"""muse#53 item 7 -- `muse code checkout-symbol "file.py::Symbol@{N}"`.

ADDRESS may embed a symlog ref directly instead of requiring a separate
--commit flag -- the natural extension of `muse code cat`/`muse symlog
resolve`'s addr@{N} syntax: cat reads, checkout-symbol restores.
"""

from __future__ import annotations

import json
import pathlib
import textwrap

import pytest

from tests.cli_test_helper import CliRunner

cli = None
runner = CliRunner()


@pytest.fixture
def repo(tmp_path: pathlib.Path, monkeypatch: pytest.MonkeyPatch) -> pathlib.Path:
    monkeypatch.chdir(tmp_path)
    monkeypatch.setenv("MUSE_REPO_ROOT", str(tmp_path))
    result = runner.invoke(cli, ["init", "--domain", "code"])
    assert result.exit_code == 0, result.output
    return tmp_path


@pytest.fixture
def two_commit_repo(repo: pathlib.Path) -> pathlib.Path:
    (repo / "billing.py").write_text(textwrap.dedent("""\
        def compute(items):
            return sum(items)
    """))
    runner.invoke(cli, ["code", "add", "."])
    r1 = runner.invoke(cli, ["commit", "-m", "v1"])
    assert r1.exit_code == 0, r1.output

    (repo / "billing.py").write_text(textwrap.dedent("""\
        def compute(items):
            return sum(items) * 2
    """))
    runner.invoke(cli, ["code", "add", "."])
    r2 = runner.invoke(cli, ["commit", "-m", "v2"])
    assert r2.exit_code == 0, r2.output
    return repo


class TestCheckoutSymbolWithSymlogRef:
    def test_restores_older_version_via_symlog_ref(self, two_commit_repo: pathlib.Path) -> None:
        result = runner.invoke(
            cli, ["code", "checkout-symbol", "billing.py::compute@{1}", "--json"],
        )
        assert result.exit_code == 0, result.output
        data = json.loads(result.output)
        assert data["changed"] is True
        assert data["address"] == "billing.py::compute"

        content = (two_commit_repo / "billing.py").read_text()
        assert "* 2" not in content
        assert "return sum(items)" in content

    def test_at_index_0_is_a_noop(self, two_commit_repo: pathlib.Path) -> None:
        result = runner.invoke(
            cli, ["code", "checkout-symbol", "billing.py::compute@{0}", "--json"],
        )
        assert result.exit_code == 0, result.output
        data = json.loads(result.output)
        assert data["changed"] is False

        content = (two_commit_repo / "billing.py").read_text()
        assert "* 2" in content

    def test_symlog_ref_and_commit_flag_together_errors(self, two_commit_repo: pathlib.Path) -> None:
        result = runner.invoke(
            cli, [
                "code", "checkout-symbol", "billing.py::compute@{1}",
                "--commit", "HEAD", "--json",
            ],
        )
        assert result.exit_code != 0

    def test_out_of_range_index_errors(self, two_commit_repo: pathlib.Path) -> None:
        result = runner.invoke(
            cli, ["code", "checkout-symbol", "billing.py::compute@{99}", "--json"],
        )
        assert result.exit_code != 0

    def test_plain_address_without_commit_still_errors(self, two_commit_repo: pathlib.Path) -> None:
        """Non-regression: a plain address (no @{N}) still requires --commit."""
        result = runner.invoke(
            cli, ["code", "checkout-symbol", "billing.py::compute", "--json"],
        )
        assert result.exit_code != 0

    def test_plain_address_with_commit_still_works(self, two_commit_repo: pathlib.Path) -> None:
        """Non-regression: the original --commit REF form still works."""
        result = runner.invoke(
            cli, ["code", "checkout-symbol", "billing.py::compute", "--commit", "HEAD~1", "--json"],
        )
        assert result.exit_code == 0, result.output
        data = json.loads(result.output)
        assert data["changed"] is True