"""muse#53 item 11 -- symlog entries for `muse revert`.

`muse revert` records a reflog entry for the branch ref move, but
previously wrote no symlog entries for the symbols it touched. A revert
of a commit that modified a symbol should produce a symbol-modified
entry in that symbol's journal, just like a normal `muse commit` would.
"""

from __future__ import annotations

import json
import pathlib
from collections.abc import Mapping

import pytest

from tests.cli_test_helper import CliRunner

cli = None
runner = CliRunner()


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


@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))
    r = runner.invoke(cli, ["init"], env=_env(tmp_path), catch_exceptions=False)
    assert r.exit_code == 0, r.output
    return tmp_path


def _write(repo: pathlib.Path, rel: str, content: str) -> None:
    p = repo / rel
    p.parent.mkdir(parents=True, exist_ok=True)
    p.write_text(content)


def _commit(repo: pathlib.Path, msg: str) -> str:
    runner.invoke(cli, ["code", "add", "."], env=_env(repo), catch_exceptions=False)
    result = runner.invoke(cli, ["commit", "-m", msg, "--json"], env=_env(repo), catch_exceptions=False)
    assert result.exit_code == 0, result.output
    return json.loads(result.output)["commit_id"]


def _symlog(repo: pathlib.Path, *args: str):
    return runner.invoke(cli, ["symlog", *args], env=_env(repo), catch_exceptions=False)


class TestRevertWritesSymlog:
    def test_revert_of_symbol_modifying_commit_writes_symlog_entry(self, repo: pathlib.Path) -> None:
        _write(repo, "src/billing.py", "def compute_total(items):\n    return sum(items)\n")
        _commit(repo, "add compute_total")
        _write(repo, "src/billing.py", "def compute_total(items):\n    return sum(items) * 2\n")
        doubled_commit = _commit(repo, "double the total")

        # Before revert: 2 symlog entries (created + modified).
        before = json.loads(_symlog(repo, "src/billing.py::compute_total", "--json").output)
        assert before["total"] == 2

        # Revert the "double the total" commit, restoring the prior body.
        result = runner.invoke(
            cli, ["revert", doubled_commit, "--json"], env=_env(repo), catch_exceptions=False,
        )
        assert result.exit_code == 0, result.output

        after = json.loads(_symlog(repo, "src/billing.py::compute_total", "--json").output)
        assert after["total"] == 3
        assert after["entries"][0]["operation"].startswith("symbol-modified")

    def test_revert_no_commit_does_not_write_symlog(self, repo: pathlib.Path) -> None:
        """--no-commit only stages changes -- no commit record exists yet,
        so there's nothing for a symlog entry to attach to."""
        _write(repo, "src/billing.py", "def compute_total(items):\n    return sum(items)\n")
        _commit(repo, "add compute_total")
        _write(repo, "src/billing.py", "def compute_total(items):\n    return sum(items) * 2\n")
        doubled_commit = _commit(repo, "double the total")

        before = json.loads(_symlog(repo, "src/billing.py::compute_total", "--json").output)

        result = runner.invoke(
            cli, ["revert", doubled_commit, "--no-commit", "--json"], env=_env(repo), catch_exceptions=False,
        )
        assert result.exit_code == 0, result.output

        after = json.loads(_symlog(repo, "src/billing.py::compute_total", "--json").output)
        assert after["total"] == before["total"]