert "/files/dl/***" in bare
    assert "eyJvcCI6ImRsIn0" not in bare
    in_url = redact("open https://files.test/files/ul/eyJvcCI6InVsIn0.bWFjbWFj?x=1 now")
    assert "/files/ul/***" in in_url
    assert "eyJvcCI6InVsIn0" not in in_url
    # A malformed multi-dot token leaves no tail.
    multidot = redact("/files/dl/a.b.c")
    assert multidot == "/files/dl/***"


@pytest.mark.parametrize(
    ("message", "leaked", "expected_fragment"),
    [
        (
            "open /home/alice/.notebooklm/default/storage_state.json failed",
            "alice",
            "/home/***/.notebooklm/default/storage_state.json",
        ),
        # macOS account name with a space (the round-1 codex concern).
        (
            "read /Users/Alice Smith/Library/data.json",
            "Smith",
            "/Users/***/Library/data.json",
        ),
        # Windows account name with a space.
        (r"open C:\Users\Bob Smith\app\state failed", "Bob", r"C:\Users\***\app\state"),
    ],
)
def test_redact_masks_home_directory_usernames(message, leaked, expected_fragment) -> None:
    out = redact(message)
    assert leaked not in out
    assert expected_fragment in out


@pytest.mark.parametrize(
    "message",
    [
        # A single-word terminal username IS redacted, but surrounding prose /
        # punctuation must survive verbatim.
        "/home/alice: permission denied",
        # Multi-path prose must NOT be eaten reaching for a later separator.
        "Could not find /home/alice or /home/bob/config",
        "/Users/Alice Smith: permission denied for /Users/Bob/x",
    ],
)
def test_redact_never_eats_prose_between_paths(message) -> None:
    out = redact(message)
    # The prose words between path-ish fragments survive verbatim.
    for word in ("permission", "denied", "Could", "find", "or", "for"):
        if word in message:
            assert word in out


def test_redact_masks_terminal_and_punctuation_bounded_usernames() -> None:
    """A single-word username is redacted even without a trailing separator.

    It cannot eat prose (the token stops at whitespace/punctuation), so requiring a
    trailing ``/`` would needlessly leak terminal usernames (gemini #1695). Internal
    dots/hyphens are part of the name; a trailing ``.``/``)`` of prose is preserved.
    """
    assert redact("dir is /home/alice") == "dir is /home/***"
    assert redact("/home/alice: permission denied") == "/home/***: permission denied"
    assert redact("Could not find /home/alice.") == "Could not find /home/***."
    assert redact("see (/home/alice)") == "see (/home/***)"
    assert redact("/home/john.doe/x") == "/home/***/x"  # internal dot kept inside name
    assert redact("/home/web-admin") == "/home/***"  # internal hyphen kept inside name


def test_redact_exact_output_for_multi_path_prose() -> None:
    """Exact-output guards: every path component is masked, all prose survives."""
    assert (
        redact("Could not find /home/alice or /home/bob/config")
        == "Could not find /home/*** or /home/***/config"
    )
    # A two-word username NOT followed by a separator masks only its first word
    # (documented fail-safe bound); the prose is still fully preserved.
    assert (
        redact("/Users/Alice Smith: permission denied for /Users/Bob/x")
        == "/Users/*** Smith: permission denied for /Users/***/x"
    )


def test_redact_home_pattern_capture_group_is_only_the_prefix() -> None:
    """The ``\\1`` capture is just the ``/home/`` prefix — the username is the part
    dropped, not coincidentally preserved (gemini #1695 testing guidance)."""
    from notebooklm._redact import _EXTRA_PATTERNS

    home_pattern = _EXTRA_PATTERNS[1][0]
    m = home_pattern.search("Could not find /home/alice")
    assert m is not None
    assert m.group(1) == "/home/"
    assert m.group(0) == "/home/alice"  # the whole match (prefix + username) is replaced


def test_unexpected_exception_message_is_generic_not_raw_text() -> None:
    """A non-library bug's raw ``str(exc)`` is never echoed (redact is a denylist).

    ``redact`` only masks KNOWN credential/path shapes, so an unexpected exception
    could otherwise leak arbitrary text (env detail, non-home paths). The UNEXPECTED
    category therefore returns a fixed generic message while preserving code +
    retriable (mirrors the REST server policy).
    """
    leaky = RuntimeError("kaboom: opened /var/lib/notebooklm/secret.cfg key=hunter2")
    payload = tool_error_payload(leaky)
    assert payload["code"] == "UNEXPECTED"
    assert payload["retriable"] is False
    assert "secret.cfg" not in payload["message"]
    assert "hunter2" not in payload["message"]
    assert "/var/lib/notebooklm" not in payload["message"]


def test_redact_runs_before_truncation_so_secret_not_half_cut() -> None:
    """A secret sitting near the length cap must be fully redacted, never half-shown."""
    filler = "x" * 290
    secret = "AAAA1111-this-is-a-secret-cookie-value"
    out = redact(f"{filler} Cookie: SID={secret}")
    assert secret not in out
    assert "1111-this-is-a-secret" not in out  # no partial tail survived the cap