/*!

* Versioned cache manifest and versioned resources index files builder

* ====================================================================

* WebApp Bootloader

* =================

* Copyright 2012, Eyal Weiss

* This may be freely distributed under the MIT license.

*/

var fs = require('fs'),

crypto = require('crypto');

var writeManifest = function (baseDir, src, dest, callback) {

fs.readFile(baseDir + src, function (err, data) {

var template = data.toString();

var filesStartIdx = template.indexOf('#{versioned.resources_list:') + 27;

var filesStr = template.substr(filesStartIdx);

var filesEndIdx = filesStr.indexOf('#}');

filesStr = filesStr.substr(0, filesEndIdx);

var files = filesStr.trim().split('\n').map(function(s){ return s.trim(); });

template = template.substring(0, filesStartIdx - 27) + filesStr.trim() + template.substring(filesStartIdx + filesEndIdx + 2);

var concatFiles = function(files, callback, str){

str = str || '';

var resource = files.shift();

if (resource) {

fs.readFile(baseDir + '/' + resource, function (err, data) {

if (err) {

console.log('Error during reading file ' + resource, err);

} else {

}

str += baseDir + '/' + resource + '=[' + (data || '') + '];';

concatFiles(files, callback, str);

});

} else {

callback(str);

}

};

concatFiles(files, function(data){

var hash = crypto.createHash('md5').update(data.toString()).digest("hex");

var manifestStr = template.replace(/{versioned.hash}/g, hash);

fs.writeFile(baseDir + '/' + dest, manifestStr, function (err) {

callback && callback(err, manifestStr, hash);

});

});

});

};

var versionResources = function (baseDir, dest, files, result, callback) {

var resource = files.shift();

result = result || [];

if (resource) {

fs.readFile(baseDir + '/' + resource.url, function (err, data) {

if (err) {

console.log('Error during reading file ' + resource.url, err);

resource.ver = '';

} else {

var hash = crypto.createHash('md5').update(data.toString()).digest("hex");

resource.ver = hash;

}

result.push(resource);

versionResources(baseDir, dest, files, result, callback);

});

} else {

var resData = {resources: result};

fs.writeFile(baseDir + '/' + dest, JSON.stringify(resData), function (err) {

callback && callback(err, resData);

});

}

};

/*

options argument:

{

files: {...},

baseDir: './assets',

dest: 'resources.json',

manifestSrc: '../cache.manifest.template',

manifestDest: 'cache.manifest'

}

*/

module.exports = function (options) {

this.write = function (callback) {

writeManifest(options.baseDir, options.manifestSrc, options.manifestDest, function(err1, manifestStr){

versionResources(options.baseDir, options.dest, options.files, [], function(err2, resData){

callback && callback(err1 || err2, manifestStr, resData);

});

});

};

};