import { memo, useRef, useState } from "react";
import AddImageModal from "../modals/AddImageModal";
import ConfirmBuyModal from "../modals/ConfirmBuyModal";

function GroceryListItem({ item, onClick, onImageAdded, onLongPress, allItems = [], compact = false }) {
  const [showAddImageModal, setShowAddImageModal] = useState(false);
  const [showConfirmBuyModal, setShowConfirmBuyModal] = useState(false);
  const [currentItem, setCurrentItem] = useState(item);

  const longPressTimer = useRef(null);
  const pressStartPos = useRef({ x: 0, y: 0 });

  const handleTouchStart = (e) => {
    const touch = e.touches[0];
    pressStartPos.current = { x: touch.clientX, y: touch.clientY };

    longPressTimer.current = setTimeout(() => {
      if (onLongPress) {
        onLongPress(item);
      }
    }, 500); // 500ms for long press
  };

  const handleTouchMove = (e) => {
    // Cancel long press if finger moves too much
    const touch = e.touches[0];
    const moveDistance = Math.sqrt(
      Math.pow(touch.clientX - pressStartPos.current.x, 2) +
      Math.pow(touch.clientY - pressStartPos.current.y, 2)
    );

    if (moveDistance > 10) {
      clearTimeout(longPressTimer.current);
    }
  };

  const handleTouchEnd = () => {
    clearTimeout(longPressTimer.current);
  };

  const handleMouseDown = () => {
    longPressTimer.current = setTimeout(() => {
      if (onLongPress) {
        onLongPress(item);
      }
    }, 500);
  };

  const handleMouseUp = () => {
    clearTimeout(longPressTimer.current);
  };

  const handleMouseLeave = () => {
    clearTimeout(longPressTimer.current);
  };

  const handleItemClick = () => {
    if (onClick) {
      setCurrentItem(item);
      setShowConfirmBuyModal(true);
    }
  };

  const handleConfirmBuy = (quantity) => {
    if (onClick) {
      onClick(currentItem.id, quantity);
    }
    setShowConfirmBuyModal(false);
  };

  const handleCancelBuy = () => {
    setShowConfirmBuyModal(false);
  };

  const handleNavigate = (newItem) => {
    setCurrentItem(newItem);
  };

  const handleImageClick = (e) => {
    e.stopPropagation(); // Prevent triggering the bought action
    if (item.item_image) {
      // Open buy modal which now shows the image
      setCurrentItem(item);
      setShowConfirmBuyModal(true);
    } else {
      setShowAddImageModal(true);
    }
  };

  const handleAddImage = async (imageFile) => {
    if (onImageAdded) {
      await onImageAdded(item.id, item.item_name, item.quantity, imageFile);
    }
    setShowAddImageModal(false);
  };

  const imageUrl = item.item_image && item.image_mime_type
    ? `data:${item.image_mime_type};base64,${item.item_image}`
    : null;
  const addedByUsers = Array.isArray(item.added_by_users)
    ? item.added_by_users.filter(
      (name) => typeof name === "string" && name.trim().length > 0
    )
    : [];

  const getTimeAgo = (dateString) => {
    if (!dateString) return null;

    const addedDate = new Date(dateString);
    const now = new Date();
    const diffMs = now - addedDate;
    const diffDays = Math.floor(diffMs / (1000 * 60 * 60 * 24));

    if (diffDays < 7) {
      return `${diffDays}d ago`;
    } else if (diffDays < 30) {
      const weeks = Math.floor(diffDays / 7);
      return `${weeks}w ago`;
    } else {
      const months = Math.floor(diffDays / 30);
      return `${months}m ago`;
    }
  };

  return (
    <>
      <li
        className={`glist-li ${compact ? 'compact' : ''}`}
        onClick={handleItemClick}
        onTouchStart={handleTouchStart}
        onTouchMove={handleTouchMove}
        onTouchEnd={handleTouchEnd}
        onMouseDown={handleMouseDown}
        onMouseUp={handleMouseUp}
        onMouseLeave={handleMouseLeave}
      >
        <div className="glist-item-layout">
          <div
            className={`glist-item-image ${item.item_image ? "has-image" : ""}`}
            onClick={handleImageClick}
            style={{ cursor: "pointer" }}
          >
            {item.item_image ? (
              <img src={imageUrl} alt={item.item_name} />
            ) : (
              <span>📦</span>
            )}
            <span className="glist-item-quantity">x{item.quantity}</span>
          </div>
          <div className="glist-item-content">
            <div className="glist-item-header">
              <span className="glist-item-name">{item.item_name}</span>
            </div>
            {addedByUsers.length > 0 && (
              <div className="glist-item-users">
                {item.last_added_on && `${getTimeAgo(item.last_added_on)} -- `}
                {addedByUsers.join(" | ")}
              </div>
            )}
          </div>
        </div>
      </li>

      {showAddImageModal && (
        <AddImageModal
          itemName={item.item_name}
          onClose={() => setShowAddImageModal(false)}
          onAddImage={handleAddImage}
        />
      )}

      {showConfirmBuyModal && (
        <ConfirmBuyModal
          item={currentItem}
          onConfirm={handleConfirmBuy}
          onCancel={handleCancelBuy}
          allItems={allItems}
          onNavigate={handleNavigate}
        />
      )}
    </>
  );
}

// Memoize component to prevent re-renders when props haven't changed
export default memo(GroceryListItem, (prevProps, nextProps) => {
  // Only re-render if the item data or handlers have changed
  return (
    prevProps.item.id === nextProps.item.id &&
    prevProps.item.item_name === nextProps.item.item_name &&
    prevProps.item.quantity === nextProps.item.quantity &&
    prevProps.item.item_image === nextProps.item.item_image &&
    prevProps.item.bought === nextProps.item.bought &&
    prevProps.item.last_added_on === nextProps.item.last_added_on &&
    prevProps.item.zone === nextProps.item.zone &&
    prevProps.item.added_by_users?.join(',') === nextProps.item.added_by_users?.join(',') &&
    prevProps.onClick === nextProps.onClick &&
    prevProps.onImageAdded === nextProps.onImageAdded &&
    prevProps.onLongPress === nextProps.onLongPress &&
    prevProps.allItems?.length === nextProps.allItems?.length
  );
});