"""
novelWriter – Project Item Class
================================

File History:
Created: 2018-10-27 [0.0.1] NWItem

This file is a part of novelWriter
Copyright 2018–2023, Veronica Berglyd Olsen

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
"""
from __future__ import annotations

import logging

from typing import TYPE_CHECKING, Any, Literal, overload

from PyQt5.QtGui import QIcon

from novelwriter.enum import nwItemType, nwItemClass, nwItemLayout
from novelwriter.common import (
    checkInt, isHandle, isItemClass, isItemLayout, isItemType, simplified, yesNo
)
from novelwriter.constants import nwHeaders, nwLabels, trConst

if TYPE_CHECKING:  # pragma: no cover
    from novelwriter.core.project import NWProject

logger = logging.getLogger(__name__)


class NWItem:
    """Core: Item Data Class

    This class holds all the project information about a project item.
    Each item must be associated with a project and have a valid handle.
    Only the NWTree class should create instances of this class, and
    must ensure that the handle is valid for all items in the tree.
    """

    __slots__ = (
        "_project", "_name", "_handle", "_parent", "_root", "_order",
        "_type", "_class", "_layout", "_status", "_import", "_active",
        "_expanded", "_heading", "_charCount", "_wordCount",
        "_paraCount", "_cursorPos", "_initCount",
    )

    def __init__(self, project: NWProject, handle: str) -> None:

        self._project  = project
        self._name     = ""
        self._handle   = handle
        self._parent   = None
        self._root     = None
        self._order    = 0
        self._type     = nwItemType.NO_TYPE
        self._class    = nwItemClass.NO_CLASS
        self._layout   = nwItemLayout.NO_LAYOUT
        self._status   = None
        self._import   = None
        self._active   = True
        self._expanded = False

        # Document Meta Data
        self._heading   = "H0"  # The main heading
        self._charCount = 0     # Current character count
        self._wordCount = 0     # Current word count
        self._paraCount = 0     # Current paragraph count
        self._cursorPos = 0     # Last cursor position
        self._initCount = 0     # Initial word count

        return

    def __repr__(self) -> str:
        return f"<NWItem handle={self._handle}, parent={self._parent}, name='{self._name}'>"

    def __bool__(self) -> bool:
        """The truthiness of the class. The handle used to be initiated
        to None, but this is no longer the case. It should always
        evaluate to True since 2.1-beta1, although unpack and the NWTree
        class can leave it as an empty string.
        """
        return bool(self._handle)

    ##
    #  Properties
    ##

    @property
    def itemName(self) -> str:
        return self._name

    @property
    def itemHandle(self) -> str:
        return self._handle

    @property
    def itemParent(self) -> str | None:
        return self._parent

    @property
    def itemRoot(self) -> str | None:
        return self._root

    @property
    def itemOrder(self) -> int:
        return self._order

    @property
    def itemType(self) -> nwItemType:
        return self._type

    @property
    def itemClass(self) -> nwItemClass:
        return self._class

    @property
    def itemLayout(self) -> nwItemLayout:
        return self._layout

    @property
    def itemStatus(self) -> str | None:
        return self._status

    @property
    def itemImport(self) -> str | None:
        return self._import

    @property
    def isActive(self) -> bool:
        return self._active

    @property
    def isExpanded(self) -> bool:
        return self._expanded

    @property
    def mainHeading(self) -> str:
        return self._heading

    @property
    def charCount(self) -> int:
        return self._charCount

    @property
    def wordCount(self) -> int:
        return self._wordCount

    @property
    def paraCount(self) -> int:
        return self._paraCount

    @property
    def initCount(self) -> int:
        return self._initCount

    @property
    def cursorPos(self) -> int:
        return self._cursorPos

    ##
    #  Pack/Unpack/Duplicate Data
    ##

    def pack(self) -> dict:
        """Pack all the data in the class instance into a dictionary."""
        item: dict[str, str] = {}
        meta: dict[str, str] = {}
        name: dict[str, str] = {}

        item["handle"]   = str(self._handle)
        item["parent"]   = str(self._parent)
        item["root"]     = str(self._root)
        item["order"]    = str(self._order)
        item["type"]     = str(self._type.name)
        item["class"]    = str(self._class.name)
        meta["expanded"] = yesNo(self._expanded)
        name["status"]   = str(self._status)
        name["import"]   = str(self._import)

        if self._type == nwItemType.FILE:
            item["layout"]    = str(self._layout.name)
            meta["heading"]   = str(self._heading)
            meta["charCount"] = str(self._charCount)
            meta["wordCount"] = str(self._wordCount)
            meta["paraCount"] = str(self._paraCount)
            meta["cursorPos"] = str(self._cursorPos)
            name["active"]    = yesNo(self._active)

        data = {
            "name": str(self._name),
            "itemAttr": item,
            "metaAttr": meta,
            "nameAttr": name,
        }

        return data

    def unpack(self, data: dict) -> bool:
        """Set the values from a data dictionary."""
        item = data.get("itemAttr", {})
        meta = data.get("metaAttr", {})
        name = data.get("nameAttr", {})

        handle = item.get("handle", "")
        if isHandle(handle):
            self._handle = handle
        else:
            logger.error("Item does not have a handle")
            return False

        self.setName(data.get("name", ""))
        self.setParent(item.get("parent", None))
        self.setRoot(item.get("root", None))
        self.setOrder(item.get("order", 0))
        self.setType(item.get("type", nwItemType.NO_TYPE))
        self.setClass(item.get("class", nwItemClass.NO_CLASS))
        self.setExpanded(meta.get("expanded", False))
        self.setStatus(name.get("status", None))
        self.setImport(name.get("import", None))

        if self._type == nwItemType.FILE:
            self.setLayout(item.get("layout", nwItemLayout.NO_LAYOUT))
            self.setMainHeading(meta.get("heading", "H0"))
            self.setCharCount(meta.get("charCount", 0))
            self.setWordCount(meta.get("wordCount", 0))
            self.setParaCount(meta.get("paraCount", 0))
            self.setCursorPos(meta.get("cursorPos", 0))
            self.setActive(name.get("active", True))

        # Make some checks to ensure consistency
        if self._type == nwItemType.ROOT:
            self._root = self._handle  # Root items are their own ancestor
            self._parent = None        # Root items cannot have a parent

        if self._type != nwItemType.FILE:
            # Reset values that should only be set for files
            self._layout = nwItemLayout.NO_LAYOUT
            self._heading = "H0"
            self._active = False
            self._charCount = 0
            self._wordCount = 0
            self._paraCount = 0
            self._cursorPos = 0

        return True

    @classmethod
    def duplicate(cls, source: NWItem, handle: str) -> NWItem:
        """Make a copy of an item."""
        cls = NWItem(source._project, handle)
        cls._name      = source._name
        cls._parent    = source._parent
        cls._root      = source._root
        cls._order     = source._order
        cls._type      = source._type
        cls._class     = source._class
        cls._layout    = source._layout
        cls._status    = source._status
        cls._import    = source._import
        cls._active    = source._active
        cls._expanded  = source._expanded
        cls._heading   = source._heading
        cls._charCount = source._charCount
        cls._wordCount = source._wordCount
        cls._paraCount = source._paraCount
        cls._cursorPos = source._cursorPos
        cls._initCount = source._initCount
        return cls

    ##
    #  Lookup Methods
    ##

    def describeMe(self) -> str:
        """Return a string description of the item."""
        descKey = "none"
        if self._type == nwItemType.ROOT:
            descKey = "root"
        elif self._type == nwItemType.FOLDER:
            descKey = "folder"
        elif self._type == nwItemType.FILE:
            if self._layout == nwItemLayout.DOCUMENT:
                if self._heading == "H1":
                    descKey = "doc_h1"
                elif self._heading == "H2":
                    descKey = "doc_h2"
                elif self._heading == "H3":
                    descKey = "doc_h3"
                elif self._heading == "H4":
                    descKey = "doc_h4"
                else:
                    descKey = "document"
            elif self._layout == nwItemLayout.NOTE:
                descKey = "note"

        return trConst(nwLabels.ITEM_DESCRIPTION.get(descKey, ""))

    @overload  # pragma: no cover
    def getImportStatus(self, incIcon: Literal[True] = True) -> tuple[str, QIcon]:
        pass

    @overload  # pragma: no cover
    def getImportStatus(self, incIcon: Literal[False]) -> tuple[str, None]:
        pass

    def getImportStatus(self, incIcon=True):
        """Return the relevant importance or status label and icon for
        the current item based on its class.
        """
        if self.isNovelLike():
            stName = self._project.data.itemStatus.name(self._status)
            stIcon = self._project.data.itemStatus.icon(self._status) if incIcon else None
        else:
            stName = self._project.data.itemImport.name(self._import)
            stIcon = self._project.data.itemImport.icon(self._import) if incIcon else None
        return stName, stIcon

    ##
    #  Checker Methods
    ##

    def isNovelLike(self) -> bool:
        """Check if the item is of a novel-like class."""
        return self._class in (nwItemClass.NOVEL, nwItemClass.ARCHIVE)

    def documentAllowed(self) -> bool:
        """Check if the item is allowed to be of document layout."""
        return self._class in (nwItemClass.NOVEL, nwItemClass.ARCHIVE, nwItemClass.TRASH)

    def isInactiveClass(self) -> bool:
        """Check if the item is in an inactive class."""
        return self._class in (nwItemClass.NO_CLASS, nwItemClass.ARCHIVE, nwItemClass.TRASH)

    def isRootType(self) -> bool:
        """Check if item is a root item."""
        return self._type == nwItemType.ROOT

    def isFolderType(self) -> bool:
        """Check if item is a folder item."""
        return self._type == nwItemType.FOLDER

    def isFileType(self) -> bool:
        """Check if item is a file item."""
        return self._type == nwItemType.FILE

    def isNoteLayout(self) -> bool:
        """Check if item is a project note."""
        return self._layout == nwItemLayout.NOTE

    def isDocumentLayout(self) -> bool:
        """Check if item is a novel document."""
        return self._layout == nwItemLayout.DOCUMENT

    ##
    #  Special Setters
    ##

    def setClassDefaults(self, itemClass: nwItemClass) -> None:
        """Set the default values based on the item's class and the
        project settings.
        """
        if self._parent is not None:
            # Only update for child items
            self.setClass(itemClass)

        if self._layout == nwItemLayout.NO_LAYOUT:
            # If no layout is set, pick one
            if self.isNovelLike():
                self._layout = nwItemLayout.DOCUMENT
            else:
                self._layout = nwItemLayout.NOTE
        elif not self.documentAllowed():
            # Change layout to note if it is not in an allowed folder
            self._layout = nwItemLayout.NOTE

        if self._status is None:
            self.setStatus("New")  # This forces a default value lookup

        if self._import is None:
            self.setImport("New")  # This forces a default value lookup

        return

    ##
    #  Set Item Values
    ##

    def setName(self, name: Any) -> None:
        """Set the item name."""
        if isinstance(name, str):
            self._name = simplified(name)
        else:
            self._name = ""
        return

    def setParent(self, handle: Any) -> None:
        """Set the parent handle, and ensure it is valid."""
        if handle is None:
            self._parent = None
        elif isHandle(handle):
            self._parent = handle
        else:
            self._parent = None
        return

    def setRoot(self, handle: Any) -> None:
        """Set the root handle, and ensure it is valid."""
        if handle is None:
            self._root = None
        elif isHandle(handle):
            self._root = handle
        else:
            self._root = None
        return

    def setOrder(self, order: Any) -> None:
        """Set the item order, and ensure that it is valid. This value
        is purely a meta value, and not actually used by novelWriter at
        the moment.
        """
        self._order = checkInt(order, 0)
        return

    def setType(self, value: Any) -> None:
        """Set the item type from either a proper nwItemType, or set it
        from a string representing an nwItemType.
        """
        if isinstance(value, nwItemType):
            self._type = value
        elif isItemType(value):
            self._type = nwItemType[value]
        else:
            logger.error("Unrecognised item type '%s'", value)
            self._type = nwItemType.NO_TYPE
        return

    def setClass(self, value: Any) -> None:
        """Set the item class from either a proper nwItemClass, or set
        it from a string representing an nwItemClass.
        """
        if isinstance(value, nwItemClass):
            self._class = value
        elif isItemClass(value):
            self._class = nwItemClass[value]
        else:
            logger.error("Unrecognised item class '%s'", value)
            self._class = nwItemClass.NO_CLASS
        return

    def setLayout(self, value: Any) -> None:
        """Set the item layout from either a proper nwItemLayout, or set
        it from a string representing an nwItemLayout.
        """
        if isinstance(value, nwItemLayout):
            self._layout = value
        elif isItemLayout(value):
            self._layout = nwItemLayout[value]
        else:
            logger.error("Unrecognised item layout '%s'", value)
            self._layout = nwItemLayout.NO_LAYOUT
        return

    def setStatus(self, value: Any) -> None:
        """Set the item status by looking it up in the valid status
        items of the current project.
        """
        self._status = self._project.data.itemStatus.check(value)
        return

    def setImport(self, value: Any) -> None:
        """Set the item importance by looking it up in the valid import
        items of the current project.
        """
        self._import = self._project.data.itemImport.check(value)
        return

    def setActive(self, state: Any) -> None:
        """Set the active flag."""
        if isinstance(state, bool):
            self._active = state
        else:
            self._active = False
        return

    def setExpanded(self, state: Any) -> None:
        """Set the expanded status of an item in the project tree."""
        if isinstance(state, bool):
            self._expanded = state
        else:
            self._expanded = False
        return

    ##
    #  Set Document Meta Data
    ##

    def setMainHeading(self, value: str) -> None:
        """Set the main heading level."""
        if value in nwHeaders.H_LEVEL:
            self._heading = value
        return

    def setCharCount(self, count: Any) -> None:
        """Set the character count, and ensure that it is an integer."""
        if isinstance(count, int):
            self._charCount = max(0, count)
        else:
            self._charCount = 0
        return

    def setWordCount(self, count: Any) -> None:
        """Set the word count, and ensure that it is an integer."""
        if isinstance(count, int):
            self._wordCount = max(0, count)
        else:
            self._wordCount = 0
        return

    def setParaCount(self, count: Any) -> None:
        """Set the paragraph count, and ensure that it is an integer."""
        if isinstance(count, int):
            self._paraCount = max(0, count)
        else:
            self._paraCount = 0
        return

    def setCursorPos(self, position: Any) -> None:
        """Set the cursor position, and ensure that it is an integer."""
        if isinstance(position, int):
            self._cursorPos = max(0, position)
        else:
            self._cursorPos = 0
        return

    def saveInitialCount(self) -> None:
        """Save the initial word count."""
        self._initCount = self._wordCount
        return

# END Class NWItem
