"""Supercharge tests for ``muse name-rev``.

Coverage tiers
--------------
- JSON envelope: exit_code and duration_ms present on all resolution outcomes
- Error payload: errors go to stdout as JSON in --json mode, no dual stderr prose
- Prefix resolution: bare hex short-prefix matches sha256:-prefixed keys in name_map
- TypedDicts: _NameRevJson and _NameRevErrorJson with required annotations
- Docstring: module docstring covers exit_code and duration_ms
- No-prose pollution: JSON stdout is valid on all non-error paths
- Stress: 100-commit chain, all entries have exit_code and duration_ms
"""
from __future__ import annotations
from collections.abc import Mapping

import datetime
import json
import pathlib
from typing import get_type_hints

from muse.core.ids import hash_commit as compute_commit_id, hash_snapshot as compute_snapshot_id
from muse.core.commits import (
    CommitRecord,
    write_commit,
)
from muse.core.snapshots import (
    SnapshotRecord,
    write_snapshot,
)
from muse.core.paths import ref_path, muse_dir
from tests.cli_test_helper import CliRunner, InvokeResult

runner = CliRunner()

_DT = datetime.datetime(2026, 1, 1, tzinfo=datetime.timezone.utc)


# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------


def _init_repo(tmp_path: pathlib.Path) -> pathlib.Path:
    dot_muse = muse_dir(tmp_path)
    for d in ("commits", "snapshots", "objects", "refs/heads"):
        (dot_muse / d).mkdir(parents=True, exist_ok=True)
    (dot_muse / "HEAD").write_text("ref: refs/heads/main", encoding="utf-8")
    (dot_muse / "repo.json").write_text(
        json.dumps({"repo_id": "nr-supercharge", "domain": "midi"}), encoding="utf-8"
    )
    return tmp_path


def _env(root: pathlib.Path) -> Mapping[str, str]:
    return {"MUSE_REPO_ROOT": str(root)}


def _commit(
    root: pathlib.Path,
    msg: str,
    branch: str = "main",
    parent: str | None = None,
) -> str:
    sid = compute_snapshot_id({})
    write_snapshot(root, SnapshotRecord(snapshot_id=sid, manifest={}, created_at=_DT))
    parent_ids = [parent] if parent else []
    cid = compute_commit_id(        parent_ids=parent_ids,
        snapshot_id=sid,
        message=msg,
        committed_at_iso=_DT.isoformat(),
    )
    write_commit(root, CommitRecord(
        commit_id=cid, branch=branch,
        snapshot_id=sid, message=msg, committed_at=_DT,
        parent_commit_id=parent,
    ))
    ref = ref_path(root, branch)
    ref.parent.mkdir(parents=True, exist_ok=True)
    ref.write_text(cid, encoding="utf-8")
    return cid


def _nr(root: pathlib.Path, *args: str, stdin: str | None = None) -> InvokeResult:
    from muse.cli.app import main as cli
    extra = [] if "--json" in args or "-j" in args else ["--json"]
    return runner.invoke(cli, ["name-rev", *extra, *args], env=_env(root), input=stdin)


def _hex_prefix(cid: str, n: int = 8) -> str:
    """Extract n hex chars from a sha256:-prefixed commit ID."""
    return cid[len("sha256:"):len("sha256:") + n]


# ---------------------------------------------------------------------------
# JSON envelope — exit_code
# ---------------------------------------------------------------------------


class TestJsonEnvelopeExitCode:
    def test_found_has_exit_code_zero(self, tmp_path: pathlib.Path) -> None:
        root = _init_repo(tmp_path)
        cid = _commit(root, "c1")
        r = _nr(root, cid)
        assert r.exit_code == 0
        d = json.loads(r.output)
        assert "exit_code" in d, "exit_code missing from found envelope"
        assert d["exit_code"] == 0

    def test_undefined_result_still_exit_code_zero(self, tmp_path: pathlib.Path) -> None:
        """undefined entries are a valid outcome — exit_code must still be 0."""
        root = _init_repo(tmp_path)
        _commit(root, "c1")
        fake = "a" * 64
        r = _nr(root, fake)
        assert r.exit_code == 0
        d = json.loads(r.output)
        assert "exit_code" in d
        assert d["exit_code"] == 0

    def test_mixed_found_and_undefined_exit_code_zero(self, tmp_path: pathlib.Path) -> None:
        root = _init_repo(tmp_path)
        cid = _commit(root, "c1")
        fake = "b" * 64
        r = _nr(root, cid, fake)
        assert r.exit_code == 0
        d = json.loads(r.output)
        assert d["exit_code"] == 0


# ---------------------------------------------------------------------------
# JSON envelope — duration_ms
# ---------------------------------------------------------------------------


class TestJsonEnvelopeDurationMs:
    def test_found_has_duration_ms(self, tmp_path: pathlib.Path) -> None:
        root = _init_repo(tmp_path)
        cid = _commit(root, "c1")
        r = _nr(root, cid)
        d = json.loads(r.output)
        assert "duration_ms" in d, "duration_ms missing from found envelope"
        assert isinstance(d["duration_ms"], float)
        assert d["duration_ms"] >= 0.0

    def test_undefined_has_duration_ms(self, tmp_path: pathlib.Path) -> None:
        root = _init_repo(tmp_path)
        _commit(root, "c1")
        r = _nr(root, "a" * 64)
        d = json.loads(r.output)
        assert "duration_ms" in d

    def test_branches_filter_has_duration_ms(self, tmp_path: pathlib.Path) -> None:
        root = _init_repo(tmp_path)
        cid = _commit(root, "c1", "main")
        r = _nr(root, cid, "--branches", "main")
        d = json.loads(r.output)
        assert "duration_ms" in d
        assert isinstance(d["duration_ms"], float)


# ---------------------------------------------------------------------------
# Error payload — errors route to stdout as JSON in --json mode
# ---------------------------------------------------------------------------


class TestErrorPayload:
    def test_no_inputs_error_goes_to_stdout(self, tmp_path: pathlib.Path) -> None:
        root = _init_repo(tmp_path)
        r = _nr(root, "--json")
        assert r.exit_code != 0
        assert not r.stderr.strip(), f"unexpected stderr: {r.stderr!r}"
        d = json.loads(r.output)
        assert d["status"] == "error"

    def test_invalid_hex_error_goes_to_stdout(self, tmp_path: pathlib.Path) -> None:
        root = _init_repo(tmp_path)
        r = _nr(root, "--json", "not-hex!")
        assert r.exit_code != 0
        assert not r.stderr.strip(), f"unexpected stderr: {r.stderr!r}"
        d = json.loads(r.output)
        assert d["status"] == "error"

    def test_bad_max_walk_error_goes_to_stdout(self, tmp_path: pathlib.Path) -> None:
        root = _init_repo(tmp_path)
        cid = _commit(root, "c1")
        r = _nr(root, "--json", cid, "--max-walk", "0")
        assert r.exit_code != 0
        assert not r.stderr.strip(), f"unexpected stderr: {r.stderr!r}"
        d = json.loads(r.output)
        assert d["status"] == "error"

    def test_error_payload_has_status_error(self, tmp_path: pathlib.Path) -> None:
        root = _init_repo(tmp_path)
        r = _nr(root, "--json", "not-valid!")
        d = json.loads(r.output)
        assert d["status"] == "error"

    def test_error_payload_has_exit_code(self, tmp_path: pathlib.Path) -> None:
        root = _init_repo(tmp_path)
        r = _nr(root, "--json", "not-valid!")
        d = json.loads(r.output)
        assert "exit_code" in d
        assert d["exit_code"] != 0

    def test_error_payload_has_error_field(self, tmp_path: pathlib.Path) -> None:
        root = _init_repo(tmp_path)
        r = _nr(root, "--json")
        d = json.loads(r.output)
        assert "error" in d
        assert d["error"]

    def test_no_emoji_on_stderr_in_json_mode(self, tmp_path: pathlib.Path) -> None:
        root = _init_repo(tmp_path)
        r = _nr(root, "--json", "not-valid!")
        assert "❌" not in r.stderr


# ---------------------------------------------------------------------------
# Prefix resolution — bare hex prefix against sha256:-prefixed keys
# ---------------------------------------------------------------------------


class TestPrefixResolutionSha256:
    def test_bare_hex_8char_prefix_resolves(self, tmp_path: pathlib.Path) -> None:
        """Bare 8-char hex prefix must resolve against sha256:-prefixed name_map keys."""
        root = _init_repo(tmp_path)
        cid = _commit(root, "c1")
        prefix = _hex_prefix(cid, 8)  # first 8 hex chars, no sha256: prefix
        r = _nr(root, prefix)
        assert r.exit_code == 0
        entry = json.loads(r.output)["results"][0]
        assert entry["commit_id"] == cid
        assert entry["undefined"] is False

    def test_bare_hex_4char_prefix_resolves(self, tmp_path: pathlib.Path) -> None:
        """4-char bare hex prefix must resolve when unambiguous."""
        root = _init_repo(tmp_path)
        cid = _commit(root, "unique-c1-msg")
        prefix = _hex_prefix(cid, 4)
        r = _nr(root, prefix)
        assert r.exit_code == 0
        entry = json.loads(r.output)["results"][0]
        # Either resolves to cid or is ambiguous — must not crash or error
        assert entry["input"] == prefix
        assert r.exit_code == 0

    def test_sha256_prefixed_short_id_resolves(self, tmp_path: pathlib.Path) -> None:
        """sha256:-prefixed short IDs (e.g. sha256:abcd1234) must also resolve."""
        root = _init_repo(tmp_path)
        cid = _commit(root, "c1")
        short = cid[:len("sha256:") + 8]  # keep sha256: + 8 hex chars
        r = _nr(root, short)
        assert r.exit_code == 0
        entry = json.loads(r.output)["results"][0]
        assert entry["commit_id"] == cid

    def test_input_field_preserves_bare_hex_prefix(self, tmp_path: pathlib.Path) -> None:
        """input field echoes the caller's original value, not the resolved full ID."""
        root = _init_repo(tmp_path)
        cid = _commit(root, "c1")
        prefix = _hex_prefix(cid, 8)
        r = _nr(root, prefix)
        entry = json.loads(r.output)["results"][0]
        assert entry["input"] == prefix


# ---------------------------------------------------------------------------
# No-prose pollution
# ---------------------------------------------------------------------------


class TestNoProsePollution:
    def test_found_stdout_is_valid_json(self, tmp_path: pathlib.Path) -> None:
        root = _init_repo(tmp_path)
        cid = _commit(root, "c1")
        r = _nr(root, cid)
        json.loads(r.output)  # must not raise

    def test_undefined_stdout_is_valid_json(self, tmp_path: pathlib.Path) -> None:
        root = _init_repo(tmp_path)
        _commit(root, "c1")
        json.loads(_nr(root, "a" * 64).output)

    def test_no_emoji_in_success_json(self, tmp_path: pathlib.Path) -> None:
        root = _init_repo(tmp_path)
        cid = _commit(root, "c1")
        r = _nr(root, cid)
        assert "✅" not in r.output
        assert "❌" not in r.output


# ---------------------------------------------------------------------------
# TypedDicts
# ---------------------------------------------------------------------------


class TestTypedDicts:
    def test_name_rev_json_typeddict_exists(self) -> None:
        from muse.cli.commands.name_rev import _NameRevJson
        assert _NameRevJson is not None

    def test_name_rev_error_json_typeddict_exists(self) -> None:
        from muse.cli.commands.name_rev import _NameRevErrorJson
        assert _NameRevErrorJson is not None

    def test_name_rev_json_has_exit_code_annotation(self) -> None:
        from muse.cli.commands.name_rev import _NameRevJson
        hints = get_type_hints(_NameRevJson)
        assert "exit_code" in hints

    def test_name_rev_json_has_duration_ms_annotation(self) -> None:
        from muse.cli.commands.name_rev import _NameRevJson
        hints = get_type_hints(_NameRevJson)
        assert "duration_ms" in hints

    def test_name_rev_error_json_has_required_fields(self) -> None:
        from muse.cli.commands.name_rev import _NameRevErrorJson
        hints = get_type_hints(_NameRevErrorJson)
        for field in ("status", "error", "exit_code"):
            assert field in hints, f"Missing annotation: {field!r}"


# ---------------------------------------------------------------------------
# Docstring coverage
# ---------------------------------------------------------------------------


class TestDocstring:
    def _doc(self) -> str:
        import muse.cli.commands.name_rev as mod
        return mod.__doc__ or ""

    def test_docstring_documents_exit_code(self) -> None:
        assert "exit_code" in self._doc()

    def test_docstring_documents_duration_ms(self) -> None:
        assert "duration_ms" in self._doc()


# ---------------------------------------------------------------------------
# Stress
# ---------------------------------------------------------------------------


class TestStress:
    def test_100_commit_chain_all_have_envelope_fields(self, tmp_path: pathlib.Path) -> None:
        root = _init_repo(tmp_path)
        parent: str | None = None
        commits: list[str] = []
        for i in range(100):
            cid = _commit(root, f"c{i:03d}", parent=parent)
            commits.append(cid)
            parent = cid

        r = _nr(root, commits[0], commits[49], commits[-1])
        assert r.exit_code == 0
        d = json.loads(r.output)
        assert "exit_code" in d
        assert "duration_ms" in d
        assert d["exit_code"] == 0
        assert isinstance(d["duration_ms"], float)
        # Tip at distance 0, midpoint at 50, root at 99
        by_id = {e["commit_id"]: e for e in d["results"]}
        assert by_id[commits[-1]]["distance"] == 0
        assert by_id[commits[49]]["distance"] == 50
        assert by_id[commits[0]]["distance"] == 99