From c05384d3043e386c9fe31b581ab51d01d5375aef Mon Sep 17 00:00:00 2001
From: Don McCurdy <dm@donmccurdy.com>
Date: Wed, 7 Sep 2022 21:52:23 -0400
Subject: [PATCH] [cli] Handle conflicting URIs during merge()

---
 packages/cli/src/transforms/merge.ts | 59 ++++++++++++++++++++++++----
 1 file changed, 51 insertions(+), 8 deletions(-)

diff --git a/packages/cli/src/transforms/merge.ts b/packages/cli/src/transforms/merge.ts
index 77f3ff0da..2cb245a44 100644
--- a/packages/cli/src/transforms/merge.ts
+++ b/packages/cli/src/transforms/merge.ts
@@ -1,6 +1,15 @@
 import fs from 'fs';
-import { Document, FileUtils, ImageUtils, NodeIO, Transform } from '@gltf-transform/core';
-import { unpartition } from '@gltf-transform/functions';
+import {
+	Document,
+	FileUtils,
+	ImageUtils,
+	NodeIO,
+	Transform,
+	Texture,
+	Buffer,
+	PropertyType,
+} from '@gltf-transform/core';
+import { dedup, unpartition } from '@gltf-transform/functions';
 
 const NAME = 'merge';
 
@@ -13,8 +22,8 @@ export interface MergeOptions {
 const merge = (options: MergeOptions): Transform => {
 	const { paths, io } = options;
 
-	return async (doc: Document): Promise<void> => {
-		const logger = doc.getLogger();
+	return async (document: Document): Promise<void> => {
+		const logger = document.getLogger();
 
 		for (let i = 0; i < paths.length; i++) {
 			const path = paths[i];
@@ -24,21 +33,28 @@ const merge = (options: MergeOptions): Transform => {
 			const basename = FileUtils.basename(path);
 			const extension = FileUtils.extension(path).toLowerCase();
 			if (['png', 'jpg', 'jpeg', 'webp', 'ktx2'].includes(extension)) {
-				doc.createTexture(basename)
+				document
+					.createTexture(basename)
 					.setImage(fs.readFileSync(path))
 					.setMimeType(ImageUtils.extensionToMimeType(extension))
 					.setURI(basename + '.' + extension);
 			} else if (['gltf', 'glb'].includes(extension)) {
-				doc.merge(renameScenes(basename, await io.read(path)));
+				document.merge(renameScenes(basename, await io.read(path)));
 			} else {
 				throw new Error(`Unknown file extension: "${extension}".`);
 			}
 		}
 
-		doc.getRoot().setDefaultScene(doc.getRoot().listScenes()[0]);
+		document.getRoot().setDefaultScene(document.getRoot().listScenes()[0]);
+
+		// De-duplicate textures, then ensure that all remaining textures and buffers
+		// have unique URIs. See https://github.com/donmccurdy/glTF-Transform/issues/586.
+		await document.transform(dedup({ propertyTypes: [PropertyType.TEXTURE] }));
+		createUniqueURIs(document.getRoot().listBuffers());
+		createUniqueURIs(document.getRoot().listTextures());
 
 		if (!options.partition) {
-			await doc.transform(unpartition());
+			await document.transform(unpartition());
 		}
 
 		logger.debug(`${NAME}: Complete.`);
@@ -57,4 +73,31 @@ function renameScenes(name: string, document: Document): Document {
 	return document;
 }
 
+/** Replaces conflicting URIs to ensure all URIs are unique. */
+function createUniqueURIs(resources: Buffer[] | Texture[]): void {
+	const total = {} as Record<string, number>;
+	const used = {} as Record<string, boolean>;
+
+	for (const resource of resources) {
+		const uri = resource.getURI();
+		if (!uri) continue;
+		if (!total[uri]) total[uri] = 0;
+		total[uri]++;
+		used[uri] = false;
+	}
+
+	for (const resource of resources) {
+		let uri = resource.getURI();
+		if (!uri || total[uri] === 1) continue;
+
+		const extension = FileUtils.extension(uri);
+		const prefix = uri.replace(new RegExp(`\\.${extension}`), '');
+		for (let i = 2; used[uri]; i++) {
+			uri = `${prefix}_${i++}.${extension}`;
+		}
+		resource.setURI(uri);
+		used[uri] = true;
+	}
+}
+
 export { merge };