"""muse#53 item 10 -- `muse symlog stat [FILE::SYMBOL] [--file path] [--json]`.

Summary statistics over a symbol's (or an entire file's) symlog journal.
"""

from __future__ import annotations

import json
import os
import pathlib
import textwrap

from tests.cli_test_helper import CliRunner

runner = CliRunner()


def _invoke(repo: pathlib.Path, args: list[str]):
    saved = os.getcwd()
    try:
        os.chdir(repo)
        return runner.invoke(None, args)
    finally:
        os.chdir(saved)


def _init_repo(repo: pathlib.Path) -> None:
    repo.mkdir(parents=True, exist_ok=True)
    _invoke(repo, ["init"])


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


def _commit(repo: pathlib.Path, msg: str, author: str = "claude-code") -> str:
    _invoke(repo, ["code", "add", "."])
    result = _invoke(repo, [
        "commit", "-m", msg,
        "--agent-id", "claude-code",
        "--model-id", "claude-sonnet-4-6",
        "--author", author,
        "--json",
    ])
    data = json.loads(result.stdout)
    return data["commit_id"]


def _make_repo(tmp_path: pathlib.Path) -> pathlib.Path:
    _init_repo(tmp_path)
    return tmp_path


def _symlog(repo: pathlib.Path, *args: str):
    return _invoke(repo, ["symlog", *args])


class TestSymlogStatSingleSymbol:
    def test_empty_symlog_reports_zero(self, tmp_path: pathlib.Path) -> None:
        repo = _make_repo(tmp_path)
        result = _symlog(repo, "stat", "src/billing.py::compute_total", "--json")
        data = json.loads(result.stdout)
        assert data["symbol"] == "src/billing.py::compute_total"
        assert data["total_entries"] == 0
        assert data["operation_breakdown"] == {}
        assert data["most_active_author"] is None
        assert data["first_commit_id"] is None
        assert data["last_commit_id"] is None

    def test_counts_created_and_modified(self, tmp_path: pathlib.Path) -> None:
        repo = _make_repo(tmp_path)
        _write_file(repo, "src/billing.py", "def compute_total(items):\n    return sum(items)\n")
        _commit(repo, "add compute_total")
        _write_file(repo, "src/billing.py", "def compute_total(items):\n    return sum(items) + 1\n")
        _commit(repo, "fix off-by-one")

        result = _symlog(repo, "stat", "src/billing.py::compute_total", "--json")
        data = json.loads(result.stdout)
        assert data["total_entries"] == 2
        assert data["operation_breakdown"]["symbol-created"] == 1
        assert data["operation_breakdown"]["symbol-modified"] == 1
        assert data["most_active_author"] == "claude-code"
        assert data["first_commit_id"] is not None
        assert data["last_commit_id"] is not None

    def test_missing_symbol_and_file_errors(self, tmp_path: pathlib.Path) -> None:
        repo = _make_repo(tmp_path)
        result = _symlog(repo, "stat", "--json")
        assert result.exit_code == 1

    def test_symbol_and_file_both_given_errors(self, tmp_path: pathlib.Path) -> None:
        repo = _make_repo(tmp_path)
        result = _symlog(repo, "stat", "src/billing.py::compute_total", "--file", "src/billing.py", "--json")
        assert result.exit_code == 1

    def test_invalid_symbol_address_errors(self, tmp_path: pathlib.Path) -> None:
        repo = _make_repo(tmp_path)
        result = _symlog(repo, "stat", "no-double-colon-here", "--json")
        assert result.exit_code == 1


class TestSymlogStatFileMode:
    def test_aggregates_across_symbols_in_file(self, tmp_path: pathlib.Path) -> None:
        repo = _make_repo(tmp_path)
        _write_file(repo, "src/billing.py", (
            "def compute_total(items):\n    return sum(items)\n\n"
            "def apply_discount(total, pct):\n    return total * (1 - pct)\n"
        ))
        _commit(repo, "add two functions")

        result = _symlog(repo, "stat", "--file", "src/billing.py", "--json")
        data = json.loads(result.stdout)
        assert data["file"] == "src/billing.py"
        assert data["symbol"] is None
        assert data["total_entries"] == 2
        assert data["operation_breakdown"]["symbol-created"] == 2

    def test_file_with_no_symlogs_reports_zero(self, tmp_path: pathlib.Path) -> None:
        repo = _make_repo(tmp_path)
        result = _symlog(repo, "stat", "--file", "src/nonexistent.py", "--json")
        data = json.loads(result.stdout)
        assert data["total_entries"] == 0