@ddegtyarev/aws-tools/dist/src/chartUtils.js

This project contains AWS API integration tools for use in Vertex AI SDK.

// src/chartUtils.ts
import * as fs from 'fs';
import * as path from 'path';
// Note: These imports are optional and only needed if chart generation is used
// They're not included in the main dependencies to keep the package lightweight
let vega = null;
let vegaLite = null;
/**
 * Dynamically imports Vega and Vega-Lite libraries
 * This allows the chart generation to be optional
 */
async function loadVegaLibraries() {
    if (!vega || !vegaLite) {
        try {
            vega = await import('vega');
            // @ts-expect-error: ignore the linter error for vega-lite import
            vegaLite = await import('vega-lite');
        }
        catch (error) {
            throw new Error('Vega and Vega-Lite libraries are required for chart generation. Please install them: npm install vega vega-lite');
        }
    }
}
/**
 * Generates PNG and SVG files from a Vega-Lite chart specification
 * @param chartSpec - The Vega-Lite chart specification
 * @param filename - Base filename without extension
 * @param outputDir - Directory to save the files (default: current directory)
 * @returns Promise that resolves when files are generated
 */
export async function generateChartFiles(chartSpec, filename, outputDir = '.') {
    await loadVegaLibraries();
    try {
        // Compile Vega-Lite to Vega specification
        const vegaSpec = vegaLite.compile(chartSpec).spec;
        // Ensure output directories exist
        const svgDir = path.join(outputDir, 'svg');
        const pngDir = path.join(outputDir, 'png');
        if (!fs.existsSync(svgDir)) {
            fs.mkdirSync(svgDir, { recursive: true });
        }
        if (!fs.existsSync(pngDir)) {
            fs.mkdirSync(pngDir, { recursive: true });
        }
        // Generate SVG file
        const view = new vega.View(vega.parse(vegaSpec), { renderer: 'none' });
        const svg = await view.toSVG();
        fs.writeFileSync(path.join(svgDir, `${filename}.svg`), svg);
        console.log(`SVG file created successfully at ${path.join(svgDir, `${filename}.svg`)}`);
        // Generate PNG file using canvas
        const canvasView = new vega.View(vega.parse(vegaSpec), { renderer: 'none' });
        const canvas = await canvasView.toCanvas();
        const out = fs.createWriteStream(path.join(pngDir, `${filename}.png`));
        const stream = canvas.createPNGStream();
        stream.pipe(out);
        return new Promise((resolve, reject) => {
            out.on('finish', () => {
                console.log(`PNG file created successfully at ${path.join(pngDir, `${filename}.png`)}`);
                resolve();
            });
            out.on('error', reject);
        });
    }
    catch (error) {
        console.error('Error generating chart files:', error);
        console.log('Chart specification:', JSON.stringify(chartSpec, null, 2));
        throw error;
    }
}
/**
 * Generates only a PNG file from a Vega-Lite chart specification
 * @param chartSpec - The Vega-Lite chart specification
 * @param filename - Base filename without extension
 * @param outputDir - Directory to save the file (default: current directory)
 * @returns Promise that resolves when file is generated
 */
export async function generatePNGChart(chartSpec, filename, outputDir = '.') {
    await loadVegaLibraries();
    try {
        // Compile Vega-Lite to Vega specification
        const vegaSpec = vegaLite.compile(chartSpec).spec;
        // Ensure output directory exists
        const pngDir = path.join(outputDir, 'png');
        if (!fs.existsSync(pngDir)) {
            fs.mkdirSync(pngDir, { recursive: true });
        }
        // Generate PNG file using canvas
        const canvasView = new vega.View(vega.parse(vegaSpec), { renderer: 'none' });
        const canvas = await canvasView.toCanvas();
        const out = fs.createWriteStream(path.join(pngDir, `${filename}.png`));
        const stream = canvas.createPNGStream();
        stream.pipe(out);
        return new Promise((resolve, reject) => {
            out.on('finish', () => {
                console.log(`PNG file created successfully at ${path.join(pngDir, `${filename}.png`)}`);
                resolve();
            });
            out.on('error', reject);
        });
    }
    catch (error) {
        console.error('Error generating PNG chart:', error);
        console.log('Chart specification:', JSON.stringify(chartSpec, null, 2));
        throw error;
    }
}
/**
 * Generates only an SVG file from a Vega-Lite chart specification
 * @param chartSpec - The Vega-Lite chart specification
 * @param filename - Base filename without extension
 * @param outputDir - Directory to save the file (default: current directory)
 * @returns Promise that resolves when file is generated
 */
export async function generateSVGChart(chartSpec, filename, outputDir = '.') {
    await loadVegaLibraries();
    try {
        // Compile Vega-Lite to Vega specification
        const vegaSpec = vegaLite.compile(chartSpec).spec;
        // Create a Vega view
        const view = new vega.View(vega.parse(vegaSpec), {
            renderer: 'canvas',
        });
        // Ensure output directory exists
        const svgDir = path.join(outputDir, 'svg');
        if (!fs.existsSync(svgDir)) {
            fs.mkdirSync(svgDir, { recursive: true });
        }
        // Generate SVG file
        const svg = await view.toSVG();
        fs.writeFileSync(path.join(svgDir, `${filename}.svg`), svg);
        console.log(`SVG file created successfully at ${path.join(svgDir, `${filename}.svg`)}`);
    }
    catch (error) {
        console.error('Error generating SVG chart:', error);
        console.log('Chart specification:', JSON.stringify(chartSpec, null, 2));
        throw error;
    }
}