'use strict';
var when = require('when');
var _    = require('underscore');

module.exports = function (markers) {
	function replace(text, marker, getReplacement, once) {
		var deferred = when.defer();
		var regExp   = new RegExp(markers.prefix + marker + markers.postfix, 'gmi');
		var matches  = text && text.match && text.match(regExp);
		if (matches) {
			if (once) {
				matches = [matches[0]];
			}
			var match_promises = [];
			_.forEach(matches, function handleMatch(result) {
				var deferred2 = when.defer();
				match_promises.push(deferred2.promise);
				getReplacement(result, function resolveReplacement(err, replacement) {
					if (err) {
						deferred2.reject(err);
					} else {
						var replace_result = {
							regExp:      replacement.regExp || regExp,
							replacement: replacement.value
						};
						deferred2.resolve(replace_result);
					}
				});
			});
			when.all(match_promises).then(
				function onSuccess(results) {
					deferred.resolve(results);
				},
				function onFailure(err) {
					deferred.reject(err);
				}
			);
		} else {
			deferred.resolve({});
		}
		return deferred.promise;
	}

	function handTextManipulation(text, promises, handler, callback) {
		when.all(promises).then(
			function onSuccess(all_results) {
				try {
					_.forEach(all_results, function loopResults(results) {
						_.forEach(results, function handleResult(result) {
							text = handler(text, result);
						});
					});
				} catch (e) {
					return callback && callback(e);
				}
				return callback && callback(null, text);
			},
			function onFailure(err) {
				return callback && callback(err);
			}
		);
	}

	return {
		replace:              replace,
		handTextManipulation: handTextManipulation
	};
};