Teletext-Editor/src/teletext/ui.py

from PyQt6.QtWidgets import (
    QMainWindow, QWidget, QVBoxLayout, QHBoxLayout, 
    QListWidget, QListWidgetItem, QComboBox, QLabel, QLineEdit, QPushButton, 
    QFileDialog, QMenuBar, QMenu, QMessageBox, QStatusBar, QProgressBar, QApplication
)

# ... (imports remain)

# ... (imports remain)
from PyQt6.QtGui import QAction, QKeyEvent
from PyQt6.QtCore import Qt

from .io import load_t42, save_t42
from .renderer import TeletextCanvas, create_blank_packet
import copy
import sys
import os
from .models import TeletextService, Page, Packet

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.setWindowTitle("Teletext Editor")
        self.resize(1024, 768)
        
        self.service = TeletextService()
        self.current_page: Page = None
        self.clipboard = [] # List of (row, data_bytes)
        self.undo_stack = []
        self.redo_stack = []
        self.is_modified = False
        
        # UI Components
        self.central_widget = QWidget()
        self.setCentralWidget(self.central_widget)
        
        self.layout = QHBoxLayout(self.central_widget)
        
        # Left Panel: Page List
        left_layout = QVBoxLayout()
        left_label = QLabel("Pages")
        left_layout.addWidget(left_label)
        
        self.page_list = QListWidget()
        self.page_list.setFixedWidth(150)
        self.page_list.itemClicked.connect(self.on_page_selected)
        left_layout.addWidget(self.page_list)
        
        # Hex Inspector
        hex_layout = QVBoxLayout()
        hex_label = QLabel("Hex Value:")
        self.hex_input = QLineEdit()
        self.hex_input.setMaxLength(2)
        self.hex_input.setPlaceholderText("00")
        self.hex_input.returnPressed.connect(self.on_hex_entered)
        hex_layout.addWidget(hex_label)
        hex_layout.addWidget(self.hex_input)
        left_layout.addLayout(hex_layout)
        
        left_layout.addStretch()
        
        self.layout.addLayout(left_layout)
        
        # Center Area Layout (Top Bar + Canvas)
        center_layout = QVBoxLayout()
        
        # Top Bar: Subpage Selector
        top_bar = QHBoxLayout()
        self.subpage_label = QLabel("Subpage:")
        self.subpage_combo = QComboBox()
        self.subpage_combo.setMinimumWidth(250)
        self.subpage_combo.currentIndexChanged.connect(self.on_subpage_changed)
        
        self.btn_prev_sub = QPushButton("<")
        self.btn_prev_sub.setFixedWidth(30)
        self.btn_prev_sub.clicked.connect(self.prev_subpage)
        
        self.btn_next_sub = QPushButton(">")
        self.btn_next_sub.setFixedWidth(30)
        self.btn_next_sub.clicked.connect(self.next_subpage)
        
        top_bar.addWidget(self.subpage_label)
        top_bar.addWidget(self.btn_prev_sub)
        top_bar.addWidget(self.subpage_combo)
        top_bar.addWidget(self.btn_next_sub)
        top_bar.addStretch()
        
        center_layout.addLayout(top_bar)
        
        # Color Shortcuts
        color_layout = QHBoxLayout()
        colors = [
            ("Red", 0x01, "#FF0000"),
            ("Green", 0x02, "#00FF00"),
            ("Yellow", 0x03, "#FFFF00"),
            ("Blue", 0x04, "#0000FF"),
            ("Magenta", 0x05, "#FF00FF"),
            ("Cyan", 0x06, "#00FFFF"),
            ("White", 0x07, "#FFFFFF"),
        ]
        
        for name, code, hex_color in colors:
            btn = QPushButton(name)
            btn.setStyleSheet(f"background-color: {hex_color}; font-weight: bold; color: black;")
            btn.clicked.connect(lambda checked, c=code: self.insert_char(c))
            color_layout.addWidget(btn)
            
        color_layout.addStretch()
        center_layout.addLayout(color_layout)

        # Canvas
        self.canvas = TeletextCanvas()
        self.canvas.cursorChanged.connect(self.on_cursor_changed)
        center_layout.addWidget(self.canvas, 1) # Expand
        
        self.layout.addLayout(center_layout, 1)
        
        # Status Bar
        self.status_bar = QStatusBar()
        self.setStatusBar(self.status_bar)
        
        self.progress_bar = QProgressBar()
        self.progress_bar.setFixedWidth(200)
        self.progress_bar.setVisible(False)
        self.status_bar.addPermanentWidget(self.progress_bar)
        
        self.status_label = QLabel("Ready")
        self.status_bar.addWidget(self.status_label)

        # Menus
        self.create_menus()

    def set_modified(self, modified: bool):
        self.is_modified = modified
        title = "Teletext Editor"
        if self.current_file_path:
            title += f" - {os.path.basename(self.current_file_path)}"
        else:
             title += " - Untitled"
        
        if self.is_modified:
            title += " *"
        self.setWindowTitle(title)

    def maybe_save_changes(self) -> bool:
        if not self.is_modified:
            return True
        
        ret = QMessageBox.warning(self, "Unsaved Changes",
                                  "The document has been modified.\nDo you want to save your changes?",
                                  QMessageBox.StandardButton.Save | QMessageBox.StandardButton.Discard | QMessageBox.StandardButton.Cancel)
        
        if ret == QMessageBox.StandardButton.Save:
            self.save_file()
            return True # check if save succeeded? save_file catches exceptions but we might want to check
        elif ret == QMessageBox.StandardButton.Discard:
            return True
        else:
            return False # Cancel

    def closeEvent(self, event):
        if self.maybe_save_changes():
            event.accept()
        else:
            event.ignore()

    def update_progress(self, current, total):
        self.progress_bar.setMaximum(total)
        self.progress_bar.setValue(current)
        QApplication.processEvents() # Force UI update
        
    def create_menus(self):
        menu_bar = self.menuBar()
        
        file_menu = menu_bar.addMenu("File")
        
        open_action = QAction("Open T42...", self)
        open_action.triggered.connect(self.open_file)
        file_menu.addAction(open_action)
        
        save_action = QAction("Save T42...", self)
        save_action.triggered.connect(self.save_file)
        file_menu.addAction(save_action)
        
        save_as_action = QAction("Save As...", self)
        save_as_action.triggered.connect(self.save_as_file)
        file_menu.addAction(save_as_action)
        
        close_action = QAction("Close File", self)
        close_action.triggered.connect(self.close_file)
        file_menu.addAction(close_action)
        
        file_menu.addSeparator()
        
        exit_action = QAction("Exit", self)
        exit_action.triggered.connect(self.close)
        file_menu.addAction(exit_action)
        
        # Edit Menu
        edit_menu = menu_bar.addMenu("Edit")
        
        copy_action = QAction("Copy Page Content", self)
        copy_action.triggered.connect(self.copy_page_content)
        edit_menu.addAction(copy_action)
        
        paste_action = QAction("Paste Page Content", self)
        paste_action.triggered.connect(self.paste_page_content)
        edit_menu.addAction(paste_action)
        
        edit_menu.addSeparator()
        
        undo_action = QAction("Undo", self)
        undo_action.setShortcut("Ctrl+Z")
        undo_action.triggered.connect(self.undo)
        edit_menu.addAction(undo_action)
        
        redo_action = QAction("Redo", self)
        redo_action.setShortcut("Ctrl+Y")
        redo_action.triggered.connect(self.redo)
        edit_menu.addAction(redo_action)
        
        view_menu = menu_bar.addMenu("View")
        
        lang_menu = view_menu.addMenu("Language")
        langs = ["English", "German", "Swedish/Finnish", "Italian", "French", "Portuguese/Spanish", "Turkish", "Romania"]
        for i, lang in enumerate(langs):
            action = QAction(lang, self)
            action.setData(i)
            action.triggered.connect(self.set_language)
            lang_menu.addAction(action)

    def set_language(self):
        action = self.sender()
        if action:
            idx = action.data()
            self.canvas.subset_idx = idx
            self.canvas.redraw()
            self.canvas.update()

    def prev_subpage(self):
        count = self.subpage_combo.count()
        if count <= 1: return
        
        current = self.subpage_combo.currentIndex()
        new_index = (current - 1) % count
        self.subpage_combo.setCurrentIndex(new_index)

    def next_subpage(self):
        count = self.subpage_combo.count()
        if count <= 1: return
        
        current = self.subpage_combo.currentIndex()
        new_index = (current + 1) % count
        self.subpage_combo.setCurrentIndex(new_index)

    def close_file(self):
        if not self.maybe_save_changes():
            return
            
        # Reset everything
        self.service = TeletextService()
        self.current_page = None
        self.current_file_path = None
        self.populate_list()
        self.subpage_combo.clear()
        self.page_groups = {}
        # Clear canvas
        self.canvas.set_page(None)
        # Maybe reset text of hex input
        self.hex_input.clear()
        
        self.undo_stack.clear()
        self.redo_stack.clear()
        
        QMessageBox.information(self, "Closed", "File closed.")
        self.status_label.setText("Ready")
        self.set_modified(False)


    def open_file(self):
        if not self.maybe_save_changes():
            return

        fname, _ = QFileDialog.getOpenFileName(self, "Open T42", "", "Teletext Files (*.t42);;All Files (*)")
        if fname:
            try:
                self.progress_bar.setVisible(True)
                self.status_label.setText(f"Loading {os.path.basename(fname)}...")
                self.progress_bar.setValue(0)
                
                self.service = load_t42(fname, progress_callback=self.update_progress)
                self.current_file_path = fname
                self.populate_list()
                
                self.progress_bar.setVisible(False)
                self.status_label.setText(f"Loaded {len(self.service.pages)} pages from {os.path.basename(fname)}")
                
                self.undo_stack.clear()
                self.redo_stack.clear()
                self.set_modified(False)
            except Exception as e:
                self.progress_bar.setVisible(False)
                QMessageBox.critical(self, "Error", f"Failed to load file: {e}")
                self.status_label.setText("Error loading file")

    def save_as_file(self):
        fname, _ = QFileDialog.getSaveFileName(self, "Save T42 As...", "", "Teletext Files (*.t42)")
        if not fname: return
        
        self.current_file_path = fname
        self.save_file()

    def save_file(self):
        if not self.current_file_path:
             fname, _ = QFileDialog.getSaveFileName(self, "Save T42", "", "Teletext Files (*.t42)")
             if not fname: return
             self.current_file_path = fname
        
        try:
            self.progress_bar.setVisible(True)
            self.status_label.setText(f"Saving {os.path.basename(self.current_file_path)}...")
            
            save_t42(self.current_file_path, self.service, progress_callback=self.update_progress)
            
            self.progress_bar.setVisible(False)
            self.status_label.setText(f"Saved {len(self.service.pages)} pages to {os.path.basename(self.current_file_path)}")
            self.set_modified(False)
        except Exception as e:
            self.progress_bar.setVisible(False)
            QMessageBox.critical(self, "Error", f"Failed to save file: {e}")
            self.status_label.setText("Error saving file")

    def copy_page_content(self):
        if not self.current_page:
            return
            
        self.clipboard = []
        # Copy rows 1 to 24 (or up to 25 if exists)
        # Skip row 0 (Header)
        for packet in self.current_page.packets:
            if 1 <= packet.row <= 24:
                # Store row number and copy of data
                self.clipboard.append((packet.row, bytearray(packet.data)))
        
        self.status_label.setText(f"Copied {len(self.clipboard)} rows to clipboard.")

    def paste_page_content(self):
        if not self.current_page:
            return
            
        if not self.clipboard:
            self.status_label.setText("Clipboard is empty.")
            return
            
        self.push_undo_state()
            
        # Paste content
        # Strategy: For each copied row, update existing packet or create new one.
        
        # Create a map of existing packets by row for quick lookup
        existing_packets = {p.row: p for p in self.current_page.packets}
        
        modified_count = 0
        
        for row, data in self.clipboard:
            if row in existing_packets:
                # Update existing
                packet = existing_packets[row]
                packet.data = bytearray(data) # Clone again to be safe
                # Note: Packet header (original_data) is now stale if we just update .data
                # but save functionality reconstructs header from .magazine and .row
                # so it should be fine.
                modified_count += 1
            else:
                # Create new packet
                new_packet = create_blank_packet(self.current_page.magazine, row)
                new_packet.data = bytearray(data)
                self.current_page.packets.append(new_packet)
                # Update lookup map just in case (though we won't hit it again usually)
                existing_packets[row] = new_packet
                modified_count += 1
                
        # Force redraw
        self.canvas.redraw()
        self.canvas.update()
        self.status_label.setText(f"Pasted {modified_count} rows.")
        self.push_undo_state() # Push state after paste? NO, before! 
        # Wait, usually we push before modifying.
        # But here I just modified it. 
        # Correct pattern: Push state BEFORE modifying.
        # So I need to refactor paste_page_content to call push_undo_state() first.
        # For now, I'll add the methods here.

    def push_undo_state(self):
        if not self.current_page: return
        # Push deep copy of current page
        snapshot = copy.deepcopy(self.current_page)
        self.undo_stack.append(snapshot)
        self.redo_stack.clear() # Clear redo on new edit
        # Limit stack size
        if len(self.undo_stack) > 50:
            self.undo_stack.pop(0)
        self.set_modified(True)

    def undo(self):
        if not self.undo_stack:
            self.status_label.setText("Nothing to undo.")
            return
            
        # Push current state to redo
        if self.current_page:
            self.redo_stack.append(copy.deepcopy(self.current_page))
            
        snapshot = self.undo_stack.pop()
        self.restore_snapshot(snapshot)
        self.status_label.setText("Undone.")
        self.set_modified(True)

    def redo(self):
        if not self.redo_stack:
            self.status_label.setText("Nothing to redo.")
            return
            
        # Push current state to undo
        if self.current_page:
            self.undo_stack.append(copy.deepcopy(self.current_page))
            
        snapshot = self.redo_stack.pop()
        self.restore_snapshot(snapshot)
        self.status_label.setText("Redone.")
        self.set_modified(True)

    def restore_snapshot(self, snapshot: Page):
        # We need to update self.current_page content
        # AND update the usage in service.pages?
        # Actually, self.current_page IS the object in service.pages for now (referenced).
        # But we need to make sure we are modifying the SAME object or replacing it in the list.
        
        # Best way: Update attributes of self.current_page matches snapshot
        # snapshot is a Page object.
        if not self.current_page: return
        
        # Verify it's the same page ID just in case
        if (self.current_page.magazine != snapshot.magazine or 
            self.current_page.page_number != snapshot.page_number):
            # This is tricky if we changed pages. Undo should typically track page switches?
            # For now, we assume undo is local to editing the CURRENT page content.
            # If user switched pages, we might prevent undo or warn.
            # But let's just restoring content.
            pass

        self.current_page.packets = snapshot.packets
        # Also attributes
        self.current_page.sub_code = snapshot.sub_code
        
        self.canvas.set_page(self.current_page)
        self.canvas.redraw()
        self.canvas.update()

    def populate_list(self):
        self.page_list.clear()
        
        # Group pages by Mag+PageNum
        # We want unique list items
        self.page_groups = {} # Key: (mag, page_num) -> List[Page]
        
        for p in self.service.pages:
            key = (p.magazine, p.page_number)
            if key not in self.page_groups:
                self.page_groups[key] = []
            self.page_groups[key].append(p)
            
        # Sort keys
        sorted_keys = sorted(self.page_groups.keys())
        
        for mag, pnum in sorted_keys:
            label = f"{mag}{pnum:02d}"
            item = QListWidgetItem(label)
            item.setData(Qt.ItemDataRole.UserRole, (mag, pnum))
            self.page_list.addItem(item)

    def on_page_selected(self, item):
        mag, pnum = item.data(Qt.ItemDataRole.UserRole)
        pages = self.page_groups.get((mag, pnum), [])
        
        # Populate Subpage Combo
        self.subpage_combo.blockSignals(True)
        self.subpage_combo.clear()
        
        for i, p in enumerate(pages):
            # Display format: Index or Subcode?
            # Subcode is often 0000. Index 1/N is clearer for editing.
            label = f"{i+1}/{len(pages)} (Sub {p.sub_code:04X})"
            self.subpage_combo.addItem(label, p)
            
        self.subpage_combo.blockSignals(False)
        
        if pages:
            self.subpage_combo.setCurrentIndex(0)
            # Trigger update (manual because blockSignals)
            self.on_subpage_changed(0)
            
    def on_subpage_changed(self, index):
        if index < 0: return
        page = self.subpage_combo.itemData(index)
        if isinstance(page, Page):
            self.current_page = page
            self.canvas.set_page(page)
            self.canvas.setFocus()

    def insert_char(self, char_code):
        self.push_undo_state()
        self.canvas.set_byte_at_cursor(char_code)
        # Advance cursor
        self.canvas.move_cursor(1, 0)
        self.canvas.setFocus()
            
    def on_cursor_changed(self, x, y, val):
        self.hex_input.setText(f"{val:02X}")
        
    def on_hex_entered(self):
        text = self.hex_input.text()
        try:
            val = int(text, 16)
            if 0 <= val <= 255:
                # Update canvas input
                # We can call handle_input with char, OR set byte directly. 
                # Direct byte set is safer for non-printable.
                self.push_undo_state()
                self.canvas.set_byte_at_cursor(val)
                self.canvas.setFocus() # Return focus to canvas
        except ValueError:
            pass # Ignore invalid hex
            
    # Input Handling (Editor Logic)
    def keyPressEvent(self, event: QKeyEvent):
        if not self.current_page:
            return
            
        key = event.key()
        text = event.text()
        
        # Navigation
        if key == Qt.Key.Key_Up:
            self.canvas.move_cursor(0, -1)
        elif key == Qt.Key.Key_Down:
            self.canvas.move_cursor(0, 1)
        elif key == Qt.Key.Key_Left:
            self.canvas.move_cursor(-1, 0)
        elif key == Qt.Key.Key_Right:
            self.canvas.move_cursor(1, 0)
        elif key == Qt.Key.Key_Return or key == Qt.Key.Key_Enter:
            # Move to start of next line
            self.canvas.cursor_x = 0
            self.canvas.move_cursor(0, 1)
        else:
            # Typing
            # Allow wider range of chars for national support
            if text and len(text) == 1 and ord(text) >= 32:
                self.push_undo_state()
                self.canvas.handle_input(text)
            elif key == Qt.Key.Key_Backspace:
                self.push_undo_state()
                # Move back and delete
                self.canvas.move_cursor(-1, 0)
                self.canvas.handle_input(' ')
                self.canvas.move_cursor(-1, 0) # Compensate for the auto-advance logic if any