# Copyright (c) 2019 Ultimaker B.V.
# Cura is released under the terms of the LGPLv3 or higher.

import copy  # To duplicate materials.
from PyQt5.QtCore import QObject, pyqtSignal, pyqtSlot  # To allow the preference page proxy to be used from the actual preferences page.
from typing import Any, Dict, Optional, TYPE_CHECKING
import uuid  # To generate new GUIDs for new materials.

from UM.i18n import i18nCatalog
from UM.Logger import Logger
from UM.Signal import postponeSignals, CompressTechnique

import cura.CuraApplication  # Imported like this to prevent circular imports.
from cura.Machines.ContainerTree import ContainerTree
from cura.Settings.CuraContainerRegistry import CuraContainerRegistry  # To find the sets of materials belonging to each other, and currently loaded extruder stacks.

if TYPE_CHECKING:
    from cura.Machines.MaterialNode import MaterialNode

catalog = i18nCatalog("cura")

class MaterialManagementModel(QObject):
    """Proxy class to the materials page in the preferences.

    This class handles the actions in that page, such as creating new materials, renaming them, etc.
    """

    favoritesChanged = pyqtSignal(str)
    """Triggered when a favorite is added or removed.

    :param The base file of the material is provided as parameter when this emits
    """

    @pyqtSlot("QVariant", result = bool)
    def canMaterialBeRemoved(self, material_node: "MaterialNode") -> bool:
        """Can a certain material be deleted, or is it still in use in one of the container stacks anywhere?

        We forbid the user from deleting a material if it's in use in any stack. Deleting it while it's in use can
        lead to corrupted stacks. In the future we might enable this functionality again (deleting the material from
        those stacks) but for now it is easier to prevent the user from doing this.

        :param material_node: The ContainerTree node of the material to check.

        :return: Whether or not the material can be removed.
        """

        container_registry = CuraContainerRegistry.getInstance()
        ids_to_remove = {metadata.get("id", "") for metadata in container_registry.findInstanceContainersMetadata(base_file = material_node.base_file)}
        for extruder_stack in container_registry.findContainerStacks(type = "extruder_train"):
            if extruder_stack.material.getId() in ids_to_remove:
                return False
        return True

    @pyqtSlot("QVariant", str)
    def setMaterialName(self, material_node: "MaterialNode", name: str) -> None:
        """Change the user-visible name of a material.

        :param material_node: The ContainerTree node of the material to rename.
        :param name: The new name for the material.
        """

        container_registry = CuraContainerRegistry.getInstance()
        root_material_id = material_node.base_file
        if container_registry.isReadOnly(root_material_id):
            Logger.log("w", "Cannot set name of read-only container %s.", root_material_id)
            return
        return container_registry.findContainers(id = root_material_id)[0].setName(name)

    @pyqtSlot("QVariant")
    def removeMaterial(self, material_node: "MaterialNode") -> None:
        """Deletes a material from Cura.

        This function does not do any safety checking any more. Please call this function only if:
            - The material is not read-only.
            - The material is not used in any stacks.

        If the material was not lazy-loaded yet, this will fully load the container. When removing this material
        node, all other materials with the same base fill will also be removed.

        :param material_node: The material to remove.
        """

        container_registry = CuraContainerRegistry.getInstance()
        materials_this_base_file = container_registry.findContainersMetadata(base_file = material_node.base_file)

        # The material containers belonging to the same material file are supposed to work together. This postponeSignals()
        # does two things:
        #   - optimizing the signal emitting.
        #   - making sure that the signals will only be emitted after all the material containers have been removed.
        with postponeSignals(container_registry.containerRemoved, compress = CompressTechnique.CompressPerParameterValue):
            # CURA-6886: Some containers may not have been loaded. If remove one material container, its material file
            # will be removed. If later we remove a sub-material container which hasn't been loaded previously, it will
            # crash because removeContainer() requires to load the container first, but the material file was already
            # gone.
            for material_metadata in materials_this_base_file:
                container_registry.findInstanceContainers(id = material_metadata["id"])
            for material_metadata in materials_this_base_file:
                container_registry.removeContainer(material_metadata["id"])

    def duplicateMaterialByBaseFile(self, base_file: str, new_base_id: Optional[str] = None,
                                    new_metadata: Optional[Dict[str, Any]] = None) -> Optional[str]:
        """Creates a duplicate of a material with the same GUID and base_file metadata

        :param base_file: The base file of the material to duplicate.
        :param new_base_id: A new material ID for the base material. The IDs of the submaterials will be based off this
        one. If not provided, a material ID will be generated automatically.
        :param new_metadata: Metadata for the new material. If not provided, this will be duplicated from the original
        material.

        :return: The root material ID of the duplicate material.
        """

        container_registry = CuraContainerRegistry.getInstance()

        root_materials = container_registry.findContainers(id = base_file)
        if not root_materials:
            Logger.log("i", "Unable to duplicate the root material with ID {root_id}, because it doesn't exist.".format(root_id = base_file))
            return None
        root_material = root_materials[0]

        # Ensure that all settings are saved.
        application = cura.CuraApplication.CuraApplication.getInstance()
        application.saveSettings()

        # Create a new ID and container to hold the data.
        if new_base_id is None:
            new_base_id = container_registry.uniqueName(root_material.getId())
        new_root_material = copy.deepcopy(root_material)
        new_root_material.getMetaData()["id"] = new_base_id
        new_root_material.getMetaData()["base_file"] = new_base_id
        if new_metadata is not None:
            new_root_material.getMetaData().update(new_metadata)
        new_containers = [new_root_material]

        # Clone all submaterials.
        for container_to_copy in container_registry.findInstanceContainers(base_file = base_file):
            if container_to_copy.getId() == base_file:
                continue  # We already have that one. Skip it.
            new_id = new_base_id
            definition = container_to_copy.getMetaDataEntry("definition")
            if definition != "fdmprinter":
                new_id += "_" + definition
                variant_name = container_to_copy.getMetaDataEntry("variant_name")
                if variant_name:
                    new_id += "_" + variant_name.replace(" ", "_")

            new_container = copy.deepcopy(container_to_copy)
            new_container.getMetaData()["id"] = new_id
            new_container.getMetaData()["base_file"] = new_base_id
            if new_metadata is not None:
                new_container.getMetaData().update(new_metadata)
            new_containers.append(new_container)

        # CURA-6863: Nodes in ContainerTree will be updated upon ContainerAdded signals, one at a time. It will use the
        # best fit material container at the time it sees one. For example, if you duplicate and get generic_pva #2,
        # if the node update function sees the containers in the following order:
        #
        #   - generic_pva #2
        #   - generic_pva #2_um3_aa04
        #
        # It will first use "generic_pva #2" because that's the best fit it has ever seen, and later "generic_pva #2_um3_aa04"
        # once it sees that. Because things run in the Qt event loop, they don't happen at the same time. This means if
        # between those two events, the ContainerTree will have nodes that contain invalid data.
        #
        # This sort fixes the problem by emitting the most specific containers first.
        new_containers = sorted(new_containers, key = lambda x: x.getId(), reverse = True)

        # Optimization. Serving the same purpose as the postponeSignals() in removeMaterial()
        # postpone the signals emitted when duplicating materials. This is easier on the event loop; changes the
        # behavior to be like a transaction. Prevents concurrency issues.
        with postponeSignals(container_registry.containerAdded, compress=CompressTechnique.CompressPerParameterValue):
            for container_to_add in new_containers:
                container_to_add.setDirty(True)
                container_registry.addContainer(container_to_add)

            # If the duplicated material was favorite then the new material should also be added to the favorites.
            favorites_set = set(application.getPreferences().getValue("cura/favorite_materials").split(";"))
            if base_file in favorites_set:
                favorites_set.add(new_base_id)
                application.getPreferences().setValue("cura/favorite_materials", ";".join(favorites_set))

        return new_base_id

    @pyqtSlot("QVariant", result = str)
    def duplicateMaterial(self, material_node: "MaterialNode", new_base_id: Optional[str] = None,
                          new_metadata: Optional[Dict[str, Any]] = None) -> Optional[str]:
        """Creates a duplicate of a material with the same GUID and base_file metadata

        :param material_node: The node representing the material to duplicate.
        :param new_base_id: A new material ID for the base material. The IDs of the submaterials will be based off this
        one. If not provided, a material ID will be generated automatically.
        :param new_metadata: Metadata for the new material. If not provided, this will be duplicated from the original
        material.

        :return: The root material ID of the duplicate material.
        """
        return self.duplicateMaterialByBaseFile(material_node.base_file, new_base_id, new_metadata)

    @pyqtSlot(result = str)
    def createMaterial(self) -> str:
        """Create a new material by cloning the preferred material for the current material diameter and generate a new
        GUID.

        The material type is explicitly left to be the one from the preferred material, since this allows the user to
        still have SOME profiles to work with.

        :return: The ID of the newly created material.
        """

        # Ensure all settings are saved.
        application = cura.CuraApplication.CuraApplication.getInstance()
        application.saveSettings()

        # Find the preferred material.
        extruder_stack = application.getMachineManager().activeStack
        active_variant_name = extruder_stack.variant.getName()
        approximate_diameter = int(extruder_stack.approximateMaterialDiameter)
        global_container_stack = application.getGlobalContainerStack()
        if not global_container_stack:
            return ""
        machine_node = ContainerTree.getInstance().machines[global_container_stack.definition.getId()]
        preferred_material_node = machine_node.variants[active_variant_name].preferredMaterial(approximate_diameter)

        # Create a new ID & new metadata for the new material.
        new_id = CuraContainerRegistry.getInstance().uniqueName("custom_material")
        new_metadata = {"name": catalog.i18nc("@label", "Custom Material"),
                        "brand": catalog.i18nc("@label", "Custom"),
                        "GUID": str(uuid.uuid4()),
                        }

        self.duplicateMaterial(preferred_material_node, new_base_id = new_id, new_metadata = new_metadata)
        return new_id

    @pyqtSlot(str)
    def addFavorite(self, material_base_file: str) -> None:
        """Adds a certain material to the favorite materials.

        :param material_base_file: The base file of the material to add.
        """

        application = cura.CuraApplication.CuraApplication.getInstance()
        favorites = application.getPreferences().getValue("cura/favorite_materials").split(";")
        if material_base_file not in favorites:
            favorites.append(material_base_file)
            application.getPreferences().setValue("cura/favorite_materials", ";".join(favorites))
            application.saveSettings()
            self.favoritesChanged.emit(material_base_file)

    @pyqtSlot(str)
    def removeFavorite(self, material_base_file: str) -> None:
        """Removes a certain material from the favorite materials.

        If the material was not in the favorite materials, nothing happens.
        """

        application = cura.CuraApplication.CuraApplication.getInstance()
        favorites = application.getPreferences().getValue("cura/favorite_materials").split(";")
        try:
            favorites.remove(material_base_file)
            application.getPreferences().setValue("cura/favorite_materials", ";".join(favorites))
            application.saveSettings()
            self.favoritesChanged.emit(material_base_file)
        except ValueError:  # Material was not in the favorites list.
            Logger.log("w", "Material {material_base_file} was already not a favorite material.".format(material_base_file = material_base_file))
