"""Contract tests for ``deerflow.subagents.status_contract``."""

from __future__ import annotations

import json
from pathlib import Path

from deerflow.subagents.status_contract import (
    SUBAGENT_ERROR_KEY,
    SUBAGENT_METADATA_TEXT_MAX_CHARS,
    SUBAGENT_RESULT_BRIEF_KEY,
    SUBAGENT_RESULT_SHA256_KEY,
    SUBAGENT_STATUS_KEY,
    SUBAGENT_STATUS_VALUES,
    _bound_metadata_text,
    make_subagent_additional_kwargs,
    read_subagent_result_metadata,
)

_REPO_ROOT = Path(__file__).resolve().parents[2]
_CONTRACT_PATH = _REPO_ROOT / "contracts" / "subagent_status_contract.json"


def _load_contract() -> dict:
    return json.loads(_CONTRACT_PATH.read_text(encoding="utf-8"))


def test_contract_file_exists():
    assert _CONTRACT_PATH.is_file(), f"missing shared fixture: {_CONTRACT_PATH}"


def test_status_values_match_contract():
    """Backend status enum stays aligned with the contract document."""
    contract = _load_contract()
    assert set(SUBAGENT_STATUS_VALUES) == set(contract["valid_status_values"])


def test_make_subagent_additional_kwargs_includes_status():
    kwargs = make_subagent_additional_kwargs("completed")
    assert kwargs == {SUBAGENT_STATUS_KEY: "completed"}


def test_make_subagent_additional_kwargs_includes_error_when_present():
    kwargs = make_subagent_additional_kwargs("failed", error="boom")
    assert kwargs == {SUBAGENT_STATUS_KEY: "failed", SUBAGENT_ERROR_KEY: "boom"}


def test_make_subagent_additional_kwargs_includes_bounded_result_metadata():
    kwargs = make_subagent_additional_kwargs("completed", result="done")
    assert kwargs[SUBAGENT_STATUS_KEY] == "completed"
    assert kwargs[SUBAGENT_RESULT_BRIEF_KEY] == "done"
    assert len(kwargs[SUBAGENT_RESULT_SHA256_KEY]) == 64
    assert SUBAGENT_ERROR_KEY not in kwargs


def test_make_subagent_additional_kwargs_bounds_large_result_metadata():
    huge = "x" * (SUBAGENT_METADATA_TEXT_MAX_CHARS + 5000)
    kwargs = make_subagent_additional_kwargs("completed", result=huge)
    assert len(kwargs[SUBAGENT_RESULT_BRIEF_KEY]) <= SUBAGENT_METADATA_TEXT_MAX_CHARS
    assert kwargs[SUBAGENT_RESULT_BRIEF_KEY] != huge
    assert len(kwargs[SUBAGENT_RESULT_SHA256_KEY]) == 64


def test_bound_metadata_text_respects_small_caps():
    text = "A" * 100

    assert _bound_metadata_text(text, cap=0) == ""
    assert _bound_metadata_text(text, cap=1) == "A"
    assert len(_bound_metadata_text(text, cap=15)) <= 15


def test_make_subagent_additional_kwargs_omits_blank_error():
    """Empty / whitespace error must not leak as ``subagent_error: ""``."""
    assert make_subagent_additional_kwargs("failed", error="") == {SUBAGENT_STATUS_KEY: "failed"}
    assert make_subagent_additional_kwargs("failed", error="   ") == {SUBAGENT_STATUS_KEY: "failed"}
    assert make_subagent_additional_kwargs("failed", error=None) == {SUBAGENT_STATUS_KEY: "failed"}


def test_make_subagent_additional_kwargs_bounds_large_error_metadata():
    huge = "boom " * 2000
    kwargs = make_subagent_additional_kwargs("failed", error=huge)
    assert kwargs[SUBAGENT_STATUS_KEY] == "failed"
    assert len(kwargs[SUBAGENT_ERROR_KEY]) <= SUBAGENT_METADATA_TEXT_MAX_CHARS
    assert SUBAGENT_RESULT_BRIEF_KEY not in kwargs


def test_read_subagent_result_metadata_returns_bounded_payload():
    parsed = read_subagent_result_metadata(
        {
            SUBAGENT_STATUS_KEY: "completed",
            SUBAGENT_RESULT_BRIEF_KEY: "structured",
            SUBAGENT_RESULT_SHA256_KEY: "a" * 64,
            SUBAGENT_ERROR_KEY: "ignored",
        }
    )
    assert parsed == {
        "status": "completed",
        "result_brief": "structured",
        "result_sha256": "a" * 64,
    }


def test_read_subagent_result_metadata_rejects_unknown_status():
    assert read_subagent_result_metadata({SUBAGENT_STATUS_KEY: "future"}) is None


def test_read_subagent_result_metadata_rejects_non_hex_sha256():
    """A 64-char value that is not a lowercase hex digest must be dropped."""
    base = {SUBAGENT_STATUS_KEY: "completed", SUBAGENT_RESULT_BRIEF_KEY: "structured"}
    for bad_hash in ("z" * 64, "A" * 64, "a" * 63, "a" * 65, ("a" * 63) + " "):
        parsed = read_subagent_result_metadata({**base, SUBAGENT_RESULT_SHA256_KEY: bad_hash})
        assert parsed == {"status": "completed", "result_brief": "structured"}, bad_hash


def test_make_subagent_additional_kwargs_rejects_unknown_status():
    import pytest

    with pytest.raises(ValueError, match="invalid subagent status"):
        make_subagent_additional_kwargs("garbage")  # type: ignore[arg-type]