import { useEffect, useState, useRef } from "react";

import { type Employee } from "../../services/api";

// 多选用户下拉框组件 - 带 tag 显示
export function UserMultiSelect({
  users,
  selectedUserIds,
  onChange,
}: {
  users: Employee[];
  selectedUserIds: string[];
  onChange: (ids: string[]) => void;
}) {
  const [isOpen, setIsOpen] = useState(false);
  const containerRef = useRef<HTMLDivElement>(null);

  // 点击外部关闭下拉框
  useEffect(() => {
    const handleClickOutside = (event: MouseEvent) => {
      if (containerRef.current && !containerRef.current.contains(event.target as Node)) {
        setIsOpen(false);
      }
    };
    document.addEventListener("mousedown", handleClickOutside);
    return () => document.removeEventListener("mousedown", handleClickOutside);
  }, []);

  const selectedUsers = users.filter((user) => selectedUserIds.includes(user.user_id));

  const toggleUser = (userId: string) => {
    if (selectedUserIds.includes(userId)) {
      onChange(selectedUserIds.filter((id) => id !== userId));
    } else {
      onChange([...selectedUserIds, userId]);
    }
  };

  const removeUser = (userId: string, event: React.MouseEvent) => {
    event.stopPropagation();
    onChange(selectedUserIds.filter((id) => id !== userId));
  };

  return (
    <div ref={containerRef} style={{ position: "relative" }}>
      {/* 选择框 - 显示 tag */}
      <div
        className="admin-toolbar__input"
        onClick={() => setIsOpen(!isOpen)}
        style={{
          display: "flex",
          alignItems: "center",
          flexWrap: "wrap",
          gap: "4px",
          padding: "6px 32px 6px 8px",
          minHeight: "36px",
          border: "1px solid #ddd",
          borderRadius: "4px",
          cursor: "pointer",
          backgroundColor: "#fff",
        }}
      >
        {selectedUsers.length === 0 ? (
          <span style={{ color: "#999" }}>请选择用户</span>
        ) : (
          selectedUsers.map((user) => (
            <span
              key={user.user_id}
              style={{
                display: "inline-flex",
                alignItems: "center",
                backgroundColor: "#e6f7ff",
                color: "#1890ff",
                border: "1px solid #91d5ff",
                borderRadius: "2px",
                padding: "2px 6px",
                fontSize: "13px",
              }}
            >
              {user.display_name}
              <span
                onClick={(e) => removeUser(user.user_id, e)}
                style={{
                  marginLeft: "4px",
                  cursor: "pointer",
                  fontWeight: "bold",
                  fontSize: "14px",
                }}
              >
                ×
              </span>
            </span>
          ))
        )}
        <span
          style={{
            position: "absolute",
            right: "12px",
            top: "50%",
            transform: "translateY(-50%)",
            color: "#999",
            pointerEvents: "none",
          }}
        >
          {isOpen ? "▲" : "▼"}
        </span>
      </div>

      {/* 下拉列表 */}
      {isOpen && (
        <div
          style={{
            position: "absolute",
            top: "100%",
            left: 0,
            right: 0,
            maxHeight: "200px",
            overflowY: "auto",
            border: "1px solid #1890ff",
            borderRadius: "4px",
            backgroundColor: "#fff",
            zIndex: 1000,
            marginTop: "2px",
            boxShadow: "0 2px 8px rgba(0,0,0,0.15)",
          }}
        >
          {users.map((user) => {
            const isSelected = selectedUserIds.includes(user.user_id);
            return (
              <div
                key={user.user_id}
                onClick={() => toggleUser(user.user_id)}
                style={{
                  display: "flex",
                  justifyContent: "space-between",
                  alignItems: "center",
                  padding: "8px 12px",
                  cursor: "pointer",
                  backgroundColor: isSelected ? "#e6f7ff" : "transparent",
                  borderBottom: "1px solid #f0f0f0",
                }}
              >
                <span>
                  {user.display_name} <span style={{ color: "#999" }}>({user.username})</span>
                </span>
                {isSelected && <span style={{ color: "#1890ff" }}>✓</span>}
              </div>
            );
          })}
        </div>
      )}
    </div>
  );
}