import React, { useState, useRef, forwardRef, useEffect } from 'react';
import { getEmptyImage } from 'react-dnd-html5-backend';
import range from 'lodash/range';
import filter from 'lodash/filter';
import classnames from 'classnames';
import { useDrag, useDrop } from 'react-dnd';
import { IconChevronRight, IconDots } from '@tabler/icons';
import { useSelector, useDispatch } from 'react-redux';
import { addTab, focusTab, makeTabPermanent } from 'providers/ReduxStore/slices/tabs';
import { handleCollectionItemDrop, sendRequest, showInFolder, pasteItem, saveRequest } from 'providers/ReduxStore/slices/collections/actions';
import { toggleCollectionItem, addResponseExample } from 'providers/ReduxStore/slices/collections';
import { insertTaskIntoQueue } from 'providers/ReduxStore/slices/app';
import { uuid } from 'utils/common';
import { copyRequest } from 'providers/ReduxStore/slices/app';
import Dropdown from 'components/Dropdown';
import NewRequest from 'components/Sidebar/NewRequest';
import NewFolder from 'components/Sidebar/NewFolder';
import RenameCollectionItem from './RenameCollectionItem';
import CloneCollectionItem from './CloneCollectionItem';
import DeleteCollectionItem from './DeleteCollectionItem';
import RunCollectionItem from './RunCollectionItem';
import GenerateCodeItem from './GenerateCodeItem';
import { isItemARequest, isItemAFolder } from 'utils/tabs';
import { doesRequestMatchSearchText, doesFolderHaveItemsMatchSearchText } from 'utils/collections/search';
import { getDefaultRequestPaneTab } from 'utils/collections';
import { hideHomePage } from 'providers/ReduxStore/slices/app';
import toast from 'react-hot-toast';
import StyledWrapper from './StyledWrapper';
import NetworkError from 'components/ResponsePane/NetworkError/index';
import CollectionItemInfo from './CollectionItemInfo/index';
import CollectionItemIcon from './CollectionItemIcon';
import ExampleItem from './ExampleItem';
import { scrollToTheActiveTab } from 'utils/tabs';
import { isTabForItemActive as isTabForItemActiveSelector, isTabForItemPresent as isTabForItemPresentSelector } from 'src/selectors/tab';
import { isEqual } from 'lodash';
import { calculateDraggedItemNewPathname, getInitialExampleName } from 'utils/collections/index';
import { sortByNameThenSequence } from 'utils/common/index';
import CreateExampleModal from 'components/ResponseExample/CreateExampleModal';

const CollectionItem = ({ item, collectionUid, collectionPathname, searchText }) => {
  const _isTabForItemActiveSelector = isTabForItemActiveSelector({ itemUid: item.uid });
  const isTabForItemActive = useSelector(_isTabForItemActiveSelector, isEqual);

  const _isTabForItemPresentSelector = isTabForItemPresentSelector({ itemUid: item.uid });
  const isTabForItemPresent = useSelector(_isTabForItemPresentSelector, isEqual);
  
  const isSidebarDragging = useSelector((state) => state.app.isDragging);
  const collection = useSelector((state) => state.collections.collections?.find((c) => c.uid === collectionUid));
  const { hasCopiedItems } = useSelector((state) => state.app.clipboard);
  const dispatch = useDispatch();

  // We use a single ref for drag and drop.
  const ref = useRef(null);

  const [renameItemModalOpen, setRenameItemModalOpen] = useState(false);
  const [cloneItemModalOpen, setCloneItemModalOpen] = useState(false);
  const [deleteItemModalOpen, setDeleteItemModalOpen] = useState(false);
  const [createExampleModalOpen, setCreateExampleModalOpen] = useState(false);
  const [generateCodeItemModalOpen, setGenerateCodeItemModalOpen] = useState(false);
  const [newRequestModalOpen, setNewRequestModalOpen] = useState(false);
  const [newFolderModalOpen, setNewFolderModalOpen] = useState(false);
  const [runCollectionModalOpen, setRunCollectionModalOpen] = useState(false);
  const [itemInfoModalOpen, setItemInfoModalOpen] = useState(false);
  const [examplesExpanded, setExamplesExpanded] = useState(false);
  const hasSearchText = searchText && searchText?.trim()?.length;
  const itemIsCollapsed = hasSearchText ? false : item.collapsed;
  const isFolder = isItemAFolder(item);

  // Check if request has examples (only for HTTP requests)
  const hasExamples = isItemARequest(item) && item.type === 'http-request' && item.examples && item.examples.length > 0;

  const [dropType, setDropType] = useState(null); // 'adjacent' or 'inside'

  const [{ isDragging }, drag, dragPreview] = useDrag({
    type: 'collection-item',
    item: { ...item, sourceCollectionUid: collectionUid },
    collect: (monitor) => ({
      isDragging: monitor.isDragging()
    }),
    options: {
      dropEffect: "move"
    }
  });

  useEffect(() => {
    dragPreview(getEmptyImage(), { captureDraggingState: true });
  }, []);

  // Auto-scroll to show this item when its tab becomes active
  useEffect(() => {
    if (isTabForItemActive && ref.current) {
      try {
        ref.current.scrollIntoView({ behavior: 'smooth', block: 'nearest' });
      } catch (err) {
        // ignore scroll errors (some environments may not support smooth scrolling)
      }
    }
  }, [isTabForItemActive]);

  const determineDropType = (monitor) => {
    const hoverBoundingRect = ref.current?.getBoundingClientRect();
    const clientOffset = monitor.getClientOffset();
    if (!hoverBoundingRect || !clientOffset) return null;

    const clientY = clientOffset.y - hoverBoundingRect.top;
    const folderUpperThreshold = hoverBoundingRect.height * 0.35;
    const fileUpperThreshold = hoverBoundingRect.height * 0.5;

    if (isItemAFolder(item)) {
      return clientY < folderUpperThreshold ? 'adjacent' : 'inside';
    } else {
      return clientY < fileUpperThreshold ? 'adjacent' : null;
    }
  };

  const canItemBeDropped = ({ draggedItem, targetItem, dropType }) => {
    const { uid: targetItemUid, pathname: targetItemPathname } = targetItem;
    const { uid: draggedItemUid, pathname: draggedItemPathname, sourceCollectionUid } = draggedItem;

    if (draggedItemUid === targetItemUid) return false;

    // For cross-collection moves, we allow the drop
    if (sourceCollectionUid !== collectionUid) {
      return true;
    }

    const newPathname = calculateDraggedItemNewPathname({ draggedItem, targetItem, dropType, collectionPathname });
    if (!newPathname) return false;

    if (targetItemPathname?.startsWith(draggedItemPathname)) return false;
    
    return true;
  };

  const [{ isOver, canDrop }, drop] = useDrop({
    accept: 'collection-item',
    hover: (draggedItem, monitor) => {
      const { uid: targetItemUid } = item;
      const { uid: draggedItemUid } = draggedItem;

      if (draggedItemUid === targetItemUid) return;

      const dropType = determineDropType(monitor);

      const _canItemBeDropped = canItemBeDropped({ draggedItem, targetItem: item, dropType });

      setDropType(_canItemBeDropped ? dropType : null);
    },
    drop: async (draggedItem, monitor) => {
      const { uid: targetItemUid } = item;
      const { uid: draggedItemUid } = draggedItem;
  
      if (draggedItemUid === targetItemUid) return;
  
      const dropType = determineDropType(monitor);
      if (!dropType) return;

      await dispatch(handleCollectionItemDrop({ targetItem: item, draggedItem, dropType, collectionUid }))
      setDropType(null);
    },
    canDrop: (draggedItem) => draggedItem.uid !== item.uid,
    collect: (monitor) => ({
      isOver: monitor.isOver()
    }),
  });

  const dropdownTippyRef = useRef();
  const MenuIcon = forwardRef((props, ref) => {
    return (
      <div ref={ref}>
        <IconDots size={22} />
      </div>
    );
  });

  const iconClassName = classnames({
    'rotate-90': !itemIsCollapsed
  });

  const examplesIconClassName = classnames({
    'rotate-90': examplesExpanded
  });

  const itemRowClassName = classnames('flex collection-item-name relative items-center', {
    'item-focused-in-tab': isTabForItemActive,
    'item-hovered': isOver && canDrop,
    'drop-target': isOver && dropType === 'inside',
    'drop-target-above': isOver && dropType === 'adjacent'
  });

  const handleRun = async () => {
    dispatch(sendRequest(item, collectionUid)).catch((err) =>
      toast.custom((t) => <NetworkError onClose={() => toast.dismiss(t.id)} />, {
        duration: 5000
      })
    );
  };

  const handleClick = (event) => {
    if (event && event.detail != 1) return;
    //scroll to the active tab
    setTimeout(scrollToTheActiveTab, 50);
    const isRequest = isItemARequest(item);
    if (isRequest) {
      dispatch(hideHomePage());
      if (isTabForItemPresent) {
        dispatch(
          focusTab({
            uid: item.uid
          })
        );
        return;
      }
      dispatch(
        addTab({
          uid: item.uid,
          collectionUid: collectionUid,
          requestPaneTab: getDefaultRequestPaneTab(item),
          type: 'request',
        })
      );
    } else {
      dispatch(
        addTab({
          uid: item.uid,
          collectionUid: collectionUid,
          type: 'folder-settings',
        })
      );
      if(item.collapsed) {
        dispatch(
          toggleCollectionItem({
            itemUid: item.uid,
            collectionUid: collectionUid
          })
        );
      }
    }
  };

  const handleFolderCollapse = (e) => {
    e.stopPropagation();
    e.preventDefault();
    dispatch(
      toggleCollectionItem({
        itemUid: item.uid,
        collectionUid: collectionUid
      })
    );
  };

  // prevent the parent's double-click handler from firing
  const handleFolderDoubleClick = (e) => {
    e.stopPropagation();
    e.preventDefault();
  };

  const handleExamplesCollapse = (e) => {
    e.stopPropagation();
    e.preventDefault();
    setExamplesExpanded(!examplesExpanded);
  };

  // prevent the parent's double-click handler from firing
  const handleExamplesDoubleClick = (e) => {
    e.stopPropagation();
    e.preventDefault();
  };

  const handleRightClick = (event) => {
    const _menuDropdown = dropdownTippyRef.current;
    if (_menuDropdown) {
      let menuDropdownBehavior = 'show';
      if (_menuDropdown.state.isShown) {
        menuDropdownBehavior = 'hide';
      }
      _menuDropdown[menuDropdownBehavior]();
    }
  };

  let indents = range(item.depth);
  const onDropdownCreate = (ref) => (dropdownTippyRef.current = ref);

  const className = classnames('flex flex-col w-full', {
    'is-sidebar-dragging': isSidebarDragging
  });

  if (searchText && searchText.length) {
    if (isItemARequest(item)) {
      if (!doesRequestMatchSearchText(item, searchText)) {
        return null;
      }
    } else {
      if (!doesFolderHaveItemsMatchSearchText(item, searchText)) {
        return null;
      }
    }
  }

  const handleDoubleClick = (event) => {
    dispatch(makeTabPermanent({ uid: item.uid }));
  };

    // Sort items by their "seq" property.
  const sortItemsBySequence = (items = []) => {
    return items.sort((a, b) => a.seq - b.seq);
  };

  const handleShowInFolder = () => {
    dispatch(showInFolder(item.pathname)).catch((error) => {
      console.error('Error opening the folder', error);
      toast.error('Error opening the folder');
    });
  };

  const handleCreateExample = async (name, description = '') => {
    // Create example with default values
    const exampleData = {
      name: name,
      description: description,
      status: '200',
      statusText: 'OK',
      headers: [],
      body: {
        type: 'text',
        content: ''
      }
    };

    // Calculate the index where the example will be saved
    const existingExamples = item.draft?.examples || item.examples || [];
    const exampleIndex = existingExamples.length;
    const exampleUid = uuid();

    dispatch(addResponseExample({
      itemUid: item.uid,
      collectionUid: collectionUid,
      example: {
        ...exampleData,
        uid: exampleUid
      }
    }));

    // Save the request
    await dispatch(saveRequest(item.uid, collectionUid));

    // Task middleware will track this and open the example in a new tab once the file is reloaded
    dispatch(insertTaskIntoQueue({
      uid: exampleUid,
      type: 'OPEN_EXAMPLE',
      collectionUid: collectionUid,
      itemUid: item.uid,
      exampleIndex: exampleIndex
    }));

    toast.success(`Example "${name}" created successfully`);
    setCreateExampleModalOpen(false);
  };

  const folderItems = sortByNameThenSequence(filter(item.items, (i) => isItemAFolder(i))); 
  const requestItems = sortItemsBySequence(filter(item.items, (i) => isItemARequest(i)));
 
  const handleGenerateCode = (e) => {
    e.stopPropagation();
    dropdownTippyRef.current.hide();
    if (
      (item?.request?.url !== '') ||
      (item?.draft?.request?.url !== undefined && item?.draft?.request?.url !== '')
    ) {
      setGenerateCodeItemModalOpen(true);
    } else {
      toast.error('URL is required');
    }
  };

  const viewFolderSettings = () => {
    if (isItemAFolder(item)) {
      if (isTabForItemPresent) {
        dispatch(focusTab({ uid: item.uid }));
        return;
      }
      dispatch(
        addTab({
          uid: item.uid,
          collectionUid,
          type: 'folder-settings'
        })
      );
    }
  };

  const handleCopyRequest = () => {
    dropdownTippyRef.current.hide();
    dispatch(copyRequest(item));
    toast.success('Request copied to clipboard');
  };

  const handlePasteRequest = () => {
    dropdownTippyRef.current.hide();
    dispatch(pasteItem(collectionUid, item.uid))
      .then(() => {
        toast.success('Request pasted successfully');
      })
      .catch((err) => {
        toast.error(err ? err.message : 'An error occurred while pasting the request');
      });
  };

  return (
    <StyledWrapper className={className}>
      {renameItemModalOpen && (
        <RenameCollectionItem item={item} collectionUid={collectionUid} onClose={() => setRenameItemModalOpen(false)} />
      )}
      {cloneItemModalOpen && (
        <CloneCollectionItem item={item} collectionUid={collectionUid} onClose={() => setCloneItemModalOpen(false)} />
      )}
      {deleteItemModalOpen && (
        <DeleteCollectionItem item={item} collectionUid={collectionUid} onClose={() => setDeleteItemModalOpen(false)} />
      )}
      {newRequestModalOpen && (
        <NewRequest item={item} collectionUid={collectionUid} onClose={() => setNewRequestModalOpen(false)} />
      )}
      {newFolderModalOpen && (
        <NewFolder item={item} collectionUid={collectionUid} onClose={() => setNewFolderModalOpen(false)} />
      )}
      {runCollectionModalOpen && (
        <RunCollectionItem collectionUid={collectionUid} item={item} onClose={() => setRunCollectionModalOpen(false)} />
      )}
      {generateCodeItemModalOpen && (
        <GenerateCodeItem collectionUid={collectionUid} item={item} onClose={() => setGenerateCodeItemModalOpen(false)} />
      )}
      {itemInfoModalOpen && (
        <CollectionItemInfo item={item} onClose={() => setItemInfoModalOpen(false)} />
      )}
      <CreateExampleModal
        isOpen={createExampleModalOpen}
        onClose={() => setCreateExampleModalOpen(false)}
        onSave={handleCreateExample}
        title="Create Response Example"
        initialName={getInitialExampleName(item)}
      />
      <div
        className={itemRowClassName}
        ref={(node) => {
          ref.current = node;
          drag(drop(node));
        }}
      >
        <div className="flex items-center h-full w-full">
          {indents && indents.length
            ? indents.map((i) => (
                <div
                  onClick={handleClick}
                  onContextMenu={handleRightClick}
                  onDoubleClick={handleDoubleClick}
                  className="indent-block"
                  key={i}
                  style={{ width: 16, minWidth: 16, height: '100%' }}
                >
                  &nbsp;{/* Indent */}
                </div>
              ))
            : null}
          <div
            className="flex flex-grow items-center h-full overflow-hidden"
            style={{ paddingLeft: 8 }}
            onClick={handleClick}
            onContextMenu={handleRightClick}
            onDoubleClick={handleDoubleClick}
          >
            <div style={{ width: 16, minWidth: 16 }}>
              {isFolder ? (
                <IconChevronRight
                  size={16}
                  strokeWidth={2}
                  className={iconClassName}
                  style={{ color: 'rgb(160 160 160)' }}
                  onClick={handleFolderCollapse}
                  onDoubleClick={handleFolderDoubleClick}
                  data-testid="folder-chevron"
                />
              ) : hasExamples ? (
                <IconChevronRight
                  size={16}
                  strokeWidth={2}
                  className={examplesIconClassName}
                  style={{ color: 'rgb(160 160 160)' }}
                  onClick={handleExamplesCollapse}
                  onDoubleClick={handleExamplesDoubleClick}
                  data-testid="request-item-chevron"
                />
              ) : null}
            </div>
            <div className="ml-1 flex w-full h-full items-center overflow-hidden">
              <CollectionItemIcon item={item} />
              <span className="item-name" title={item.name}>
                {item.name}
              </span>
            </div>
          </div>
          <div className="menu-icon pr-2">
            <Dropdown onCreate={onDropdownCreate} icon={<MenuIcon />} placement="bottom-start">
              {isFolder && (
                <>
                  <div
                    className="dropdown-item"
                    onClick={(e) => {
                      dropdownTippyRef.current.hide();
                      setNewRequestModalOpen(true);
                    }}
                  >
                    New Request
                  </div>
                  <div
                    className="dropdown-item"
                    onClick={(e) => {
                      dropdownTippyRef.current.hide();
                      setNewFolderModalOpen(true);
                    }}
                  >
                    New Folder
                  </div>
                  <div
                    className="dropdown-item"
                    onClick={(e) => {
                      dropdownTippyRef.current.hide();
                      setRunCollectionModalOpen(true);
                    }}
                  >
                    Run
                  </div>
                </>
              )}
              <div
                className="dropdown-item"
                onClick={(e) => {
                  dropdownTippyRef.current.hide();
                  setRenameItemModalOpen(true);
                }}
              >
                Rename
              </div>
              <div
                className="dropdown-item"
                onClick={(e) => {
                  dropdownTippyRef.current.hide();
                  setCloneItemModalOpen(true);
                }}
              >
                Clone
              </div>
              {!isFolder && (
                <div
                  className="dropdown-item"
                  onClick={handleCopyRequest}
                >
                  Copy
                </div>
              )}
              {isFolder && hasCopiedItems && (
                <div
                  className="dropdown-item"
                  onClick={handlePasteRequest}
                >
                  Paste
                </div>
              )}
              {!isFolder && (
                <div
                  className="dropdown-item"
                  onClick={(e) => {
                    dropdownTippyRef.current.hide();
                    handleClick(null);
                    handleRun();
                  }}
                >
                  Run
                </div>
              )}
              {!isFolder && (item.type === 'http-request' || item.type === 'graphql-request') && (
                <div
                  className="dropdown-item"
                  onClick={(e) => {
                    handleGenerateCode(e);
                  }}
                >
                  Generate Code
                </div>
              )}
              {!isFolder && isItemARequest(item) && item.type === 'http-request' && (
                <div
                  className="dropdown-item"
                  onClick={(e) => {
                    dropdownTippyRef.current.hide();
                    setCreateExampleModalOpen(true);
                  }}
                >
                  Create Example
                </div>
              )}
              <div
                className="dropdown-item"
                onClick={(e) => {
                  dropdownTippyRef.current.hide();
                  handleShowInFolder();
                }}
              >
                Show in Folder
              </div>
              <div
                className="dropdown-item delete-item"
                onClick={(e) => {
                  dropdownTippyRef.current.hide();
                  setDeleteItemModalOpen(true);
                }}
              >
                Delete
              </div>
              {isFolder && (
                <div
                  className="dropdown-item"
                  onClick={(e) => {
                    dropdownTippyRef.current.hide();
                    viewFolderSettings();
                  }}
                >
                  Settings
                </div>
              )}
              <div
                className="dropdown-item item-info"
                onClick={(e) => {
                  dropdownTippyRef.current.hide();
                  setItemInfoModalOpen(true);
                }}
              >
                Info
              </div>
            </Dropdown>
          </div>
        </div>
      </div>
      {!itemIsCollapsed ? (
        <div>
          {folderItems && folderItems.length
            ? folderItems.map((i) => {
                return <CollectionItem key={i.uid} item={i} collectionUid={collectionUid} collectionPathname={collectionPathname} searchText={searchText} />;
              })
            : null}
          {requestItems && requestItems.length
            ? requestItems.map((i) => {
                return <CollectionItem key={i.uid} item={i} collectionUid={collectionUid} collectionPathname={collectionPathname} searchText={searchText} />;
              })
            : null}
        </div>
      ) : null}

      {/* Show examples when expanded (only for HTTP requests) */}
      {isItemARequest(item) && item.type === 'http-request' && examplesExpanded && hasExamples && (
        <div>
          {(item.examples || []).map((example, index) => {
            return (
              <ExampleItem
                key={example.uid || index}
                example={example}
                item={item}
                index={index}
                collection={collection}
              />
            );
          })}
        </div>
      )}
    </StyledWrapper>
  );
};

export default React.memo(CollectionItem);