import os
import tkinter as tk
from typing import Optional, TYPE_CHECKING

from .cfd_app_config import LocaleStrings

if TYPE_CHECKING:
    from custom_file_dialog import CustomFileDialog


class NavigationManager:
    """Manages directory navigation, history, and path handling."""

    def __init__(self, dialog: 'CustomFileDialog') -> None:
        """
        Initializes the NavigationManager.

        Args:
            dialog: The main CustomFileDialog instance.
        """
        self.dialog = dialog

    def handle_path_entry_return(self, event: tk.Event) -> None:
        """
        Handles the Return key press in the path entry field.
        """
        path_text = self.dialog.widget_manager.path_entry.get().strip()
        is_sftp = self.dialog.current_fs_type == "sftp"

        if is_sftp:
            self.navigate_to(path_text)
        else:
            potential_path = os.path.realpath(os.path.expanduser(path_text))
            if os.path.isdir(potential_path):
                self.navigate_to(potential_path)
            elif os.path.isfile(potential_path):
                directory = os.path.dirname(potential_path)
                filename = os.path.basename(potential_path)
                self.navigate_to(directory, file_to_select=filename)
            else:
                self.dialog.widget_manager.search_status_label.config(
                    text=f"{LocaleStrings.CFD['path_not_found']}: {self.dialog.shorten_text(path_text, 50)}")

    def navigate_to(self, path: str, file_to_select: Optional[str] = None) -> None:
        """
        Navigates to a specified directory path, supporting both local and SFTP filesystems.
        """
        try:
            is_sftp = self.dialog.current_fs_type == "sftp"
            
            if is_sftp:
                # Resolve tilde to the remote home directory for SFTP
                if path == '~' or path.startswith('~/'):
                    home_dir = self.dialog.sftp_manager.home_dir
                    if home_dir:
                        # Manual path joining with forward slashes
                        if path.startswith('~/'):
                            # home_dir might be '/', so avoid '//'
                            path = home_dir.rstrip('/') + '/' + path[2:]
                        else:
                            path = home_dir
                    else: # Fallback if home_dir is not set
                        path = '/'

                # The SFTP manager will handle path validation.
                if not self.dialog.sftp_manager.path_is_dir(path):
                    self.dialog.widget_manager.search_status_label.config(
                        text=f"Error: Directory '{os.path.basename(path)}' not found on SFTP server.")
                    return
                real_path = path
            else:
                # Local filesystem logic
                real_path = os.path.realpath(os.path.abspath(os.path.expanduser(path)))
                if not os.path.isdir(real_path):
                    self.dialog.widget_manager.search_status_label.config(
                        text=f"{LocaleStrings.CFD['error_title']}: {LocaleStrings.CFD['directory']} '{os.path.basename(path)}' {LocaleStrings.CFD['not_found']}")
                    return
                if not os.access(real_path, os.R_OK):
                    self.dialog.widget_manager.search_status_label.config(
                        text=f"{LocaleStrings.CFD['access_to']} '{os.path.basename(path)}' {LocaleStrings.CFD['denied']}")
                    return

            self.dialog.current_dir = real_path
            if self.dialog.history_pos < len(self.dialog.history) - 1:
                self.dialog.history = self.dialog.history[:self.dialog.history_pos + 1]
            if not self.dialog.history or self.dialog.history[-1] != self.dialog.current_dir:
                self.dialog.history.append(self.dialog.current_dir)
                self.dialog.history_pos = len(self.dialog.history) - 1

            self.dialog.widget_manager.search_animation.stop()
            self.dialog.selected_item_frames.clear()
            self.dialog.result = None

            self.dialog.view_manager.populate_files(item_to_select=file_to_select)
            self.update_nav_buttons()
            self.dialog.update_selection_info()
            self.dialog.update_action_buttons_state()

        except Exception as e:
            error_message = f"Error navigating to '{path}': {e}"
            self.dialog.widget_manager.search_status_label.config(text=error_message)

    def go_back(self) -> None:
        """Navigates to the previous directory in the history."""
        if self.dialog.history_pos > 0:
            self.dialog.history_pos -= 1
            self.dialog.current_dir = self.dialog.history[self.dialog.history_pos]
            self._update_ui_after_navigation()

    def go_forward(self) -> None:
        """Navigates to the next directory in the history."""
        if self.dialog.history_pos < len(self.dialog.history) - 1:
            self.dialog.history_pos += 1
            self.dialog.current_dir = self.dialog.history[self.dialog.history_pos]
            self._update_ui_after_navigation()

    def go_up_level(self) -> None:
        """Navigates to the parent directory of the current directory."""
        if self.dialog.current_fs_type == "sftp":
            if self.dialog.current_dir and self.dialog.current_dir != "/":
                new_path = self.dialog.current_dir.rsplit('/', 1)[0]
                if not new_path:
                    new_path = "/"
                self.navigate_to(new_path)
        else:
            new_path = os.path.dirname(self.dialog.current_dir)
            if new_path != self.dialog.current_dir:
                self.navigate_to(new_path)

    def _update_ui_after_navigation(self) -> None:
        """Updates all necessary UI components after a navigation action."""
        self.dialog.view_manager.populate_files()
        self.update_nav_buttons()
        self.dialog.update_selection_info()
        self.dialog.update_action_buttons_state()

    def update_nav_buttons(self) -> None:
        """Updates the state of the back and forward navigation buttons."""
        self.dialog.widget_manager.back_button.config(
            state=tk.NORMAL if self.dialog.history_pos > 0 else tk.DISABLED)
        self.dialog.widget_manager.forward_button.config(state=tk.NORMAL if self.dialog.history_pos < len(
            self.dialog.history) - 1 else tk.DISABLED)