/* eslint-disable @typescript-eslint/no-unsafe-argument */
/* eslint-disable prefer-const */
import type { IActivityHandler } from "@vertigis/workflow";
import html2canvas from 'html2canvas';

/** An interface that defines the inputs of the activity. */
interface LegendCreatorInputs {
    /**
     * @displayName Class Name
     * @description Legend Class name
     * @required
     */
    className: string;
}
/** An interface that defines the outputs of the activity. */
interface LegendCreatorOutputs {
    /**
     * @description The result of the activity.
     */
    imageBase64: string;
}

/**
 * @displayName Create Legend
 * @category EBTA Utilities
 * @description Create Legend Ver1.4
 */
function convertSVGTagstoIMG(container) {
    let svgElements: NodeListOf<SVGElement> = container.querySelectorAll('svg[role="img"]');
    let SVGDom = Array.from(svgElements).filter(svg => {
        let svgElement = svg;
        let gTag = svgElement.querySelector('g');
        return gTag && gTag.querySelector('image');
    });
    

    SVGDom.forEach(svg => {
        let svgElement = svg;
        // Create a new <img> element
        let img = document.createElement('img');

    
        let imageDOM = svgElement.querySelector('image');
        if (imageDOM) {

    
            let imageurl = imageDOM.getAttribute('href');
    
            // Transfer the relevant attributes
            img.alt = imageDOM.getAttribute('alt') || '';
            img.src = imageurl || ''; // Use xlink:href for the src
            img.width = parseInt(imageDOM.getAttribute('width') || '0');
            img.height = parseInt(imageDOM.getAttribute('height') || '0');

    
            svg.parentNode!.replaceChild(img, svg);
        } else {
            console.log('No image found inside svg.');
        }
    });
    console.log('IMG conversion finished');
}


async function captureElementByClassToFile(className: string): Promise<string> {
    // Query the DOM for the first element with the specified class name
    const element :HTMLElement = document.querySelector(`.${className}`)!;
    if (!element) {
        throw new Error(`Element with class ${className} not found`);
    }



    // Ensure all external images have the crossOrigin attribute set
   
    try {
        convertSVGTagstoIMG(element)
        const images:NodeListOf<HTMLImageElement>  = element.querySelectorAll('img[src]') ;
        images.forEach((img) => {
            if (!img.crossOrigin) {
                img.crossOrigin = 'anonymous';
            }
        });


        const originalStyles = {
            backgroundColor: element.style.backgroundColor,
            color: element.style.color
        };
    
        // Reverse the dark mode styles
        element.style.backgroundColor = 'white';
        element.style.color = 'black';
    
        // Apply the same style changes to all children, and backup the original
        const children : NodeListOf<HTMLElement> = element.querySelectorAll('*');
        const originalChildStyles:{element: HTMLElement, backgroundColor: string, color: string}[] = [];
    
        children.forEach(child => {
            originalChildStyles.push({
                element: child,
                backgroundColor: child.style.backgroundColor,
                color: child.style.color
            });
            child.style.backgroundColor = 'white';
            child.style.color = 'black';
        });
    



        // Capture the element using html2canvas with useCORS option
        const canvas = await html2canvas(element, { 
            useCORS: true,
            logging: true,
            backgroundColor: '#ffffff',
            allowTaint: true ,
            scale:2.5
        });

        // Convert the canvas to Base64 image
        let imageBase64 = canvas.toDataURL("image/jpeg");

        // Revert to the original styles
        element.style.backgroundColor = originalStyles.backgroundColor;
        element.style.color = originalStyles.color;
    
        // Revert the styles of all children
        originalChildStyles.forEach(({ element, backgroundColor, color }) => {
            element.style.backgroundColor = backgroundColor;
            element.style.color = color;
        });


        return imageBase64;
    } catch (error) {
        throw new Error(`Failed to capture legend screenshot: ${(error as Error).message}`);
    }
}

/**
 * @displayName Legend Creator
 * @category VertiGIS Utilities
 * @description Create Legend Ver1.4
 */
export default class LegendCreatorActivity implements IActivityHandler {
    /** Perform the execution logic of the activity. */
    async execute(inputs: LegendCreatorInputs): Promise<LegendCreatorOutputs> {
        const imageBase64 = await captureElementByClassToFile(inputs.className);
        console.log('Legend creator version 1.4');
        return {
            imageBase64: imageBase64
        };
    }
}