import GlobalInfos from '../../utils/GlobalInfos';
import style from './PopupBase.module.css';
import {Line} from '../PageTitle/PageTitle';
import React, {RefObject} from 'react';

interface props {
    width?: string;
    height?: string;
    banner?: JSX.Element;
    title: string;
    onHide: () => void
}

/**
 * wrapper class for generic types of popups
 */
class PopupBase extends React.Component<props> {
    private wrapperRef: RefObject<HTMLDivElement>;
    private framedimensions: { minHeight: string | undefined; width: string | undefined; height: string | undefined };

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

        this.state = {items: []};

        this.wrapperRef = React.createRef();

        this.handleClickOutside = this.handleClickOutside.bind(this);
        this.keypress = this.keypress.bind(this);

        // parse style props
        this.framedimensions = {
            width: (this.props.width ? this.props.width : undefined),
            height: (this.props.height ? this.props.height : undefined),
            minHeight: (this.props.height ? this.props.height : undefined)
        };
    }

    componentDidMount(): void {
        document.addEventListener('mousedown', this.handleClickOutside);
        document.addEventListener('keyup', this.keypress);

        // add element drag drop events
        if (this.wrapperRef != null) {
            this.dragElement();
        }
    }

    componentWillUnmount(): void {
        // remove the appended listeners
        document.removeEventListener('mousedown', this.handleClickOutside);
        document.removeEventListener('keyup', this.keypress);
    }

    render(): JSX.Element {
        const themeStyle = GlobalInfos.getThemeStyle();
        return (
            <div style={this.framedimensions} className={[style.popup, themeStyle.thirdbackground].join(' ')} ref={this.wrapperRef}>
                <div className={style.header}>
                    <div className={[style.title, themeStyle.textcolor].join(' ')}>{this.props.title}</div>
                    <div className={style.banner}>{this.props.banner}</div>
                </div>

                <Line/>
                <div className={style.content}>
                    {this.props.children}
                </div>
            </div>
        );
    }

    /**
     * Alert if clicked on outside of element
     */
    handleClickOutside(event: MouseEvent): void {
        if (this.wrapperRef && this.wrapperRef.current && !this.wrapperRef.current.contains(event.target as Node)) {
            this.props.onHide();
        }
    }

    /**
     * key event handling
     * @param event keyevent
     */
    keypress(event: KeyboardEvent): void {
        // hide if escape is pressed
        if (event.key === 'Escape') {
            this.props.onHide();
        }
    }

    /**
     * make the element drag and droppable
     */
    dragElement(): void {
        let xOld = 0, yOld = 0;

        const elmnt = this.wrapperRef.current;
        if (elmnt === null) return;
        if (elmnt.firstChild === null) return;

        (elmnt.firstChild as HTMLDivElement).onmousedown = dragMouseDown;


        function dragMouseDown(e: MouseEvent): void {
            e.preventDefault();
            // get the mouse cursor position at startup:
            xOld = e.clientX;
            yOld = e.clientY;
            document.onmouseup = closeDragElement;
            // call a function whenever the cursor moves:
            document.onmousemove = elementDrag;
        }

        function elementDrag(e: MouseEvent): void {
            e.preventDefault();
            // calculate the new cursor position:
            const dx = xOld - e.clientX;
            const dy = yOld - e.clientY;
            xOld = e.clientX;
            yOld = e.clientY;
            // set the element's new position:
            if (elmnt === null) return;
            elmnt.style.top = (elmnt.offsetTop - dy) + 'px';
            elmnt.style.left = (elmnt.offsetLeft - dx) + 'px';
        }

        function closeDragElement(): void {
            // stop moving when mouse button is released:
            document.onmouseup = null;
            document.onmousemove = null;
        }
    }
}

export default PopupBase;