"use client";

import { cn } from "@/lib/utils";
import React, { useEffect, useId, useRef, useState } from "react";
import {
  type FieldErrors,
  type FieldValues,
  type Path,
  type UseFormRegisterReturn,
} from "react-hook-form";

interface Option {
  value: string;
  text: string;
  selected: boolean;
}

type MultiSelectProps<T extends FieldValues> = {
  label: string;
  items: { value: string; text: string }[];
  value?: string[];
  errors?: FieldErrors<T>;
  required?: boolean;
  placeholder?: string;
  className?: string;
  disabled?: boolean;
  active?: boolean;
  height?: "sm" | "default";
} & UseFormRegisterReturn<Path<T>>;

function MultiSelect<T extends FieldValues>({
  name,
  label,
  items,
  errors,
  placeholder = "Select an option",
  className,
  disabled,
  active,
  height,
  onChange,
  onBlur,
  ref,
  value,
  required,
}: MultiSelectProps<T>) {
  const id = useId();
  const error = errors && errors[name];

  const [options, setOptions] = useState<Option[]>([]);
  const [selected, setSelected] = useState<number[]>([]);
  const [show, setShow] = useState(false);
  const dropdownRef = useRef<HTMLDivElement>(null);
  const trigger = useRef<HTMLDivElement | null>(null);

  useEffect(() => {
    const newOptions = items.map((item) => ({
      ...item,
      selected: value?.includes(item.value) ?? false,
    }));
    setOptions(newOptions);

    const newSelectedIndices = items
      .map((item, index) => (value?.includes(item.value) ? index : -1))
      .filter((index) => index !== -1);
    setSelected(newSelectedIndices);
  }, [items, value]);

  const open = () => {
    if (!disabled) {
      setShow(true);
    }
  };

  const isOpen = () => {
    return show === true;
  };

  const combinedRef = (el: HTMLDivElement) => {
    trigger.current = el;
    if (typeof ref === "function") {
      ref(el);
    }
  };

  const handleSelect = (index: number) => {
    if (disabled) return;

    const newOptions = [...options];
    let newSelected = [...selected];

    if (!newOptions[index].selected) {
      newOptions[index].selected = true;
      newSelected.push(index);
    } else {
      newOptions[index].selected = false;
      newSelected = newSelected.filter((i) => i !== index);
    }

    setOptions(newOptions);
    setSelected(newSelected);

    const selectedValues = newSelected.map((i) => newOptions[i].value);
    onChange?.({ target: { name, value: selectedValues } });
  };

  const remove = (index: number, event: React.MouseEvent) => {
    if (disabled) return;

    event.stopPropagation();
    const newOptions = [...options];
    const newSelected = selected.filter((i) => i !== index);
    newOptions[index].selected = false;

    setOptions(newOptions);
    setSelected(newSelected);

    const selectedValues = newSelected.map((i) => newOptions[i].value);
    onChange?.({ target: { name, value: selectedValues } });
  };

  useEffect(() => {
    const clickHandler = ({ target }: MouseEvent) => {
      if (!dropdownRef.current) return;
      if (
        !show ||
        dropdownRef.current.contains(target as Node) ||
        trigger.current?.contains(target as Node)
      )
        return;
      setShow(false);
    };
    document.addEventListener("click", clickHandler);
    return () => document.removeEventListener("click", clickHandler);
  }, [show]);

  return (
    <div className={className}>
      <label
        htmlFor={id}
        className="text-body-sm font-medium text-dark dark:text-white"
      >
        {label}
        {required && <span className="ml-1 select-none text-error">*</span>}
      </label>

      <div className="relative mt-3">
        <div
          ref={combinedRef}
          onClick={open}
          onBlur={onBlur}
          tabIndex={0}
          className={cn(
            "w-full rounded-lg border-[1.5px] border-stroke bg-transparent outline-none transition focus:border-primary disabled:cursor-default disabled:bg-gray-2 data-[active=true]:border-primary dark:border-dark-3 dark:bg-dark-2 dark:focus:border-primary dark:disabled:bg-dark dark:data-[active=true]:border-primary",
            error && "border-red focus:border-red dark:border-red",
            "flex min-h-[50px] cursor-pointer flex-wrap items-center gap-2 px-3 py-2",
            height === "sm" && "min-h-[42px]",
            disabled && "pointer-events-none opacity-60",
          )}
          data-active={active}
        >
          <div className="flex flex-1 flex-wrap items-center gap-2">
            {selected.map((index) => (
              <span
                key={index}
                className="inline-flex items-center gap-1 rounded-md bg-primary/10 px-2.5 py-1 text-sm font-medium text-primary dark:bg-primary/20"
              >
                {options[index]?.text}
                {!disabled && (
                  <button
                    type="button"
                    onClick={(e) => remove(index, e)}
                    className="ml-1 flex h-4 w-4 items-center justify-center rounded-full text-xs hover:bg-primary/20"
                  >
                    ×
                  </button>
                )}
              </span>
            ))}
            {selected.length === 0 && (
              <span className="text-dark-6 dark:text-dark-6">
                {placeholder}
              </span>
            )}
          </div>

          <div className="flex items-center">
            <svg
              className={cn(
                "fill-current text-dark-4 transition-transform duration-200 dark:text-dark-6",
                isOpen() && "rotate-180",
              )}
              width="20"
              height="20"
              viewBox="0 0 20 20"
              fill="none"
              xmlns="http://www.w3.org/2000/svg"
            >
              <path
                fillRule="evenodd"
                clipRule="evenodd"
                d="M3.69149 7.09327C3.91613 6.83119 4.31069 6.80084 4.57277 7.02548L9.99936 11.6768L15.4259 7.02548C15.688 6.80084 16.0826 6.83119 16.3072 7.09327C16.5319 7.35535 16.5015 7.74991 16.2394 7.97455L10.4061 12.9745C10.172 13.1752 9.82667 13.1752 9.59261 12.9745L3.75928 7.97455C3.4972 7.74991 3.46685 7.35535 3.69149 7.09327Z"
                fill="currentColor"
              />
            </svg>
          </div>
        </div>

        <div
          className={cn(
            "absolute left-0 top-full z-40 mt-1 max-h-60 w-full overflow-y-auto rounded-lg border border-stroke bg-white shadow-lg dark:border-dark-3 dark:bg-dark-2",
            !isOpen() && "hidden",
          )}
          ref={dropdownRef}
        >
          <div className="py-1">
            {options.map((option, index) => (
              <div
                key={index}
                className={cn(
                  "flex cursor-pointer items-center px-3 py-2 text-sm text-dark hover:bg-primary/5 dark:text-white dark:hover:bg-primary/5",
                  option.selected && "bg-primary/10 dark:bg-primary/20",
                )}
                onClick={() => handleSelect(index)}
              >
                <div
                  className={cn(
                    "mr-3 h-4 w-4 rounded border-2",
                    option.selected
                      ? "border-primary bg-primary"
                      : "border-stroke dark:border-dark-3",
                  )}
                >
                  {option.selected && (
                    <svg
                      className="h-full w-full text-white"
                      fill="currentColor"
                      viewBox="0 0 20 20"
                    >
                      <path
                        fillRule="evenodd"
                        d="M16.707 5.293a1 1 0 010 1.414l-8 8a1 1 0 01-1.414 0l-4-4a1 1 0 011.414-1.414L8 12.586l7.293-7.293a1 1 0 011.414 0z"
                        clipRule="evenodd"
                      />
                    </svg>
                  )}
                </div>
                {option.text}
              </div>
            ))}
          </div>
        </div>
      </div>

      {error && (
        <p className="text-red mt-1.5 text-sm">{error.message as string}</p>
      )}
    </div>
  );
}

export default MultiSelect;