1 files changed, 173 insertions, 0 deletions
diff --git a/cmd/main.js b/cmd/main.js
new file mode 100755
index 0000000..b71bbed
--- /dev/null
+++ b/cmd/main.js
@@ -0,0 +1,173 @@
+#!/usr/bin/env node
+
+const fs = require('fs');
+const os = require('os');
+const path = require('path');
+const process = require('process');
+const {
+    execSync
+} = require('child_process');
+
+const render = require('../lib/template');
+
+var url = null,
+    revision = null;
+
+function log(msg) {
+    console.error(msg);
+}
+
+function printHelp() {
+    console.log(`
+npm4nix converts NPM packages into build instructions for Nix.
+
+Usage: npm4nix [options] URL
+
+Options:
+  -r, --revision revision to fetching from Git (tag, branch, hash)
+  -h, --help     show this help screen
+
+URL can be:
+  - a local directory with package.json
+  - a local archive (tarball)
+  - a remote Git URL
+  - a remote archive (tarball)
+
+Examples:
+
+  $ npm4nix -r 0.5.1 https://github.com/substack/node-mkdirp.git > mkdirp.nix
+  $ npm4nix . > mypkg.nix
+  `);
+}
+
+function exec(cmd) {
+    log(`executing ${cmd}`);
+    return execSync(cmd, {
+        encoding: 'utf-8'
+    }).trim();
+}
+
+function getSHA256(p) {
+    var flat = '';
+    if (fs.statSync(p).isFile()) {
+        flat = ' --flat';
+    }
+
+    return exec(`nix-hash${flat} --base32 --type sha256 '${p}'`);
+}
+
+function mkdtemp() {
+    const tmpdir = os.tmpdir();
+    return fs.mkdtempSync(`${tmpdir}${path.sep}npm4nix-`);
+}
+
+function rmTree(dir) {
+    fs.readdirSync(dir).forEach(function(entry, index) {
+        const p = path.join(dir, entry);
+        if (fs.lstatSync(p).isDirectory()) {
+            rmTree(p);
+        } else {
+            fs.unlinkSync(p);
+        }
+    });
+    fs.rmdirSync(dir);
+};
+
+function readPackage(p) {
+    var pkgFile = path.join(p, 'package.json');
+    return JSON.parse(fs.readFileSync(pkgFile));
+}
+
+function isLocal(p) {
+    return fs.existsSync(p);
+}
+
+function processLocal(p) {
+    console.log(render(p, readPackage(p)));
+}
+
+function isArchive(url) {
+    return url.match(new RegExp('(https?://)?.+/[^/]+\.t(ar\.)?(gz|bz2|xz)', 'i'));
+}
+
+function processArchive(url) {
+    const dir = mkdtemp();
+    const file = path.join(dir, path.basename(url));
+    var sha256, pkg;
+    try {
+        exec(`curl -LsSf -o '${file}' '${url}'`);
+        sha256 = getSHA256(file);
+        pkg = JSON.parse(exec(`tar -xOf '${file}' --wildcards '*/package.json'`));
+    } finally {
+        rmTree(dir);
+    }
+    console.log(render({
+        fetch: 'fetchurl',
+        url: url,
+        sha256: sha256
+    }, pkg));
+}
+
+function isGit(url) {
+    return url.match(new RegExp('(.*https://)?(github|gitlab)\.com/[^/]+/[^/]+(\.git)?$', 'i')) ||
+        url.match(new RegExp('(.*https://)?bitbucket\.org/[^/]+/[^/]+(\.git)?$', 'i')) ||
+        url.match(new RegExp('^git(\\+https)?://.+', 'i'));
+}
+
+function processGit(url) {
+    const dir = mkdtemp();
+    var rev, sha256, pkg;
+    try {
+        exec(`git clone '${url}' '${dir}'`);
+        if (revision !== null) {
+            exec(`git -C '${dir}' checkout '${revision}'`);
+        }
+        rev = exec(`git -C '${dir}' rev-parse HEAD`);
+        rmTree(path.join(dir, '.git'));
+        sha256 = getSHA256(dir);
+        pkg = readPackage(dir);
+    } finally {
+        rmTree(dir);
+    }
+    console.log(render({
+        fetch: 'fetchgit',
+        url: url,
+        rev: rev,
+        sha256: sha256
+    }, pkg));
+}
+
+
+const args = process.argv.slice(2);
+
+for (var i = 0; i < args.length; i++) {
+    switch (args[i]) {
+        case '-r':
+        case '--revision':
+            revision = args[++i];
+            break;
+        case '-h':
+        case '--help':
+            printHelp();
+            process.exit();
+            break;
+        default:
+            url = args[i];
+    }
+}
+
+if (url === null) {
+    log('Missing URL. Add --help for usage info');
+    process.exit(1);
+}
+
+if (isLocal(url)) {
+    processLocal(url);
+} else if (isGit(url)) {
+    processGit(url);
+} else if (isArchive(url)) {
+    processArchive(url);
+} else {
+    log(`unsupported URL: '${url}'`);
+    process.exit(1);
+}