import sys
import pkgutil
import importlib
import inspect
from PyQt5.QtWidgets import QApplication, QMainWindow, QWidget, QVBoxLayout, QGraphicsView, QGraphicsScene, QGraphicsItem
from PyQt5.QtCore import Qt, QTimer, QRectF, QPointF
from PyQt5.QtGui import QColor, QPainter, QPen, QBrush, QGradient, QLinearGradient
from PyQt5 import QtWidgets, QtCore, QtGui

# --- Custom Graph Scene ---
class CustomGraphScene(QGraphicsScene):
    """
    Custom scene that draws a blueprint-style transparent grid with gradient shading.
    """
    def __init__(self, parent=None):
        super().__init__(parent)
        self.setBackgroundBrush(QtCore.Qt.transparent)
        self.grid_color = QtGui.QColor(100, 160, 160, 160)  # Blueprint grid color (10% more transparent)
        self.grid_size = 115

    def drawBackground(self, painter, rect):
        """
        Custom draw function to render a blueprint-style grid with gradient shading.
        """
        painter.save()
        painter.setRenderHint(QPainter.Antialiasing, False)
        painter.setBrush(QtCore.Qt.NoBrush)  # No background fill
        pen = QPen(self.grid_color, 0.5)

        left = int(rect.left()) - (int(rect.left()) % self.grid_size)
        top = int(rect.top()) - (int(rect.top()) % self.grid_size)
        
        # Draw vertical lines
        lines = []
        for x in range(left, int(rect.right()), self.grid_size):
            lines.append(QtCore.QLineF(x, rect.top(), x, rect.bottom()))
        
        # Draw horizontal lines
        for y in range(top, int(rect.bottom()), self.grid_size):
            lines.append(QtCore.QLineF(rect.left(), y, rect.right(), y))
        
        painter.setPen(pen)
        painter.drawLines(lines)
        
        # Draw gradient shading (top and bottom)
        gradient = QLinearGradient(QPointF(rect.left(), rect.top()), QPointF(rect.left(), rect.bottom()))
        gradient.setColorAt(0.0, QColor(0, 40, 100, 220))  # Darker blue at the top
        gradient.setColorAt(0.5, QColor(0, 0, 0, 0))  # Transparent in the middle
        gradient.setColorAt(1.0, QColor(0, 40, 100, 220))  # Darker blue at the bottom
        painter.fillRect(rect, QBrush(gradient))
        
        painter.restore()

# --- Custom Graph View ---
class CustomGraphView(QGraphicsView):
    """
    Custom view for the graph that applies full transparency.
    """
    def __init__(self, scene, parent=None):
        super().__init__(scene, parent)
        self.setRenderHints(QtGui.QPainter.Antialiasing | QtGui.QPainter.SmoothPixmapTransform)
        self.setViewportUpdateMode(QGraphicsView.FullViewportUpdate)
        self.setHorizontalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
        self.setVerticalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
        self.setStyleSheet("background: transparent; border: none;")
        self.setAttribute(QtCore.Qt.WA_TranslucentBackground, True)

# --- Main Window ---
class MainWindow(QMainWindow):
    """A frameless, transparent overlay with a custom graph."""
    def __init__(self):
        super().__init__()

        # Full-screen overlay
        app = QApplication.instance()
        screen_geo = app.primaryScreen().geometry()
        self.setGeometry(screen_geo)

        # Frameless, top-most, fully transparent
        self.setWindowFlags(Qt.FramelessWindowHint | Qt.WindowStaysOnTopHint)
        self.setAttribute(Qt.WA_TranslucentBackground, True)

        # Transparent central widget
        central = QWidget(self)
        central.setAttribute(Qt.WA_TranslucentBackground, True)
        layout = QVBoxLayout(central)
        layout.setContentsMargins(0, 0, 0, 0)
        self.setCentralWidget(central)

        # Initialize Custom Graph Scene & View
        self.scene = CustomGraphScene()
        self.view = CustomGraphView(self.scene)
        layout.addWidget(self.view)

        # Global update timer
        self.timer = QTimer(self)
        self.timer.timeout.connect(self.global_update)
        self.timer.start(500)

    def global_update(self):
        """Update all nodes periodically (to be implemented)."""
        pass

# --- Entry Point ---
if __name__ == '__main__':
    app = QApplication(sys.argv)
    window = MainWindow()
    window.show()
    sys.exit(app.exec_())