"""Pure-function tests for outputs retention (v1.1 task add-outputs-retention)."""

import json
import os
import re
import textwrap
from pathlib import Path

# We import the runner module to test helpers directly.
import importlib.util
spec = importlib.util.spec_from_file_location(
    "lr", str(Path(__file__).resolve().parent.parent / "scripts" / "loop-runner.py")
)
lr = importlib.util.module_from_spec(spec)
spec.loader.exec_module(lr)


def _make_tick_file(out_dir: Path, tick_num: int, role: str, ext: str = ".json"):
    """Create a single tick output file for testing."""
    name = f"tick{tick_num}-{role}{ext}"
    (out_dir / name).write_text("{}")
    return name


def _make_tick_group(out_dir: Path, tick_num: int):
    """Create all 6 files for a tick group."""
    for role in ("implement", "verify", "orchestrate"):
        _make_tick_file(out_dir, tick_num, role, ".json")
        _make_tick_file(out_dir, tick_num, role + "-prompt", ".md")


class TestGetRetention:
    def test_default_main(self):
        assert lr._get_retention({}) == 20
        assert lr._get_retention({"outputs": {}}) == 20
        assert lr._get_retention({"outputs": {"retention": None}}) == 20

    def test_explicit_value(self):
        assert lr._get_retention({"outputs": {"retention": 5}}) == 5
        assert lr._get_retention({"outputs": {"retention": 0}}) == 0
        assert lr._get_retention({"outputs": {"retention": 100}}) == 100

    def test_negative_is_zero(self):
        assert lr._get_retention({"outputs": {"retention": -1}}) == 0
        assert lr._get_retention({"outputs": {"retention": -100}}) == 0

    def test_non_int_falls_back(self):
        assert lr._get_retention({"outputs": {"retention": "garbage"}}) == 20
        assert lr._get_retention({"outputs": {"retention": []}}) == 20

    def test_none_cfg_falls_back(self):
        assert lr._get_retention(None) == 20


class TestGcOutputs:
    def test_gc_keeps_recent_deletes_old(self, tmp_path):
        out = tmp_path / "outputs"
        out.mkdir()
        for i in range(1, 31):
            _make_tick_group(out, i)
        assert len(os.listdir(str(out))) == 30 * 6
        lr._gc_outputs(tmp_path, 20)
        remaining = os.listdir(str(out))
        assert len(remaining) == 20 * 6
        for i in range(11, 31):
            assert any(f"tick{i}-" in n for n in remaining), f"tick{i} should be kept"
        for i in range(1, 11):
            assert not any(f"tick{i}-" in n for n in remaining), f"tick{i} should be deleted"

    def test_retention_zero_skips_gc(self, tmp_path):
        out = tmp_path / "outputs"
        out.mkdir()
        for i in range(1, 31):
            _make_tick_group(out, i)
        lr._gc_outputs(tmp_path, 0)
        assert len(os.listdir(str(out))) == 30 * 6

    def test_retention_greater_than_file_count(self, tmp_path):
        out = tmp_path / "outputs"
        out.mkdir()
        for i in range(1, 6):
            _make_tick_group(out, i)
        lr._gc_outputs(tmp_path, 20)
        assert len(os.listdir(str(out))) == 5 * 6

    def test_missing_outputs_dir(self, tmp_path):
        lr._gc_outputs(tmp_path, 20)  # should not crash

    def test_non_tick_files_preserved(self, tmp_path):
        out = tmp_path / "outputs"
        out.mkdir()
        for i in range(1, 31):
            _make_tick_group(out, i)
        (out / "README.txt").write_text("keep me")
        (out / "loop-info.md").write_text("also keep")
        lr._gc_outputs(tmp_path, 20)
        remaining = os.listdir(str(out))
        assert "README.txt" in remaining
        assert "loop-info.md" in remaining

    def test_unrelated_tick_prefix_preserved(self, tmp_path):
        out = tmp_path / "outputs"
        out.mkdir()
        _make_tick_group(out, 1)
        (out / "tick-foo.md").write_text("no numeric index")
        lr._gc_outputs(tmp_path, 0)  # no gc; just verify regex doesn't break on tick-foo
        assert "tick-foo.md" in os.listdir(str(out))


    def test_gc_single_tick_group(self, tmp_path):
        out = tmp_path / "outputs"
        out.mkdir()
        _make_tick_group(out, 1)
        _make_tick_group(out, 2)
        lr._gc_outputs(tmp_path, 1)
        remaining = os.listdir(str(out))
        assert len(remaining) == 6
        assert any("tick2-" in n for n in remaining)
        assert not any("tick1-" in n for n in remaining)

    def test_gc_error_swallowed(self, tmp_path):
        out = tmp_path / "outputs"
        out.mkdir()
        _make_tick_group(out, 1)
        _make_tick_group(out, 2)
        # Make the directory read-only so unlink fails.
        prev_mode = os.stat(str(out)).st_mode
        os.chmod(str(out), 0o555)
        try:
            lr._gc_outputs(tmp_path, 1)
        finally:
            os.chmod(str(out), prev_mode)