import os
from pathlib import Path
from ..items.AItems import AItem
from ..items.Folder import Folder
from ..items.Symlink import Symlink
from . import Sort
from .Config import Config
from .Cursor import Cursor


class Navigator:

    def __init__(self, path: Path, config: Config) -> None:
        self._config = config
        self._sort_mode = config.sort_mode
        self._history = [path]
        self._cursor = Cursor()
        self._current: Folder | None = None
        self._items: list[AItem] = []
        self._error: str | None = None
        self._load()

    def _load(self) -> None:
        self._error = None
        try:
            self._current = Folder(self._history[-1])
            self._items = Sort.sort_items(self._current.children(),
                                           self._sort_mode)
        except FileNotFoundError:
            self._items = []
        except PermissionError:
            self._items = []
            self._error = f"Permission denied: {self._history[-1]}"

    def refresh(self) -> None:
        self._load()

    def cycle_sort(self) -> None:
        self._sort_mode = Sort.next_mode(self._sort_mode)
        self._items = Sort.sort_items(self._items, self._sort_mode)

    def _reset_cursor(self) -> None:
        if self._config.cursor_reset == "keep":
            self._cursor.clamp(len(self._items))
        else:
            self._cursor.resete()

    def _navigate_to(self, path: Path) -> bool:
        if not os.access(path, os.R_OK | os.X_OK):
            self._error = f"Permission denied: {path}"
            return False
        self._history.append(path)
        self._error = None
        self._load()
        self._reset_cursor()
        return True

    def enter(self, item: AItem) -> bool:
        if not item.is_navigable():
            return False
        path = item.point_to if isinstance(item, Symlink) else item.path
        return self._navigate_to(path)

    def up(self) -> bool:
        parent = self._history[-1].parent
        if parent == self._history[-1]:
            return False
        return self._navigate_to(parent)

    def back(self) -> bool:
        if len(self._history) <= 1:
            return False
        self._history.pop()
        self._load()
        self._reset_cursor()
        return True

    @property
    def current(self) -> Folder:
        return self._current

    @property
    def items(self) -> list[AItem]:
        return self._items

    @property
    def history(self) -> list[Path]:
        return self._history

    @property
    def cursor(self) -> Cursor:
        return self._cursor

    @property
    def error(self) -> str | None:
        return self._error