import React, { useState, useRef, useEffect } from "react";
import { CaretDownIcon, XIcon, CheckIcon } from "@phosphor-icons/react";
import DropdownPortal from "./DropdownPortal";

interface Option {
  label: string;
  value: string | number;
}

interface CustomSearchableDropdownProps
  extends Omit<React.InputHTMLAttributes<HTMLInputElement>, 'onChange' | 'size'> {
  label?: string;
  options: Option[];
  value?: string | number;
  onChange?: (value: string) => void;
  placeholder?: string;
  leftIcon?: React.ReactNode;
  error?: string;
  size?: "sm" | "md" | "lg";
}

const CustomSearchableDropdown = React.forwardRef<
  HTMLDivElement,
  CustomSearchableDropdownProps
>(
  (
    {
      label,
      options,
      value,
      onChange,
      placeholder = "Select...",
      disabled,
      className = "",
      required,
      leftIcon,
      size = "md",
      ...props
    },
    ref
  ) => {
    const [isOpen, setIsOpen] = useState(false);
    const [searchTerm, setSearchTerm] = useState("");
    const [highlightedIndex, setHighlightedIndex] = useState(0);
    const dropdownRef = useRef<HTMLDivElement>(null);
    const inputRef = useRef<HTMLInputElement>(null);
    const panelRef = useRef<HTMLDivElement>(null);

    const sizeClasses = {
      sm: "py-1 text-sm",
      md: "py-1.5 text-sm",
      lg: "py-2.5 text-base",
    };

    // Sync search term with selected value on mount or value update
    useEffect(() => {
      const selectedOption = options.find((opt) => String(opt.value) === String(value));
      if (selectedOption) {
        setSearchTerm(selectedOption.label);
      } else {
        setSearchTerm("");
      }
    }, [value, options]);

    const filteredOptions = options.filter((option) =>
      option.label.toLowerCase().includes(searchTerm.toLowerCase())
    );

    useEffect(() => {
      const handleClickOutside = (event: MouseEvent) => {
        const target = event.target as Node;
        if (
          dropdownRef.current &&
          !dropdownRef.current.contains(target) &&
          !(panelRef.current && panelRef.current.contains(target))
        ) {
          setIsOpen(false);
          // Revert to selected value label if closing without selection
          const selectedOption = options.find((opt) => String(opt.value) === String(value));
          if (selectedOption) {
            setSearchTerm(selectedOption.label);
          } else if (!value) {
            setSearchTerm("");
          }
        }
      };

      document.addEventListener("mousedown", handleClickOutside);
      return () => document.removeEventListener("mousedown", handleClickOutside);
    }, [value, options]);

    useEffect(() => {
      if (!isOpen) {
        setHighlightedIndex(0);
      }
    }, [isOpen]);

    const handleInputChange = (e: React.ChangeEvent<HTMLInputElement>) => {
      setSearchTerm(e.target.value);
      setIsOpen(true);
      if (e.target.value === "") {
        onChange?.(""); // Clear selection if input is cleared
      }
    };

    const handleKeyDown = (e: React.KeyboardEvent) => {
      if (!isOpen && e.key !== "Tab") {
        setIsOpen(true);
      }

      switch (e.key) {
        case "ArrowDown":
          e.preventDefault();
          setHighlightedIndex((prev) =>
            prev < filteredOptions.length - 1 ? prev + 1 : prev
          );
          break;
        case "ArrowUp":
          e.preventDefault();
          setHighlightedIndex((prev) => (prev > 0 ? prev - 1 : prev));
          break;
        case "Enter":
          e.preventDefault();
          if (isOpen && filteredOptions[highlightedIndex]) {
            handleSelect(filteredOptions[highlightedIndex]);
          }
          break;
        case "Escape":
          e.preventDefault();
          setIsOpen(false);
          break;
        case "Tab":
          setIsOpen(false);
          break;
      }
    };

    const handleSelect = (option: Option) => {
      onChange?.(String(option.value));
      setSearchTerm(option.label);
      setIsOpen(false);
    };

    const handleClear = (e: React.MouseEvent) => {
      e.stopPropagation();
      onChange?.("");
      setSearchTerm("");
      inputRef.current?.focus();
    };

    const handleFocus = () => {
      if (!disabled) setIsOpen(true);
    };

    return (
      <div className="w-full flex flex-col gap-1.5" ref={ref}>
        {label && (
          <label className="text-sm font-medium text-gray-900">
            {label}
            {required && <span className="text-red-500 ml-1">*</span>}
          </label>
        )}

        <div className="relative w-full" ref={dropdownRef}>
          {leftIcon && (
            <span className="absolute left-3 top-1/2 -translate-y-1/2 text-gray-500 pointer-events-none z-[99999]">
              {leftIcon}
            </span>
          )}

          <input
            {...props}
            ref={inputRef}
            type="text"
            value={searchTerm}
            onChange={handleInputChange}
            onKeyDown={handleKeyDown}
            onFocus={handleFocus}
            placeholder={placeholder}
            disabled={disabled}
            className={`
              w-full rounded-lg
              bg-white text-gray-900
              border ${props.error ? 'border-red-500' : 'border-gray-300'}
              ${sizeClasses[size]}
              outline-none
              transition-all duration-200
              hover:border-primary
              focus:border-primary focus:ring-2 focus:ring-primary/20
              disabled:bg-gray-50 disabled:text-gray-500 disabled:cursor-not-allowed disabled:border-gray-300
              placeholder:text-gray-500
              ${leftIcon ? "pl-10" : "px-3"}
              pr-16
              ${className}
            `}
            autoComplete="off"
          />

          <div className="absolute right-3 top-1/2 -translate-y-1/2 flex items-center gap-1">
            {!value && (
              <button
                type="button"
                onClick={() => !disabled && setIsOpen(!isOpen)}
                className="text-gray-500 hover:text-gray-900 cursor-pointer disabled:cursor-not-allowed p-0.5"
                disabled={disabled}
                tabIndex={-1}
              >
                <CaretDownIcon
                  size={16}
                  className={`transition-transform duration-200 ${isOpen ? "rotate-180" : ""}`}
                />
              </button>
            )}

            {searchTerm && !disabled && (
              <button type="button" onClick={handleClear} className="text-gray-500 hover:text-gray-900 p-0.5">
                <XIcon size={16} />
              </button>
            )}
          </div>

          {/* Dropdown Menu */}
          <DropdownPortal
            anchorRef={dropdownRef}
            isOpen={isOpen && !disabled}
            ref={panelRef}
            className="bg-white border border-gray-200 rounded-lg shadow-lg overflow-y-auto flex flex-col"
          >
            {filteredOptions.length === 0 ? (
              <div className="px-4 py-3 text-sm text-gray-500 text-center">No results found</div>
            ) : (
              filteredOptions.map((option, index) => {
                const isSelected = String(option.value) === String(value);
                return (
                  <button
                    key={option.value}
                    type="button"
                    onClick={() => handleSelect(option)}
                    onMouseEnter={() => setHighlightedIndex(index)}
                    className={`
                        w-full text-left px-3 min-h-[42px] text-[14px] leading-none
                        transition-colors duration-150 flex items-center gap-2
                        ${isSelected
                        ? "bg-[#EEF9EF]"
                        : highlightedIndex === index
                          ? "bg-gray-50 text-gray-900"
                          : "text-gray-700 hover:bg-gray-50"
                      }
                      `}
                  >
                    {isSelected && <CheckIcon size={16} className="text-primary shrink-0" strokeWidth={2.5} />}
                    <span
                      className={
                        isSelected
                          ? "ml-1 font-medium bg-gradient-to-b from-[#1B9869] to-[#14704E] bg-clip-text text-transparent"
                          : "ml-6"
                      }
                    >
                      {option.label}
                    </span>
                  </button>
                );
              })
            )}
          </DropdownPortal>
        </div>
        {props.error && <p className="text-xs text-red-500 mt-1">{props.error}</p>}
      </div>
    );
  }
);

CustomSearchableDropdown.displayName = "CustomSearchableDropdown";

export default CustomSearchableDropdown;