import sys
import traceback
from typing import Dict, List, Optional, Sequence, Tuple, TypeAlias

import PIL.Image
import gi

gi.require_version("Gtk", "3.0")
from gi.repository import GLib, Gio, Gtk, GObject

gi.require_foreign("cairo")
import cairo

import fitz

Coords: TypeAlias = Tuple[float, float]


class Selection:
    def __init__(self, bounds: Tuple[Coords, Coords], columns: Optional[Sequence[float]] = None):
        self.bounds = bounds
        self.columns = columns


class Document:
    def __init__(self, filename: str):
        self.filename = filename
        self.document = fitz.Document(filename)
        self.selections: Dict[int, List[Selection]] = {}


class PdfPage(Gtk.DrawingArea):
    def __init__(self, page, *args, **kwargs):
        super().__init__(*args, **kwargs)

        self.page: fitz.Page = page
        pix = self.page.get_pixmap(dpi=96)  # type: ignore
        self.set_size_request(pix.width, pix.height)
        self.set_app_paintable(True)  # type: ignore
        self.connect("draw", self.on_draw, {})

    def on_draw(self, widget: Gtk.DrawingArea, cr: cairo.Context, data: GObject.GPointer):
        # app: Application =  widget.get_window().get_application() # type: ignore
        width = widget.get_allocated_width()
        height = widget.get_allocated_height()

        sctx = widget.get_style_context()
        Gtk.render_background(sctx, cr, 0, 0, width, height)

        pix = self.page.get_pixmap(dpi=96)  # type: ignore
        img = PIL.Image.frombytes("RGBA" if pix.alpha else "RGB", [pix.width, pix.height], pix.samples)
        img.putalpha(1)
        mv: memoryview = memoryview(bytearray(img.tobytes()))
        ims = cairo.ImageSurface.create_for_data(mv, cairo.Format.RGB24, pix.width, pix.height)
        cr.set_source_surface(ims, 0, 0)
        cr.paint()


@Gtk.Template.from_file("MainWindow.glade")
class MainWindow(Gtk.ApplicationWindow):
    __gtype_name__ = "main_window"

    open_button: Gtk.Button = Gtk.Template.Child()  # type: ignore
    header_bar: Gtk.HeaderBar = Gtk.Template.Child()  # type: ignore
    main_paned: Gtk.Paned = Gtk.Template.Child()  # type: ignore

    pdf_list_box: Gtk.ListBox = Gtk.Template.Child()  # type: ignore

    pdfFileFilter: Gtk.FileFilter = Gtk.Template.Child()  # type: ignore

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

        self.app: Application = self.get_application()  # type: ignore
        assert self.app is not None

        self.app.connect("notify::document", self.on_document_updated)

        # self.pdf_list_box.add(PdfPage())

    # @Gtk.Template.Callback()
    # def example_button_released_cb(self, widget: Gtk.Button, **kwargs):
    #    assert self.example_button == widget
    #    print(widget.get_label())
    #    widget.set_label("woah")

    @Gtk.Template.Callback()
    def on_open_button_clicked(self, widget, *args, **kwargs):
        dialog = Gtk.FileChooserDialog(
            title="Choose PDF File to open",
            transient_for=self,  # equivalent to parent=
            action=Gtk.FileChooserAction.OPEN,
            filter=self.pdfFileFilter,
            modal=True,
        )
        dialog.add_button("Cancel", Gtk.ResponseType.CANCEL)
        dialog.add_button("Open", Gtk.ResponseType.ACCEPT)

        response = dialog.run()  # type: ignore
        if response == Gtk.ResponseType.ACCEPT:
            filename: str = dialog.get_filename()  # type: ignore
            try:
                self.app.set_property("document", Document(filename))
            except Exception as e:
                message_dialog = Gtk.MessageDialog(
                    title="An error has occured.",
                    transient_for=self,
                    modal=True,
                    message_type=Gtk.MessageType.ERROR,
                    text=repr(e),
                    secondary_text=traceback.format_exc(),
                    buttons=Gtk.ButtonsType.OK,
                )
                message_dialog.run()  # type: ignore
                message_dialog.destroy()
        dialog.destroy()

    # Note: this won't run unless a new document object is put into place
    #       editing an existing one won't trigger it
    def on_document_updated(self, recvobj, gparamstring):
        document: Document = self.app.get_property("document")
        self.header_bar.set_title(document.filename.split("/")[-1])  # type: ignore
        self.header_bar.set_subtitle(document.filename)  # type: ignore

        for i in document.document.pages():  # type: ignore
            row = Gtk.ListBoxRow()
            page = PdfPage(i)
            row.add(page)
            self.pdf_list_box.add(row)  # type: ignore

        self.pdf_list_box.show_all()

    @Gtk.Template.Callback()
    def on_open_button_small_clicked(self, widget, **kwargs):
        pass


class Application(Gtk.Application):
    document = GObject.Property(type=GObject.TYPE_PYOBJECT, flags=GObject.ParamFlags.READWRITE)

    def __init__(self, *args, **kwargs):
        super().__init__(
            *args,
            application_id="zone.lunareclipse.pdf_table_extractor",
            flags=Gio.ApplicationFlags.FLAGS_NONE,
            # flags=Gio.ApplicationFlags.HANDLES_COMMAND_LINE, # TODO
            **kwargs
        )
        self.window = None

    def do_activate(self):
        self.window = self.window or MainWindow(application=self)
        self.window.show_all()  # type: ignore


if __name__ == "__main__":
    app = Application()
    app.run(sys.argv)