gitDiffContent.ts

/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the MIT License. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/

import { decodeHex, encodeHex, VSBuffer } from '../../../base/common/buffer.js';
import { basename } from '../../../base/common/path.js';
import { URI } from '../../../base/common/uri.js';

const GIT_BLOB_SCHEME = 'git-blob';

/**
 * Builds a `git-blob:` URI that references a file blob at a specific git
 * commit, scoped to a given session. Resolved by reading the session's
 * working directory and shelling out to `git show <sha>:<path>`.
 *
 * The session URI is preserved so the resolver can find the session's
 * working directory; the SHA and repository-relative path identify the
 * blob to fetch.
 */
export function buildGitBlobUri(sessionUri: string, sha: string, repoRelativePath: string): string {
	return URI.from({
		scheme: GIT_BLOB_SCHEME,
		authority: encodeHex(VSBuffer.fromString(sessionUri)).toString(),
		path: `/${encodeURIComponent(sha)}/${encodeHex(VSBuffer.fromString(repoRelativePath))}/${basename(repoRelativePath)}`,
	}).toString();
}

/** Parsed fields from a `git-blob:` content URI. */
export interface IGitBlobUriFields {
	readonly sessionUri: string;
	readonly sha: string;
	readonly repoRelativePath: string;
}

/**
 * Parses a `git-blob:` URI produced by {@link buildGitBlobUri}.
 * Returns `undefined` if the URI is not a valid `git-blob:` URI.
 */
export function parseGitBlobUri(raw: string): IGitBlobUriFields | undefined {
	let parsed: URI;
	try {
		parsed = URI.parse(raw);
	} catch {
		return undefined;
	}
	if (parsed.scheme !== GIT_BLOB_SCHEME) {
		return undefined;
	}
	const [, sha, encodedPath] = parsed.path.split('/');
	if (!sha || !encodedPath) {
		return undefined;
	}
	try {
		return {
			sessionUri: decodeHex(parsed.authority).toString(),
			sha: decodeURIComponent(sha),
			repoRelativePath: decodeHex(encodedPath).toString(),
		};
	} catch {
		return undefined;
	}
}