import math

from PySide6.QtCore import QFile, QModelIndex, QPoint, Signal, Slot
from PySide6.QtPdf import QPdfBookmarkModel, QPdfDocument
from PySide6.QtPdfWidgets import QPdfView
from PySide6.QtWidgets import QComboBox, QDialog, QMenuBar, QSpinBox, QWidget
from ui.pdfViewer import Ui_pdfViewer

ZOOM_MULTIPLIER = math.sqrt(2.0)

class ZoomSelector(QComboBox):
    zoom_mode_changed = Signal(QPdfView.ZoomMode)
    zoom_factor_changed = Signal(float)
    
    def __init__(self, parent: QWidget|None = None) -> None:
        super(ZoomSelector, self).__init__(parent)
        self.setEditable(True)

        for text in [ 'Fit Width', 'Fit Page', '12%', '25%', '33%', '50%', '66%', '75%', '100%', '125%', '150%', '200%', '400%']:
            self.addItem(text)
        self.currentTextChanged.connect(self.on_current_text_changed)
        lineEdit = self.lineEdit()
        assert lineEdit is not None
        lineEdit.editingFinished.connect(self._editing_finished)
        return
    @Slot(float) # type: ignore
    def set_zoom_factor(self, zoomFactor: float) -> None:
        percent = int(zoomFactor * 100)
        self.setCurrentText(f"{percent}%")
        return
    @Slot()
    def reset(self) -> None:
        self.setCurrentIndex(8) # 100%
        return
    @Slot(str) # type: ignore
    def on_current_text_changed(self, text: str) -> None:
        if text == "Fit Width":
            self.zoom_mode_changed.emit(QPdfView.ZoomMode.FitToWidth)
        elif text == "Fit Page":
            self.zoom_mode_changed.emit(QPdfView.ZoomMode.FitInView)
        elif text.endswith("%"):
            zoom_level = int(text[:-1])
            factor = zoom_level / 100.0
            self.zoom_mode_changed.emit(QPdfView.ZoomMode.Custom)
            self.zoom_factor_changed.emit(factor)
        return
    @Slot()
    def _editing_finished(self) -> None:
        lineEdit = self.lineEdit()
        assert lineEdit is not None
        self.on_current_text_changed(lineEdit.text())
        return
    

class PDFViewer(QDialog, Ui_pdfViewer):
    menubar: QMenuBar
    zoomSelector: ZoomSelector
    pageSelector: QSpinBox
    document: QPdfDocument

    def __init__(self, parent: QWidget | None) -> None:
        super(PDFViewer, self).__init__(parent)
        self.setupUi(self)

        self.zoomSelector = ZoomSelector(self)
        self.pageSelector = QSpinBox(self)
        self.document = QPdfDocument(self)

        self.zoomSelector.setMaximumWidth(150)
        self.mainToolBar.insertWidget(self.actionZoom_In, self.zoomSelector)
        self.mainToolBar.insertWidget(self.actionForward, self.pageSelector)
        self.pageSelector.valueChanged.connect(self.page_selected)
        nav = self.pdfView.pageNavigator()
        nav.currentPageChanged.connect(self.pageSelector.setValue)
        nav.backAvailableChanged.connect(self.actionBack.setEnabled)
        nav.forwardAvailableChanged.connect(self.actionForward.setEnabled)
        self.zoomSelector.zoom_mode_changed.connect(self.pdfView.setZoomMode)
        self.zoomSelector.zoom_factor_changed.connect(self.pdfView.setZoomFactor)
        self.zoomSelector.reset()

        bookmark_model = QPdfBookmarkModel(self)
        bookmark_model.setDocument(self.document)

        self.bookmarkView.setModel(bookmark_model)
        self.bookmarkView.activated.connect(self.bookmark_selected)

        self.tabWidget.setTabEnabled(1, False) # disable pages tabwidget
        self.pdfView.setDocument(self.document)
        self.pdfView.zoomFactorChanged.connect(self.zoomSelector.set_zoom_factor)
        return

    @Slot(QFile) # type: ignore
    def open(self, file: QFile) -> None:
        #assert file.exists()
        #if not file.isOpen():
            #file.open(QFile.OpenModeFlag.ReadOnly)
        #self.document.load(file)
        self.document.load(file.fileName())
        document_title = self.document.metaData(QPdfDocument.MetaDataField.Title)
        self.setWindowTitle(document_title if document_title else "PDF Viewer")
        self.page_selected(0)
        self.pageSelector.setMaximum(self.document.pageCount() -1 )
        return

    @Slot(QModelIndex) # type: ignore
    def bookmark_selected(self, index: QModelIndex) -> None:
        if not index.isValid():
            return

        page = index.data(int(QPdfBookmarkModel.Role.Page))
        zoom_level = index.data(int(QPdfBookmarkModel.Role.Level))
        nav = self.pdfView.pageNavigator()
        assert nav is not None
        nav.jump(page, QPoint(), zoom_level)
        return

    @Slot(int) # type: ignore
    def page_selected(self, page: int) -> None:
        nav = self.pdfView.pageNavigator()
        nav.jump(page, QPoint(), nav.currentZoom())
        return

    @Slot()
    def on_actionOpen_triggered(self) -> None:
        print("What are you doing in actionOpen_triggered?")
        return

    @Slot()
    def on_actionQuit_triggered(self) -> None:
        self.close()
        return

    @Slot()
    def on_actionZoom_In_triggered(self) -> None:
        factor = self.pdfView.zoomFactor() * ZOOM_MULTIPLIER
        self.pdfView.setZoomFactor(factor)
        return

    @Slot()
    def on_actionZoom_Out_triggered(self) -> None:
        factor = self.pdfView.zoomFactor() / ZOOM_MULTIPLIER
        self.pdfView.setZoomFactor(factor)
        return

    @Slot()
    def on_actionPrevious_Page_triggered(self) -> None:
        nav = self.pdfView.pageNavigator()
        nav.jump(nav.currentPage() - 1, QPoint(), nav.currentZoom())
        return

    @Slot()
    def on_actionNext_Page_triggered(self) -> None:
        nav = self.pdfView.pageNavigator()
        nav.jump(nav.currentPage() + 1, QPoint(), nav.currentZoom())
        return

    @Slot()
    def on_actionContinuous_triggered(self) -> None:
        cont_checked = self.actionContinuous.isChecked()
        mode = QPdfView.PageMode.MultiPage if cont_checked else QPdfView.PageMode.SinglePage
        self.pdfView.setPageMode(mode)
        return

    @Slot()
    def on_actionBack_triggered(self) -> None:
        self.pdfView.pageNavigator().back()
        return

    @Slot()
    def on_actionForward_triggered(self) -> None:
        self.pdfView.pageNavigator().forward()
        return