import logging
from copy import copy
from dataclasses import dataclass, field
from enum import IntEnum, auto
from pathlib import Path
from typing import Any, Optional, Self

from PySide6.QtCore import (
    QAbstractListModel, QAbstractItemModel, QByteArray, QModelIndex, QObject,
    QPersistentModelIndex, QStandardPaths, QUrl, Qt, Signal, Slot, Property
)
from PySide6.QtQml import QmlElement

from kodereviewer.project import Project
from kodereviewer.data import ChangedFile, Label, PullRequest

QML_IMPORT_NAME = "org.deprecated.kodereviewer"
QML_IMPORT_MAJOR_VERSION = 1

logger = logging.getLogger(__name__)


@dataclass
class FileItem:
    path: str
    icon: str
    name: str
    parent: Self | None
    patch: str | None = None
    children: list[Self] = field(default_factory=list)

    def append(self, child: Self):
        self.children.append(child)

    def child(self, row: int) -> Self | None:
        if row >= 0 and row < len(self.children):
            return self.children[row]
        return None

    def row(self) -> int:
        """Reports the item's location within it's parent."""
        if self.parent is None:
            return 0
        for i, child in enumerate(self.parent.children):
            if self is child:
                return i

        raise Exception('Should not happen!')

    def column_count(self) -> int:
        """Only the filename."""
        return 1

    def is_file(self) -> bool:
        return self.patch is not None

    def __str__(self) -> str:
        return f'{self.name} | {id(self.parent)} | {[x.name for x in self.children]}'


@QmlElement
class TreeFileModel(QAbstractItemModel):

    filenames: list[str] = field(default_factory=list)
    dir_mapping: dict[str, FileItem] = field(default_factory=dict)
    root_node: FileItem
    _pull_request: Optional[PullRequest]

    class Roles(IntEnum):
        Filename = Qt.ItemDataRole.UserRole + 1
        Path = auto()
        IconName = auto()
        Patch = auto()
        IsFile = auto()

    def __init__(self):
        super().__init__()
        self.root_node = FileItem('./', '', './', parent=None)
        self._pull_request = None

    def load_files(self, files: list[ChangedFile]):
        self.dir_mapping: dict[str, FileItem] = {}
        root_node = FileItem('./', '', './', parent=None)
        for file in files:
            p = Path(file.filename)
            directories = p.parts[:-1]
            fname = p.name
            current_path = Path('')
            parent: FileItem = root_node
            for dir in directories:
                current_path = current_path / dir
                if str(current_path) not in self.dir_mapping:
                    self.dir_mapping[str(current_path)] = FileItem(
                        path=str(current_path), name=current_path.name, icon='inode-directory-symbolic', parent=parent
                    )
                    parent.append(self.dir_mapping[str(current_path)])

                parent = self.dir_mapping[str(current_path)]
            file_item = FileItem(path=str(p), name=fname, icon='document-open-symbolic', patch=file.patch, parent=parent)
            parent.append(file_item)
        self.root_node = root_node
        logger.info(self.root_node)

    pullRequestChanged = Signal()

    def get_pull_request(self) -> Optional[PullRequest]:
        return self._pull_request

    def set_pull_request(self, pull_request: Optional[PullRequest]) -> None:
        if pull_request is None:
            return

        if self._pull_request is not None and self._pull_request == pull_request:
            return

        self.beginResetModel()
        self._pull_request = pull_request
        self._pull_request.filesLoaded.connect(self._reset_model)
        self.endResetModel()
        self.pullRequestChanged.emit()

    pullRequest = Property(PullRequest, fget=get_pull_request, fset=set_pull_request,
                           notify=pullRequestChanged)

    def _reset_model(self) -> None:
        logger.info('reseting model')
        self.beginResetModel()
        self.load_files(self._pull_request.files)
        self.endResetModel()

    def index(self, row: int, column: int,
              parent: QModelIndex = QModelIndex()) -> QModelIndex:
        """Returns the index of the item in the model specified by the given row, column and parent index."""
        if not self.hasIndex(row, column, parent):
            return QModelIndex()
        item: FileItem
        if not parent.isValid():
            item = self.root_node
        else:
            item = parent.internalPointer()

        if item.child(row):
            return self.createIndex(row, column, item.child(row))
        return QModelIndex()

    def parent(self, index: QModelIndex) -> QModelIndex:
        """Returns the parent of the model item with the given index

        If the item has no parent, an invalid QModelIndex is returned.
        """
        if not index.isValid():
            return QModelIndex()

        item: FileItem = index.internalPointer()
        parent: FileItem = item.parent
        if parent == self.root_node:
            return QModelIndex()
        return self.createIndex(parent.row(), 0, parent)

    def rowCount(self, index: QModelIndex = QModelIndex()) -> int:
        """Returns the number of rows under the given parent

        When the parent is valid it means that rowCount is returning
        the number of children of parent. """

        parent: FileItem
        if index.isValid():
            parent = index.internalPointer()
        else:
            parent = self.root_node

        return len(parent.children)

    def columnCount(self, parent: QModelIndex = QModelIndex()) -> int:
        return 1

    def data(self, index: QModelIndex, role: int) -> Any:
        if not index.isValid():
            return ''
        item: FileItem = index.internalPointer()

        if role == Qt.ItemDataRole.DisplayRole:
            return item.name
        if role == self.Roles.Filename:
            return item.name
        if role == self.Roles.Path:
            return item.path
        if role == self.Roles.IconName:
            return item.icon
        if role == self.Roles.Patch:
            return item.patch
        if role == self.Roles.IsFile:
            return item.is_file()
        return None

    def roleNames(self) -> dict[int, QByteArray]:
        return {
            self.Roles.Filename: QByteArray(b'filename'),
            self.Roles.IconName: QByteArray(b'iconName'),
            self.Roles.Path: QByteArray(b'path'),
            self.Roles.Patch: QByteArray(b'patch'),
            self.Roles.IsFile: QByteArray(b'isFile'),
        }


@QmlElement
class FileModel(QAbstractListModel):

    _pull_request: Optional[PullRequest]

    class Roles(IntEnum):
        Sha = Qt.ItemDataRole.UserRole + 1
        Filename = auto()
        Status = auto()
        Additions = auto()
        Deletions = auto()
        Changes = auto()
        Patch = auto()

    def  __init__(self):
        super().__init__()
        self._pull_request = None

    pullRequestChanged = Signal()

    def get_pull_request(self) -> Optional[PullRequest]:
        return self._pull_request

    def set_pull_request(self, pull_request: Optional[PullRequest]) -> None:
        if pull_request is None:
            return

        if self._pull_request is not None and self._pull_request == pull_request:
            return

        self.beginResetModel()
        self._pull_request = pull_request
        self._pull_request.filesLoaded.connect(self._reset_model)
        self.endResetModel()
        self.pullRequestChanged.emit()

    pullRequest = Property(PullRequest, fget=get_pull_request, fset=set_pull_request,
                           notify=pullRequestChanged)

    def _reset_model(self) -> None:
        self.beginResetModel()
        self.endResetModel()

    def data(self,
             index: QModelIndex | QPersistentModelIndex,
             role: int = Qt.ItemDataRole.DisplayRole) -> object:
        if self._pull_request is None:
            return None

        file: ChangedFile = self._pull_request.files[index.row()]

        if role == self.Roles.Sha:
            return file.sha
        if role == self.Roles.Filename:
            return file.filename
        if role == self.Roles.Additions:
            return file.additions
        if role == self.Roles.Deletions:
            return file.deletions
        if role == self.Roles.Changes:
            return file.changes
        if role == self.Roles.Patch:
            return file.patch
        if role == Qt.ItemDataRole.DisplayRole:
            return file.filename
        return None

    def rowCount(self, parent: QModelIndex | QPersistentModelIndex = QModelIndex()) -> int:
        if self._pull_request is None:
            return 0
        return len(self._pull_request.files)

    def roleNames(self) -> dict[int, QByteArray]:
        return {
            self.Roles.Sha: QByteArray(b'sha'),
            self.Roles.Filename: QByteArray(b'filename'),
            self.Roles.Additions: QByteArray(b'additions'),
            self.Roles.Deletions: QByteArray(b'deletions'),
            self.Roles.Changes: QByteArray(b'changes'),
            self.Roles.Patch: QByteArray(b'patch'),
        }