"""Main window for the microscopy object detection application."""

import shutil
from pathlib import Path

from PySide6.QtWidgets import (
    QMainWindow,
    QTabWidget,
    QMenuBar,
    QMenu,
    QStatusBar,
    QMessageBox,
    QWidget,
    QVBoxLayout,
    QLabel,
)
from PySide6.QtCore import Qt, QTimer, QSettings
from PySide6.QtGui import QAction, QKeySequence

from src.database.db_manager import DatabaseManager
from src.utils.config_manager import ConfigManager
from src.utils.logger import get_logger
from src.gui.dialogs.config_dialog import ConfigDialog
from src.gui.dialogs.delete_model_dialog import DeleteModelDialog
from src.gui.tabs.detection_tab import DetectionTab
from src.gui.tabs.training_tab import TrainingTab
from src.gui.tabs.validation_tab import ValidationTab
from src.gui.tabs.results_tab import ResultsTab
from src.gui.tabs.annotation_tab import AnnotationTab


logger = get_logger(__name__)


class MainWindow(QMainWindow):
    """Main application window."""

    def __init__(self):
        super().__init__()

        # Initialize managers
        self.config_manager = ConfigManager()

        db_path = self.config_manager.get_database_path()
        self.db_manager = DatabaseManager(db_path)

        logger.info("Main window initializing")

        # Setup UI
        self.setWindowTitle("Microscopy Object Detection")
        self.setMinimumSize(1200, 800)

        self._create_menu_bar()
        self._create_tab_widget()
        self._create_status_bar()

        # Restore window geometry or center window on screen
        self._restore_window_state()

        logger.info("Main window initialized")

    def _create_menu_bar(self):
        """Create application menu bar."""
        menubar = self.menuBar()

        # File menu
        file_menu = menubar.addMenu("&File")

        settings_action = QAction("&Settings", self)
        settings_action.setShortcut(QKeySequence("Ctrl+,"))
        settings_action.triggered.connect(self._show_settings)
        file_menu.addAction(settings_action)

        file_menu.addSeparator()

        exit_action = QAction("E&xit", self)
        exit_action.setShortcut(QKeySequence("Ctrl+Q"))
        exit_action.triggered.connect(self.close)
        file_menu.addAction(exit_action)

        # View menu
        view_menu = menubar.addMenu("&View")

        refresh_action = QAction("&Refresh", self)
        refresh_action.setShortcut(QKeySequence("F5"))
        refresh_action.triggered.connect(self._refresh_current_tab)
        view_menu.addAction(refresh_action)

        # Tools menu
        tools_menu = menubar.addMenu("&Tools")

        db_stats_action = QAction("Database &Statistics", self)
        db_stats_action.triggered.connect(self._show_database_stats)
        tools_menu.addAction(db_stats_action)

        tools_menu.addSeparator()

        delete_model_action = QAction("Delete &Model…", self)
        delete_model_action.triggered.connect(self._show_delete_model_dialog)
        tools_menu.addAction(delete_model_action)

        # Help menu
        help_menu = menubar.addMenu("&Help")

        about_action = QAction("&About", self)
        about_action.triggered.connect(self._show_about)
        help_menu.addAction(about_action)

        docs_action = QAction("&Documentation", self)
        docs_action.triggered.connect(self._show_documentation)
        help_menu.addAction(docs_action)

    def _create_tab_widget(self):
        """Create main tab widget with all tabs."""
        self.tab_widget = QTabWidget()
        self.tab_widget.setTabPosition(QTabWidget.North)

        # Create tabs
        try:
            self.detection_tab = DetectionTab(self.db_manager, self.config_manager)
            self.training_tab = TrainingTab(self.db_manager, self.config_manager)
            self.validation_tab = ValidationTab(self.db_manager, self.config_manager)
            self.results_tab = ResultsTab(self.db_manager, self.config_manager)
            self.annotation_tab = AnnotationTab(self.db_manager, self.config_manager)

            # Add tabs to widget
            self.tab_widget.addTab(self.detection_tab, "Detection")
            self.tab_widget.addTab(self.results_tab, "Results")
            self.tab_widget.addTab(self.annotation_tab, "Annotation")
            self.tab_widget.addTab(self.training_tab, "Training")
            self.tab_widget.addTab(self.validation_tab, "Validation")

            # Connect tab change signal
            self.tab_widget.currentChanged.connect(self._on_tab_changed)

        except Exception as e:
            logger.error(f"Error creating tabs: {e}")
            # Create placeholder
            placeholder = QWidget()
            layout = QVBoxLayout()
            layout.addWidget(QLabel(f"Error creating tabs: {e}"))
            placeholder.setLayout(layout)
            self.tab_widget.addTab(placeholder, "Error")

        self.setCentralWidget(self.tab_widget)

    def _create_status_bar(self):
        """Create status bar."""
        self.status_bar = QStatusBar()
        self.setStatusBar(self.status_bar)

        # Add permanent widgets to status bar
        self.status_label = QLabel("Ready")
        self.status_bar.addWidget(self.status_label)

        # Initial status message
        self._update_status("Ready")

    def _center_window(self):
        """Center window on screen."""
        screen = self.screen().geometry()
        size = self.geometry()
        self.move((screen.width() - size.width()) // 2, (screen.height() - size.height()) // 2)

    def _restore_window_state(self):
        """Restore window geometry from settings or center window."""
        settings = QSettings("microscopy_app", "object_detection")
        geometry = settings.value("main_window/geometry")

        if geometry:
            self.restoreGeometry(geometry)
            logger.debug("Restored window geometry from settings")
        else:
            self._center_window()
            logger.debug("Centered window on screen")

    def _save_window_state(self):
        """Save window geometry to settings."""
        settings = QSettings("microscopy_app", "object_detection")
        settings.setValue("main_window/geometry", self.saveGeometry())
        logger.debug("Saved window geometry to settings")

    def _show_settings(self):
        """Show settings dialog."""
        logger.info("Opening settings dialog")
        dialog = ConfigDialog(self.config_manager, self)
        if dialog.exec():
            self._apply_settings()
            self._update_status("Settings saved")

    def _apply_settings(self):
        """Apply changed settings."""
        logger.info("Applying settings changes")
        # Reload configuration in all tabs if needed
        try:
            if hasattr(self, "detection_tab"):
                self.detection_tab.refresh()
            if hasattr(self, "training_tab"):
                self.training_tab.refresh()
            if hasattr(self, "results_tab"):
                self.results_tab.refresh()
        except Exception as e:
            logger.error(f"Error applying settings: {e}")

    def _refresh_current_tab(self):
        """Refresh the current tab."""
        current_widget = self.tab_widget.currentWidget()
        if hasattr(current_widget, "refresh"):
            current_widget.refresh()
            self._update_status("Tab refreshed")

    def _on_tab_changed(self, index: int):
        """Handle tab change event."""
        tab_name = self.tab_widget.tabText(index)
        logger.debug(f"Switched to tab: {tab_name}")
        self._update_status(f"Viewing: {tab_name}")

    def _show_database_stats(self):
        """Show database statistics dialog."""
        try:
            stats = self.db_manager.get_detection_statistics()

            message = f"""
            <h3>Database Statistics</h3>
            <p><b>Total Detections:</b> {stats.get('total_detections', 0)}</p>
            <p><b>Average Confidence:</b> {stats.get('average_confidence', 0):.2%}</p>
            <p><b>Classes:</b></p>
            <ul>
            """

            for class_name, count in stats.get("class_counts", {}).items():
                message += f"<li>{class_name}: {count}</li>"

            message += "</ul>"

            QMessageBox.information(self, "Database Statistics", message)

        except Exception as e:
            logger.error(f"Error getting database stats: {e}")
            QMessageBox.warning(self, "Error", f"Failed to get database statistics:\n{str(e)}")

    def _show_delete_model_dialog(self) -> None:
        """Open the model deletion dialog."""
        dialog = DeleteModelDialog(self.db_manager, self)
        if not dialog.exec():
            return

        model_ids = dialog.selected_model_ids
        if not model_ids:
            return

        self._delete_models(model_ids)

    def _delete_models(self, model_ids: list[int]) -> None:
        """Delete one or more models from the database and remove artifacts from disk."""

        deleted_count = 0
        removed_paths: list[str] = []
        remove_errors: list[str] = []

        for model_id in model_ids:
            model = None
            try:
                model = self.db_manager.get_model_by_id(int(model_id))
            except Exception as exc:
                logger.error(f"Failed to load model {model_id} before deletion: {exc}")

            if not model:
                remove_errors.append(f"Model id {model_id} not found in database.")
                continue

            try:
                deleted = self.db_manager.delete_model(int(model_id))
            except Exception as exc:
                logger.error(f"Failed to delete model {model_id}: {exc}")
                remove_errors.append(f"Failed to delete model id {model_id} from DB: {exc}")
                continue

            if not deleted:
                remove_errors.append(f"Model id {model_id} was not deleted (already removed?).")
                continue

            deleted_count += 1
            removed, errors = self._delete_model_artifacts_from_disk(model)
            removed_paths.extend(removed)
            remove_errors.extend(errors)

        # Refresh tabs to reflect the deletion(s).
        try:
            if hasattr(self, "detection_tab"):
                self.detection_tab.refresh()
            if hasattr(self, "results_tab"):
                self.results_tab.refresh()
            if hasattr(self, "validation_tab"):
                self.validation_tab.refresh()
            if hasattr(self, "training_tab"):
                self.training_tab.refresh()
        except Exception as exc:
            logger.warning(f"Failed to refresh tabs after model deletion: {exc}")

        details: list[str] = []
        if removed_paths:
            details.append("Removed from disk:\n" + "\n".join(removed_paths))
        if remove_errors:
            details.append("\nDisk cleanup warnings:\n" + "\n".join(remove_errors))

        QMessageBox.information(
            self,
            "Delete Model",
            f"Deleted {deleted_count} model(s) from database." + ("\n\n" + "\n".join(details) if details else ""),
        )

    def _delete_model(self, model_id: int) -> None:
        """Delete a model from the database and remove its artifacts from disk."""

        model = None
        try:
            model = self.db_manager.get_model_by_id(model_id)
        except Exception as exc:
            logger.error(f"Failed to load model {model_id} before deletion: {exc}")

        if not model:
            QMessageBox.warning(self, "Delete Model", "Selected model was not found in the database.")
            return

        model_path = str(model.get("model_path") or "")

        try:
            deleted = self.db_manager.delete_model(model_id)
        except Exception as exc:
            logger.error(f"Failed to delete model {model_id}: {exc}")
            QMessageBox.critical(self, "Delete Model", f"Failed to delete model from database:\n{exc}")
            return

        if not deleted:
            QMessageBox.warning(self, "Delete Model", "No model was deleted (it may have already been removed).")
            return

        removed_paths, remove_errors = self._delete_model_artifacts_from_disk(model)

        # Refresh tabs to reflect the deletion.
        try:
            if hasattr(self, "detection_tab"):
                self.detection_tab.refresh()
            if hasattr(self, "results_tab"):
                self.results_tab.refresh()
            if hasattr(self, "validation_tab"):
                self.validation_tab.refresh()
            if hasattr(self, "training_tab"):
                self.training_tab.refresh()
        except Exception as exc:
            logger.warning(f"Failed to refresh tabs after model deletion: {exc}")

        details = []
        if model_path:
            details.append(f"Deleted model record for: {model_path}")
        if removed_paths:
            details.append("\nRemoved from disk:\n" + "\n".join(removed_paths))
        if remove_errors:
            details.append("\nDisk cleanup warnings:\n" + "\n".join(remove_errors))

        QMessageBox.information(
            self,
            "Delete Model",
            "Model deleted from database." + ("\n\n" + "\n".join(details) if details else ""),
        )

    def _delete_model_artifacts_from_disk(self, model: dict) -> tuple[list[str], list[str]]:
        """Best-effort removal of model artifacts on disk.

        Strategy:
        - Remove run directories inferred from:
          - model.model_path (…/<run>/weights/*.pt => <run>)
          - training_params.stage_results[].results.save_dir
          but only if they are under the configured models directory.
        - If the weights file itself exists and is outside the models directory, delete only the file.

        Returns:
            (removed_paths, errors)
        """

        removed: list[str] = []
        errors: list[str] = []

        models_root = Path(self.config_manager.get_models_directory() or "data/models").expanduser()
        try:
            models_root_resolved = models_root.resolve()
        except Exception:
            models_root_resolved = models_root

        inferred_dirs: list[Path] = []

        # 1) From model_path
        model_path_value = model.get("model_path")
        if model_path_value:
            try:
                p = Path(str(model_path_value)).expanduser()
                p_resolved = p.resolve() if p.exists() else p
                if p_resolved.is_file():
                    if p_resolved.parent.name == "weights" and p_resolved.parent.parent.exists():
                        inferred_dirs.append(p_resolved.parent.parent)
                    elif p_resolved.parent.exists():
                        inferred_dirs.append(p_resolved.parent)
            except Exception:
                pass

        # 2) From training_params.stage_results[].results.save_dir
        training_params = model.get("training_params") or {}
        if isinstance(training_params, dict):
            stage_results = training_params.get("stage_results")
            if isinstance(stage_results, list):
                for stage in stage_results:
                    results = (stage or {}).get("results")
                    save_dir = (results or {}).get("save_dir") if isinstance(results, dict) else None
                    if not save_dir:
                        continue
                    try:
                        d = Path(str(save_dir)).expanduser()
                        if d.exists() and d.is_dir():
                            inferred_dirs.append(d)
                    except Exception:
                        continue

        # Deduplicate inferred_dirs
        unique_dirs: list[Path] = []
        seen: set[str] = set()
        for d in inferred_dirs:
            try:
                key = str(d.resolve())
            except Exception:
                key = str(d)
            if key in seen:
                continue
            seen.add(key)
            unique_dirs.append(d)

        # Delete directories under models_root
        for d in unique_dirs:
            try:
                d_resolved = d.resolve()
            except Exception:
                d_resolved = d
            try:
                if d_resolved.exists() and d_resolved.is_dir() and d_resolved.is_relative_to(models_root_resolved):
                    shutil.rmtree(d_resolved)
                    removed.append(str(d_resolved))
            except Exception as exc:
                errors.append(f"Failed to remove directory {d_resolved}: {exc}")

        # If nothing matched (e.g., model_path outside models_root), delete just the file.
        if model_path_value:
            try:
                p = Path(str(model_path_value)).expanduser()
                if p.exists() and p.is_file():
                    p_resolved = p.resolve()
                    if not p_resolved.is_relative_to(models_root_resolved):
                        p_resolved.unlink()
                        removed.append(str(p_resolved))
            except Exception as exc:
                errors.append(f"Failed to remove model file {model_path_value}: {exc}")

        return removed, errors

    def _show_about(self):
        """Show about dialog."""
        about_text = """
        <h2>Microscopy Object Detection Application</h2>
        <p><b>Version:</b> 1.0.0</p>
        <p>A desktop application for detecting organelles and membrane branching 
        structures in microscopy images using YOLOv8.</p>
        
        <p><b>Features:</b></p>
        <ul>
            <li>Object detection with YOLOv8</li>
            <li>Model training and validation</li>
            <li>Detection results storage</li>
            <li>Interactive visualization</li>
            <li>Export capabilities</li>
        </ul>
        
        <p><b>Technologies:</b></p>
        <ul>
            <li>Ultralytics YOLOv8</li>
            <li>PySide6</li>
            <li>pyqtgraph</li>
            <li>SQLite</li>
        </ul>
        """

        QMessageBox.about(self, "About", about_text)

    def _show_documentation(self):
        """Show documentation."""
        QMessageBox.information(
            self,
            "Documentation",
            "Please refer to README.md and ARCHITECTURE.md files in the project directory.",
        )

    def _update_status(self, message: str, timeout: int = 5000):
        """
        Update status bar message.

        Args:
            message: Status message to display
            timeout: Time in milliseconds to show message (0 for permanent)
        """
        self.status_label.setText(message)
        if timeout > 0:
            QTimer.singleShot(timeout, lambda: self.status_label.setText("Ready"))

    def closeEvent(self, event):
        """Handle window close event."""
        reply = QMessageBox.question(
            self,
            "Confirm Exit",
            "Are you sure you want to exit?",
            QMessageBox.Yes | QMessageBox.No,
            QMessageBox.No,
        )

        if reply == QMessageBox.Yes:
            # Save window state before closing
            self._save_window_state()

            # Persist tab state and stop background work before exit
            if hasattr(self, "training_tab"):
                self.training_tab.shutdown()
            if hasattr(self, "annotation_tab"):
                self.annotation_tab.save_state()

            logger.info("Application closing")
            event.accept()
        else:
            event.ignore()