import { useCallback, useEffect, useRef, useState } from "react";
import { IoCheckmark, IoChevronDown, IoClose } from "react-icons/io5";
import SimpleBar from "simplebar-react";
import "simplebar-react/dist/simplebar.min.css";
import "./Select.css";

function cx(...parts) {
  return parts.filter(Boolean).join(" ");
}

/**
 * Custom select with optional search. onChange receives a synthetic event
 * `{ target: { value, name } }` like a native select element. With `multiple`,
 * `value` and the emitted value are arrays and options toggle on click.
 *
 * @param {object} props
 * @param {string | string[]} props.value
 * @param {boolean} [props.multiple]
 * @param {(e: { target: { value: string, name?: string } }) => void} [props.onChange]
 * @param {{ value: string, label: string, disabled?: boolean, search?: string }[]} [props.options]
 * @param {string} [props.placeholder]
 * @param {boolean} [props.disabled]
 * @param {string} [props.id]
 * @param {boolean} [props.searchable]
 * @param {(option: object) => import('react').ReactNode} [props.renderOption]
 * @param {(option: object) => import('react').ReactNode} [props.renderSelected]
 * @param {string} [props.className]
 * @param {string} [props.name]
 */
export function Select({
  value,
  onChange,
  options = [],
  placeholder = "Select an option",
  disabled = false,
  id,
  searchable = false,
  renderOption,
  renderSelected,
  className = "",
  name,
  multiple = false,
}) {
  const [isOpen, setIsOpen] = useState(false);
  const [searchTerm, setSearchTerm] = useState("");
  const wrapperRef = useRef(null);
  const searchInputRef = useRef(null);

  const selectedValues = multiple
    ? Array.isArray(value)
      ? value
      : []
    : [value];
  const isSelected = (optionValue) => selectedValues.includes(optionValue);
  const selectedOption = multiple
    ? null
    : options.find((opt) => opt.value === value);
  const selectedOptions = multiple
    ? selectedValues.map(
        (v) => options.find((opt) => opt.value === v) ?? { value: v, label: v },
      )
    : [];

  const emit = (next) => onChange?.({ target: { value: next, name } });

  const filteredOptions =
    searchable && searchTerm
      ? options.filter(
          (opt) =>
            opt.label.toLowerCase().includes(searchTerm.toLowerCase()) ||
            opt?.search?.toLowerCase()?.includes(searchTerm.toLowerCase()),
        )
      : options;

  useEffect(() => {
    const handleClickOutside = (event) => {
      if (wrapperRef.current && !wrapperRef.current.contains(event.target)) {
        setIsOpen(false);
        setSearchTerm("");
      }
    };

    if (isOpen) {
      document.addEventListener("mousedown", handleClickOutside);
    }

    return () => {
      document.removeEventListener("mousedown", handleClickOutside);
    };
  }, [isOpen]);

  useEffect(() => {
    if (isOpen && searchable && searchInputRef.current) {
      searchInputRef.current.focus();
    }
  }, [isOpen, searchable]);

  const handleKeyDown = useCallback(
    (event) => {
      if (disabled) return;

      switch (event.key) {
        case "Enter":
        case " ":
          if (!isOpen) {
            event.preventDefault();
            setIsOpen(true);
          }
          break;
        case "Escape":
          setIsOpen(false);
          setSearchTerm("");
          break;
        case "ArrowDown":
          if (!isOpen) {
            event.preventDefault();
            setIsOpen(true);
          }
          break;
        default:
          break;
      }
    },
    [disabled, isOpen],
  );

  const handleTriggerClick = () => {
    if (!disabled) {
      setIsOpen(!isOpen);
      if (isOpen) {
        setSearchTerm("");
      }
    }
  };

  const handleOptionClick = (option) => {
    if (option.disabled) return;

    if (multiple) {
      emit(
        isSelected(option.value)
          ? selectedValues.filter((v) => v !== option.value)
          : [...selectedValues, option.value],
      );
      return;
    }
    emit(option.value);
    setIsOpen(false);
    setSearchTerm("");
  };

  const handleTagRemove = (event, optionValue) => {
    event.stopPropagation();
    if (disabled) return;
    emit(selectedValues.filter((v) => v !== optionValue));
  };

  const handleSearchChange = (e) => {
    setSearchTerm(e.target.value);
  };

  const renderSelectedContent = () => {
    if (searchable && isOpen) {
      return (
        <input
          ref={searchInputRef}
          type="text"
          className="select-search-input"
          placeholder={placeholder}
          value={searchTerm}
          onChange={handleSearchChange}
          onClick={(e) => e.stopPropagation()}
          onFocus={(e) => e.stopPropagation()}
        />
      );
    }

    if (multiple) {
      if (selectedOptions.length === 0) {
        return <span className="select-placeholder">{placeholder}</span>;
      }
      return (
        <span className="select-tags">
          {selectedOptions.map((option) => (
            <span key={option.value} className="select-tag">
              <span className="select-tag-label">
                {renderSelected ? renderSelected(option) : option.label}
              </span>
              <span
                role="button"
                tabIndex={-1}
                aria-label={`Remove ${option.label}`}
                className="select-tag-remove"
                onClick={(e) => handleTagRemove(e, option.value)}
              >
                <IoClose size={12} />
              </span>
            </span>
          ))}
        </span>
      );
    }

    if (!selectedOption) {
      return <span className="select-placeholder">{placeholder}</span>;
    }

    if (renderSelected) {
      return renderSelected(selectedOption);
    }

    return (
      <span className="select-selected-label">{selectedOption.label}</span>
    );
  };

  const renderOptionContent = (option) => {
    if (renderOption) {
      return renderOption(option);
    }

    return <span className="select-option-label">{option.label}</span>;
  };

  return (
    <div
      ref={wrapperRef}
      className={cx("select-wrap", className)}
      onKeyDown={handleKeyDown}
    >
      <button
        type="button"
        id={id}
        className={cx(
          "select-trigger",
          isOpen && "select-trigger--open",
          multiple && "select-trigger--multiple",
        )}
        onClick={handleTriggerClick}
        disabled={disabled}
        aria-haspopup="listbox"
        aria-expanded={isOpen}
      >
        <div className="select-value">{renderSelectedContent()}</div>
        <span className="select-chevron" aria-hidden>
          <IoChevronDown size={18} />
        </span>
      </button>

      <div
        className={cx("select-dropdown", isOpen && "select-dropdown--open")}
        role="listbox"
      >
        <SimpleBar className="select-options">
          {filteredOptions.length === 0 ? (
            <div className="select-empty">No options found</div>
          ) : (
            filteredOptions.map((option) => (
              <div
                key={option.value}
                className={cx(
                  "select-option",
                  isSelected(option.value) && "select-option--selected",
                  option.disabled && "select-option--disabled",
                )}
                onClick={() => handleOptionClick(option)}
                role="option"
                aria-selected={isSelected(option.value)}
              >
                {renderOptionContent(option)}
                {multiple && isSelected(option.value) ? (
                  <IoCheckmark className="select-option-check" size={16} />
                ) : null}
              </div>
            ))
          )}
        </SimpleBar>
      </div>
    </div>
  );
}