import { action } from 'mobx';
import { observer } from 'mobx-react';
import * as React from 'react';
import { Doc } from '../../../../fields/Doc';
import { NumCast, StrCast } from '../../../../fields/Types';
import { UndoManager } from '../../../util/UndoManager';
import { StyleProp } from '../../StyleProvider';
import { StyleProviderFuncType } from '../../nodes/FieldView';
import { DimUnit } from './CollectionMulticolumnView';

interface ResizerProps {
    width: number;
    styleProvider?: StyleProviderFuncType;
    isContentActive?: () => boolean | undefined;
    columnUnitLength(): number | undefined;
    toLeft?: Doc;
    toRight?: Doc;
    select: (isCtrlPressed: boolean) => void;
}

@observer
export default class ResizeBar extends React.Component<ResizerProps> {
    private _resizeUndo?: UndoManager.Batch;

    @action
    private registerResizing = (e: React.PointerEvent<HTMLDivElement>) => {
        this.props.select(false);
        e.stopPropagation();
        e.preventDefault();
        window.removeEventListener('pointermove', this.onPointerMove);
        window.removeEventListener('pointerup', this.onPointerUp);
        window.addEventListener('pointermove', this.onPointerMove);
        window.addEventListener('pointerup', this.onPointerUp);
        this._resizeUndo = UndoManager.StartBatch('multcol resizing');
    };

    private onPointerMove = ({ movementX }: PointerEvent) => {
        const { toLeft, toRight, columnUnitLength } = this.props;
        const movingRight = movementX > 0;
        const toNarrow = movingRight ? toRight : toLeft;
        const toWiden = movingRight ? toLeft : toRight;
        const unitLength = columnUnitLength();
        if (unitLength) {
            if (toNarrow) {
                const scale = StrCast(toNarrow._dimUnit, '*') === DimUnit.Ratio ? unitLength : 1;
                toNarrow._dimMagnitude = Math.max(0.05, NumCast(toNarrow._dimMagnitude, 1) - Math.abs(movementX) / scale);
            }
            if (toWiden) {
                const scale = StrCast(toWiden._dimUnit, '*') === DimUnit.Ratio ? unitLength : 1;
                toWiden._dimMagnitude = Math.max(0.05, NumCast(toWiden._dimMagnitude, 1) + Math.abs(movementX) / scale);
            }
        }
    };

    private get isActivated() {
        const { toLeft, toRight } = this.props;
        if (toLeft && toRight) {
            if (StrCast(toLeft._dimUnit, '*') === DimUnit.Pixel && StrCast(toRight._dimUnit, '*') === DimUnit.Pixel) {
                return false;
            }
            return true;
        } else if (toLeft) {
            if (StrCast(toLeft._dimUnit, '*') === DimUnit.Pixel) {
                return false;
            }
            return true;
        } else if (toRight) {
            if (StrCast(toRight._dimUnit, '*') === DimUnit.Pixel) {
                return false;
            }
            return true;
        }
        return false;
    }

    @action
    private onPointerUp = () => {
        window.removeEventListener('pointermove', this.onPointerMove);
        window.removeEventListener('pointerup', this.onPointerUp);
        this._resizeUndo?.end();
        this._resizeUndo = undefined;
    };

    render() {
        return (
            <div
                className="multiColumnResizer"
                style={{
                    pointerEvents: this.props.isContentActive?.() ? 'all' : 'none',
                    width: this.props.width,
                    backgroundColor: !this.props.isContentActive?.() ? '' : this.props.styleProvider?.(undefined, undefined, StyleProp.WidgetColor),
                }}>
                <div className={'multiColumnResizer-hdl'} onPointerDown={e => this.registerResizing(e)} />
            </div>
        );
    }
}
