"""
User Selection Dialog - Allows Admin to choose which user identity to use
"""

import tkinter as tk
from tkinter import ttk, messagebox
from typing import Optional, Dict, Any, List


class UserSelectionDialog:
    """
    Modal dialog for Admin users to select which user identity to use

    Usage:
        dialog = UserSelectionDialog(parent, users_list, current_username)
        selected_user = dialog.get_selected_user()
        if selected_user:
            # Use the selected user info
    """

    def __init__(self, parent, users: List[Dict[str, Any]], current_username: str):
        """
        Initialize the user selection dialog

        Args:
            parent: The parent Tkinter window
            users: List of user dictionaries [{id, username, user_type}]
            current_username: The currently logged-in Admin's username
        """
        self.parent = parent
        self.users = users
        self.current_username = current_username
        self.selected_user = None
        self.dialog = None
        self.selected_var = None

        self._create_dialog()
        self.parent.wait_window(self.dialog)

    def _create_dialog(self):
        """Create the user selection dialog UI"""
        self.dialog = tk.Toplevel(self.parent)
        self.dialog.title("选择用户身份")
        self.dialog.geometry("450x400")
        self.dialog.resizable(False, False)

        # Center on screen (not parent)
        self.dialog.transient(self.parent)
        self.dialog.grab_set()

        screen_width = self.dialog.winfo_screenwidth()
        screen_height = self.dialog.winfo_screenheight()
        dialog_width = 450
        dialog_height = 400
        x = (screen_width - dialog_width) // 2
        y = (screen_height - dialog_height) // 2
        self.dialog.geometry(f"{dialog_width}x{dialog_height}+{x}+{y}")

        self._create_widgets()

    def _create_widgets(self):
        """Create dialog widgets"""
        main_frame = ttk.Frame(self.dialog, padding="20")
        main_frame.pack(fill=tk.BOTH, expand=True)

        # Title
        title_label = ttk.Label(
            main_frame, text="请选择要使用的用户身份", font=("", 14, "bold")
        )
        title_label.pack(pady=(0, 20))

        # User list with scrollbar
        list_frame = ttk.Frame(main_frame)
        list_frame.pack(fill=tk.BOTH, expand=True)

        scrollbar = ttk.Scrollbar(list_frame)
        scrollbar.pack(side=tk.RIGHT, fill=tk.Y)

        self.selected_var = tk.StringVar()

        # Sort users: current user first, then by username
        sorted_users = sorted(
            self.users,
            key=lambda u: (
                0 if u["username"] == self.current_username else 1,
                u["username"],
            ),
        )

        for user in sorted_users:
            username = user["username"]
            user_type = user["user_type"]
            is_current = username == self.current_username

            # Mark current user
            display_text = f"{username} ({user_type})"
            if is_current:
                display_text += " [当前]"

            rb = ttk.Radiobutton(
                list_frame,
                text=display_text,
                variable=self.selected_var,
                value=username,
            )
            rb.pack(anchor=tk.W, pady=3, padx=5)

        # Select current user by default
        self.selected_var.set(self.current_username)

        # Buttons
        button_frame = ttk.Frame(main_frame)
        button_frame.pack(pady=(20, 0))

        confirm_btn = ttk.Button(
            button_frame, text="确认", command=self._on_confirm, width=10
        )
        confirm_btn.pack(side=tk.LEFT, padx=5)

        cancel_btn = ttk.Button(
            button_frame, text="取消", command=self._on_cancel, width=10
        )
        cancel_btn.pack(side=tk.LEFT, padx=5)

    def _on_confirm(self):
        """Handle confirm button click"""
        selected_username = self.selected_var.get()

        if not selected_username:
            messagebox.showwarning("未选择", "请选择一个用户")
            return

        # Find the selected user
        for user in self.users:
            if user["username"] == selected_username:
                self.selected_user = user
                break

        self.dialog.destroy()

    def _on_cancel(self):
        """Handle cancel button click"""
        self.selected_user = None
        self.dialog.destroy()

    def get_selected_user(self) -> Optional[Dict[str, Any]]:
        """
        Get the selected user info

        Returns:
            User dict {id, username, user_type} if confirmed, None if cancelled
        """
        return self.selected_user