/**
* URL Encoder for Chhart.app
* Encodes chart data into URL-safe format for shareable links
*/
/**
* Encodes chart content into a URL-safe base64 string.
* Converts the content to base64 and replaces characters that are not URL-safe.
*
* @param content - The chart content to encode (Chhart DSL format)
* @returns A URL-safe base64 encoded string
* @example
* ```typescript
* const encoded = encodeChartData("Start\n End");
* // Returns: "U3RhcnQKICBFbmQ"
* ```
*/
export function encodeChartData(content: string): string {
// Convert to base64 and make URL-safe
const base64 = Buffer.from(content, 'utf-8').toString('base64');
return base64
.replace(/\+/g, '-')
.replace(/\//g, '_')
.replace(/=/g, '');
}
/**
* Generates a shareable URL for a flowchart on chhart.app.
* The URL includes the encoded flowchart content and optional title in the hash fragment.
*
* @param content - The flowchart content in Chhart DSL format
* @param title - Optional title for the flowchart
* @returns A complete URL to view the flowchart on chhart.app
* @example
* ```typescript
* const url = generateFlowchartUrl("Start\n End", "My Flowchart");
* // Returns: "https://chhart.app/#flowchart=U3RhcnQKICBFbmQ&title=My%20Flowchart"
* ```
*/
export function generateFlowchartUrl(content: string, title?: string): string {
const encoded = encodeChartData(content);
const baseUrl = 'https://chhart.app';
// Build URL with encoded content
let url = `${baseUrl}/#flowchart=${encoded}`;
if (title) {
const encodedTitle = encodeURIComponent(title);
url += `&title=${encodedTitle}`;
}
return url;
}
/**
* Generates a shareable URL for a Sankey diagram on chhart.app.
* The URL includes the encoded Sankey diagram content and optional title in the hash fragment.
*
* @param content - The Sankey diagram content in Chhart DSL format
* @param title - Optional title for the Sankey diagram
* @returns A complete URL to view the Sankey diagram on chhart.app
* @example
* ```typescript
* const url = generateSankeyUrl("Revenue [value=100]\n Profit [value=60]", "Budget");
* // Returns: "https://chhart.app/#sankey=...&title=Budget"
* ```
*/
export function generateSankeyUrl(content: string, title?: string): string {
const encoded = encodeChartData(content);
const baseUrl = 'https://chhart.app';
let url = `${baseUrl}/#sankey=${encoded}`;
if (title) {
const encodedTitle = encodeURIComponent(title);
url += `&title=${encodedTitle}`;
}
return url;
}
/**
* Decodes a URL-safe base64 string back to original content.
* Reverses the URL-safe encoding and converts base64 back to UTF-8 text.
*
* @param encoded - The URL-safe base64 encoded string
* @returns The original decoded content
* @example
* ```typescript
* const decoded = decodeChartData("U3RhcnQKICBFbmQ");
* // Returns: "Start\n End"
* ```
*/
export function decodeChartData(encoded: string): string {
// Restore standard base64 format
let base64 = encoded
.replace(/-/g, '+')
.replace(/_/g, '/');
// Add padding if needed
while (base64.length % 4) {
base64 += '=';
}
return Buffer.from(base64, 'base64').toString('utf-8');
}
