"""MCP as the standard entry: the method travels, and describe fans out.

Subagents inherit a session's MCP tools; they do not inherit its skills. So a
working method that lives only in a skill reaches the main thread and no arm
below it, and the one place it can reach every caller is the server's own
`instructions` and tool descriptions -- both capped by Claude Code at 2 KB
each, which is why what travels is the SHORT version and the long one stays in
the skill.
"""

from __future__ import annotations

import sys
from pathlib import Path

import pytest

PROJECT_ROOT = Path(__file__).resolve().parents[1]
sys.path.insert(0, str(PROJECT_ROOT / "src"))

from llm_ingestion_okf import consume as okf_consume  # noqa: E402
from llm_ingestion_okf import mcp_server, project  # noqa: E402

GOLDEN = PROJECT_ROOT / "examples" / "ingest-golden-segmented-okf-v0-2" / "expected-bundle"
FIXTURE = PROJECT_ROOT / "tests" / "fixtures" / "consume-bundle"

#: Claude Code truncates server instructions and each tool description at 2 KB
#: (`docs-en-mcp.md`). A description over it is not rejected -- it is CUT, which
#: is worse: the reader gets the first half of a method and no sign that the
#: rest existed.
CLIENT_TRUNCATION_BYTES = 2048


@pytest.fixture
def served(tmp_path: Path) -> mcp_server.Surface:
    root = tmp_path / "root"
    (root / "a").mkdir(parents=True)
    (root / "b").mkdir(parents=True)
    for name, source in (("a", GOLDEN), ("b", FIXTURE)):
        for path in source.rglob("*"):
            if path.is_file():
                target = root / name / path.relative_to(source)
                target.parent.mkdir(parents=True, exist_ok=True)
                target.write_bytes(path.read_bytes())
    return mcp_server.Surface(roots=(root,), fixed=None, profile=okf_consume.DEFAULT_PROFILE)


def _instructions(surface: mcp_server.Surface) -> str:
    result = mcp_server.handle(surface, "initialize", {})
    assert isinstance(result["instructions"], str)
    return result["instructions"]


def test_the_instructions_carry_the_short_working_method(served: mcp_server.Surface) -> None:
    text = _instructions(served)
    for mark in ("bundle's own words", "sub-question", "ask again", "outside the cut"):
        assert mark in text, f"the instructions do not say {mark!r}"


def test_the_instructions_fit_inside_what_the_client_keeps(
    served: mcp_server.Surface,
) -> None:
    text = _instructions(served)
    assert len(text.encode("utf-8")) <= CLIENT_TRUNCATION_BYTES
    # The control: the limit is one this text could realistically cross, so
    # the assertion above is a measurement and not a tautology.
    assert len(text.encode("utf-8")) > CLIENT_TRUNCATION_BYTES // 4


def test_every_tool_description_fits_and_the_asking_one_carries_the_method(
    served: mcp_server.Surface,
) -> None:
    by_name = {tool.name: tool for tool in mcp_server.tools(served)}
    for name, tool in by_name.items():
        assert len(tool.description.encode("utf-8")) <= CLIENT_TRUNCATION_BYTES, name
    assert "ask again" in by_name["okf_ask"].description
    assert "withheld" in by_name["okf_ask"].description


def test_describe_without_a_bundle_id_answers_for_every_served_bundle(
    served: mcp_server.Surface,
) -> None:
    """It refused instead, where `okf_ask` in the same position fans out.

    A tool that refuses the call a sibling tool accepts is a shape a client
    has to learn out of band, which is the configuration this server exists to
    remove.
    """
    result = mcp_server.call_describe(served, {})
    assert sorted(result["asked"]) == ["b-golden-segmented-okf-v0-2", "consume-fixture"]
    cards = result["cards"]
    assert isinstance(cards, list) and len(cards) == 2
    assert sorted(str(card["bundle_id"]) for card in cards) == sorted(result["asked"])


def test_describe_with_a_bundle_id_is_the_card_it_always_was(
    served: mcp_server.Surface,
) -> None:
    named = mcp_server.call_describe(served, {"bundle_id": "consume-fixture"})
    assert named["bundle_id"] == "consume-fixture"
    assert "cards" not in named


def test_a_one_to_one_server_still_answers_with_its_own_card(tmp_path: Path) -> None:
    surface = mcp_server.Surface(
        roots=(GOLDEN,), fixed="b-golden-segmented-okf-v0-2", profile=okf_consume.DEFAULT_PROFILE
    )
    assert mcp_server.call_describe(surface, {})["bundle_id"] == "b-golden-segmented-okf-v0-2"


def test_the_ask_answer_carries_the_compact_withheld_block(
    served: mcp_server.Surface,
) -> None:
    """A2 reaches the MCP arm because the payload is the payload."""
    result = mcp_server.call_ask(served, {"question": "Hva sier veiledningen om krav?"})
    for answer in result["answers"]:
        block = answer["payload"]["withheld"]
        assert set(block) == {"total", "by_rule", "nearest", "complete"}


def test_the_readme_carries_the_one_line_that_registers_the_server() -> None:
    """The user runs it. This package never starts Claude Code."""
    readme = (PROJECT_ROOT / "README.md").read_text(encoding="utf-8")
    assert "claude mcp add --scope user okf -- okf mcp --root" in readme


def test_the_project_summary_says_what_to_do_next_with_the_server(tmp_path: Path) -> None:
    folder = tmp_path / "Dokumenter"
    folder.mkdir()
    (folder / "krav.md").write_text(
        "## 4 Grunnforhold\n\nGrunnen er morene over berg.\n", encoding="utf-8", newline=""
    )
    _, _, summary = project.create(folder, out=tmp_path / "project")
    assert "claude mcp add --scope user okf -- okf mcp --root" in summary


def test_a_project_bundle_is_where_a_root_server_finds_it(tmp_path: Path) -> None:
    """`--root <the directory holding projects>` must reach `<project>/.okf/<id>`.

    Measured rather than reasoned: the walk is bounded at
    `MAX_DISCOVERY_DEPTH`, and `.okf` spends one level of it.
    """
    projects = tmp_path / "okf"
    folder = projects / "Mitt Prosjekt" / "kilder"
    folder.mkdir(parents=True)
    (folder / "krav.md").write_text(
        "## 4 Grunnforhold\n\nGrunnen er morene over berg.\n", encoding="utf-8", newline=""
    )
    project.create(folder, out=projects / "Mitt Prosjekt", bundle_id="mitt-prosjekt")
    found = mcp_server.discover((projects,))
    assert [served.bundle_id for served in found.bundles] == ["mitt-prosjekt"]


def test_the_skill_command_refuses_a_missing_out_in_its_own_form(tmp_path: Path) -> None:
    """A5: exit 2 was already right; the TEXT was argparse's, not okf's.

    Every other refusal in this chain reads `refused (<code>): <what>`, and a
    caller parsing that form got one line that did not match on the one flag
    everybody forgets. The code stays 2 -- "the run did not happen" -- because
    that is what it is.
    """
    import subprocess

    result = subprocess.run(
        [sys.executable, "-m", "llm_ingestion_okf.cli", "skill"],
        capture_output=True,
        text=True,
        check=False,
        cwd=PROJECT_ROOT,
    )
    assert result.returncode == 2
    assert "refused (out_missing)" in result.stderr
    assert "--out" in result.stderr