/**

* Utility functions for nostr-git-client

*/

import LightningFS from '@isomorphic-git/lightning-fs';

/**

* Create a LightningFS instance for IndexedDB storage

* @param {string} name - Database name

* @returns {LightningFS} Filesystem instance

*/

export function createFS(name = 'nostr-git-client') {

return new LightningFS(name);

}

/**

* Create an HTTP client for isomorphic-git

* Works with JSS and other git HTTP servers

* @param {Object} options

* @param {string} options.corsProxy - CORS proxy URL (optional)

* @param {Object} options.headers - Additional headers

* @returns {Object} HTTP client for isomorphic-git

*/

export function createHttpClient(options = {}) {

const { corsProxy, headers = {} } = options;

return {

async request({ url, method, headers: reqHeaders, body }) {

// Apply CORS proxy if specified

const finalUrl = corsProxy ? `${corsProxy}${encodeURIComponent(url)}` : url;

// isomorphic-git may pass body as array of Uint8Arrays - concatenate them

let requestBody = body;

if (Array.isArray(body)) {

const chunks = [];

for (const chunk of body) {

chunks.push(chunk instanceof Uint8Array ? chunk : new Uint8Array(chunk));

}

const totalLength = chunks.reduce((sum, chunk) => sum + chunk.length, 0);

requestBody = new Uint8Array(totalLength);

let offset = 0;

for (const chunk of chunks) {

requestBody.set(chunk, offset);

offset += chunk.length;

}

}

const res = await fetch(finalUrl, {

method,

headers: { ...reqHeaders, ...headers },

body: requestBody

});

return {

url: res.url,

method,

statusCode: res.status,

statusMessage: res.statusText,

headers: Object.fromEntries(res.headers.entries()),

body: [new Uint8Array(await res.arrayBuffer())]

};

}

};

}

/**

* Verify Nostr event signature

* @param {Object} event - Nostr event

* @returns {boolean} True if valid

*/

export async function verifyEvent(event) {

try {

const { verifyEvent } = await import('nostr-tools/pure');

return verifyEvent(event);

} catch {

// Fallback: assume valid if nostr-tools not available

console.warn('nostr-tools not available for signature verification');

return true;

}

}

/**

* Parse a 30618 repo state event

* @param {Object} event - Nostr event

* @returns {Object|null} Parsed event data

*/

export function parseRepoEvent(event) {

if (event.kind !== 30618) return null;

const repoId = event.tags.find(t => t[0] === 'd')?.[1];

const refTag = event.tags.find(t => t[0].startsWith('refs/'));

const anchorTag = event.tags.find(t => t[0] === 'c');

if (!repoId || !refTag) return null;

return {

pubkey: event.pubkey,

repoId,

ref: refTag[0],

branch: refTag[0].replace('refs/heads/', ''),

commit: refTag[1],

anchor: anchorTag?.[1] || null,

createdAt: event.created_at,

raw: event

};

}