define([
  'angular',
  'underscore',
  'kbn',
  './influxSeries'
],
function (angular, _, kbn, InfluxSeries) {
  'use strict';

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

  module.factory('InfluxDatasource', function($q, $http) {

    function InfluxDatasource(datasource) {
      this.type = 'influxDB';
      this.editorSrc = 'app/partials/influxdb/editor.html';
      this.urls = datasource.urls;
      this.username = datasource.username;
      this.password = datasource.password;
      this.name = datasource.name;
      this.templateSettings = {
        interpolate : /\[\[([\s\S]+?)\]\]/g,
      };
    }

    InfluxDatasource.prototype.query = function(filterSrv, options) {
      var promises = _.map(options.targets, function(target) {
        var query;
        var alias = '';

        if (target.hide || !((target.series && target.column) || target.query)) {
          return [];
        }

        var timeFilter = getTimeFilter(options);
        var groupByField;

        if (target.rawQuery) {
          query = target.query;
          query = query.replace(";", "");
          var queryElements = query.split(" ");
          var lowerCaseQueryElements = query.toLowerCase().split(" ");
          var whereIndex = lowerCaseQueryElements.indexOf("where");
          var groupByIndex = lowerCaseQueryElements.indexOf("group");
          var orderIndex = lowerCaseQueryElements.indexOf("order");

          if (lowerCaseQueryElements[1].indexOf(',') !== -1) {
            groupByField = lowerCaseQueryElements[1].replace(',', '');
          }

          if (whereIndex !== -1) {
            queryElements.splice(whereIndex + 1, 0, timeFilter, "and");
          }
          else {
            if (groupByIndex !== -1) {
              queryElements.splice(groupByIndex, 0, "where", timeFilter);
            }
            else if (orderIndex !== -1) {
              queryElements.splice(orderIndex, 0, "where", timeFilter);
            }
            else {
              queryElements.push("where");
              queryElements.push(timeFilter);
            }
          }

          query = queryElements.join(" ");
          query = filterSrv.applyTemplateToTarget(query);
        }
        else {

          var template = "select [[group]][[group_comma]] [[func]]([[column]]) from [[series]] " +
                         "where  [[timeFilter]] [[condition_add]] [[condition_key]] [[condition_op]] [[condition_value]] " +
                         "group by time([[interval]])[[group_comma]] [[group]] order asc";

          var templateData = {
            series: target.series,
            column: target.column,
            func: target.function,
            timeFilter: timeFilter,
            interval: target.interval || options.interval,
            condition_add: target.condition_filter ? 'and' : '',
            condition_key: target.condition_filter ? target.condition_key : '',
            condition_op: target.condition_filter ? target.condition_op : '',
            condition_value: target.condition_filter ? target.condition_value : '',
            group_comma: target.groupby_field_add && target.groupby_field ? ',' : '',
            group: target.groupby_field_add ? target.groupby_field : '',
          };

          if(!templateData.series.match('^/.*/')) {
            templateData.series = '"' + templateData.series + '"';
          }

          query = _.template(template, templateData, this.templateSettings);
          query = filterSrv.applyTemplateToTarget(query);

          if (target.groupby_field_add) {
            groupByField = target.groupby_field;
          }

          target.query = query;
        }

        if (target.alias) {
          alias = filterSrv.applyTemplateToTarget(target.alias);
        }

        var handleResponse = _.partial(handleInfluxQueryResponse, alias, groupByField);
        return this.doInfluxRequest(query, alias).then(handleResponse);

      }, this);

      return $q.all(promises).then(function(results) {
        return { data: _.flatten(results) };
      });

    };

    InfluxDatasource.prototype.listColumns = function(seriesName) {
      return this.doInfluxRequest('select * from /' + seriesName + '/ limit 1').then(function(data) {
        if (!data) {
          return [];
        }
        return data[0].columns;
      });
    };

    InfluxDatasource.prototype.listSeries = function() {
      return this.doInfluxRequest('select * from /.*/ limit 1').then(function(data) {
        return _.map(data, function(series) {
          return series.name;
        });
      });
    };

    InfluxDatasource.prototype.metricFindQuery = function (filterSrv, query) {
      var interpolated;
      try {
        interpolated = filterSrv.applyTemplateToTarget(query);
      }
      catch (err) {
        return $q.reject(err);
      }

      return this.doInfluxRequest(interpolated)
        .then(function (results) {
          return _.map(results[0].points, function (metric) {
            return {
              text: metric[1],
              expandable: false
            };
          });
        });
    };

    function retry(deferred, callback, delay) {
      return callback().then(undefined, function(reason) {
        if (reason.status !== 0 || reason.status >= 300) {
          deferred.reject(reason);
        }
        else {
          setTimeout(function() {
            return retry(deferred, callback, Math.min(delay * 2, 30000));
          }, delay);
        }
      });
    }

    InfluxDatasource.prototype.doInfluxRequest = function(query) {
      var _this = this;
      var deferred = $q.defer();

      retry(deferred, function() {
        var currentUrl = _this.urls.shift();
        _this.urls.push(currentUrl);

        var params = {
          u: _this.username,
          p: _this.password,
          time_precision: 's',
          q: query
        };

        var options = {
          method: 'GET',
          url:    currentUrl + '/series',
          params: params,
        };

        return $http(options).success(function (data) {
          deferred.resolve(data);
        });
      }, 10);

      return deferred.promise;
    };

    function handleInfluxQueryResponse(alias, groupByField, seriesList) {
      var influxSeries = new InfluxSeries({
        seriesList: seriesList,
        alias: alias,
        groupByField: groupByField
      });

      return influxSeries.getTimeSeries();
    }

    function getTimeFilter(options) {
      var from = getInfluxTime(options.range.from);
      var until = getInfluxTime(options.range.to);

      if (until === 'now()') {
        return 'time > now() - ' + from;
      }

      return 'time > ' + from + ' and time < ' + until;
    }

    function getInfluxTime(date) {
      if (_.isString(date)) {
        if (date === 'now') {
          return 'now()';
        }
        else if (date.indexOf('now') >= 0) {
          return date.substring(4);
        }

        date = kbn.parseDate(date);
      }

      return to_utc_epoch_seconds(date);
    }

    function to_utc_epoch_seconds(date) {
      return (date.getTime() / 1000).toFixed(0) + 's';
    }

    return InfluxDatasource;

  });

});