import json

from PySide6.QtCore import QByteArray, QMimeData, QModelIndex, Qt, Signal
from PySide6.QtGui import QStandardItem, QStandardItemModel

from bedit.core.model import Component
from bedit.gui.controllers.document import DocumentController
from bedit.gui.graphics.icon_renderer import library_icon
from bedit.gui.models.library_repository import LibraryRepository


COMPONENT_ROLE = Qt.ItemDataRole.UserRole + 1
COMPONENT_ID_ROLE = Qt.ItemDataRole.UserRole + 2
ITEM_KIND_ROLE = Qt.ItemDataRole.UserRole + 3
COMPONENT_INSTANCE_ROLE = Qt.ItemDataRole.UserRole + 4
COMPONENT_MIME_TYPE = "application/x-bedit-component"


class LibraryTreeModel(QStandardItemModel):
    rebuilt = Signal()
    def __init__(
        self,
        repository: LibraryRepository,
        controller: DocumentController,
        parent=None,
    ) -> None:
        super().__init__(parent)
        self.repository = repository
        self.controller = controller
        repository.librariesChanged.connect(self.rebuild)
        self.rebuild()

    def rebuild(self) -> None:
        self.clear()
        self.setHorizontalHeaderLabels(["Libraries"])
        for library in self.repository.libraries:
            root = QStandardItem(library.name)
            root.setDragEnabled(False)
            root.setToolTip(library.source_path)
            for component in library.document.roots.values():
                root.appendRow(self._component_item(component))
            self.appendRow(root)
        self.rebuilt.emit()

    def _component_item(self, component: Component, current: bool = False) -> QStandardItem:
        item = QStandardItem(component.name)
        item.setEditable(False)
        item.setIcon(library_icon(component.icon))
        item.setData(component.to_dict(), COMPONENT_ROLE)
        item.setData(component.id, COMPONENT_ID_ROLE)
        item.setData("current-component" if current else "library-component", ITEM_KIND_ROLE)
        item.setData(component, COMPONENT_INSTANCE_ROLE)
        if component.show_subtree_in_library:
            for child in component.graph.blocks.values():
                item.appendRow(self._component_item(child, current=current))
        return item

    def mimeTypes(self) -> list[str]:  # noqa: N802
        return [COMPONENT_MIME_TYPE]

    def mimeData(self, indexes: list[QModelIndex]) -> QMimeData:  # noqa: N802
        mime_data = QMimeData()
        for index in indexes:
            component = index.data(COMPONENT_ROLE)
            if component:
                encoded = json.dumps(component).encode("utf-8")
                mime_data.setData(COMPONENT_MIME_TYPE, QByteArray(encoded))
                break
        return mime_data

    def supportedDragActions(self):  # noqa: N802
        return Qt.DropAction.CopyAction


class DocumentTreeModel(LibraryTreeModel):
    def __init__(self, controller: DocumentController, parent=None) -> None:
        QStandardItemModel.__init__(self, parent)
        self.controller = controller
        controller.documentReset.connect(self.rebuild)
        controller.componentMoved.connect(lambda _component_id, _position: self.rebuild())
        controller.connectionAdded.connect(lambda _connection_id: self.rebuild())
        controller.connectionRemoved.connect(lambda _connection_id: self.rebuild())
        self.rebuild()

    def rebuild(self) -> None:
        self.clear()
        self.setHorizontalHeaderLabels(["Document"])
        if self.controller.document is not None:
            current_root = QStandardItem(
                str(self.controller.document.metadata.get("name") or "Current Document")
            )
            current_root.setDragEnabled(False)
            current_root.setData("current-document", ITEM_KIND_ROLE)
            for component in self.controller.document.roots.values():
                current_root.appendRow(self._component_item(component, current=True))
            self.appendRow(current_root)
        self.rebuilt.emit()