'''
This script is licensed CC 0 1.0, so that you can learn from it.

------ CC 0 1.0 ---------------

The person who associated a work with this deed has dedicated the work to the public domain by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.

You can copy, modify, distribute and perform the work, even for commercial purposes, all without asking permission.

https://creativecommons.org/publicdomain/zero/1.0/legalcode
'''
from PyQt5.QtCore import QAbstractItemModel, QFile, QIODevice, QModelIndex, Qt
from PyQt5.QtWidgets import QApplication, QTreeView
from . import filtermanagertreeitem
from PyQt5.QtGui import QPixmap


class FilterManagerTreeModel(QAbstractItemModel):

    TYPE_COLUMN = 1
    NODE_COLUMN = 3
    DOCUMENT_COLUMN = 4

    def __init__(self, uiFilterManager, parent=None):
        super(FilterManagerTreeModel, self).__init__(parent)

        self.rootItem = filtermanagertreeitem.FilterManagerTreeItem(("Name", "Type", "Thumbnail"))
        self.uiFilterManager = uiFilterManager
        self._loadTreeModel(self.rootItem)

    def index(self, row, column, parent):
        if not self.hasIndex(row, column, parent):
            return QModelIndex()

        if parent.isValid():
            parentItem = parent.internalPointer()
        else:
            parentItem = self.rootItem

        # It's a FilterManagerTreeItem
        childItem = parentItem.child(row)
        if childItem:
            return self.createIndex(row, column, childItem)
        else:
            return QModelIndex()

    def parent(self, index):
        if not index.isValid():
            return QModelIndex()

        childItem = index.internalPointer()
        parentItem = childItem.parent()

        if parentItem == self.rootItem:
            return QModelIndex()

        return self.createIndex(parentItem.row(), 0, parentItem)

    def rowCount(self, parent):
        if parent.column() > 0:
            return 0

        if not parent.isValid():
            parentItem = self.rootItem
        else:
            parentItem = parent.internalPointer()
        return parentItem.childCount()

    def columnCount(self, parent):
        if parent.isValid():
            return parent.internalPointer().columnCount()
        else:
            return self.rootItem.columnCount()

    def data(self, index, role):
        if not index.isValid():
            return None

        item = index.internalPointer()

        if role == Qt.UserRole + 1:
            return item.data(self.NODE_COLUMN)

        if role == Qt.UserRole + 2:
            return item.data(self.DOCUMENT_COLUMN)

        if role == Qt.UserRole + 3:
            return item.data(self.TYPE_COLUMN)

        if role != Qt.DisplayRole and role != Qt.DecorationRole:
            return None

        return item.data(index.column())

    def flags(self, index):
        if not index.isValid():
            return Qt.NoItemFlags

        return Qt.ItemIsEnabled | Qt.ItemIsSelectable

    def headerData(self, section, orientation, role):
        if orientation == Qt.Horizontal and role == Qt.DisplayRole:
            return self.rootItem.data(section)

        return None

    def _loadTreeModel(self, parent):
        for index, document in enumerate(self.uiFilterManager.documents):
            rootNode = document.rootNode()
            columnData = (document.fileName(),
                          "Document",
                          QPixmap.fromImage(document.thumbnail(30, 30)),
                          rootNode, index)
            item = filtermanagertreeitem.FilterManagerTreeItem(columnData, parent)
            parent.appendChild(item)

            childNodes = rootNode.childNodes()
            if len(childNodes):
                self._addSubNodes(childNodes[::-1], item, index)

    def _addSubNodes(self, nodes, parent, documentIndex):
        for node in nodes:
            nodeName = node.name()
            nodeType = node.type()
            columnData = ("Unnamed" if nodeName == '' else nodeName,
                          "Untyped" if nodeType == '' else nodeType,
                          QPixmap.fromImage(node.thumbnail(30, 30)),
                          node, documentIndex)
            item = filtermanagertreeitem.FilterManagerTreeItem(columnData, parent)
            parent.appendChild(item)

            childNodes = node.childNodes()
            if len(childNodes):
                self._addSubNodes(childNodes[::-1], item, documentIndex)
