from __future__ import annotations

from collections import deque
from dataclasses import dataclass
from typing import Deque, List, Sequence

from ameba_control_panel import config
from ameba_control_panel.utils.timeutils import timestamp_ms


@dataclass
class LogLine:
    text: str
    direction: str  # "rx", "tx", "info"
    timestamp: str

    def as_display(self) -> str:
        return f"{self.timestamp} {self.text}"


class LogBuffer:
    """Keeps a full archive plus a bounded UI tail."""

    def __init__(self, max_tail: int = config.UI_LOG_TAIL_LINES) -> None:
        self._max_tail = max_tail
        self._tail: Deque[LogLine] = deque(maxlen=max_tail)
        self._archive: List[LogLine] = []

    def append(self, text: str, direction: str) -> LogLine:
        line = LogLine(text=text.rstrip("\n"), direction=direction, timestamp=timestamp_ms())
        self._tail.append(line)
        self._archive.append(line)
        return line

    def extend(self, items: Sequence[LogLine]) -> None:
        for line in items:
            self._tail.append(line)
            self._archive.append(line)

    def tail(self) -> Deque[LogLine]:
        return self._tail

    def archive(self) -> List[LogLine]:
        return self._archive

    def clear(self) -> None:
        self._tail.clear()
        self._archive.clear()

    def as_text(self, full: bool = False) -> str:
        source = self._archive if full else self._tail
        return "\n".join(line.as_display() for line in source)