
import pytest
import tempfile
from pathlib import Path
import sys
import asyncio

sys.path.insert(0, str(Path(__file__).parent.parent / "src"))

from fs_mcp.edit_tool import propose_and_review_logic

@pytest.fixture
def temp_env():
    """Sets up a temporary directory with a non-blank file."""
    temp_dir = Path(tempfile.mkdtemp(prefix="test_append_"))
    test_file = temp_dir / "existing_file.txt"
    test_file.write_text("Original content.\n", encoding='utf-8')

    def validate_path(path_str: str) -> Path:
        return Path(path_str)

    yield {
        "temp_dir": temp_dir,
        "test_file": test_file,
        "validate_path": validate_path
    }

    import shutil
    shutil.rmtree(temp_dir, ignore_errors=True)

class TestAppendSentinel:
    """Tests for the APPEND_TO_FILE sentinel functionality."""

    @pytest.mark.asyncio
    async def test_append_sentinel_functionality(self, temp_env):
        """APPEND_TO_FILE should append content to the end of the file."""
        
        # This currently fails (ValueError or timeout waiting for user review of "APPEND_TO_FILE" literal match)
        # We expect it to eventually PASS by creating a proposal that has:
        # Original content + new_string
        
        try:
            # We use a short timeout because if it works, it waits for user review
            # If it fails validation, it raises immediately
            await asyncio.wait_for(
                propose_and_review_logic(
                    validate_path=temp_env["validate_path"],
                    IS_VSCODE_CLI_AVAILABLE=False,
                    path=str(temp_env["test_file"]),
                    new_string="Appended line.",
                    match_text="APPEND_TO_FILE",
                    expected_replacements=1
                ),
                timeout=2.0
            )
        except asyncio.TimeoutError:
            # If it timed out, it means it passed validation and is waiting for user
            # This is GOOD for the validation part, but we want to verify the CONTENT
            pass
        except ValueError as e:
            # Currently expected failure: "Match not found" or similar
            # Once implemented, this should NOT raise
            raise e