from pathlib import Path

from PySide6.QtCore import QSettings, Signal
from PySide6.QtWidgets import QDialog, QFileDialog, QFormLayout, QGroupBox, QSpinBox

from bedit.core.libraries import default_library_paths
from bedit.gui.preferences import application_settings
from bedit.gui.generated.ui_settings_dialog import Ui_SettingsDialog


class SettingsDialog(QDialog):
    """Edit application preferences defined in the Designer form."""

    settingsChanged = Signal()

    def __init__(self, parent=None) -> None:
        super().__init__(parent)
        self.ui = Ui_SettingsDialog()
        self.ui.setupUi(self)
        self.grid_group = QGroupBox("Editor grids", self.ui.generalTab)
        grid_form = QFormLayout(self.grid_group)
        self.graph_grid_spin = QSpinBox()
        self.graph_grid_spin.setRange(8, 512)
        self.graph_grid_spin.setSuffix(" units")
        self.graph_snap_spin = QSpinBox()
        self.graph_snap_spin.setRange(1, 128)
        self.graph_snap_spin.setSuffix(" units")
        self.graph_grid_spin.valueChanged.connect(self.graph_snap_spin.setMaximum)
        self.icon_grid_spin = QSpinBox()
        self.icon_grid_spin.setRange(1, 64)
        self.icon_grid_spin.setSuffix(" units")
        grid_form.addRow("Workspace grid size:", self.graph_grid_spin)
        grid_form.addRow("Workspace snapping size:", self.graph_snap_spin)
        grid_form.addRow("Icon grid size:", self.icon_grid_spin)
        self.ui.generalLayout.insertWidget(1, self.grid_group)
        self.settings = application_settings()
        self.ui.addLibraryFileButton.clicked.connect(self._add_library_file)
        self.ui.addLibraryFolderButton.clicked.connect(self._add_library_folder)
        self.ui.removeLibraryPathButton.clicked.connect(self._remove_library_path)
        self.ui.libraryPathsList.itemSelectionChanged.connect(self._update_remove_button)
        self._load_settings()

    def _load_settings(self) -> None:
        enabled = self.settings.value("autosave/enabled", None)
        if enabled is None:
            enabled = self.settings.value("General/autosaveEnabled", False)
        interval = self.settings.value("autosave/intervalMinutes", None)
        if interval is None:
            interval = self.settings.value("General/autosaveInterval", 5)
        self.ui.autosaveGroupBox.setChecked(
            self._as_bool(enabled)
        )
        self.ui.autosaveIntervalSpinBox.setValue(int(interval))
        self.ui.libraryPathsList.clear()
        self.ui.libraryPathsList.addItems(self.library_paths(self.settings))
        self.graph_grid_spin.setValue(self.graph_grid_size(self.settings))
        self.graph_snap_spin.setValue(self.graph_snap_size(self.settings))
        self.icon_grid_spin.setValue(self.icon_grid_size(self.settings))
        self._update_remove_button()

    @staticmethod
    def _as_bool(value) -> bool:
        if isinstance(value, str):
            return value.strip().lower() in {"1", "true", "yes", "on"}
        return bool(value)

    @staticmethod
    def library_paths(settings: QSettings | None = None) -> list[str]:
        settings = settings if settings is not None else application_settings()
        value = settings.value("libraries/paths", default_library_paths())
        if isinstance(value, str):
            return [value]
        return [str(path) for path in value]

    @staticmethod
    def graph_grid_size(settings: QSettings | None = None) -> int:
        settings = settings if settings is not None else application_settings()
        return settings.value("grid/graphSize", 64, type=int)

    @staticmethod
    def graph_snap_size(settings: QSettings | None = None) -> int:
        settings = settings if settings is not None else application_settings()
        return settings.value("grid/graphSnapSize", 8, type=int)

    @staticmethod
    def icon_grid_size(settings: QSettings | None = None) -> int:
        settings = settings if settings is not None else application_settings()
        return settings.value("grid/iconSize", 8, type=int)

    def _add_library_file(self) -> None:
        path, _ = QFileDialog.getOpenFileName(
            self,
            "Add library",
            "",
            "BEdit libraries (*.json);;All files (*)",
        )
        if path:
            self._append_unique_path(path)

    def _add_library_folder(self) -> None:
        path = QFileDialog.getExistingDirectory(self, "Add library folder")
        if path:
            self._append_unique_path(path)

    def _append_unique_path(self, path: str) -> None:
        normalized = str(Path(path).expanduser().resolve())
        existing = {
            self.ui.libraryPathsList.item(row).text()
            for row in range(self.ui.libraryPathsList.count())
        }
        if normalized not in existing:
            self.ui.libraryPathsList.addItem(normalized)

    def _remove_library_path(self) -> None:
        for item in self.ui.libraryPathsList.selectedItems():
            self.ui.libraryPathsList.takeItem(self.ui.libraryPathsList.row(item))

    def _update_remove_button(self) -> None:
        self.ui.removeLibraryPathButton.setEnabled(bool(self.ui.libraryPathsList.selectedItems()))

    def accept(self) -> None:
        self.settings.setValue("autosave/enabled", self.ui.autosaveGroupBox.isChecked())
        self.settings.setValue(
            "autosave/intervalMinutes", self.ui.autosaveIntervalSpinBox.value()
        )
        self.settings.remove("General/autosaveEnabled")
        self.settings.remove("General/autosaveInterval")
        paths = [
            self.ui.libraryPathsList.item(row).text()
            for row in range(self.ui.libraryPathsList.count())
        ]
        self.settings.setValue("libraries/paths", paths)
        self.settings.setValue("grid/graphSize", self.graph_grid_spin.value())
        self.settings.setValue("grid/graphSnapSize", self.graph_snap_spin.value())
        self.settings.setValue("grid/iconSize", self.icon_grid_spin.value())
        self.settings.sync()
        self.settingsChanged.emit()
        super().accept()