from __future__ import annotations

from PySide6.QtCore import Qt
from PySide6.QtGui import QColor, QFont, QFontMetrics, QPainter
from PySide6.QtWidgets import QWidget


class OverlayWidget(QWidget):
    def __init__(self, parent: QWidget | None = None) -> None:
        super().__init__(parent)
        self.setAttribute(Qt.WA_TransparentForMouseEvents)
        self.setAttribute(Qt.WA_NoSystemBackground)
        self._visible = True
        self._metrics: dict[str, float | int | str] = {}

    def set_visible(self, visible: bool) -> None:
        self._visible = visible
        self.update()

    def set_metrics(self, metrics: dict[str, float | int | str]) -> None:
        self._metrics = metrics
        self.update()

    def paintEvent(self, event) -> None:  # noqa: N802
        if not self._visible or not self._metrics:
            return

        painter = QPainter(self)
        painter.setRenderHint(QPainter.TextAntialiasing)

        if "error" in self._metrics:
            self._paint_error(painter)
        else:
            self._paint_metrics(painter)

    def _paint_metrics(self, painter: QPainter) -> None:
        lines = [
            f"FPS:     {self._metrics.get('fps', 0):>7}",
            f"Frame:   {self._metrics.get('frame_time_ms', 0):>7.1f} ms",
            f"Frames:  {self._metrics.get('frame_count', 0):>7}",
        ]

        font = QFont("monospace", 11)
        painter.setFont(font)
        fm = QFontMetrics(font)

        text_width = max(fm.horizontalAdvance(line) for line in lines) + 24
        text_height = len(lines) * (fm.height() + 6) + 12

        painter.fillRect(8, 8, text_width, text_height, QColor(0, 0, 0, 160))
        painter.setPen(QColor(0, 255, 0))

        for i, line in enumerate(lines):
            y = 22 + i * (fm.height() + 6)
            painter.drawText(16, y, line)

    def _paint_error(self, painter: QPainter) -> None:
        msg = str(self._metrics.get("error", "Unknown error"))
        lines = msg.split("\n")

        font = QFont("monospace", 12)
        painter.setFont(font)
        fm = QFontMetrics(font)

        text_width = max(fm.horizontalAdvance(line) for line in lines) + 24
        text_height = len(lines) * (fm.height() + 6) + 12

        painter.fillRect(8, 8, text_width, text_height, QColor(0, 0, 0, 200))
        painter.setPen(QColor(200, 50, 50))

        for i, line in enumerate(lines):
            y = 22 + i * (fm.height() + 6)
            painter.drawText(16, y, line)