import { FontAwesomeIcon } from '@fortawesome/react-fontawesome';
import { action, computed, makeObservable, observable } from 'mobx';
import { observer } from 'mobx-react';
import * as React from 'react';
import { StopEvent, returnOne, returnZero } from '../../../ClientUtils';
import { Doc, Opt } from '../../../fields/Doc';
import { BoolCast, DocCast, NumCast, ScriptCast, StrCast } from '../../../fields/Types';
import { DragManager } from '../../util/DragManager';
import { StyleProp } from '../StyleProp';
import { DocumentView } from '../nodes/DocumentView';
import { FieldViewProps } from '../nodes/FieldView';
import { FormattedTextBox } from '../nodes/formattedText/FormattedTextBox';
import './CollectionCarouselView.scss';
import { CollectionSubView, SubCollectionViewProps } from './CollectionSubView';

@observer
export class CollectionCarouselView extends CollectionSubView() {
    private _dropDisposer?: DragManager.DragDropDisposer;

    _fadeTimer: NodeJS.Timeout | undefined;
    @observable _last_index = this.carouselIndex;
    @observable _last_opacity = 1;

    constructor(props: SubCollectionViewProps) {
        super(props);
        makeObservable(this);
    }

    componentWillUnmount() {
        this._dropDisposer?.();
    }

    protected createDashEventsTarget = (ele: HTMLDivElement | null) => {
        this._dropDisposer?.();
        if (ele) {
            this._dropDisposer = DragManager.MakeDropTarget(ele, this.onInternalDrop.bind(this), this.layoutDoc);
        }
    };

    @computed get captionMarginX(){ return NumCast(this.layoutDoc.caption_xMargin, 50); } // prettier-ignore
    @computed get carouselIndex() { return NumCast(this.layoutDoc._carousel_index) % this.carouselItems.length; } // prettier-ignore
    @computed get carouselItems() { return this.childLayoutPairs.filter(pair => !pair.layout.layout_isSvg); } // prettier-ignore

    /**
     * Move forward or backward the specified number of Docs
     * @param dir signed number indicating Docs to move forward or backward
     */
    move = action((dir: number) => {
        this._last_index = this.carouselIndex;
        this.layoutDoc._carousel_index = this.carouselItems.length ? (this.carouselIndex + dir + this.carouselItems.length) % this.carouselItems.length : 0;
    });

    /**
     * Goes to the next Doc in the stack subject to the currently selected filter option.
     */
    advance = (e?: React.MouseEvent) => {
        e?.stopPropagation();
        this.move(1);
    };

    /**
     * Goes to the previous Doc in the stack subject to the currently selected filter option.
     */
    goback = (e: React.MouseEvent) => {
        e.stopPropagation();
        this.move(-1);
    };

    curDoc = () => this.carouselItems[this.carouselIndex]?.layout;

    captionStyleProvider = (doc: Doc | undefined, captionProps: Opt<FieldViewProps>, property: string) => {
        // first look for properties on the document in the carousel, then fallback to properties on the container
        const childValue = doc?.['caption_' + property] ? this._props.styleProvider?.(doc, captionProps, property) : undefined;
        return childValue ?? this._props.styleProvider?.(this.layoutDoc, captionProps, property);
    };
    contentPanelWidth = () => this._props.PanelWidth() - 2 * NumCast(this.layoutDoc.xMargin);
    contentPanelHeight = () => this._props.PanelHeight() - (StrCast(this.layoutDoc._layout_showCaption) ? 50 : 0) - 2 * NumCast(this.layoutDoc.yMargin);
    onContentDoubleClick = () => ScriptCast(this.layoutDoc.onChildDoubleClick);
    onContentClick = () => ScriptCast(this.layoutDoc.onChildClick);
    captionWidth = () => this._props.PanelWidth() - 2 * this.captionMarginX;
    contentScreenToLocalXf = () =>
        this._props
            .ScreenToLocalTransform()
            .translate(-NumCast(this.layoutDoc.xMargin), -NumCast(this.layoutDoc.yMargin))
            .scale(this._props.NativeDimScaling?.() || 1);
    isChildContentActive = () =>
        this._props.isContentActive?.() === false
            ? false
            : this._props.isDocumentActive?.() && (this._props.childDocumentsActive?.() || BoolCast(this.Document.childDocumentsActive))
              ? true
              : this._props.childDocumentsActive?.() === false || this.Document.childDocumentsActive === false
                ? false
                : undefined;
    renderDoc = (doc: Doc, showCaptions: boolean, overlayFunc?: (r: DocumentView | null) => void) => {
        return (
            <DocumentView
                {...this._props}
                ref={overlayFunc}
                Document={doc}
                NativeWidth={returnZero}
                NativeHeight={returnZero}
                fitWidth={this._props.childLayoutFitWidth}
                hideFilterStatus={true}
                showTags={BoolCast(this.layoutDoc.showChildTags)}
                containerViewPath={this.childContainerViewPath}
                setContentViewBox={undefined}
                onDoubleClickScript={this.onContentDoubleClick}
                onClickScript={this.onContentClick}
                isDocumentActive={this._props.childDocumentsActive?.() ? this._props.isDocumentActive : this._props.isContentActive}
                isContentActive={this.isChildContentActive}
                hideCaptions={showCaptions}
                renderDepth={this._props.renderDepth + 1}
                LayoutTemplate={this._props.childLayoutTemplate}
                LayoutTemplateString={this._props.childLayoutString}
                TemplateDataDocument={DocCast(Doc.Layout(doc).resolvedDataDoc)}
                childFilters={this.childDocFilters}
                hideDecorations={BoolCast(this.layoutDoc.layout_hideDecorations)}
                addDocument={this._props.addDocument}
                ScreenToLocalTransform={this.contentScreenToLocalXf}
                PanelWidth={this.contentPanelWidth}
                PanelHeight={this.contentPanelHeight}
                screenXPadding={this.screenXPadding}
            />
        );
    };
    /**
     * Display an overlay of the previous card that crossfades to the next card
     */
    @computed get overlay() {
        const fadeTime = 500;
        const lastDoc = this.carouselItems?.[this._last_index]?.layout;
        return !lastDoc || this.carouselIndex === this._last_index ? null : (
            <div className="collectionCarouselView-image" style={{ opacity: this._last_opacity, transition: `opacity ${fadeTime}ms` }}>
                {this.renderDoc(
                    lastDoc,
                    false, // hide captions if the carousel is configured to show the captions
                    action((r: DocumentView | null) => {
                        if (r) {
                            this._fadeTimer && clearTimeout(this._fadeTimer);
                            this._last_opacity = 0;
                            this._fadeTimer = setTimeout(
                                action(() => {
                                    this._last_index = -1;
                                    this._last_opacity = 1;
                                }),
                                fadeTime
                            );
                        }
                    })
                )}
            </div>
        );
    }
    @computed get renderedDoc() {
        const carouselShowsCaptions = StrCast(this.layoutDoc._layout_showCaption);
        return this.renderDoc(this.curDoc(), !!carouselShowsCaptions);
    }

    @computed get content() {
        const captionProps = { ...this._props, NativeScaling: returnOne, PanelWidth: this.captionWidth, fieldKey: 'caption', setHeight: undefined, setContentView: undefined };
        const carouselShowsCaptions = StrCast(this.layoutDoc._layout_showCaption);
        return !this.curDoc() ? null : (
            <>
                <div className="collectionCarouselView-image" key="image">
                    {this.renderedDoc}
                    {this.overlay}
                </div>
                {!carouselShowsCaptions ? null : (
                    <div
                        className="collectionCarouselView-caption"
                        key="caption"
                        onWheel={StopEvent}
                        style={{
                            borderRadius: this._props.styleProvider?.(this.layoutDoc, captionProps, StyleProp.BorderRounding) as string,
                            marginRight: this.captionMarginX,
                            marginLeft: this.captionMarginX,
                            width: `calc(100% - ${this.captionMarginX * 2}px)`,
                        }}>
                        <FormattedTextBox xPadding={10} yPadding={10} {...captionProps} fieldKey={carouselShowsCaptions} styleProvider={this.captionStyleProvider} Document={this.curDoc()} TemplateDataDocument={undefined} />
                    </div>
                )}
            </>
        );
    }

    @computed get navButtons() {
        return this.Document._chromeHidden || !this.curDoc() ? null : (
            <>
                <div key="back" className="carouselView-back" style={{ transform: `scale(${this.uiBtnScaling})` }} onClick={this.goback}>
                    <FontAwesomeIcon icon="chevron-left" size="2x" />
                </div>
                <div key="fwd" className="carouselView-fwd" style={{ transform: `scale(${this.uiBtnScaling})` }} onClick={this.advance}>
                    <FontAwesomeIcon icon="chevron-right" size="2x" />
                </div>
            </>
        );
    }

    docViewProps = () => ({
        ...this._props, //
        isDocumentActive: this._props.childDocumentsActive?.() ? this._props.isDocumentActive : this._props.isContentActive,
        isContentActive: this.isChildContentActive,
        ScreenToLocalTransform: this.contentScreenToLocalXf,
    });
    answered = () => this.advance();

    render() {
        return (
            <div
                className="collectionCarouselView-outer"
                ref={this.createDashEventsTarget}
                style={{
                    background: this._props.styleProvider?.(this.layoutDoc, this._props, StyleProp.BackgroundColor) as string,
                    color: this._props.styleProvider?.(this.layoutDoc, this._props, StyleProp.Color) as string,
                    width: `calc(100% - ${NumCast(this.layoutDoc._xMargin)}px)`,
                    height: `calc(100% - ${NumCast(this.layoutDoc._yMargin)}px)`,
                    left: NumCast(this.layoutDoc._xMargin),
                    top: NumCast(this.layoutDoc._yMargin),
                }}>
                {this.content}
                {this.flashCardUI(this.curDoc, this.docViewProps, this.answered)}
                {this.navButtons}
            </div>
        );
    }
}