from PyQt6.QtWidgets import (
    QWidget, QVBoxLayout, QHBoxLayout, 
    QLabel, QColorDialog, QScrollArea, QFrame, QSplitter, QMainWindow,
    QMessageBox
)
from PyQt6.QtGui import QColor, QAction, QKeySequence
from PyQt6.QtSvgWidgets import QSvgWidget
from PyQt6.QtCore import Qt

from svg_parser import SvgColorParser

class ColorSwatch(QFrame):
    def __init__(self, tag, color_hex, on_click):
        super().__init__()
        self.tag = tag
        self.color_hex = color_hex
        self.on_click = on_click
        
        self.setFrameStyle(QFrame.Shape.StyledPanel | QFrame.Shadow.Raised)
        self.setLineWidth(1)
        
        layout = QHBoxLayout()
        self.setLayout(layout)
        
        self.lbl_tag = QLabel(tag)
        self.lbl_color = QLabel(color_hex)
        
        self.swatch = QLabel()
        self.swatch.setFixedSize(30, 30)
        self.swatch.setAutoFillBackground(True)
        self.update_swatch_color(color_hex)
        
        layout.addWidget(self.swatch)
        layout.addWidget(self.lbl_tag)
        layout.addWidget(self.lbl_color)
        layout.addStretch()
        
    def update_swatch_color(self, hex_color):
        self.color_hex = hex_color
        self.lbl_color.setText(hex_color)
        self.swatch.setStyleSheet(f"background-color: {hex_color}; border: 1px solid black;")
        
    def mousePressEvent(self, event):
        if event.button() == Qt.MouseButton.LeftButton:
            self.on_click(self.tag, self.color_hex, self)

class MainWindow(QMainWindow):
    def __init__(self, svg_path):
        super().__init__()
        self.setWindowTitle(f"SVG Color Editor - {svg_path}")
        self.resize(800, 600)
        
        self.parser = SvgColorParser(svg_path)
        self.svg_path = svg_path
        
        self.setup_ui()
        self.setup_menu()
        
        if not self.parser.colors:
            QMessageBox.warning(self, "No Colors Found", "No ColorScheme tags were found in the SVG file.")
        
    def setup_menu(self):
        menubar = self.menuBar()
        edit_menu = menubar.addMenu("Edit")
        
        self.undo_action = QAction("Undo", self)
        self.undo_action.setShortcut(QKeySequence.StandardKey.Undo)
        self.undo_action.triggered.connect(self.undo)
        edit_menu.addAction(self.undo_action)
        
        self.redo_action = QAction("Redo", self)
        self.redo_action.setShortcut(QKeySequence.StandardKey.Redo)
        self.redo_action.triggered.connect(self.redo)
        edit_menu.addAction(self.redo_action)
        
    def setup_ui(self):
        central_widget = QWidget()
        self.setCentralWidget(central_widget)
        main_layout = QVBoxLayout(central_widget)
        
        splitter = QSplitter(Qt.Orientation.Horizontal)
        main_layout.addWidget(splitter)
        
        # Left Panel - Colors
        scroll_area = QScrollArea()
        scroll_area.setWidgetResizable(True)
        
        self.colors_widget = QWidget()
        self.colors_layout = QVBoxLayout(self.colors_widget)
        scroll_area.setWidget(self.colors_widget)
        
        splitter.addWidget(scroll_area)
        
        # Right Panel - SVG Preview
        preview_container = QWidget()
        preview_layout = QVBoxLayout(preview_container)
        
        self.svg_widget = QSvgWidget(str(self.svg_path))
        self.svg_widget.renderer().setAspectRatioMode(Qt.AspectRatioMode.KeepAspectRatio)
        preview_layout.addWidget(self.svg_widget)
        
        splitter.addWidget(preview_container)
        splitter.setSizes([350, 450])
        
        self.populate_colors()
        
    def populate_colors(self):
        # Clear layout
        while self.colors_layout.count():
            item = self.colors_layout.takeAt(0)
            widget = item.widget()
            if widget:
                widget.deleteLater()
                
        for tag, color in self.parser.colors.items():
            swatch = ColorSwatch(tag, color, self.on_swatch_click)
            self.colors_layout.addWidget(swatch)
            
        self.colors_layout.addStretch()
        
    def on_swatch_click(self, tag, current_color, swatch_widget):
        color = QColorDialog.getColor(QColor(current_color), self, f"Select Color for {tag}")
        if color.isValid():
            new_hex = color.name() # Returns #RRGGBB
            self.parser.update_color(tag, new_hex)
            swatch_widget.update_swatch_color(new_hex)
            self.refresh_preview()
            self.populate_colors()
            
    def refresh_preview(self):
        self.svg_widget.load(self.parser.content.encode('utf-8'))
        
    def undo(self):
        if self.parser.undo():
            self.refresh_preview()
            self.populate_colors()
            
    def redo(self):
        if self.parser.redo():
            self.refresh_preview()
            self.populate_colors()