define([
  'angular',
  'lodash',
  'config',
  'kbn',
  'moment',
  './queryBuilder',
  './queryCtrl',
  './directives'
],
function (angular, _, config, kbn, moment, ElasticQueryBuilder) {
  'use strict';

  var module = angular.module('grafana.services');

  module.factory('ElasticDatasource', function($q, backendSrv, templateSrv) {

    function ElasticDatasource(datasource) {
      this.type = 'elasticsearch';
      this.basicAuth = datasource.basicAuth;
      this.url = datasource.url;
      this.name = datasource.name;
      this.index = datasource.index;
      this.searchMaxResults = config.search.max_results || 20;

      this.saveTemp = _.isUndefined(datasource.save_temp) ? true : datasource.save_temp;
      this.saveTempTTL = _.isUndefined(datasource.save_temp_ttl) ? '30d' : datasource.save_temp_ttl;
    }

    ElasticDatasource.prototype._request = function(method, url, index, data) {
      var options = {
        url: this.url + "/" + index + url,
        method: method,
        data: data
      };

      if (this.basicAuth) {
        options.withCredentials = true;
        options.headers = {
          "Authorization": this.basicAuth
        };
      }

      return backendSrv.datasourceRequest(options);
    };

    ElasticDatasource.prototype._get = function(url) {
      return this._request('GET', url, this.index)
        .then(function(results) {
          return results.data;
        });
    };

    ElasticDatasource.prototype._post = function(url, data) {
      return this._request('POST', url, this.index, data)
        .then(function(results) {
          return results.data;
        });
    };

    ElasticDatasource.prototype.annotationQuery = function(annotation, rangeUnparsed) {
      var range = {};
      var timeField = annotation.timeField || '@timestamp';
      var queryString = annotation.query || '*';
      var tagsField = annotation.tagsField || 'tags';
      var titleField = annotation.titleField || 'desc';
      var textField = annotation.textField || null;

      range[timeField]= {
        from: rangeUnparsed.from,
        to: rangeUnparsed.to,
      };

      var queryInterpolated = templateSrv.replace(queryString);
      var filter = { "bool": { "must": [{ "range": range }] } };
      var query = { "bool": { "should": [{ "query_string": { "query": queryInterpolated } }] } };
      var data = {
        "fields": [timeField, "_source"],
        "query" : { "filtered": { "query" : query, "filter": filter } },
        "size": 10000
      };

      return this._request('POST', '/_search', annotation.index, data).then(function(results) {
        var list = [];
        var hits = results.data.hits.hits;

        var getFieldFromSource = function(source, fieldName) {
          if (!fieldName) { return; }

          var fieldNames = fieldName.split('.');
          var fieldValue = source;

          for (var i = 0; i < fieldNames.length; i++) {
            fieldValue = fieldValue[fieldNames[i]];
            if (!fieldValue) {
              console.log('could not find field in annotatation: ', fieldName);
              return '';
            }
          }

          if (_.isArray(fieldValue)) {
            fieldValue = fieldValue.join(', ');
          }
          return fieldValue;
        };

        for (var i = 0; i < hits.length; i++) {
          var source = hits[i]._source;
          var fields = hits[i].fields;
          var time = source[timeField];

          if (_.isString(fields[timeField]) || _.isNumber(fields[timeField])) {
            time = fields[timeField];
          }

          var event = {
            annotation: annotation,
            time: moment.utc(time).valueOf(),
            title: getFieldFromSource(source, titleField),
            tags: getFieldFromSource(source, tagsField),
            text: getFieldFromSource(source, textField)
          };

          list.push(event);
        }
        return list;
      });
    };

    ElasticDatasource.prototype.testDatasource = function() {
      var query = JSON.stringify();
      return this._post('/_search?search_type=count', query).then(function() {
        return { status: "success", message: "Data source is working", title: "Success" };
      });
    };

    ElasticDatasource.prototype.query = function(options) {
      var queryBuilder = new ElasticQueryBuilder;
      var query = queryBuilder.build(options.targets);
      query = query.replace(/\$interval/g, options.interval);
      query = query.replace(/\$rangeFrom/g, options.range.from);
      query = query.replace(/\$rangeTo/g, options.range.to);
      query = query.replace(/\$maxDataPoints/g, options.maxDataPoints);
      query = templateSrv.replace(query, options.scopedVars);
      return this._post('/_search?search_type=count', query).then(this._getTimeSeries);
    };

    ElasticDatasource.prototype._getTimeSeries = function(results) {
      var _aggregation2timeSeries = function(aggregation) {
        var datapoints = aggregation.date_histogram.buckets.map(function(entry) {
          return [entry.stats.avg, entry.key];
        });
        return { target: aggregation.key, datapoints: datapoints };
      };
      var data = [];

      if (results && results.aggregations) {
        for (var target in results.aggregations) {
          if (!results.aggregations.hasOwnProperty(target)) {
            continue;
          }
          if (results.aggregations[target].date_histogram && results.aggregations[target].date_histogram.buckets) {
            data.push(_aggregation2timeSeries(results.aggregations[target]));
          } else if (results.aggregations[target].terms && results.aggregations[target].terms.buckets) {
            [].push.apply(data, results.aggregations[target].terms.buckets.map(_aggregation2timeSeries));
          }
        }
      }
      return { data: data };
    };

    return ElasticDatasource;
  });
});