"""Large image of the hovered card, with a text fallback while it downloads."""

from __future__ import annotations

from PySide6.QtCore import QSize, Qt, Signal
from PySide6.QtGui import QMouseEvent, QPixmap, QResizeEvent
from PySide6.QtWidgets import QHBoxLayout, QLabel, QSizePolicy, QToolButton, QVBoxLayout, QWidget

from ..carddb import CardDB
from ..images import ImageCache


class CardPreview(QWidget):
    cleared = Signal()

    def __init__(self, cards: CardDB, images: ImageCache, parent=None):
        super().__init__(parent)
        self.cards = cards
        self.images = images
        self.grp_id: int | None = None
        self._pixmap: QPixmap | None = None

        self.image = QLabel()
        self.image.setAlignment(Qt.AlignmentFlag.AlignCenter)
        self.image.setSizePolicy(QSizePolicy.Policy.Ignored, QSizePolicy.Policy.Ignored)
        self.image.setMinimumSize(200, 280)
        self.caption = QLabel()
        self.caption.setWordWrap(True)
        self.caption.setAlignment(Qt.AlignmentFlag.AlignCenter)

        self.close_btn = QToolButton()
        self.close_btn.setText("✕")
        self.close_btn.setToolTip("Stop previewing this card (Esc, or click the image)")
        self.close_btn.clicked.connect(self.clear)
        top = QHBoxLayout()
        top.addStretch(1)
        top.addWidget(self.close_btn)

        lay = QVBoxLayout(self)
        lay.setContentsMargins(4, 4, 4, 4)
        lay.addLayout(top)
        lay.addWidget(self.image, 1)
        lay.addWidget(self.caption)

        images.image_ready.connect(self._on_image_ready)
        self.clear()

    def clear(self) -> None:
        """Back to the empty state."""
        was_showing = self.grp_id is not None
        self.grp_id = None
        self.caption.setText("")
        self._show_placeholder("Hover a card to preview it")
        self.close_btn.setVisible(False)
        if was_showing:
            self.cleared.emit()

    def mousePressEvent(self, event: QMouseEvent) -> None:
        if event.button() == Qt.MouseButton.LeftButton and self.grp_id is not None:
            self.clear()
            return
        super().mousePressEvent(event)

    def show_card(self, grp_id: int) -> None:
        if grp_id == self.grp_id:
            return
        self.grp_id = grp_id
        self.close_btn.setVisible(True)
        info = self.cards.get(grp_id)
        details = [info.type_line]
        if info.power or info.toughness:
            details.append(f"{info.power}/{info.toughness}")
        if info.set_code:
            details.append(f"{info.set_code} #{info.collector_number}")
        self.caption.setText(f"<b>{info.name}</b><br>{' · '.join(d for d in details if d)}")
        pm = self.images.pixmap(grp_id)
        if pm is not None:
            self._pixmap = pm
            self._rescale()
        elif self.images.is_failed(grp_id):
            self._show_placeholder("No image available")
        else:
            self._show_placeholder("Loading image…")

    def _show_placeholder(self, text: str) -> None:
        self._pixmap = None
        self.image.setPixmap(QPixmap())
        self.image.setText(text)

    def _on_image_ready(self, grp_id: int) -> None:
        if grp_id == self.grp_id:
            self.grp_id = None
            self.show_card(grp_id)

    def _rescale(self) -> None:
        if self._pixmap is None:
            return
        self.image.setPixmap(
            self._pixmap.scaled(self.image.size(), Qt.AspectRatioMode.KeepAspectRatio,
                                Qt.TransformationMode.SmoothTransformation)
        )

    def resizeEvent(self, event: QResizeEvent) -> None:
        super().resizeEvent(event)
        self._rescale()

    def sizeHint(self) -> QSize:
        return QSize(320, 600)