/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/
var Module = require("./Module");
var RawSource = require("webpack-core/lib/RawSource");

function ContextModule(resolveDependencies, context, recursive, regExp, addon) {
	Module.call(this);
	this.resolveDependencies = resolveDependencies;
	this.context = context;
	this.recursive = recursive;
	this.regExp = regExp;
	this.addon = addon;
	this.cacheable = true;
	this.contextDependencies = [context];
	this.built = false;
}
module.exports = ContextModule;

ContextModule.prototype = Object.create(Module.prototype);

ContextModule.prototype.identifier = function() {
	var identifier = "";
	identifier += this.context + " ";
	if(!this.recursive)
		identifier += "nonrecursive ";
	if(this.addon)
		identifier += this.addon;
	if(this.regExp)
		identifier += this.regExp;
	return identifier.replace(/ $/, "");
};

function prettyRegExp(str) {
	return str.substring(1, str.length - 1);
}

ContextModule.prototype.readableIdentifier = function(requestShortener) {
	var identifier = "";
	identifier += requestShortener.shorten(this.context) + " ";
	if(!this.recursive)
		identifier += "nonrecursive ";
	if(this.addon)
		identifier += requestShortener.shorten(this.addon);
	if(this.regExp)
		identifier += prettyRegExp(this.regExp + "");
	return identifier.replace(/ $/, "");
};

ContextModule.prototype.needRebuild = function(fileTimestamps, contextTimestamps) {
	var ts = contextTimestamps[this.context];
	if(!ts) return true;
	return ts >= this.builtTime;
};

ContextModule.prototype.disconnect = function disconnect() {
	this.built = false;
	Module.prototype.disconnect.call(this);
};

ContextModule.prototype.build = function(options, compilation, resolver, fs, callback) {
	this.built = true;
	this.builtTime = new Date().getTime();
	var addon = this.addon;
	this.resolveDependencies(fs, this.context, this.recursive, this.regExp, function(err, dependencies) {
		if(err) return callback(err);
		dependencies.forEach(function(dep) {
			dep.userRequest = dep.request;
			dep.request = addon + dep.userRequest;
		});
		this.dependencies = dependencies;
		callback();
	}.bind(this));
};

ContextModule.prototype.source = function(dependencyTemplates, outputOptions, requestShortener) {
	var map = {};
	this.dependencies.slice().sort(function(a,b) {
		if(a.userRequest == b.userRequest) return 0;
		return a.userRequest < b.userRequest ? -1 : 1;
	}).forEach(function(dep) {
		if(dep.module)
			map[dep.userRequest] = dep.module.id
	});
	var str = [
		"var map = ", JSON.stringify(map, null, "\t"), ";\n",
		"function webpackContext(req) {\n",
		"\treturn require(webpackContextResolve(req));\n",
		"};\n",
		"function webpackContextResolve(req) {\n",
		"\treturn map[req] || (function() { throw new Error(\"Cannot find module '\" + req + \"'.\") }());\n",
		"};\n",
		"webpackContext.keys = function webpackContextKeys() {\n",
		"\treturn Object.keys(map);\n",
		"};\n",
		"webpackContext.resolve = webpackContextResolve;\n",
		"module.exports = webpackContext;\n",
	];
	return new RawSource(str.join(""));
};

ContextModule.prototype.size = function() {
	return this.dependencies.map(function(dep) {
		return dep.userRequest.length + 5;
	}).reduce(function(a, b) { return a+b; }, 160);
};