from __future__ import annotations

from PyQt6.QtCore import Qt, pyqtSignal
from PyQt6.QtGui import QMouseEvent
from PyQt6.QtWidgets import QApplication, QFrame, QLabel, QPushButton, QVBoxLayout

from .theme import app_logo_pixmap


class DropZone(QFrame):
    """The empty-state target for drag and drop."""

    browseRequested = pyqtSignal()

    def __init__(self, parent=None):
        super().__init__(parent)
        self.setObjectName("dropZone")
        self.setProperty("dragActive", False)
        self.setCursor(Qt.CursorShape.PointingHandCursor)
        self.setMinimumHeight(250)

        layout = QVBoxLayout(self)
        layout.setContentsMargins(28, 26, 28, 26)
        layout.setSpacing(12)
        layout.addStretch(1)

        icon_label = QLabel()
        icon_label.setAlignment(Qt.AlignmentFlag.AlignCenter)
        screen = QApplication.primaryScreen()
        dpr = screen.devicePixelRatio() if screen else 1.0
        pixmap = app_logo_pixmap(max(64, int(64 * dpr)))
        pixmap.setDevicePixelRatio(dpr)
        icon_label.setPixmap(pixmap)
        layout.addWidget(icon_label)

        self.title_label = QLabel("Drop media to get started")
        self.title_label.setObjectName("emptyTitle")
        self.title_label.setAlignment(Qt.AlignmentFlag.AlignCenter)
        layout.addWidget(self.title_label)

        subtitle = QLabel(
            "Videos and images are compressed locally, on your computer.\n"
            "MP4 · MOV · MKV · JPG · PNG · WebP"
        )
        subtitle.setObjectName("emptyText")
        subtitle.setAlignment(Qt.AlignmentFlag.AlignCenter)
        subtitle.setWordWrap(True)
        layout.addWidget(subtitle)

        button = QPushButton("Browse files")
        button.setObjectName("accentSmall")
        button.setCursor(Qt.CursorShape.PointingHandCursor)
        button.clicked.connect(self.browseRequested)
        layout.addWidget(button, 0, Qt.AlignmentFlag.AlignHCenter)

        hint = QLabel("or drag and drop anywhere in this window")
        hint.setObjectName("hintLabel")
        hint.setAlignment(Qt.AlignmentFlag.AlignCenter)
        layout.addWidget(hint)
        layout.addStretch(1)

    def set_drag_active(self, active: bool) -> None:
        if bool(self.property("dragActive")) == active:
            return
        self.setProperty("dragActive", active)
        self.title_label.setText("Drop to add to the queue" if active else "Drop media to get started")
        self.style().unpolish(self)
        self.style().polish(self)
        self.update()

    def mouseReleaseEvent(self, event: QMouseEvent) -> None:
        if event.button() == Qt.MouseButton.LeftButton:
            self.browseRequested.emit()
        super().mouseReleaseEvent(event)