activator/lib/filesdriver.js

simple user activation and password reset for nodejs

/*jslint node:true, nomen:true, unused:vars */
var fs = require('fs'), _ = require('lodash'), async = require('async'), PATH = __dirname+'/templates', EXPIRY = 60,


// keep a cache of templates
mails = {};


module.exports = function (p) {
	var path = p || PATH;
	
	return function (type,lang,callback) {
		// build our list from most specific to least-specific
		var now = new Date().getTime(), found = false, list = _.reduce(
				(lang||"").split('_'),
				function(result,item){
					result.push(  result.length === 0 ? item : [].concat(result[result.length-1],item).join("_") ); 
					return(result);},
				[]).reverse();
		// default case
		list.push("");
		
		// need to get the mail from filesystem if not cached already
		// however, we must be careful of the fallback
		// e.g. we once sent an email with no matching lang, e.g. he_IL, so the default (item="") was found and cached
		// now we look for a different lang, e.g. fr_FR. Since we never looked for it, we will not have it in the cache,
		//   but we *will* have the default (item=""), which would cause us not to look for fr_FR on the filesystem
		// so it is important that we check not only "is it in the cache", but "did we ever look for it"
		// our logic is:
		// 1- go from most-specific (fr_FR) to less specific (fr) to default ("")
		// 2- with each one, if it is cached use it
		// 3- if it is not cached but also was not found on the filesystem, go to the next
		// essentially, we need a system to track which ones we searched for and when
		mails[type] = mails[type] || {};
		// look for each type in reverse order
		_.each(list,function (item) {
			// first, if it is not found at all, then we never searched for it, so go back
			if (!mails[type][item]) {
				found = false;
				return(false);
			} else if (!mails[type][item].notfound && mails[type][item].expired > now) {
				// so we searched for it. if it was found and is not expired, used it
				found = mails[type][item];
				return(false);
			}
			// else either it is expired, or it was notfound, so keep looking for the next less-specific down the line
		});
		// did we find an answer?
		if (found) {
			callback(null,found);
		} else {
			fs.readdir(path,function (err,files) {
				var actuals = [];
				if (err) {
					callback("missingmailfiles");
				} else {
					_.each(list,function (item) {
						var fileName = type+(item?'_'+item:''), txtName = fileName + '.txt', htmlName = fileName + '.html';
						if (_.includes(files,fileName)) {
							actuals.push({name:item,type:"text",path:path+'/'+fileName});
						} else if (_.includes(files,txtName)) {
							actuals.push({name:item,type:"text",path:path+'/'+txtName});
						}
						if (_.includes(files,htmlName)) {
							actuals.push({name:item,type:"html",path:path+'/'+htmlName});
						}
					});
					// actuals now contains the actual file names we have
					async.each(actuals,
						function(item,cb) {
							fs.readFile(item.path,'utf8',function (err,data) {
								if (data) {
									data = data.replace(/\r\n/g,'\n');
									data = data.match(/^([^\n]*)\n[^\n]*\n((.|\n)*)/m);
									mails[type][item.name] = mails[type][item.name] || {};
									mails[type][item.name][item.type] = {
										subject: data[1],
										content: data[2]
									};
									mails[type][item.name].expired = now + EXPIRY*60*1000;
									cb();
								} else {
									mails[type][item.name] = {
										notfound: true,
										expired : now + EXPIRY*60*1000
									};
									cb();
								}
							});
						},
						function (err) {
							// there should be no errors, we should just be complete
							_.each(list,function (item) {
								if (mails[type][item] && mails[type][item].expired > now) {
									found = mails[type][item];
									return(false);
								}
							});
							// did we find an answer?
							callback(null,found);
						}
					);
				}
			});
		}
	};
};