from __future__ import annotations

from enum import Enum, auto
from pathlib import Path

from PySide6.QtWidgets import QFileDialog, QMessageBox, QWidget


class SaveChangesChoice(Enum):
    SAVE = auto()
    DISCARD = auto()
    CANCEL = auto()


class DocumentDialogs:
    """All modal dialogs used by the document workflow."""

    FILE_FILTER = "BEdit documents (*.beb *.json);;BEdit binary (*.beb);;JSON (*.json)"

    def __init__(self, parent: QWidget) -> None:
        self._parent = parent

    def choose_open_path(self, current_path: Path | None) -> Path | None:
        directory = str(current_path.parent) if current_path else ""
        file_name, _ = QFileDialog.getOpenFileName(
            self._parent,
            "Open BEdit Document",
            directory,
            self.FILE_FILTER,
        )
        return Path(file_name) if file_name else None

    def choose_save_path(self, current_path: Path | None) -> Path | None:
        suggested = str(current_path) if current_path else "Untitled.beb"
        file_name, selected_filter = QFileDialog.getSaveFileName(
            self._parent,
            "Save BEdit Document",
            suggested,
            self.FILE_FILTER,
        )
        if not file_name:
            return None

        path = Path(file_name)
        if not path.suffix:
            suffix = ".json" if "JSON" in selected_filter else ".beb"
            path = path.with_suffix(suffix)
        return path

    def ask_save_changes(self) -> SaveChangesChoice:
        answer = QMessageBox.warning(
            self._parent,
            "Unsaved Changes",
            "The current document has unsaved changes.",
            QMessageBox.StandardButton.Save
            | QMessageBox.StandardButton.Discard
            | QMessageBox.StandardButton.Cancel,
            QMessageBox.StandardButton.Save,
        )
        if answer == QMessageBox.StandardButton.Save:
            return SaveChangesChoice.SAVE
        if answer == QMessageBox.StandardButton.Discard:
            return SaveChangesChoice.DISCARD
        return SaveChangesChoice.CANCEL

    def show_file_error(self, title: str, error: Exception) -> None:
        QMessageBox.critical(self._parent, title, str(error))