/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/
var createInnerCallback = require("./createInnerCallback");
var assign = require("object-assign");
var DescriptionFileUtils = require("./DescriptionFileUtils");

function DescriptionFilePlugin(source, filenames, target) {
	this.source = source;
	this.filenames = [].concat(filenames);
	this.target = target;
}
module.exports = DescriptionFilePlugin;

DescriptionFilePlugin.prototype.apply = function(resolver) {
	var filenames = this.filenames;
	var target = this.target;
	resolver.plugin(this.source, function(request, callback) {
		var fs = this.fileSystem;
		var directory = request.path;
		DescriptionFileUtils.loadDescriptionFile(resolver, directory, filenames, function(err, result) {
			if(err) return callback(err);
			if(!result) {
				if(callback.missing) {
					filenames.forEach(function(filename) {
						callback.missing.push(resolver.join(directory, filename));
					})
				}
				if(callback.log) callback.log("No description file found");
				return callback();
			}
			var relativePath = "." + request.path.substr(result.directory.length).replace(/\\/g, "/");
			var obj = assign({}, request, {
				descriptionFilePath: result.path,
				descriptionFileData: result.content,
				descriptionFileRoot: result.directory,
				relativePath: relativePath
			});
			resolver.doResolve(target, obj, "using description file: " + result.path + " (relative path: " + relativePath + ")", createInnerCallback(function(err, result) {
				if(err) return callback(err);
				if(result) return callback(null, result);

				// Don't allow other description files or none at all
				callback(null, null);
			}, callback));
		});
	});
};