#!/usr/bin/env python
import copy
import os
import re
import weakref
import logging

from collections.abc import Iterable, Sequence
from string import Template
from meshroom.common import BaseObject, Property, Variant, Signal, ListModel, DictModel, Slot
from meshroom.core import desc, hashValue
from meshroom.core.keyValues import KeyValues
from typing import TYPE_CHECKING

if TYPE_CHECKING:
    from meshroom.core.graph import Edge

def attributeFactory(description: str, value, isOutput: bool, node, root=None, parent=None):
    """
    Create an Attribute based on description type.

    Args:
        description: the Attribute description
        value: value of the Attribute. Will be set if not None.
        isOutput: whether the Attribute is an output attribute.
        node (Node): node owning the Attribute. Note that the created Attribute is not added to \
                     Node's attributes
        root: (optional) parent Attribute (must be ListAttribute or GroupAttribute)
        parent (BaseObject): (optional) the parent BaseObject if any
    """
    attr: Attribute = description.instanceType(node, description, isOutput, root, parent)
    if value is not None:
        attr._setValue(value)
    else:
        attr.resetToDefaultValue()
    # Only connect slot that reacts to value change once initial value has been set.
    # NOTE: This should be handled by the Node class, but we're currently limited by our core
    #       signal implementation that does not support emitting parameters.
    #       And using a lambda here to send the attribute as a parameter causes
    #       performance issues when using the pyside backend.
    attr.valueChanged.connect(attr._onValueChanged)
    return attr


class Attribute(BaseObject):
    """
    """
    LINK_EXPRESSION_REGEX = re.compile(r'^\{[A-Za-z]+[A-Za-z0-9_.\[\]]*\}$')
    VALID_IMAGE_SEMANTICS = ["image", "imageList", "sequence"]
    VALID_3D_EXTENSIONS = [".obj", ".stl", ".fbx", ".gltf", ".abc", ".ply"]

    @staticmethod
    def isLinkExpression(value) -> bool:
        """
        Return whether the given argument is a link expression.
        A link expression is a string matching the {nodeName.attrName} pattern.
        """
        return isinstance(value, str) and Attribute.LINK_EXPRESSION_REGEX.match(value)

    def __init__(self, node, attributeDesc: desc.Attribute, isOutput: bool, root=None, parent=None):
        """
        Attribute constructor

        Args:
            node (Node): the Node hosting this Attribute
            attributeDesc: the description of this Attribute
            isOutput: whether this Attribute is an output of the Node
            root (Attribute): (optional) the root Attribute (List or Group) containing this one
            parent (BaseObject): (optional) the parent BaseObject
        """
        super().__init__(parent)
        self._root = None if root is None else weakref.ref(root)
        self._node = weakref.ref(node)
        self._desc: desc.Attribute = attributeDesc
        self._isOutput: bool = isOutput
        self._enabled: bool = True
        self._invalidate = False if self._isOutput else attributeDesc.invalidate
        self._invalidationValue = "" # invalidation value for output attributes
        self._value = None
        self._keyValues = None # list of pairs (key, value) for keyable attribute
        self._initValue()

    def _getFullName(self) -> str:
        """ 
        Get the attribute name following the path from the node to the attribute.
        Return: nodeName.groupName.subGroupName.name 
        """
        return f'{self.node.name}.{self._getRootName()}'

    def _getRootName(self) -> str:
        """ 
        Get the attribute name following the path from the root attribute.
        Return: groupName.subGroupName.name 
        """
        if isinstance(self.root, ListAttribute):
            return f'{self.root.rootName}[{self.root.index(self)}]'
        elif isinstance(self.root, GroupAttribute):
            return f'{self.root.rootName}.{self._desc.name}'
        return self._desc.name

    def asLinkExpr(self) -> str:
        """ 
        Return the link expression for this Attribute 
        """
        return "{" + self._getFullName() + "}"

    def requestGraphUpdate(self):
        if self.node.graph:
            self.node.graph.markNodesDirty(self.node)
            self.node.graph.update()

    def requestNodeUpdate(self):
        # Update specific node information that do not affect the rest of the graph
        # (like internal attributes)
        if self.node:
            self.node.updateInternalAttributes()

    def _initValue(self):
        """
        Initialize the attribute value.
        Called in the attribute factory for each attributes.
        """
        if self._desc.keyable:
            # Keyable attribute, initialize keyValues from attribute description
            self._keyValues = KeyValues(self._desc)
            # Send signal and updates if keyValues changed
            self._keyValues.pairsChanged.connect(self._onKeyValuesChanged)
        elif self._desc._valueType is not None:
            self._value = self._desc._valueType()

    def _getEvalValue(self):
        """
        Return the value of a the attribute.
        For string, expressions will be evaluated.
        """
        if isinstance(self.value, str):
            env = self.node.nodePlugin.configFullEnv if self.node.nodePlugin else os.environ
            substituted = Template(self.value).safe_substitute(env)
            try:
                varResolved = substituted.format(**self.node._expVars, **self.node._staticExpVars)
                return varResolved
            except (KeyError, IndexError):
                # Catch KeyErrors and IndexErros to be able to open files created prior to the
                # support of relative variables (when self.node._expVars was not used to evaluate
                # expressions in the attribute)
                return substituted
        return self.value

    def _getValue(self):
        """
        Return the value of the attribute or the linked attribute value.
        """
        if self.keyable:
            raise RuntimeError(f"Cannot get value of {self._getFullName()}, the attribute is keyable.")
        if self.isLink:
            return self._getInputLink().value
        return self._value

    def _setValue(self, value):
        """
        Set the attribute value from a given value, a given function or a given attribute. 
        """
        if self._value == value:
            return
        if isinstance(value, Attribute) or Attribute.isLinkExpression(value):
            # if we set a link to another attribute
            self._value = value
            if self.keyable:
                self._keyValues.reset()
        elif self.keyable and isinstance(value, dict):
            # keyable attribute initialize from a dict
            self.keyValues.resetFromDict(value)
        elif self.keyable:
            # keyable attribute but value is not a dict
            raise RuntimeError(f"Cannot set value of {self._getFullName()}, the attribute is keyable.")
        elif callable(value):
            # evaluate the function
            self._value = value(self)
        else:
            # if we set a new value, we use the attribute descriptor validator to check the
            # validity of the value and apply some conversion if needed
            convertedValue = self.validateValue(value)
            self._value = convertedValue
        # Request graph update when input parameter value is set
        # and parent node belongs to a graph
        # Output attributes value are set internally during the update process,
        # which is why we don't trigger any update in this case
        # TODO: update only the nodes impacted by this change
        # TODO: only update the graph if this attribute participates to a UID
        if self.isInput:
            self.requestGraphUpdate()
            # TODO: only call update of the node if the attribute is internal
            # Internal attributes are set as inputs
            self.requestNodeUpdate()
        self.valueChanged.emit()

    def _getKeyValues(self):
        """
        Return the per-key values object of the attribute or of the linked attribute.
        """
        if not self.keyable:
            raise RuntimeError(f"Cannot get keyValues of {self._getFullName()}, the attribute is not keyable.")
        if self.isLink:
            return self._getInputLink().keyValues
        return self._keyValues

    def _applyExpr(self):
        """
        For string parameters with an expression (when loaded from file),
        this function convert the expression into a real edge in the graph
        and clear the string value.
        """
        v = self._value
        g = self.node.graph
        if not g:
            return
        if isinstance(v, Attribute):
            g.addEdge(v, self)
            self.resetToDefaultValue()
        elif self.isInput and Attribute.isLinkExpression(v):
            # value is a link to another attribute
            link = v[1:-1]
            linkNodeName, linkAttrName = "", ""
            try:
                linkNodeName, linkAttrName = link.split('.')
            except ValueError as err:
                logging.warning('Retrieve Connected Attribute from Expression failed.')
                logging.warning(f'Expression: "{link}"\nError: "{err}".')
            try:
                node = g.node(linkNodeName)
                if not node:
                    raise KeyError(f"Node '{linkNodeName}' not found")
                g.addEdge(node.attribute(linkAttrName), self)
            except KeyError as err:
                logging.warning('Connect Attribute from Expression failed.')
                logging.warning(f'Expression: "{v}"\nError: "{err}".')
            self.resetToDefaultValue()

    def resetToDefaultValue(self):
        """
        Reset the attribute to its default value.
        """
        if self.keyable:
            self._value = None
            self._keyValues.reset()
        else:
            self._setValue(copy.copy(self.getDefaultValue()))

    def getDefaultValue(self):
        """
        Get the attribute default value.
        """
        if callable(self._desc.value):
            try:
                return self._desc.value(self)
            except Exception as e:
                if not self.node.isCompatibilityNode:
                    logging.warning(f"Failed to evaluate 'defaultValue' (node lambda) for attribute '{self.fullName}': {e}")
                return None
        # keyable attribute default value
        if self.keyable:
            return {}
        # Need to force a copy, for the case where the value is a list
        # (avoid reference to the desc value)
        return copy.copy(self._desc.value)

    def getSerializedValue(self):
        """
        Get the attribute value serialized.
        """
        if self.isLink:
            return self._getInputLink().asLinkExpr()
        if self.keyable:
            return self._keyValues.getSerializedValues()
        if self.isOutput and self._desc.isExpression:
            return self.getDefaultValue()
        return self.value

    def getPrimitiveValue(self, exportDefault=True):
        return self._value

    def getValueStr(self, withQuotes=True) -> str:
        """
        Return the value formatted as a string with quotes to deal with spaces.
        If it is a string, expressions will be evaluated.
        If it is an empty string, it will returns 2 quotes.
        If it is an empty list, it will returns a really empty string.
        If it is a list with one empty string element, it will returns 2 quotes.
        """
        # Keyable attribute, for now return the list of pairs as a JSON sting
        if self.keyable:
            return self._keyValues.getJson()
        # ChoiceParam with multiple values should be combined
        if isinstance(self._desc, desc.ChoiceParam) and not self._desc.exclusive:
            # Ensure value is a list as expected
            assert (isinstance(self.value, Sequence) and not isinstance(self.value, str))
            v = self._desc.joinChar.join(self._getEvalValue())
            if withQuotes and v:
                return f'"{v}"'
            return v
        # String, File, single value Choice are based on strings and should includes quotes
        # to deal with spaces
        if withQuotes and isinstance(self._desc, (desc.StringParam, desc.File, desc.ChoiceParam)):
            return f'"{self._getEvalValue()}"'
        return str(self._getEvalValue())

    def validateValue(self, value):
        """ 
        Ensure value is compatible with the attribute description and convert value if needed. 
        """
        return self._desc.validateValue(value)

    def upgradeValue(self, exportedValue):
        """ 
        Upgrade the attribute value within a compatibility node.
        """
        self._setValue(exportedValue)

    def _isDefault(self):
        if self.keyable:
            return len(self._keyValues.pairs) == 0
        else:
            return self._getValue() == self.getDefaultValue()
        
    def _isValid(self):
        """
        Check attribute description validValue:
            - If it is a function, execute it and return the result
            - Otherwise, simply return true
        """
        if callable(self._desc.validValue):
            try:
                return self._desc.validValue(self.node)
            except Exception as e:
                if not self.node.isCompatibilityNode:
                    logging.warning(f"Failed to evaluate 'isValid' (node lambda) for attribute '{self.fullName}': {e}")
                return True
        return True

    def _is2dDisplayable(self) -> bool:
        """ 
        Return True if the current attribute is considered as a displayable 2d file 
        """
        if not self._desc.semantic:
            return False
        return next((imageSemantic for imageSemantic in Attribute.VALID_IMAGE_SEMANTICS
                     if self._desc.semantic == imageSemantic), None) is not None

    def _is3dDisplayable(self) -> bool:
        """ 
        Return True if the current attribute is considered as a displayable 3d file 
        """
        if self._desc.semantic == "3d":
            return True
        # If the attribute is a File attribute, it is an instance of str and can be iterated over
        hasSupportedExt = isinstance(self.value, str) and any(ext in self.value for ext in Attribute.VALID_3D_EXTENSIONS)
        if hasSupportedExt:
            return True
        return False

    def uid(self) -> str:
        """
        Compute the UID for the attribute.
        """
        if self.isOutput:
            if self._desc.isDynamicValue:
                # If the attribute is a dynamic output, the UID is derived from the node UID.
                # To guarantee that each output attribute receives a unique ID, we add the attribute
                # name to it.
                return hashValue((self.name, self.node._uid))
            else:
                # Only dependent on the hash of its value without the cache folder.
                # "/" at the end of the link is stripped to prevent having different UIDs depending
                # on whether the invalidation value finishes with it or not
                strippedInvalidationValue = self._invalidationValue.rstrip("/")
                return hashValue(strippedInvalidationValue)
        if self.isLink:
            linkRootAttribute = self._getInputLink(recursive=True)
            return linkRootAttribute.uid()
        if self.keyable:
            return self._keyValues.uid()
        if isinstance(self._value, (list, tuple, set,)):
            # non-exclusive choice param
            # hash of sorted values hashed
            return hashValue([hashValue(v) for v in sorted(self._value)])
        return hashValue(self._value)

    def updateInternals(self):
        """
        Update attribute internal properties.
        """
        # Emit if the enable status has changed
        self._setEnabled(self._getEnabled())

    def _getEnabled(self) -> bool:
        if callable(self._desc.enabled):
            try:
                return self._desc.enabled(self.node)
            except Exception as e:
                if not self.node.isCompatibilityNode:
                    logging.warning(f"Failed to evaluate 'enabled' (node lambda) for attribute '{self.fullName}': {e}")
                return True
        return self._desc.enabled

    def _setEnabled(self, v):
        if self._enabled == v:
            return
        self._enabled = v
        self.enabledChanged.emit()

    def _isLink(self) -> bool:
        """ 
        Whether the attribute is a link to another attribute. 
        """
        return self.node.graph and self.isInput and self.node.graph._edges and \
            self in self.node.graph._edges.keys()

    def _getInputLink(self, recursive=False) -> "Attribute":
        """ 
        Return the direct upstream connected attribute.
        :param recursive: recursive call, return the root attribute
        """
        if not self.isLink:
            return None
        linkAttribute = self.node.graph.edge(self).src
        if recursive and linkAttribute.isLink:
            return linkAttribute._getInputLink(recursive)
        return linkAttribute

    def _getOutputLinks(self) -> list["Attribute"]:
        """ 
        Return the list of direct downstream connected attributes.
        """
        # Safety check to avoid evaluation errors
        if not self.node.graph or not self.node.graph.edges:
            return []
        return [edge.dst for edge in self.node.graph.edges.values() if edge.src == self]

    def _getAllInputLinks(self) -> list["Attribute"]:
        """ 
        Return the list of upstream connected attributes for the attribute or any of its elements.
        """
        inputLink = self._getInputLink()
        if inputLink is None: 
            return []
        return [inputLink]

    def _getAllOutputLinks(self) -> list["Attribute"]:
        """ 
        Return the list of downstream connected attributes for the attribute or any of its elements.
        """
        return self._getOutputLinks()

    def _hasAnyInputLinks(self) -> bool:
        """
        Whether the attribute or any of its elements is a link to another attribute.
        """
        # Safety check to avoid evaluation errors
        if not self.node.graph or not self.node.graph.edges:
            return False
        return next((edge for edge in self.node.graph.edges.values() if edge.dst == self), None) is not None

    def _hasAnyOutputLinks(self) -> bool:
        """
        Whether the attribute or any of its elements is linked by another attribute.
        """
        # Safety check to avoid evaluation errors
        if not self.node.graph or not self.node.graph.edges:
            return False
        return next((edge for edge in self.node.graph.edges.values() if edge.src == self), None) is not None

    # Slots

    @Slot()
    def _onKeyValuesChanged(self):
        """
        For keyable attribute, when the list or pairs (key, value) is modified this method should be called.
        Emit Attribute.valueChanged and update node / graph like _setValue().
        """
        if self.isInput:
            self.requestGraphUpdate()
            self.requestNodeUpdate()
        self.valueChanged.emit()

    @Slot()
    def _onValueChanged(self):
        self.node._onAttributeChanged(self)

    @Slot(str, result=bool)
    def matchText(self, text: str) -> bool:
        return self.label.lower().find(text.lower()) > -1

    # Properties and signals 

    # The node that contains this attribute.
    node = Property(BaseObject, lambda self: self._node(), constant=True)
    # The attribute that contains this attribute.
    root = Property(BaseObject, lambda self: self._root() if self._root else None, constant=True)
    # The attribute name following the path from the node to the attribute.
    fullName = Property(str, _getFullName, constant=True)
    # The attribute name following the path from the root attribute.
    rootName = Property(str, _getRootName, constant=True)
    # The description object of the attribute.
    desc = Property(desc.Attribute, lambda self: self._desc, constant=True)
    # The name of the attribute.
    name = Property(str, lambda self: self._desc._name, constant=True)
    # The human-readable label for the attribute.
    label = Property(str, lambda self: self._desc.label, constant=True)
    # The type of attribute as a string.
    type = Property(str, lambda self: self._desc.type, constant=True)
    # The type of the elements of the attribute as a string.
    baseType = Property(str, lambda self: self._desc.type, constant=True)
    # Whether the attribute is a node input attribute.
    isInput = Property(bool, lambda self: not self._isOutput, constant=True)
    # Whether the attribute is a node output attribute.
    isOutput = Property(bool, lambda self: self._isOutput, constant=True)
    # Whether the attribute is a read-only attribute.
    isReadOnly = Property(bool, lambda self: not self._isOutput and self.node.isCompatibilityNode, constant=True)
    # Whether changing this attribute invalidates cached results.
    invalidate = Property(bool, lambda self: self._invalidate, constant=True)
    # Whether this attribute is enabled.
    enabledChanged = Signal()
    enabled = Property(bool, _getEnabled, _setEnabled, notify=enabledChanged)

    # Attribute value properties and signals
    valueChanged = Signal()
    value = Property(Variant, _getValue, _setValue, notify=valueChanged)
    evalValue = Property(Variant, _getEvalValue, notify=valueChanged)
    # Whether the attribute can have a distinct value per key.
    keyable = Property(bool, lambda self: self._desc.keyable, constant=True)
    # The list of pairs (key, value) of the attribute.
    keyValues = Property(Variant, _getKeyValues, notify=valueChanged)

    # Whether the attribute value is the default value.
    isDefault = Property(bool, _isDefault, notify=valueChanged)
    # Whether the attribute value is valid.
    isValid = Property(bool, _isValid, notify=valueChanged)
    # Whether the attribute value is displayable in 2d.
    is2dDisplayable = Property(bool, _is2dDisplayable, constant=True)
    # Whether the attribute value is displayable in 3d.
    is3dDisplayable = Property(bool, _is3dDisplayable, constant=True)
    # Whether the attribute is a shape or a shape list, managed by the ShapeEditor and ShapeViewer.
    hasDisplayableShape = Property(bool, lambda self: False, constant=True)
    
    # Attribute link properties and signals
    inputLinksChanged = Signal()
    outputLinksChanged = Signal()

    # Whether the attribute is a link to another attribute.
    isLink = Property(bool, _isLink, notify=inputLinksChanged)
    # The upstream connected root attribute.
    inputRootLink = Property(Variant, lambda self: self._getInputLink(recursive=True), notify=inputLinksChanged)
    # The upstream connected attribute.
    inputLink = Property(BaseObject, _getInputLink, notify=inputLinksChanged)
    # The list of downstream connected attributes.
    outputLinks = Property(Variant, _getOutputLinks, notify=outputLinksChanged)
    # The list of upstream connected attributes for the attribute or any of its elements.
    allInputLinks = Property(Variant, _getAllInputLinks, notify=inputLinksChanged)
    # The list of downstream connected attributes for the attribute or any of its elements.
    allOutputLinks = Property(Variant, _getAllOutputLinks, notify=outputLinksChanged)
    # Whether the attribute or any of its elements is a link to another attribute.
    hasAnyInputLinks = Property(bool, _hasAnyInputLinks, notify=inputLinksChanged)
    # Whether the attribute or any of its elements is linked by another attribute.
    hasAnyOutputLinks = Property(bool, _hasAnyOutputLinks, notify=outputLinksChanged)


def raiseIfLink(func):
    """ 
    If Attribute instance is a link, raise a RuntimeError.
    """
    def wrapper(attr, *args, **kwargs):
        if attr.isLink:
            raise RuntimeError("Can't modify connected Attribute")
        return func(attr, *args, **kwargs)
    return wrapper


class PushButtonParam(Attribute):
    def __init__(self, node, attributeDesc: desc.PushButtonParam, isOutput: bool,
                 root=None, parent=None):
        super().__init__(node, attributeDesc, isOutput, root, parent)

    @Slot()
    def clicked(self):
        self.node.onAttributeClicked(self)


class ChoiceParam(Attribute):

    def __init__(self, node, attributeDesc: desc.ChoiceParam, isOutput: bool,
                 root=None, parent=None):
        super().__init__(node, attributeDesc, isOutput, root, parent)
        self._values = None

    def __len__(self):
        return len(self.getValues())

    def getValues(self):
        if (linkParam := self._getInputLink()) is not None:
            return linkParam.getValues()
        return self._values if self._values is not None else self._desc._values

    def setValues(self, values):
        if values == self._values:
            return
        self._values = values
        self.valuesChanged.emit()

    # Override
    def validateValue(self, value):
        if self._desc.exclusive:
            return self._conformValue(value)
        if isinstance(value, str):
            value = value.split(',')
        if not isinstance(value, Iterable):
            raise ValueError("Non exclusive ChoiceParam value should be iterable (param:{}, value:{}, type:{})".
                             format(self.name, value, type(value)))
        return [self._conformValue(v) for v in value]

    def _conformValue(self, val):
        """ 
        Conform 'val' to the correct type and check for its validity
        """
        return self._desc.conformValue(val)

    # Override
    def _setValue(self, value):
        # Handle alternative serialization for ChoiceParam with overriden values.
        serializedValueWithValuesOverrides = isinstance(value, dict)
        if serializedValueWithValuesOverrides:
            super()._setValue(value[self._desc._OVERRIDE_SERIALIZATION_KEY_VALUE])
            self.setValues(value[self._desc._OVERRIDE_SERIALIZATION_KEY_VALUES])
        else:
            super()._setValue(value)

    # Override
    def getSerializedValue(self):
        useStandardSerialization = self.isLink or not self._desc._saveValuesOverride or \
            self._values is None
        if useStandardSerialization:
            return super().getSerializedValue()
        return {
            self._desc._OVERRIDE_SERIALIZATION_KEY_VALUE: self._value,
            self._desc._OVERRIDE_SERIALIZATION_KEY_VALUES: self._values,
        }

    value = Property(Variant, Attribute._getValue, _setValue, notify=Attribute.valueChanged)
    valuesChanged = Signal()
    values = Property(Variant, getValues, setValues, notify=valuesChanged)


class ListAttribute(Attribute):

    def __init__(self, node, attributeDesc: desc.ListAttribute, isOutput: bool,
                 root=None, parent=None):
        super().__init__(node, attributeDesc, isOutput, root, parent)

    def __len__(self):
        if self.value is None:
            return 0
        return len(self.value)

    def __iter__(self):
        return iter(self.value)

    def at(self, idx):
        """ 
        Returns child attribute at index 'idx'.
        """
        # Implement 'at' rather than '__getitem__'
        # since the later is called spuriously when object is used in QML
        return self.value.at(idx)

    def index(self, item):
        return self.value.indexOf(item)

    @raiseIfLink
    def append(self, value):
        self.extend([value])

    @raiseIfLink
    def extend(self, values):
        self.insert(len(self), values)

    @raiseIfLink
    def insert(self, index, value):
        if self._value is None:
            self._value = ListModel(parent=self)
        values = value if isinstance(value, list) else [value]
        attrs = [attributeFactory(self._desc.elementDesc, v, self.isOutput, self.node, self)
                 for v in values]
        self._value.insert(index, attrs)
        self.valueChanged.emit()
        self._applyExpr()
        self.requestGraphUpdate()

    @raiseIfLink
    def remove(self, index, count=1):
        if self._value is None:
            return
        if self.node.graph:
            from meshroom.core.graph import GraphModification
            with GraphModification(self.node.graph):
                # remove potential links
                for i in range(index, index + count):
                    attr = self._value.at(i)
                    if attr.isLink:
                        # delete edge if the attribute is linked
                        self.node.graph.removeEdge(attr)
        self._value.removeAt(index, count)
        self.requestGraphUpdate()
        self.valueChanged.emit()

    # Override
    def _initValue(self):
        self.resetToDefaultValue()

    # Override
    def _setValue(self, value):
        if self.node.graph:
            self.remove(0, len(self))
        # Link to another attribute
        if isinstance(value, ListAttribute) or Attribute.isLinkExpression(value):
            self._value = value
        # New value
        else:
            # During initialization self._value may not be set
            if self._value is None:
                self._value = ListModel(parent=self)
            newValue = self._desc.validateValue(value)
            self.extend(newValue)
        self.requestGraphUpdate()

    # Override
    def _applyExpr(self):
        if not self.node.graph:
            return
        if isinstance(self._value, ListAttribute) or Attribute.isLinkExpression(self._value):
            super()._applyExpr()
        else:
            for value in self._value:
                value._applyExpr()

    # Override
    def resetToDefaultValue(self):
        self._value = ListModel(parent=self)
        self.valueChanged.emit()

    # Override
    def getDefaultValue(self) -> list:
        return []

    # Override
    def getSerializedValue(self):
        if self.isLink:
            return self._getInputLink().asLinkExpr()
        return [attr.getSerializedValue() for attr in self._value]

    # Override
    def getPrimitiveValue(self, exportDefault=True):
        if exportDefault:
            return [attr.getPrimitiveValue(exportDefault=exportDefault) for attr in self._value]
        return [attr.getPrimitiveValue(exportDefault=exportDefault) for attr in self._value
                if not attr.isDefault]

    # Override
    def getValueStr(self, withQuotes=True) -> str:
        assert isinstance(self.value, ListModel)
        if self._desc.joinChar == ' ':
            return self._desc.joinChar.join([v.getValueStr(withQuotes=withQuotes)
                                                     for v in self.value])
        v = self._desc.joinChar.join([v.getValueStr(withQuotes=False)
                                              for v in self.value])
        if withQuotes and v:
            return f'"{v}"'
        return v

    # Override
    def upgradeValue(self, exportedValues):
        if not isinstance(exportedValues, list):
            if isinstance(exportedValues, ListAttribute) or \
               Attribute.isLinkExpression(exportedValues):
                self._setValue(exportedValues)
                return
            raise RuntimeError("ListAttribute.upgradeValue: the given value is of type " +
                               str(type(exportedValues)) + " but a 'list' is expected.")
        attrs = []
        for v in exportedValues:
            a = attributeFactory(self._desc.elementDesc, None, self.isOutput,
                                 self.node, self)
            a.upgradeValue(v)
            attrs.append(a)
        index = len(self._value)
        self._value.insert(index, attrs)
        self.valueChanged.emit()
        self._applyExpr()
        self.requestGraphUpdate()

    # Override
    def uid(self):
        if isinstance(self.value, ListModel):
            uids = []
            for value in self.value:
                if value.invalidate:
                    uids.append(value.uid())
            return hashValue(uids)
        return super().uid()

    # Override
    def updateInternals(self):
        super().updateInternals()
        for attr in self._value:
            attr.updateInternals()

    # Override
    def _getAllInputLinks(self) -> list["Attribute"]:
        """ 
        Return the list of upstream connected attributes for the attribute or any of its elements."
        """
        # Safety check to avoid evaluation errors
        if not self.node.graph or not self.node.graph.edges:
            return []
        return [edge.src for edge in self.node.graph.edges.values() if edge.dst == self or edge.dst in self._value]

    # Override
    def _getAllOutputLinks(self) -> list["Attribute"]:
        """ 
        Return the list of downstream connected attributes for the attribute or any of its elements."
        """
        # Safety check to avoid evaluation errors
        if not self.node.graph or not self.node.graph.edges:
            return []
        return [edge.dst for edge in self.node.graph.edges.values() if edge.src == self or edge.src in self._value]

    # Override
    def _hasAnyInputLinks(self) -> bool:
        """
        Whether the attribute or any of its elements is a link to another attribute.
        """
        return super()._hasAnyInputLinks() or \
               any(attribute.hasAnyInputLinks for attribute in self._value if hasattr(attribute, 'hasAnyInputLinks'))

    # Override
    def _hasAnyOutputLinks(self) -> bool:
        """
        Whether the attribute or any of its elements is linked by another attribute.
        """
        return super()._hasAnyOutputLinks() or \
               any(attribute.hasAnyOutputLinks for attribute in self._value if hasattr(attribute, 'hasAnyOutputLinks'))


    # Override value property setter
    value = Property(Variant, Attribute._getValue, _setValue, notify=Attribute.valueChanged)
    isDefault = Property(bool, lambda self: len(self.value) == 0, notify=Attribute.valueChanged)
    baseType = Property(str, lambda self: self._desc.elementDesc.__class__.__name__, constant=True)

    # Override attribute link properties
    allInputLinks = Property(Variant, _getAllInputLinks, notify=Attribute.inputLinksChanged)
    allOutputLinks = Property(Variant, _getAllOutputLinks, notify=Attribute.outputLinksChanged)
    hasAnyInputLinks = Property(bool, _hasAnyInputLinks, notify=Attribute.inputLinksChanged)
    hasAnyOutputLinks = Property(bool, _hasAnyOutputLinks, notify=Attribute.outputLinksChanged)


class GroupAttribute(Attribute):

    def __init__(self, node, attributeDesc: desc.GroupAttribute, isOutput: bool,
                 root=None, parent=None):
        super().__init__(node, attributeDesc, isOutput, root, parent)

    def __getattr__(self, key):
        try:
            return super().__getattr__(key)
        except AttributeError:
            try:
                return self._value.get(key)
            except KeyError:
                raise AttributeError(key)

    # Override
    def _initValue(self):
        self._value = DictModel(keyAttrName='name', parent=self)
        subAttributes = []
        for subAttrDesc in self._desc.groupDesc:
            childAttr = attributeFactory(subAttrDesc, None, self.isOutput, self.node, self)
            subAttributes.append(childAttr)
            childAttr.valueChanged.connect(self.valueChanged)
        self._value.reset(subAttributes)

    # Override
    def _setValue(self, exportedValue):
        value = self.validateValue(exportedValue)
        if isinstance(value, dict):
            # set individual child attribute values
            for key, v in value.items():
                self._value.get(key).value = v
        elif isinstance(value, (list, tuple)):
            if len(self._desc._groupDesc) != len(value):
                raise AttributeError(f"Incorrect number of values on GroupAttribute: {str(value)}")
            for attrDesc, v in zip(self._desc._groupDesc, value):
                self._value.get(attrDesc.name).value = v
        else:
            raise AttributeError(f"Failed to set on GroupAttribute: {str(value)}")

    # Override
    def _applyExpr(self):
        for value in self._value:
            value._applyExpr()

    # Override
    def resetToDefaultValue(self):
        for attrDesc in self._desc._groupDesc:
            self._value.get(attrDesc.name).resetToDefaultValue()

    # Override
    def getDefaultValue(self):
        return {key: attr.getDefaultValue() for key, attr in self._value.items()}

    # Override
    def getSerializedValue(self):
        return {key: attr.getSerializedValue() for key, attr in self._value.objects.items()}

    # Override
    def getPrimitiveValue(self, exportDefault=True):
        if exportDefault:
            return {name: attr.getPrimitiveValue(exportDefault=exportDefault) for name, attr in self._value.items()}
        return {name: attr.getPrimitiveValue(exportDefault=exportDefault) for name, attr in self._value.items()
                if not attr.isDefault}

    # Override
    def getValueStr(self, withQuotes=True):
        # add brackets if requested
        strBegin = ''
        strEnd = ''
        if self._desc.brackets is not None:
            if len(self._desc.brackets) == 2:
                strBegin = self._desc.brackets[0]
                strEnd = self._desc.brackets[1]
            else:
                raise AttributeError(f"Incorrect brackets on GroupAttribute: {self._desc.brackets}")
        # particular case when using space separator
        spaceSep = self._desc.joinChar == ' '
        # sort values based on child attributes group description order
        sortedSubValues = [self._value.get(attr.name).getValueStr(withQuotes=spaceSep)
                           for attr in self._desc.groupDesc]
        s = self._desc.joinChar.join(sortedSubValues)
        if withQuotes and not spaceSep:
            return f'"{strBegin}{s}{strEnd}"'
        return f'{strBegin}{s}{strEnd}'

    # Override
    def upgradeValue(self, exportedValue):
        value = self.validateValue(exportedValue)
        if isinstance(value, dict):
            # set individual child attribute values
            for key, v in value.items():
                if key in self._value.keys():
                    self._value.get(key).upgradeValue(v)
        elif isinstance(value, (list, tuple)):
            if len(self._desc._groupDesc) != len(value):
                raise AttributeError(f"Incorrect number of values on GroupAttribute: {str(value)}")
            for attrDesc, v in zip(self._desc._groupDesc, value):
                self._value.get(attrDesc.name).upgradeValue(v)
        else:
            raise AttributeError(f"Failed to set on GroupAttribute: {str(value)}")

    # Override
    def uid(self):
        uids = []
        for k, v in self._value.items():
            if v.enabled and v.invalidate:
                uids.append(v.uid())
        return hashValue(uids)

    # Override
    def updateInternals(self):
        super().updateInternals()
        for attr in self._value:
            attr.updateInternals()

    @Slot(str, result=Attribute)
    def childAttribute(self, key: str) -> Attribute:
        """
        Get child attribute by name or None if none was found.

        Args:
            key: the name of the child attribute

        Returns:
            Attribute: the child attribute or None
        """
        try:
            return self._value.get(key)
        except KeyError:
            return None

    # Override
    @Slot(str, result=bool)
    def matchText(self, text: str) -> bool:
        return super().matchText(text) or any(c.matchText(text) for c in self._value)

    # Override value property
    value = Property(Variant, Attribute._getValue, _setValue, notify=Attribute.valueChanged)
    isDefault = Property(bool, lambda self: all(v.isDefault for v in self.value), notify=Attribute.valueChanged)


class ShapeAttribute(GroupAttribute):
    """
    GroupAttribute subtype tailored for shape-specific handling.
    """

    def __init__(self, node, attributeDesc: desc.Shape, isOutput: bool,
                 root=None, parent=None):
        self._visible = True
        self._color = "#2A82DA" # default shape color
        super().__init__(node, attributeDesc, isOutput, root, parent)

    # Override
    # Signal observationsChanged should be emitted.
    def _setValue(self, exportedValue):
        super()._setValue(exportedValue)
        self.observationsChanged.emit()

    # Override
    # Signal observationsChanged should be emitted.
    def resetToDefaultValue(self):
        super().resetToDefaultValue()
        self.observationsChanged.emit()

    # Override
    # Signal observationsChanged should be emitted.
    def upgradeValue(self, exportedValue):
        super().upgradeValue(exportedValue)
        self.observationsChanged.emit()

    # Override
    # Fix missing link expression serialization.
    # Should be remove if link expression serialization is added in GroupAttribute.
    def getSerializedValue(self):
        if self.isLink:
            return self._getInputLink().asLinkExpr() 
        return {key: attr.getSerializedValue() for key, attr in self._value.objects.items()}
    
    def getValueAsDict(self) -> dict:
        """
        Return the shape attribute value as dict.
        For not keyable shape, this is the same as getSerializedValue().
        For keyable shape, the dict is indexed by key.
        """
        from collections import defaultdict
        outValue = defaultdict(dict)
        if self.isLink:
            return self._getInputLink().asLinkExpr() 
        if not self.shapeKeyable:
            return super().getSerializedValue()
        for attribute in self.value:
            if isinstance(attribute, ShapeAttribute):
                attributeDict = attribute.getValueAsDict()
                if attributeDict:
                    for key, value in attributeDict.items():
                        outValue[key][attribute.name] = value
            else:
                for pair in attribute.keyValues.pairs:
                    outValue[str(pair.key)][attribute.name] = pair.value
        return dict(outValue)
    
    def _getVisible(self) -> bool:
        """ 
        Return whether the shape attribute is visible for display.
        """
        return self._visible
    
    def _setVisible(self, visible:bool):
        """ 
        Set the shape attribute visibility for display.
        """
        self._visible = visible
        self.shapeChanged.emit()

    def _getColor(self) -> str:
        """ 
        Return the shape attribute color for display.
        """
        if self.isLink:
            return self.inputLink.shapeColor
        return self._color
    
    @raiseIfLink
    def _setColor(self, color: str):
        """ 
        Set the shape attribute color for display.
        """
        self._color = color
        self.shapeChanged.emit()

    def _hasKeyableChilds(self) -> bool:
        """
        Whether all child attributes are keyable.
        """
        return all((isinstance(attribute, ShapeAttribute) and attribute.shapeKeyable) or
                    attribute.keyable for attribute in self.value)

    def _getNbObservations(self) -> int:
        """
        Return the shape attribute number of observations.
        Note: Observation is a value defined across all child attributes for a specific key.
        """
        if self.shapeKeyable:
            firstAttribute = next(iter(self.value.values()))
            if isinstance(firstAttribute, ShapeAttribute):
                return firstAttribute.nbObservations
            return len(firstAttribute.keyValues.pairs)
        return 1

    def _getObservationKeys(self) -> list:
        """
        Return the shape attribute list of observation keys.
        Note: Observation is a value defined across all child attributes for a specific key.
        """
        if not self.shapeKeyable:
            return []
        firstAttribute = next(iter(self.value.values()))
        if isinstance(firstAttribute, ShapeAttribute):
            return firstAttribute.observationKeys
        return firstAttribute.keyValues.getKeys()

    @Slot(str, result=bool)
    def hasObservation(self, key: str) -> bool:
        """
        Whether the shape attribute has an observation for the given key.
        Note: Observation is a value defined across all child attributes for a specific key.
        """
        if not self.shapeKeyable:
            return True
        return all((isinstance(attribute, ShapeAttribute) and attribute.hasObservation(key)) or
                   (not isinstance(attribute, ShapeAttribute) and attribute.keyValues.hasKey(key))
                   for attribute in self.value)
    
    @raiseIfLink
    def removeObservation(self, key: str):
        """
        Remove the shape attribute observation for the given key.
        Note: Observation is a value defined across all child attributes for a specific key.
        """
        for attribute in self.value:
            if isinstance(attribute, ShapeAttribute):
                attribute.removeObservation(key)
            else:
                if attribute.keyable:
                    attribute.keyValues.remove(key)
                else:
                    attribute.resetToDefaultValue()
        self.observationsChanged.emit()

    @raiseIfLink
    def setObservation(self, key: str, observation: Variant):
        """
        Set the shape attribute observation for the given key with the given observation.
        Note: Observation is a value defined across all child attributes for a specific key.
        """
        for attributeStr, value in observation.items():
            attribute = self.childAttribute(attributeStr)
            if attribute is None:
                raise RuntimeError(f"Cannot set shape observation for attribute {self._getFullName()} \
                                   observation is incorrect.")
            if isinstance(attribute, ShapeAttribute):
                attribute.setObservation(key, value)
            else:
                if attribute.keyable:
                    attribute.keyValues.add(key, value)
                else:
                    attribute.value = value
        self.observationsChanged.emit()

    @Slot(str, result=Variant)
    def getObservation(self, key: str) -> Variant:
        """
        Return the shape attribute observation for the given key.
        Note: Observation is a value defined across all child attributes for a specific key.
        """
        observation = {}
        for attribute in self.value:
            if isinstance(attribute, ShapeAttribute):
                shapeObservation = attribute.getObservation(key)
                if shapeObservation is None:
                    return None
                else :
                    observation[attribute.name] = shapeObservation
            else:
                if attribute.keyable:
                    if attribute.keyValues.hasKey(key):
                        observation[attribute.name] = attribute.keyValues.getValueAtKeyOrDefault(key)
                    else:
                        return None
                else:
                    observation[attribute.name] = attribute.value
        return observation
    
    # Properties and signals
    # Emitted when a shape related property changed (color, visibility).
    shapeChanged = Signal()
    # Emitted when a shape observation changed.
    observationsChanged = Signal()
    # Whether the shape is displayable.
    isVisible = Property(bool, _getVisible, _setVisible, notify=shapeChanged)
    # The shape color for display.
    shapeColor = Property(str, _getColor, _setColor, notify=shapeChanged)
    # The shape list of observation keys.
    observationKeys = Property(Variant, _getObservationKeys, notify=observationsChanged)
    # The number of observation defined.
    nbObservations = Property(int, _getNbObservations, notify=observationsChanged) 
    # Whether the shape attribute childs are keyable.
    shapeKeyable = Property(bool,_hasKeyableChilds, constant=True)
    # Override hasDisplayableShape property.
    hasDisplayableShape = Property(bool, lambda self: True, constant=True)
    # Override value property.
    value = Property(Variant, Attribute._getValue, _setValue, notify=Attribute.valueChanged)

class ShapeListAttribute(ListAttribute):
    """
    ListAttribute subtype tailored for shape-specific handling.
    """

    def __init__(self, node, attributeDesc: desc.ShapeList, isOutput: bool,
                 root=None, parent=None):
        self._visible = True
        super().__init__(node, attributeDesc, isOutput, root, parent)

    def getShapesAsDicts(self):
        """
        Return the shape list attribute value as dict.
        """
        return [shapeAttribute.getValueAsDict() for shapeAttribute in self.value]

    def _getVisible(self) -> bool:
        """ 
        Return whether the shape list is visible for display.
        """
        if self.isLink:
            return self.inputLink.isVisible
        return self._visible
    
    def _setVisible(self, visible:bool):
        """ 
        Set the shape visibility for display.
        """
        if self.isLink:
            self.inputLink.isVisible = visible
        else:
            self._visible = visible
        for attribute in self.value:
            if isinstance(attribute, ShapeAttribute):
                attribute.isVisible = visible
        self.shapeListChanged.emit()

    # Properties and signals
    # Emitted when a shape list related property changed.
    shapeListChanged = Signal()
    # Whether the shape list is displayable.
    isVisible = Property(bool, _getVisible, _setVisible, notify=shapeListChanged)
    # Override hasDisplayableShape property.
    hasDisplayableShape = Property(bool, lambda self: True, constant=True)