import asyncio
from typing import List, Optional

from rich.console import Console
from rich.live import Live
from rich.panel import Panel
from rich.table import Table

from bot.storage import Storage

_TYPE_LABELS = {"guild": "server", "group_dm": "group", "dm": "DM"}


def _render(stats: List[dict], friend_label: Optional[str] = None) -> Panel:
    table = Table(expand=True)
    table.add_column("Target")
    table.add_column("Type")
    table.add_column("Reactions", justify="right")
    table.add_column("Last reaction (UTC)")

    total = 0
    for row in stats:
        total += row["reaction_count"]
        table.add_row(
            row["name"] or row["target_id"],
            _TYPE_LABELS.get(row["target_type"], row["target_type"]),
            str(row["reaction_count"]),
            row["last_reaction_at"] or "-",
        )

    if not stats:
        table.add_row("(no targets discovered yet)", "-", "-", "-")

    who = f" for {friend_label}" if friend_label else ""
    return Panel(table, title=f"Reaction stats{who} — total: {total}", border_style="cyan")


class StatsDisplay:
    """A stats panel pinned to the bottom of the terminal, with normal
    log/print output scrolling above it (via rich.live.Live)."""

    def __init__(self, console: Console, storage: Storage):
        self.console = console
        self.storage = storage
        self.friend_label: Optional[str] = None
        self._live = Live(
            _render([]),
            console=console,
            refresh_per_second=4,
            transient=False,
        )

    def __enter__(self):
        self._live.__enter__()
        return self

    def __exit__(self, *exc_info):
        return self._live.__exit__(*exc_info)

    def set_friend(self, label: str) -> None:
        self.friend_label = label

    def refresh_sync(self) -> None:
        stats = self.storage.get_stats()
        self._live.update(_render(stats, self.friend_label))

    async def refresh(self) -> None:
        stats = await asyncio.to_thread(self.storage.get_stats)
        self._live.update(_render(stats, self.friend_label))