"""

"""

import logging
from pathlib import Path

import aiofiles

log = logging.getLogger(__name__)


class LogFileReader:
    """
    """
    def __init__(self, file_path: Path, track_from_start: bool=False):
        if not isinstance(file_path, Path):
            raise TypeError(f"file_path must be type Path, not {type(file_path)}")

        self.file_path = file_path
        self.track_from_start = track_from_start
        self._last_line_number = 0
        log.debug("%s created with path %s", self.__class__.__name__, str(file_path))

    async def read(self) -> list[str]:
        if not self.file_path.exists():
            log.error("Cannot read non-existant file path: '%s'", self.file_path)
            raise FileNotFoundError(self.file_path)

        async with aiofiles.open(self.file_path, "r", encoding="utf-8") as file:
            log.debug("file open, and jumping to line: %s", self._last_line_number)
            if self._last_line_number == 0 and not self.track_from_start:
                await file.seek(0, 2)
                self._last_line_number = await file.tell()
                return []

            await file.seek(self._last_line_number)
            lines = await file.readlines()
            if not lines:
                log.debug("no new lines to read")
                return []

            self._last_line_number = await file.tell()
            return lines