Add a CLI to export to JSON 💾.

index.js

@@ -0,0 +1,146 @@
+#!/usr/bin/env node --experimental-json-modules
+
+import { parseArgs } from 'node:util';
+import { basename, extname } from 'node:path';
+import { open, readFile, writeFile } from 'node:fs/promises';
+import pkg from './package.json' with { type: 'json' };
+import crc32 from './src/lib/crc32.js';
+import {
+  isJapaneseVersion,
+  getResFromCrc32,
+} from './src/lib/getResFromCrc32.js';
+import parseRom from './src/lib/parseRom.js';
+import { stringify } from './src/lib/cliUtils.js';
+
+const options = {
+  version: {
+    type: 'boolean',
+    short: 'v',
+    default: false,
+  },
+  help: {
+    type: 'boolean',
+    short: 'h',
+    default: false,
+  },
+  input: {
+    type: 'string',
+    short: 'i',
+  },
+  output: {
+    type: 'string',
+    short: 'o',
+  },
+};
+
+const { values } = parseArgs({
+  options,
+  strict: true,
+});
+
+if (values.version) {
+  const { version } = pkg;
+  // See https://www.gnu.org/prep/standards/html_node/_002d_002dversion.html
+  console.log(`scumm-nes ${version}`);
+  process.exit(0);
+}
+
+if (values.help) {
+  const { description, version, bugs, homepage } = pkg;
+
+  // See https://www.gnu.org/prep/standards/html_node/_002d_002dhelp.html
+  console.log(`\x1b[1mDescription\x1b[0m
+  ${description} [version ${version}]
+
+\x1b[1mSynopsis\x1b[0m
+  This CLI exports the content of a ROM or PRG to JSON.
+
+\x1b[1mUsage\x1b[0m
+  node ${basename(import.meta.url)} --input path/to/rom --output resources.json
+
+\x1b[1mOptions\x1b[0m
+  --input, -i    Path to a ROM or PRG file.
+  --output, -o   Path to a JSON filename to be created.
+  --version, -v  Print the version number.
+
+Report bugs to: <\x1b[1m${bugs.url || bugs}\x1b[0m>
+Home page: <\x1b[1m${homepage}\x1b[0m>`);
+  process.exit(0);
+}
+
+if (!values.input && !values.output) {
+  console.error(
+    'The \x1b[1m--input\x1b[0m and \x1b[1m--output\x1b[0m arguments are required.',
+  );
+  process.exit(1);
+}
+if (!values.input) {
+  console.error('The \x1b[1m--input\x1b[0m argument is required.');
+  process.exit(1);
+}
+if (!values.output) {
+  console.error('The \x1b[1m--output\x1b[0m argument is required.');
+  process.exit(1);
+}
+
+const inputExtname = extname(values.input).toLowerCase();
+if (inputExtname !== '.prg' && inputExtname !== '.nes') {
+  console.error('Only PRG and NES files are accepted.');
+  process.exit(1);
+}
+const outputExtname = extname(values.output).toLowerCase();
+if (outputExtname !== '.json') {
+  console.error(
+    'Specify a \x1b[1m.json\x1b[0m file for the \x1b[1m--output\x1b[0m argument.',
+  );
+  process.exit(1);
+}
+
+// Check that the output file does not already exist.
+let outputFileExists = null;
+try {
+  await open(values.output);
+  outputFileExists = true;
+} catch (e) {
+  outputFileExists = false;
+}
+if (outputFileExists) {
+  console.error(`File '${values.output}' already exists.`);
+  process.exit(1);
+}
+
+// Load the input file.
+const romPath = values.input;
+let rom;
+try {
+  rom = await readFile(romPath);
+} catch (e) {
+  console.error(`Error opening input file '${romPath}'.`);
+  process.exit(1);
+}
+
+const dataView = new DataView(rom.buffer);
+const signature = crc32(dataView);
+
+if (isJapaneseVersion(signature)) {
+  console.error('The Japanese Famicom version is not supported.');
+  process.exit(1);
+}
+
+const res = getResFromCrc32(signature);
+const resources = parseRom(rom.buffer, res);
+
+if (!resources) {
+  console.error('Upload one of the ROMs of Maniac Mansion on NES.');
+  process.exit(1);
+}
+
+// Process the result of a parsing.
+const content = stringify(signature, rom.buffer.byteLength, resources, res);
+
+try {
+  await writeFile(values.output, content, { encoding: 'utf-8' });
+  console.log('Output file successfully written.');
+} catch (e) {
+  console.error(`Error writing output file '${values.output}'.`);
+}

package.json

@@ -1,6 +1,6 @@
 {
   "name": "scumm-nes",
-  "version": "0.1.0",
+  "version": "0.1.1",
   "description": "An app to explore the content of the Maniac Mansion game on NES.",
   "author": "[email protected]",
   "license": "BlueOak-1.0.0",
@@ -20,6 +20,7 @@
   "staticFiles": {
     "staticPath": "public"
   },
+  "main": "index.js",
   "scripts": {
     "test": "node --test",
     "dev": "parcel",

src/lib/cliUtils.js

@@ -0,0 +1,24 @@
+import { hex } from './utils.js';
+
+const stringify = (signature, size, resources, res) => {
+  resources.rooms.forEach((item) => {
+    delete item.buffer;
+    delete item.map;
+  });
+  resources.roomgfx.forEach((item) => delete item.buffer);
+  resources.preps.forEach((item) => delete item.buffer);
+
+  const data = {
+    metadata: {
+      crc32: `0x${hex(signature)}`,
+      size,
+      version: res.version,
+      lang: res.lang,
+    },
+    resources,
+  };
+
+  return JSON.stringify(data, null, '  ');
+};
+
+export { stringify };

src/lib/getResFromCrc32.js

@@ -1,4 +1,4 @@
-import res from './resources';
+import res from './resources.js';
 
 const isJapaneseVersion = (c) => c === 0x3da2085e || c === 0xf526cea8;
 const getResFromCrc32 = (c) =>

src/lib/parseRom.js

@@ -1,6 +1,6 @@
-import parseRooms from '../lib/parseRooms';
-import parseRoomGfx from '../lib/parseRoomGfx';
-import parsePreps from './parsePreps';
+import parseRooms from '../lib/parseRooms.js';
+import parseRoomGfx from '../lib/parseRoomGfx.js';
+import parsePreps from './parsePreps.js';
 
 const parseRom = (arrayBuffer, res) => {
   const rooms = [];