read and write python-style config files

lib/pyconf.js

@@ -1,6 +1,7 @@
 'use strict';
 
 var fs = require('fs');
+var sfs = require('safe-replace').create();
 
 function snakeCase(key) {
   if ('tlsSni01Port' === key) {
@@ -37,7 +38,7 @@ function parsePythonConf(str, cb) {
     var parts = line.trim().split('=');
     var pykey = parts.shift().trim();
     var key = camelCase(pykey);
-    var val = parts.join('=');
+    var val = parts.join('=').trim();
 
     if ('True' === val) {
       val = true;
@@ -70,6 +71,94 @@ function parsePythonConf(str, cb) {
   cb(null, obj);
 }
 
+function toPyVal(val) {
+  if (null === val) {
+    return 'None';
+  }
+  else if (true === val) {
+    return 'True';
+  }
+  else if (false === val) {
+    return 'False';
+  }
+  else if ('string' === typeof val) {
+    return val;
+  }
+  else if ('number' === typeof val) {
+    return val;
+  }
+  else if (Array.isArray(val)) {
+    return val.join(',');
+  }
+
+  return val && JSON.stringify(val);
+}
+
+function stringifyPythonConf(obj, cb) {
+  var endline;
+
+  // nix the final newline
+  if (!obj.__lines[obj.__lines.length - 1].trim()) {
+    endline = obj.__lines.pop();
+  }
+
+  Object.keys(obj).forEach(function (key) {
+    if ('__' === key.slice(0, 2)) {
+      return;
+    }
+
+    var pykey = snakeCase(key);
+    var pyval = toPyVal(obj[key]);
+    var num = obj.__keys[key];
+    var comment = '';
+
+
+    if ('number' !== typeof num) {
+      obj.__lines.push(pykey + ' = ' + pyval);
+      return;
+    }
+
+    // restore comments
+    if (-1 !== obj.__lines[num].indexOf('#')) {
+      comment = obj.__lines[num].replace(/.*?(\s*#.*)/, '$1');
+    }
+
+    if ('[' === pykey[0]) {
+      return;
+    }
+
+    if ('undefined' === typeof pyval) {
+      obj.__lines[num] = "___DELETE_ME___";
+    }
+  });
+
+  obj.__lines = obj.__lines.filter(function (line) {
+    if ("___DELETE_ME___" !== line) {
+      return true;
+    }
+  });
+
+  if ('string' === typeof endline) {
+    obj.__lines.push(endline);
+  }
+
+  cb(null, obj.__lines.join('\n'));
+}
+
+function writePythonConfFile(pathname, obj, cb) {
+  // TODO re-read file?
+  stringifyPythonConf(obj, function (err, text) {
+    sfs.writeFile(pathname, text, 'utf8', function (err) {
+      if (err) {
+        cb(err);
+        return;
+      }
+
+      cb();
+    });
+  });
+}
+
 function parsePythonConfFile(pathname, cb) {
   fs.readFile(pathname, 'utf8', function (err, text) {
     if (err) {
@@ -82,7 +171,9 @@ function parsePythonConfFile(pathname, cb) {
 }
 
 module.exports.parse = parsePythonConf;
-module.exports.parseFile = parsePythonConfFile;
+module.exports.readFile = parsePythonConfFile;
+module.exports.stringify = stringifyPythonConf;
+module.exports.writeFile = writePythonConfFile;
 
 parsePythonConfFile('examples/renewal-example.com.conf', function (err, obj) {
   if (err) {
@@ -90,5 +181,12 @@ parsePythonConfFile('examples/renewal-example.com.conf', function (err, obj) {
     return;
   }
 
+  writePythonConfFile('examples/renewal-example.com.conf.new', obj, function (err, obj) {
+    if (err) {
+      console.error(err.stack);
+      return;
+    }
+
     console.log(obj);
   });
+});