/**
* Resolves a module id to a package resource. If module id consists of just one term and resolves
* to a package directory, the main module of the package is returned. If the module id consists
* of several terms and the first term resolves to a package directory, the remaining part of the
* module id is resolved against the "lib" directory of the package.
*
* @link http://nodejs.org/docs/v0.4.4/api/modules.html#folders_as_Modules
* @param moduleName the name of the package to load
* @param localPath the path of the resource issuing this call
* @return the location of the package's main module
* @throws IOException an unrecoverable I/O exception occurred while reading the package
*/
protected Resource loadPackage(String moduleName, Repository localPath) throws IOException {
int slash = 0;
String packageName, remainingName;
do {
slash = moduleName.indexOf('/', slash + 1);
if (slash == -1) {
packageName = moduleName;
remainingName = null;
} else {
packageName = moduleName.substring(0, slash);
if (".".equals(packageName) || "..".equals(packageName)) continue;
remainingName = moduleName.substring(slash + 1);
}
Resource json = findResource(packageName + "/package.json", null, localPath);
if (json != null && json.exists()) {
Scriptable obj = parseJsonResource(json);
Repository parent = json.getParentRepository();
String moduleId;
Resource res;
if (remainingName == null) {
// get the main module of this package
moduleId = getStringProperty(obj, "main", null);
if (moduleId != null) {
// optimize for the common case where main module
// property links to the exact file name
res = parent.getResource(moduleId);
if (res != null && res.exists()) return res;
}
} else {
// map remaining name to libs directory
String lib = "lib";
Object dirs = ScriptableObject.getProperty(obj, "directories");
if (dirs instanceof Scriptable) {
lib = getStringProperty((Scriptable) dirs, "lib", "lib");
}
moduleId = lib + "/" + remainingName;
}
if (moduleId != null) {
for (ModuleLoader loader : loaders) {
res = parent.getResource(moduleId + loader.getExtension());
if (res != null && res.exists()) return res;
}
if (remainingName != null) {
res = parent.getResource(moduleId);
if (res != null && res.exists()) return res;
}
}
}
} while (slash != -1);
return findResource(moduleName + "/index", loaders, localPath);
}
