import { useState, useRef, useEffect } from 'react';
import { FaCaretRight } from 'react-icons/fa';

import './PozoMenu.scss';
import { getSession, sessionStore } from '../../Services/Others';

const PozoMenu = ({
  items = [],
  mode = 'vertical',
  style = {},
  onClick,
  collapse = false,
  selectedKey: propSelectedKey,
  isBottomMenu = false,
}) => {
  const [openKeys, setOpenKeys] = useState([]);
  const [selectedKey, setSelectedKey] = useState('');
  const [dropdownPositions, setDropdownPositions] = useState({});
  const [isMobile, setIsMobile] = useState(window.innerWidth <= 768);
  const BranchId = getSession('BranchId');
  const menuRef = useRef();

  // Update selected key when prop changes
  useEffect(() => {
    if (propSelectedKey !== undefined) {
      setSelectedKey(propSelectedKey);
    }
  }, [propSelectedKey]);

  // Close dropdown when clicking outside, window resize, or scroll
  useEffect(() => {
    const handleClickOutside = (event) => {
      if (menuRef.current && !menuRef.current.contains(event.target)) {
        setOpenKeys([]);
        setDropdownPositions({});
      }
    };

    const handleResize = () => {
      // Update mobile detection
      setIsMobile(window.innerWidth <= 768);

      // Recalculate positions on window resize
      if (openKeys.length > 0) {
        setOpenKeys([]);
        setDropdownPositions({});
      }
    };

    const handleScroll = () => {
      // 🎯 FIXED: Recalculate positions on scroll to maintain proper positioning
      if (openKeys.length > 0) {
        // Find all currently open menu elements and recalculate their positions
        const newPositions = {};
        openKeys.forEach((key) => {
          const element = document.querySelector(`[data-menu-key="${key}"]`);
          if (element) {
            const level = key.split('-').length - 1;
            newPositions[key] = calculatePosition(element, level);
          }
        });
        setDropdownPositions((prev) => ({ ...prev, ...newPositions }));
      }
    };

    document.addEventListener('mousedown', handleClickOutside);
    window.addEventListener('resize', handleResize);
    window.addEventListener('scroll', handleScroll, true); // Capture scroll events

    return () => {
      document.removeEventListener('mousedown', handleClickOutside);
      window.removeEventListener('resize', handleResize);
      window.removeEventListener('scroll', handleScroll, true);
    };
  }, [openKeys]);

  // 🎯 FIXED: Smart positioning calculation - exactly like your image behavior
  const calculatePosition = (element, level = 0) => {
    const rect = element.getBoundingClientRect();
    const viewportWidth = window.innerWidth;
    const viewportHeight = window.innerHeight;
    const scrollX = window.pageXOffset || document.documentElement.scrollLeft;
    const scrollY = window.pageYOffset || document.documentElement.scrollTop;

    // Dynamic dropdown dimensions - responsive
    const dropdownWidth = isMobile
      ? Math.min(280, viewportWidth - 20)
      : level > 0
        ? 220
        : 250;
    const dropdownHeight = Math.min(
      isMobile ? viewportHeight * 0.5 : 400,
      viewportHeight * 0.6
    );
    const gap = isMobile ? 2 : 4;
    const edgePadding = isMobile ? 10 : 8;

    // Calculate available space on both sides
    const spaceRight = viewportWidth - rect.right;
    const spaceLeft = rect.left;
    const spaceNeeded = dropdownWidth + gap + edgePadding;

    let position = {
      top: rect.top + scrollY,
      left: rect.right + gap + scrollX,
      direction: 'right',
      verticalDirection: 'down',
    };

    // 🎯 FIXED: HORIZONTAL POSITIONING - Exactly like your images
    if (level === 0) {
      console.log('🎯 Space Analysis:', {
        spaceRight,
        spaceLeft,
        spaceNeeded,
        elementPosition: { left: rect.left, right: rect.right },
      });

      if (spaceRight >= spaceNeeded) {
        // Image 1: Enough space on right - open to RIGHT
        position.left = rect.right + gap + scrollX;
        position.direction = 'right';
        console.log('✅ Opening RIGHT - space available');
      } else if (spaceLeft >= spaceNeeded) {
        // Image 2: No space on right, space on left - open to LEFT
        position.left = rect.left - dropdownWidth - gap + scrollX;
        position.direction = 'left';
      } else {
        // Edge case: Limited space on both sides
        if (spaceRight >= spaceLeft) {
          position.left = viewportWidth - dropdownWidth - edgePadding + scrollX;
          position.direction = 'right-edge';
        } else {
          position.left = edgePadding + scrollX;
          position.direction = 'left-edge';
        }
        console.log('⚠️ Edge positioning applied');
      }
    } else {
      // Nested menu positioning
      const parentKeys = Object.keys(dropdownPositions);
      const parentDirection =
        parentKeys.length > 0
          ? dropdownPositions[parentKeys[level - 1]]?.direction || 'right'
          : 'right';

      if (parentDirection.includes('right')) {
        if (spaceRight >= spaceNeeded) {
          position.left = rect.right + gap + scrollX;
          position.direction = 'right';
        } else {
          position.left = rect.left - dropdownWidth - gap + scrollX;
          position.direction = 'left';
        }
      } else {
        if (spaceLeft >= spaceNeeded) {
          position.left = rect.left - dropdownWidth - gap + scrollX;
          position.direction = 'left';
        } else {
          position.left = rect.right + gap + scrollX;
          position.direction = 'right';
        }
      }
    }

    // 🎯 FIXED: VERTICAL POSITIONING
    const spaceBelow = viewportHeight - rect.bottom;
    const spaceAbove = rect.top;

    if (isBottomMenu && level === 0) {
      if (spaceAbove >= dropdownHeight + edgePadding) {
        position.top = rect.top - dropdownHeight - gap + scrollY;
        position.verticalDirection = 'up';
      } else {
        position.top = rect.bottom + gap + scrollY;
        position.verticalDirection = 'down';
      }
    } else {
      if (spaceBelow >= dropdownHeight + edgePadding) {
        position.top = rect.top + scrollY;
        position.verticalDirection = 'down';
      } else if (spaceAbove >= dropdownHeight + edgePadding) {
        position.top = rect.bottom - dropdownHeight + scrollY;
        position.verticalDirection = 'up';
      } else {
        position.top =
          Math.max(edgePadding, (viewportHeight - dropdownHeight) / 2) +
          scrollY;
        position.verticalDirection = 'center';
      }
    }

    // 🎯 FIXED: Final boundary checks
    position.left = Math.max(
      edgePadding + scrollX,
      Math.min(
        position.left,
        viewportWidth - dropdownWidth - edgePadding + scrollX
      )
    );

    position.top = Math.max(
      edgePadding + scrollY,
      Math.min(
        position.top,
        viewportHeight - dropdownHeight - edgePadding + scrollY
      )
    );

    // Store dimensions for reference
    position.width = dropdownWidth;
    position.height = dropdownHeight;

    console.log('🎯 FIXED Position:', {
      clicked: {
        top: rect.top,
        left: rect.left,
        right: rect.right,
        bottom: rect.bottom,
      },
      spaces: {
        right: spaceRight,
        left: spaceLeft,
        above: spaceAbove,
        below: spaceBelow,
      },
      calculated: position,
      direction: position.direction,
    });

    return position;
  };

  // Handle menu item click
  const handleMenuClick = (item, event, parentKeys = []) => {
    if (item?.label === 'Branch Signin') {
      if (BranchId) {
        sessionStorage.removeItem('BranchId');
      }
    }
    event.stopPropagation();

    if (item.children && item.children.length > 0) {
      // Has children - toggle submenu
      const itemKey = item.key;
      const isOpen = openKeys.includes(itemKey);

      if (isOpen) {
        // Close this submenu and all its children
        setOpenKeys((prev) =>
          prev.filter((key) => {
            // Keep only keys that are not this item or its descendants
            return !key.startsWith(itemKey) && key !== itemKey;
          })
        );
        setDropdownPositions((prev) => {
          const newPos = { ...prev };
          Object.keys(newPos).forEach((key) => {
            if (key.startsWith(itemKey) || key === itemKey) {
              delete newPos[key];
            }
          });
          return newPos;
        });
      } else {
        // Close all submenus at the same level or deeper
        const currentPath = [...parentKeys, itemKey];
        const newOpenKeys = openKeys.filter((key) => {
          // Keep only parent keys in the current path
          return (
            currentPath.some((pathKey) => key === pathKey) ||
            currentPath.every((pathKey, index) => {
              const keyParts = key.split('-');
              const pathParts = pathKey.split('-');
              return (
                index < keyParts.length && keyParts[index] === pathParts[index]
              );
            })
          );
        });

        // Add current item to open keys
        newOpenKeys.push(itemKey);

        // Calculate position and add to dropdown positions
        const position = calculatePosition(
          event.currentTarget,
          parentKeys.length
        );

        setDropdownPositions((prev) => {
          // Remove positions for closed items
          const newPos = {};
          newOpenKeys.forEach((key) => {
            if (prev[key]) newPos[key] = prev[key];
          });
          newPos[itemKey] = position;
          return newPos;
        });

        setOpenKeys(newOpenKeys);
      }
    } else {
      // No children - select item and close all dropdowns
      setSelectedKey(item.key);
      setOpenKeys([]);
      setDropdownPositions({});

      // Fullscreen on Sales Entry click

      if (item.label === 'Sales Entry') {
        if (!document.fullscreenElement) {
          document.documentElement.requestFullscreen().catch(() => {});
        }
      }

      // Trigger onClick callback if provided
      if (onClick) {
        onClick({
          key: item.key,
          keyPath: [...parentKeys, item.key],
          item: item,
          domEvent: event,
        });
      }
    }
  };

  // Check if item is selected
  const isSelected = (key) => selectedKey === key;

  // Check if item is open
  const isOpen = (key) => openKeys.includes(key);

  // Check if item is in active path (has selected child)
  const isInActivePath = (item, parentKeys = []) => {
    if (!item.children) return false;

    const checkChildren = (children, currentPath) => {
      return children.some((child) => {
        const childPath = [...currentPath, child.key];
        if (child.key === selectedKey) return true;
        if (child.children) {
          return checkChildren(child.children, childPath);
        }
        return false;
      });
    };

    return checkChildren(item.children, [...parentKeys, item.key]);
  };

  const menuRefs = useRef({});
  const submenuRefs = useRef({});
  const [positions, setPositions] = useState({});

  const renderMenuItems = (items, parentKeys = [], level = 0) => {
    return items.map((item) => {
      if (!item) return null;

      const hasChildren = item.children && item.children.length > 0;
      const isItemSelected = isSelected(item.key);
      const isItemOpen = isOpen(item.key);
      const isItemInActivePath = isInActivePath(item, parentKeys);
      const currentKeys = [...parentKeys, item.key];

      return (
        <div
          key={item.key}
          className="pozo-menu-item-wrapper"
          ref={(el) => {
            if (el) menuRefs.current[item.key] = el;
          }}
        >
          <div
            className={`pozo-menu-item ${isItemSelected ? 'selected' : ''} ${isItemOpen ? 'open' : ''} ${isItemInActivePath ? 'active-path' : ''} ${hasChildren ? 'has-children' : ''} ${item.type === 'group' ? 'group-item' : ''}`}
            onClick={(e) => handleMenuClick(item, e, parentKeys)}
            data-menu-key={item.key}
            style={{ justifyContent: 'flex-start' }}
          >
            {item.icon && (
              <span
                className="pozo-menu-icon"
                style={{ fontSize: collapse ? '1.3rem' : '' }}
              >
                {item.icon}
              </span>
            )}

            {!collapse && <span className="pozo-menu-label">{item.label}</span>}

            {hasChildren && !collapse && (
              // <span className="pozo-menu-arrow"><FaCaretRight /></span>
              <span className={`${isItemOpen ? 'open ' : ''}pozo-menu-arrow`}>
                <FaCaretRight />
              </span>
            )}
          </div>

          {hasChildren && isItemOpen && !collapse && (
            <div
              ref={(el) => {
                if (el) submenuRefs.current[item.key] = el;
              }}
              className={`pozo-dropdown-submenu ${level > 0 ? 'nested-submenu' : ''}`}
              style={{
                position: 'fixed',
                top: (() => {
                  const defaultTop = positions[item.key]?.top || 0;
                  const submenuHeight =
                    submenuRefs.current[item.key]?.getBoundingClientRect()
                      ?.height || 0;
                  const screenHeight = window.innerHeight;

                  // ✅ If submenu would overflow screen bottom, adjust top
                  if (defaultTop + submenuHeight > screenHeight) {
                    return Math.max(
                      8, // padding from top
                      screenHeight - submenuHeight - 8
                    );
                  }
                  return defaultTop;
                })(),
                left: positions[item.key]?.left + 5 || 0,
                // width: 220,
                width: 200,
                maxHeight: 400,
                zIndex: 1000 + level,
              }}
            >
              <div className="pozo-submenu-content">
                {renderMenuItems(item.children, currentKeys, level + 1)}
              </div>
            </div>
          )}
        </div>
      );
    });
  };

  // ✅ Compute positions after render
  useEffect(() => {
    const updated = {};
    for (const [key, el] of Object.entries(menuRefs.current)) {
      if (el && typeof el.getBoundingClientRect === 'function') {
        const rect = el.getBoundingClientRect();
        updated[key] = {
          top: rect.top + window.scrollY,
          left: rect.right + window.scrollX,
        };
      }
    }
    Object.entries(submenuRefs.current).forEach(([key, el]) => {
      if (el) {
        const height = el.getBoundingClientRect().height;
        console.log(`Total submenu height for ${key}:`, height);
      }
    });
    setPositions(updated);
  }, [items, openKeys]);

  return (
    <div className={`pozo-menu pozo-menu-${mode}`} style={style}>
      <div className="pozo-menu-content" ref={menuRef}>
        {renderMenuItems(items)}
      </div>
    </div>
  );
};

export default PozoMenu;