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

# --- Fix Missing QUndoStack in QtGui ---
import OdenGraphQt.base.graph as base_graph
base_graph.QtGui.QUndoStack = QtWidgets.QUndoStack  # Monkey-patch the missing QUndoStack

# --- 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()

# --- Node Management ---
def import_nodes_from_folder(package_name):
    imported_nodes = []
    package = importlib.import_module(package_name)
    for loader, module_name, is_pkg in pkgutil.walk_packages(package.__path__, package.__name__ + "."):
        module = importlib.import_module(module_name)
        for name, obj in inspect.getmembers(module, inspect.isclass):
            if issubclass(obj, BaseNode) and obj.__module__ == module.__name__:
                imported_nodes.append(obj)
    return imported_nodes

# --- Custom Graph View ---
class CustomGraphView(QGraphicsView):
    """
    Custom view for the graph that applies full transparency and handles right-click context menu.
    """
    def __init__(self, scene, graph, parent=None):
        super().__init__(scene, parent)
        self.graph = graph  # Reference to NodeGraph
        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)
        
        # Enable context menu on right-click
        self.setContextMenuPolicy(QtCore.Qt.CustomContextMenu)
        self.customContextMenuRequested.connect(self.show_context_menu)

    def show_context_menu(self, position):
        """
        Displays the node creation context menu with dynamically loaded nodes.
        """
        menu = QMenu()
        for node_class in self.graph.registered_nodes():
            node_name = getattr(node_class, "NODE_NAME", node_class.__name__)
            menu.addAction(f"Create {node_name}", lambda nc=node_class: self.create_node(nc))
        menu.exec_(self.mapToGlobal(position))

    def create_node(self, node_class):
        """
        Creates a node instance of the given class in the NodeGraph.
        """
        try:
            node = self.graph.create_node(f"{node_class.__identifier__}.{node_class.__name__}")
            print(f"Created node: {node_class.__name__}")
        except Exception as e:
            print(f"Error creating node: {e}")

# --- 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 NodeGraph
        self.graph = NodeGraph()
        
        # Load custom nodes
        custom_nodes = import_nodes_from_folder('Nodes')
        for node_class in custom_nodes:
            self.graph.register_node(node_class)
        
        # Initialize Custom Graph Scene & View
        self.scene = CustomGraphScene()
        self.view = CustomGraphView(self.scene, self.graph, self)
        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."""
        for node in self.graph.all_nodes():
            if hasattr(node, "process_input"):
                node.process_input()

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