import React = require("react");
import { FontAwesomeIcon } from "@fortawesome/react-fontawesome";
import { CursorProperty } from "csstype";
import { action, computed, IReactionDisposer, observable, reaction, runInAction } from "mobx";
import { observer } from "mobx-react";
import { DataSym, Doc, HeightSym, Opt, WidthSym } from "../../../fields/Doc";
import { Id } from "../../../fields/FieldSymbols";
import { List } from "../../../fields/List";
import { listSpec } from "../../../fields/Schema";
import { SchemaHeaderField } from "../../../fields/SchemaHeaderField";
import { BoolCast, Cast, NumCast, ScriptCast, StrCast } from "../../../fields/Types";
import { TraceMobx } from "../../../fields/util";
import { emptyFunction, returnEmptyDoclist, returnFalse, returnTrue, returnZero, setupMoveUpEvents, smoothScroll, Utils } from "../../../Utils";
import { Docs, DocUtils } from "../../documents/Documents";
import { DragManager, dropActionType } from "../../util/DragManager";
import { SnappingManager } from "../../util/SnappingManager";
import { Transform } from "../../util/Transform";
import { undoBatch } from "../../util/UndoManager";
import { ContextMenu } from "../ContextMenu";
import { ContextMenuProps } from "../ContextMenuItem";
import { LightboxView } from "../LightboxView";
import { CollectionFreeFormDocumentView } from "../nodes/CollectionFreeFormDocumentView";
import { DocFocusOptions, DocumentView, DocumentViewProps, ViewAdjustment } from "../nodes/DocumentView";
import { StyleProp } from "../StyleProvider";
import { CollectionNoteTakingViewFieldColumn } from "./CollectionNoteTakingViewFieldColumn";
import "./CollectionNoteTakingView.scss";
import { CollectionSubView } from "./CollectionSubView";
import { CollectionViewType } from "./CollectionView";
const _global = (window /* browser */ || global /* node */) as any;


export type collectionNoteTakingViewProps = {
    chromeHidden?: boolean;
    viewType?: CollectionViewType;
    NativeWidth?: () => number;
    NativeHeight?: () => number;
};

@observer
export class CollectionNoteTakingView extends CollectionSubView<Partial<collectionNoteTakingViewProps>>() {
    //-------------------------------------------- Delete? --------------------------------------------//
    // Not sure what a pivot field is. Seems like we cause reaction in MobX get rid of it once we exit this view
    _pivotFieldDisposer?: IReactionDisposer;
    // Seems like we cause reaction in MobX get rid of our height once we exit this view
    _autoHeightDisposer?: IReactionDisposer;
    //------------------------------------------------------------------------------------------------//
    _masonryGridRef: HTMLDivElement | null = null;
    _draggerRef = React.createRef<HTMLDivElement>();
    // keeping track of documents. Updated on internal and external drops. What's the difference?
    _docXfs: { height: () => number, width: () => number, noteTakingDocTransform: () => Transform }[] = [];
    // Assuming that this is the current css cursor style
    @observable _cursor: CursorProperty = "grab";
    // gets reset whenever we scroll. Not sure what it is
    @observable _scroll = 0; // used to force the document decoration to update when scrolling
    // does this mean whether the browser is hidden? Or is chrome something else entirely?
    @computed get chromeHidden() { return this.props.chromeHidden || BoolCast(this.layoutDoc.chromeHidden); }
    // it looks like this gets the column headers that Mehek was showing just now
    @computed get columnHeaders() { return Cast(this.layoutDoc._columnHeaders, listSpec(SchemaHeaderField), null); }
    // Still not sure what a pivot is, but it appears that we can actually filter docs somehow?
    // @computed get pivotField() { return StrCast(this.layoutDoc._pivotField); }
    @computed get pivotField() { return "Col" }
    // filteredChildren is what you want to work with. It's the list of things that you're currently displaying
    @computed get filteredChildren() { return this.childLayoutPairs.filter(pair => (pair.layout instanceof Doc) && !pair.layout.hidden).map(pair => pair.layout); }
    // how much margin we give the header
    @computed get headerMargin() { return this.props.styleProvider?.(this.layoutDoc, this.props, StyleProp.HeaderMargin); }
    @computed get xMargin() { return NumCast(this.layoutDoc._xMargin, 2 * Math.min(this.gridGap, .05 * this.props.PanelWidth())); }
    @computed get yMargin() { return this.props.yPadding || NumCast(this.layoutDoc._yMargin, 5); } // 2 * this.gridGap)); }
    @computed get gridGap() { return NumCast(this.layoutDoc._gridGap, 10); }
    @computed get numGroupColumns() { return this.columnHeaders.length; }
    // @computed get columnWidth() {return this.props.PanelWidth() - 2 * this.xMargin;}

    //-------------------------------------------- Parker's Playground --------------------------------------------//
    // draggedDocBackgroundColors: string[] = []
    columnStartXCoords: number[] = []
    @computed get PanelWidth() {return this.props.PanelWidth()}
    @computed get maxColWdith() {return this.props.PanelWidth() - 2 * this.xMargin;}
    // dividerXCoords: number[] = []
    //-------------------------------------------------------------------------------------------------------------//

    constructor(props: any) {
        super(props);

        if (this.columnHeaders === undefined) {
          // TODO: what is a layout doc? Is it literally how this document is supposed to be layed out?
          // here we're making an empty list of column headers (again, what Mehek showed us)
            this.layoutDoc._columnHeaders = new List<SchemaHeaderField>();
            this.columnStartXCoords = [0]
        } else {
          //TODO instantiate columnStartXCoords and dividerXCoords
          const numHeaders = this.columnHeaders.length
          this.resizeColumns(numHeaders)
        }
    }

    // TODO: plj - these are the children
    children = (docs: Doc[]) => {
      //TODO: can somebody explain me to what exactly TraceMobX is?
        TraceMobx();
        // appears that we are going to reset the _docXfs. TODO: what is Xfs?
        this._docXfs.length = 0;
        return docs.map((d, i) => {
            const height = () => this.getDocHeight(d);
            const width = () => this.getDocWidth(d);
            //TODO change style here so that 
            const style = { width: width(), marginTop: i ? this.gridGap : 0, height: height() };
            return <div className={`collectionNoteTakingView-columnDoc`} key={d[Id]} style={style} >
                {this.getDisplayDoc(d, width)}
            </div>;
        });
    }

    get Sections() {
        // appears that pivot field IS actually for sorting
        if (!this.pivotField || this.columnHeaders instanceof Promise) return new Map<SchemaHeaderField, Doc[]>();
        const columnHeaders = Array.from(this.columnHeaders);
        const fields = new Map<SchemaHeaderField, Doc[]>(columnHeaders.map(sh => [sh, []] as [SchemaHeaderField, []]));
        let changed = false;
        this.filteredChildren.map(d => {
            if (!d[this.pivotField]) {
              d[this.pivotField] = `New Column`
            };
            const sectionValue = d[this.pivotField] as object;
            // the next five lines ensures that floating point rounding errors don't create more than one section -syip
            const parsed = parseInt(sectionValue.toString());
            const castedSectionValue = !isNaN(parsed) ? parsed : sectionValue;

            // look for if header exists already
            const existingHeader = columnHeaders.find(sh => sh.heading === (castedSectionValue ? castedSectionValue.toString() : `0`));
            if (existingHeader) {
                fields.get(existingHeader)!.push(d);
            }
            else {
                const newSchemaHeader = new SchemaHeaderField(castedSectionValue ? castedSectionValue.toString() : `0`);
                fields.set(newSchemaHeader, [d]);
                columnHeaders.push(newSchemaHeader);
                changed = true;
            }
        });
        // remove all empty columns if hideHeadings is set
        // we will want to have something like this, so that we can hide columns and add them back in
        if (this.layoutDoc._columnsHideIfEmpty) {
            Array.from(fields.keys()).filter(key => !fields.get(key)!.length).map(header => {
                fields.delete(header);
                columnHeaders.splice(columnHeaders.indexOf(header), 1);
                changed = true;
            });
        }
        changed && setTimeout(action(() => this.columnHeaders?.splice(0, this.columnHeaders.length, ...columnHeaders)), 0);
        return fields;
    }

    componentDidMount() {
        super.componentDidMount?.();

        // reset section headers when a new filter is inputted
        this._pivotFieldDisposer = reaction(
            () => this.pivotField,
            () => this.layoutDoc._columnHeaders = new List()
        );
        //TODO: where the heck are we getting filters from?
        this._autoHeightDisposer = reaction(() => this.layoutDoc._autoHeight,
            autoHeight => autoHeight && this.props.setHeight(Math.min(NumCast(this.layoutDoc._maxHeight, Number.MAX_SAFE_INTEGER),
                this.headerMargin + Math.max(...this.refList.map(r => Number(getComputedStyle(r).height.replace("px", "")))))));
    }

    componentWillUnmount() {
        super.componentWillUnmount();
        this._pivotFieldDisposer?.();
        this._autoHeightDisposer?.();
    }

    @action
    moveDocument = (doc: Doc, targetCollection: Doc | undefined, addDocument: (document: Doc) => boolean): boolean => {
        return this.props.removeDocument?.(doc) && addDocument?.(doc) ? true : false;
    }
    createRef = (ele: HTMLDivElement | null) => {
        this._masonryGridRef = ele;
        this.createDashEventsTarget(ele!); //so the whole grid is the drop target?
    }

    @computed get onChildClickHandler() { return () => this.props.childClickScript || ScriptCast(this.Document.onChildClick); }
    @computed get onChildDoubleClickHandler() { return () => this.props.childDoubleClickScript || ScriptCast(this.Document.onChildDoubleClick); }

    addDocTab = (doc: Doc, where: string) => {
        if (where === "inPlace" && this.layoutDoc.isInPlaceContainer) {
            this.dataDoc[this.props.fieldKey] = new List<Doc>([doc]);
            return true;
        }
        return this.props.addDocTab(doc, where);
    }

    scrollToBottom = () => {
        smoothScroll(500, this._mainCont!, this._mainCont!.scrollHeight);
    }

    // let's dive in and get the actual document we want to drag/move around
    focusDocument = (doc: Doc, options?: DocFocusOptions) => {
        Doc.BrushDoc(doc);

        let focusSpeed = 0;
        const found = this._mainCont && Array.from(this._mainCont.getElementsByClassName("documentView-node")).find((node: any) => node.id === doc[Id]);
        if (found) {
            const top = found.getBoundingClientRect().top;
            const localTop = this.props.ScreenToLocalTransform().transformPoint(0, top);
            if (Math.floor(localTop[1]) !== 0) {
                smoothScroll(focusSpeed = doc.presTransition || doc.presTransition === 0 ? NumCast(doc.presTransition) : 500, this._mainCont!, localTop[1] + this._mainCont!.scrollTop);
            }
        }
        const endFocus = async (moved: boolean) => options?.afterFocus ? options?.afterFocus(moved) : ViewAdjustment.doNothing;
        this.props.focus(this.rootDoc, {
            willZoom: options?.willZoom, scale: options?.scale, afterFocus: (didFocus: boolean) =>
                new Promise<ViewAdjustment>(res => setTimeout(async () => res(await endFocus(didFocus)), focusSpeed))
        });
    }

    styleProvider = (doc: Doc | undefined, props: Opt<DocumentViewProps>, property: string) => {
        if (property === StyleProp.Opacity && doc) {
            if (this.props.childOpacity) {
                return this.props.childOpacity();
            }
            if (this.Document._currentFrame !== undefined) {
                return CollectionFreeFormDocumentView.getValues(doc, NumCast(this.Document._currentFrame))?.opacity;
            }
        }
        return this.props.styleProvider?.(doc, props, property);
    }
    isContentActive = () => this.props.isSelected() || this.props.isContentActive();

    // this is what renders the document that you see on the screen
    // called in Children: this actually adds a document to our children list
    getDisplayDoc(doc: Doc, width: () => number) {
        const dataDoc = (!doc.isTemplateDoc && !doc.isTemplateForField && !doc.PARAMS) ? undefined : this.props.DataDoc;
        const height = () => this.getDocHeight(doc);

        let dref: Opt<DocumentView>;
        const noteTakingDocTransform = () => this.getDocTransform(doc, dref);
        this._docXfs.push({ noteTakingDocTransform, width, height });
        //DocumentView is how the node will be rendered
        return <DocumentView ref={r => dref = r || undefined}
            Document={doc}
            DataDoc={dataDoc || (!Doc.AreProtosEqual(doc[DataSym], doc) && doc[DataSym])}
            renderDepth={this.props.renderDepth + 1}
            PanelWidth={width}
            PanelHeight={height}
            styleProvider={this.styleProvider}
            layerProvider={this.props.layerProvider}
            docViewPath={this.props.docViewPath}
            fitWidth={this.props.childFitWidth}
            isContentActive={emptyFunction}
            //TODO: Parker added both of these fields. We may be able to observe elsewhere
            originalBackgroundColor={StrCast(doc.backgroundColor)}
            isNoteTakingView={true}

            isDocumentActive={this.isContentActive}
            LayoutTemplate={this.props.childLayoutTemplate}
            LayoutTemplateString={this.props.childLayoutString}
            freezeDimensions={this.props.childFreezeDimensions}
            NativeWidth={this.props.childIgnoreNativeSize ? returnZero : this.props.childFitWidth?.(doc) || doc._fitWidth && !Doc.NativeWidth(doc) ? width : undefined}  // explicitly ignore nativeWidth/height if childIgnoreNativeSize is set- used by PresBox
            NativeHeight={this.props.childIgnoreNativeSize ? returnZero : this.props.childFitWidth?.(doc) || doc._fitWidth && !Doc.NativeHeight(doc) ? height : undefined}
            dontCenter={this.props.childIgnoreNativeSize ? "xy" : undefined}
            dontRegisterView={dataDoc ? true : BoolCast(this.layoutDoc.childDontRegisterViews, this.props.dontRegisterView)}
            rootSelected={this.rootSelected}
            showTitle={this.props.childShowTitle}
            dropAction={StrCast(this.layoutDoc.childDropAction) as dropActionType}
            onClick={this.onChildClickHandler}
            onDoubleClick={this.onChildDoubleClickHandler}
            ScreenToLocalTransform={noteTakingDocTransform}
            focus={this.focusDocument}
            docFilters={this.childDocFilters}
            hideDecorationTitle={this.props.childHideDecorationTitle?.()}
            hideResizeHandles={this.props.childHideResizeHandles?.()}
            hideTitle={this.props.childHideTitle?.()}
            docRangeFilters={this.childDocRangeFilters}
            searchFilterDocs={this.searchFilterDocs}
            ContainingCollectionDoc={this.props.CollectionView?.props.Document}
            ContainingCollectionView={this.props.CollectionView}
            addDocument={this.props.addDocument}
            moveDocument={this.props.moveDocument}
            removeDocument={this.props.removeDocument}
            contentPointerEvents={StrCast(this.layoutDoc.contentPointerEvents)}
            whenChildContentsActiveChanged={this.props.whenChildContentsActiveChanged}
            addDocTab={this.addDocTab}
            bringToFront={returnFalse}
            scriptContext={this.props.scriptContext}
            pinToPres={this.props.pinToPres}
        />;
    }

    //TODO update this to 
    getDocTransform(doc: Doc, dref?: DocumentView) {
        const y = this._scroll; // required for document decorations to update when the text box container is scrolled
        const { scale, translateX, translateY } = Utils.GetScreenTransform(dref?.ContentDiv || undefined);
        // the document view may center its contents and if so, will prepend that onto the screenToLocalTansform.  so we have to subtract that off 
        return new Transform(- translateX + (dref?.centeringX || 0), - translateY + (dref?.centeringY || 0), 1).scale(this.props.ScreenToLocalTransform().Scale);
    }

    //TODO need to adjust so that we're basing off number of columns and dividers.
    getDocWidth(d: Doc) {
      const heading = d[this.pivotField] as object
      const castedSectionValue = heading.toString()
      const existingHeader = this.columnHeaders.find(sh => sh.heading === (castedSectionValue));
      if (existingHeader) {
        const index = this.columnHeaders.indexOf(existingHeader)
        if (this.columnHeaders.length == 1) {
          return this.props.PanelWidth() - this.columnStartXCoords[index] - 4 * this.gridGap
        } 
        return this.columnStartXCoords[index + 1] - this.columnStartXCoords[index] - 2 * this.gridGap
      }
      return 1000;
    }

    getDocHeight(d?: Doc) {
        if (!d || d.hidden) return 0;
        const childLayoutDoc = Doc.Layout(d, this.props.childLayoutTemplate?.());
        const childDataDoc = (!d.isTemplateDoc && !d.isTemplateForField && !d.PARAMS) ? undefined : this.props.DataDoc;
        const maxHeight = (lim => lim === 0 ? this.props.PanelWidth() : lim === -1 ? 10000 : lim)(NumCast(this.layoutDoc.childLimitHeight, -1));
        const nw = Doc.NativeWidth(childLayoutDoc, childDataDoc) || (!(childLayoutDoc._fitWidth || this.props.childFitWidth?.(d)) ? d[WidthSym]() : 0);
        const nh = Doc.NativeHeight(childLayoutDoc, childDataDoc) || (!(childLayoutDoc._fitWidth || this.props.childFitWidth?.(d)) ? d[HeightSym]() : 0);
        if (nw && nh) {
            // const colWid = this.columnWidth / this.numGroupColumns;
            // const docWid = this.layoutDoc._columnsFill ? colWid : Math.min(this.getDocWidth(d), colWid);
            const docWid = this.getDocWidth(d)
            return Math.min(
                maxHeight,
                docWid * nh / nw);
        }
        const childHeight = NumCast(childLayoutDoc._height);
        const panelHeight = (childLayoutDoc._fitWidth || this.props.childFitWidth?.(d)) ? Number.MAX_SAFE_INTEGER : this.props.PanelHeight() - 2 * this.yMargin;
        return Math.min(childHeight, maxHeight, panelHeight);
    }

    // This following three functions must be from the view Mehek showed
    // columnDividerDown = (e: React.PointerEvent) => {
    //     runInAction(() => this._cursor = "grabbing");
    //     setupMoveUpEvents(this, e, this.onDividerMove, action(() => this._cursor = "grab"), emptyFunction);
    // }

    // @action
    // onDividerMove = (e: PointerEvent, down: number[], delta: number[]) => {
    //     this.layoutDoc._columnWidth = Math.max(10, this.columnWidth + delta[0]);
    //     return false;
    // }

    //TODO: currently unused. How can we make use of it?
    // @computed get columnDragger() {
    //     return <div className="collectionNoteTakingView-columnDragger" onPointerDown={this.columnDividerDown} ref={this._draggerRef}
    //         style={{ cursor: this._cursor, left: `${this.columnWidth + this.xMargin}px`, top: `${Math.max(0, this.yMargin - 9)}px` }} >
    //         <FontAwesomeIcon icon={"arrows-alt-h"} />
    //     </div>;
    // }

    resizeColumns = (n: number) => {
      const totalWidth = this.PanelWidth
      const colWidth = totalWidth / n
      const newColXCoords: number[] = []
      let colStart = 0
      for (let i = 0; i < n; i++) {
          newColXCoords.push(colStart)
          colStart += colWidth
      }
      this.columnStartXCoords = newColXCoords
      console.log(newColXCoords)
    }

    // TODO: This is where you want to create a copy of the document to take its place
    @action
    onPointerOver = (e: React.PointerEvent) => {
      if (DragManager.docsBeingDragged.length && this.childDocList) {
        const col = this.getClientColumn(e)
        const colStartXCoords = this.columnStartXCoords
        // console.log(col)
        const clientY = e.clientY
        // const clientX = e.clientX
        let dropInd = -1;
        let dropAfter = 0;
        const length = this._docXfs.length
        //TODO get the nodes in the doc
        this._docXfs.forEach((cd, i) => {
          //TODO need to write your own function for this, or make sure you're properly updating the fields
          const pos = cd.noteTakingDocTransform().inverse().transformPoint(0, -2 * this.gridGap);
          const pos1 = cd.noteTakingDocTransform().inverse().transformPoint(0, cd.height());
          // checking whethere the copied element is in between the top of the doc and the grid gap
          // (meaning that this is the index it will be taking)
          const yCoordInBetween = clientY > pos[1] && (clientY < pos1[1] || i == this._docXfs.length - 1)
          // const xCoordInBetween = clientX > pos[0] && (clientX < pos1[0] || i == this._docXfs.length - 1)
          const xCoordInBetween = true
          if (yCoordInBetween && xCoordInBetween) {
            dropInd = i;
            if (clientY > (pos[1] + pos1[1]) / 2) {
              dropAfter = 1;
            }
          }
        })
        const docs = this.childDocList;
        const newDocs = DragManager.docsBeingDragged;
        const length2 = docs.length
        if (docs) {
          const insertInd = dropInd === -1 ? docs.length : dropInd + dropAfter;
          const offset = newDocs.reduce((off, ndoc) => this.filteredChildren.find((fdoc, i) => ndoc === fdoc && i < insertInd) ? off + 1 : off, 0);
          newDocs.filter(ndoc => docs.indexOf(ndoc) !== -1).forEach(ndoc => docs.splice(docs.indexOf(ndoc), 1));
          docs.splice(insertInd - offset, 0, ...newDocs);
        }
      }
    }

    //used in onPointerOver to swap two nodes in the rendered filtered children list
    swapNodes = (i: number, j: number) => {
      
    }

    //plj added this 
    @action
    onPointerDown = (e: React.PointerEvent) => {

    }

    getClientColumn = (e: React.PointerEvent): number => {
        const clientX = e.clientX
        const numColumns = this.columnHeaders.length
        const coords = this.columnStartXCoords
        coords.push(this.props.PanelWidth())
        let colIndex = 0
        for (let i = 0; i < numColumns; i++) {
            if (clientX > coords[i] && clientX < coords[i + 1]) {
              colIndex = i
              break
            }
        }
        return colIndex
    }

    // TODO: Going to be helpful to look at code to see what exactly this is doing to have the aliases. 
    // I also think that this code is now incorrect
    @undoBatch
    @action
    onInternalDrop = (e: Event, de: DragManager.DropEvent) => {
      // Fairly confident that this is where the swapping of nodes in the various arrays happens
        const where = [de.x, de.y];
        // start at -1 until we're sure we want to add it to the column
        //Parker added this to reset doc colors

        //
        let dropInd = -1;
        let dropAfter = 0;
        if (de.complete.docDragData) {
            // going to re-add the docs to the _docXFs based on position of where we just dropped
            this._docXfs.map((cd, i) => {
                const pos = cd.noteTakingDocTransform().inverse().transformPoint(-2 * this.gridGap, -2 * this.gridGap);
                const pos1 = cd.noteTakingDocTransform().inverse().transformPoint(cd.width(), cd.height());
                // const top = cd.height();
                // const pos = cd.noteTakingDocTransform().transformPoint(0, cd.height());
                // TODO: plan
                // Get the top of the box
                // Check if there could possibly be a box below
                
                // const pos1 = cd.noteTakingDocTransform().transformPoint(0, cd.height());
                // if (where[0] > pos[0] && where[0] < pos1[0] && where[1] > pos[1] && (i === this._docXfs.length - 1 || where[1] < pos1[1])) {
                if (where[1] > pos[1] && (i === this._docXfs.length - 1 || where[1] < pos1[1])) {
                    dropInd = i;
                    const axis = 1;
                    dropAfter = where[axis] > (pos[axis] + pos1[axis]) / 2 ? 1 : 0;
                }
            });
            const oldDocs = this.childDocs.length;
            if (super.onInternalDrop(e, de)) {
              // check to see if we actually need anything to the new column of nodes (if droppedDocs != empty)
                const droppedDocs = this.childDocs.slice().filter((d: Doc, ind: number) => ind >= oldDocs); // if the drop operation adds something to the end of the list, then use that as the new document (may be different than what was dropped e.g., in the case of a button which is dropped but which creates say, a note).
                const newDocs = droppedDocs.length ? droppedDocs : de.complete.docDragData.droppedDocuments; // if nothing was added to the end of the list, then presumably the dropped documents were already in the list, but possibly got reordered so we use them.

                const docs = this.childDocList;
                // reset drag manager docs, because we just dropped
                DragManager.docsBeingDragged = [];
                // still figuring out where to add the document
                if (docs && newDocs.length) {
                    const insertInd = dropInd === -1 ? docs.length : dropInd + dropAfter;
                    const offset = newDocs.reduce((off, ndoc) => this.filteredChildren.find((fdoc, i) => ndoc === fdoc && i < insertInd) ? off + 1 : off, 0);
                    newDocs.filter(ndoc => docs.indexOf(ndoc) !== -1).forEach(ndoc => docs.splice(docs.indexOf(ndoc), 1));
                    // doesn't appear to be causing issues, but potentially could create
                    // if (this.placeHolderDown) {
                    //   docs.splice(0, 1);
                    //   this.placeHolderDown = false
                    // }
                    docs.splice(insertInd - offset, 0, ...newDocs);
                }
            }
        } // it seems like we're creating a link here. Weird. I didn't know that you could establish links by dragging
        else if (de.complete.linkDragData?.dragDocument.context === this.props.Document && de.complete.linkDragData?.linkDragView?.props.CollectionFreeFormDocumentView?.()) {
            const source = Docs.Create.TextDocument("", { _width: 200, _height: 75, _fitWidth: true, title: "dropped annotation" });
            this.props.addDocument?.(source);
            de.complete.linkDocument = DocUtils.MakeLink({ doc: source }, { doc: de.complete.linkDragData.linkSourceGetAnchor() }, "doc annotation", ""); // TODODO this is where in text links get passed
            e.stopPropagation();
        }
        else if (de.complete.annoDragData?.dragDocument && super.onInternalDrop(e, de)) return this.internalAnchorAnnoDrop(e, de.complete.annoDragData);
        return false;
    }

    @undoBatch
    internalAnchorAnnoDrop(e: Event, annoDragData: DragManager.AnchorAnnoDragData) {
        const dropCreator = annoDragData.dropDocCreator;
        annoDragData.dropDocCreator = (annotationOn: Doc | undefined) => {
            const dropDoc = dropCreator(annotationOn);
            return dropDoc || this.rootDoc;
        };
        return true;
    }

    // TODO: need this, but not using atm
    @undoBatch
    @action
    //What is the difference between internal and external drop?? Does internal mean we're dropping inside of a collection?
    // I take it back: external drop means we took it out of column/collection that we were just in
    onExternalDrop = async (e: React.DragEvent): Promise<void> => {
        const where = [e.clientX, e.clientY];
        let targInd = -1;
        this._docXfs.map((cd, i) => {
            const pos = cd.noteTakingDocTransform().inverse().transformPoint(-2 * this.gridGap, -2 * this.gridGap);
            const pos1 = cd.noteTakingDocTransform().inverse().transformPoint(cd.width(), cd.height());
            if (where[0] > pos[0] && where[0] < pos1[0] && where[1] > pos[1] && where[1] < pos1[1]) {
                targInd = i;
            }
        });
        super.onExternalDrop(e, {}, () => {
            if (targInd !== -1) {
                const newDoc = this.childDocs[this.childDocs.length - 1];
                const docs = this.childDocList;
                if (docs) {
                    docs.splice(docs.length - 1, 1);
                    docs.splice(targInd, 0, newDoc);
                }
            }
        });
    }

    // sections are important 
    headings = () => Array.from(this.Sections);
    refList: any[] = [];
    sectionNoteTaking = (heading: SchemaHeaderField | undefined, docList: Doc[]) => {
        // const key = this.pivotField;
        const type = "number";
        return <CollectionNoteTakingViewFieldColumn
            unobserveHeight={ref => this.refList.splice(this.refList.indexOf(ref), 1)}
            observeHeight={ref => {
                if (ref) {
                    this.refList.push(ref);
                    this.observer = new _global.ResizeObserver(action((entries: any) => {
                        if (this.layoutDoc._autoHeight && ref && this.refList.length && !SnappingManager.GetIsDragging()) {
                            const height = this.headerMargin +
                                Math.min(NumCast(this.layoutDoc._maxHeight, Number.MAX_SAFE_INTEGER),
                                    Math.max(...this.refList.map(r => Number(getComputedStyle(r).height.replace("px", "")))));
                            if (!LightboxView.IsLightboxDocView(this.props.docViewPath())) {
                                this.props.setHeight(height);
                            }
                        }
                    }));
                    this.observer.observe(ref);
                }
            }}
            addDocument={this.addDocument}
            chromeHidden={this.chromeHidden}
            columnHeaders={this.columnHeaders}
            Document={this.props.Document}
            DataDoc={this.props.DataDoc}
            resizeColumns={this.resizeColumns.bind(this)}
            renderChildren={this.children}
            // columnWidth={this.columnWidth}
            numGroupColumns={this.numGroupColumns}
            gridGap={this.gridGap}
            pivotField={this.pivotField}
            columnStartXCoords={this.columnStartXCoords}
            maxColWidth={this.maxColWdith}
            PanelWidth={this.PanelWidth}
            key={heading?.heading ?? ""}
            headings={this.headings}
            heading={heading?.heading ?? ""}
            headingObject={heading}
            docList={docList}
            yMargin={this.yMargin}
            type={type}
            createDropTarget={this.createDashEventsTarget}
            screenToLocalTransform={this.props.ScreenToLocalTransform}
            // added this in to add column
            editableViewProps={{
              GetValue: () => "",
              SetValue: this.addGroup,
              contents: "+ New Column"
          }}
        />;
    }

    @action
    addGroup = (value: string) => {
        if (value && this.columnHeaders) {
            this.resizeColumns(this.columnHeaders.length + 1)
            const schemaHdrField = new SchemaHeaderField(value);
            this.columnHeaders.push(schemaHdrField);
            DocUtils.addFieldEnumerations(undefined, this.pivotField, [{ title: value, _backgroundColor: "schemaHdrField.color" }]);
            return true;
        }
        return false;
    }

    sortFunc = (a: [SchemaHeaderField, Doc[]], b: [SchemaHeaderField, Doc[]]): 1 | -1 => {
        const descending = StrCast(this.layoutDoc._columnsSort) === "descending";
        const firstEntry = descending ? b : a;
        const secondEntry = descending ? a : b;
        return firstEntry[0].heading > secondEntry[0].heading ? 1 : -1;
    }

    onContextMenu = (e: React.MouseEvent): void => {
        // need to test if propagation has stopped because GoldenLayout forces a parallel react hierarchy to be created for its top-level layout
        if (!e.isPropagationStopped()) {
            const subItems: ContextMenuProps[] = [];
            subItems.push({ description: `${this.layoutDoc._columnsFill ? "Variable Size" : "Autosize"} Column`, event: () => this.layoutDoc._columnsFill = !this.layoutDoc._columnsFill, icon: "plus" });
            subItems.push({ description: `${this.layoutDoc._autoHeight ? "Variable Height" : "Auto Height"}`, event: () => this.layoutDoc._autoHeight = !this.layoutDoc._autoHeight, icon: "plus" });
            subItems.push({ description: "Clear All", event: () => this.dataDoc.data = new List([]), icon: "times" });
            ContextMenu.Instance.addItem({ description: "Options...", subitems: subItems, icon: "eye" });
        }
    }

    // 
    @computed get renderedSections() {
        TraceMobx();
        let sections = [[undefined, this.filteredChildren] as [SchemaHeaderField | undefined, Doc[]]];
        if (this.pivotField) {
            const entries = Array.from(this.Sections.entries());
            sections = this.layoutDoc._columnsSort ? entries.sort(this.sortFunc) : entries;
        }
        //TODO need to add the divs in
        const eles: JSX.Element[] = []
        for (let i = 0; i < sections.length; i++) {
            const col = this.sectionNoteTaking(sections[i][0], sections[i][1])
            eles.push(col)
            //TODO make this look pretty
            // if (i < sections.length - 1) {
            //   eles.push(
            //     <div className={"collectionNoteTakingViewFieldColumn"}>
            //       new div
            //     </div>
            //     )
            // }
        }
        return eles
    }

    @computed get buttonMenu() {
        const menuDoc: Doc = Cast(this.rootDoc.buttonMenuDoc, Doc, null);
        // TODO:glr Allow support for multiple buttons
        if (menuDoc) {
            const width: number = NumCast(menuDoc._width, 30);
            const height: number = NumCast(menuDoc._height, 30);
            return (<div className="buttonMenu-docBtn"
                style={{ width: width, height: height }}>
                <DocumentView
                    Document={menuDoc}
                    DataDoc={menuDoc}
                    isContentActive={this.props.isContentActive}
                    isDocumentActive={returnTrue}
                    addDocument={this.props.addDocument}
                    moveDocument={this.props.moveDocument}
                    addDocTab={this.props.addDocTab}
                    pinToPres={emptyFunction}
                    rootSelected={this.props.isSelected}
                    removeDocument={this.props.removeDocument}
                    ScreenToLocalTransform={Transform.Identity}
                    PanelWidth={() => 35}
                    PanelHeight={() => 35}
                    renderDepth={this.props.renderDepth}
                    focus={emptyFunction}
                    styleProvider={this.props.styleProvider}
                    layerProvider={this.props.layerProvider}
                    docViewPath={returnEmptyDoclist}
                    whenChildContentsActiveChanged={emptyFunction}
                    bringToFront={emptyFunction}
                    docFilters={this.props.docFilters}
                    docRangeFilters={this.props.docRangeFilters}
                    searchFilterDocs={this.props.searchFilterDocs}
                    ContainingCollectionView={undefined}
                    ContainingCollectionDoc={undefined}
                />
            </div>
            );
        }
    }


    @computed get nativeWidth() { return this.props.NativeWidth?.() ?? Doc.NativeWidth(this.layoutDoc); }
    @computed get nativeHeight() { return this.props.NativeHeight?.() ?? Doc.NativeHeight(this.layoutDoc); }

    @computed get scaling() { return !this.nativeWidth ? 1 : this.props.PanelHeight() / this.nativeHeight; }

    @computed get backgroundEvents() { return SnappingManager.GetIsDragging(); }
    observer: any;
    render() {
        TraceMobx();
        const buttonMenu = this.rootDoc.buttonMenu;
        const noviceExplainer = this.rootDoc.explainer;
        return (
            <>
                {buttonMenu || noviceExplainer ? <div className="documentButtonMenu">
                    {buttonMenu ? this.buttonMenu : null}
                    {Doc.UserDoc().noviceMode && noviceExplainer ?
                        <div className="documentExplanation">
                            {noviceExplainer}
                        </div>
                        : null
                    }
                </div> : null}
                <div className="collectionNoteTakingView"
                    ref={this.createRef}
                    style={{
                        overflowY: this.props.isContentActive() ? "auto" : "hidden",
                        background: this.props.styleProvider?.(this.rootDoc, this.props, StyleProp.BackgroundColor),
                        pointerEvents: this.backgroundEvents ? "all" : undefined
                    }}
                    onScroll={action(e => this._scroll = e.currentTarget.scrollTop)}
                    onPointerOver={this.onPointerOver}
                    onPointerDown={this.onPointerDown}
                    onDrop={this.onExternalDrop.bind(this)}
                    onContextMenu={this.onContextMenu}
                    onWheel={e => this.props.isContentActive(true) && e.stopPropagation()} >
                    {this.renderedSections}
                </div>
            </>

        );
    }
}