///<reference path="../../../headers/common.d.ts" />

import angular from 'angular';
import _ from 'lodash';

import * as dateMath from 'app/core/utils/datemath';
import InfluxSeries from './influx_series';
import InfluxQuery from './influx_query';

/** @ngInject */
export function InfluxDatasource(instanceSettings, $q, backendSrv, templateSrv) {
  this.type = 'influxdb';
  this.urls = _.map(instanceSettings.url.split(','), function(url) {
    return url.trim();
  });

  this.username = instanceSettings.username;
  this.password = instanceSettings.password;
  this.name = instanceSettings.name;
  this.database = instanceSettings.database;
  this.basicAuth = instanceSettings.basicAuth;
  this.interval = (instanceSettings.jsonData || {}).timeInterval;
  this.supportAnnotations = true;
  this.supportMetrics = true;

  this.query = function(options) {
    var timeFilter = getTimeFilter(options);
    var queryTargets = [];
    var i, y;

    var allQueries = _.map(options.targets, function(target) {
      if (target.hide) { return []; }

      queryTargets.push(target);

      // build query
      var queryModel = new InfluxQuery(target, templateSrv, options.scopedVars);
      var query =  queryModel.render(true);
      query = query.replace(/\$interval/g, (target.interval || options.interval));
      return query;

    }).join("\n");

    // replace grafana variables
    allQueries = allQueries.replace(/\$timeFilter/g, timeFilter);

    // replace templated variables
    allQueries = templateSrv.replace(allQueries, options.scopedVars);

    return this._seriesQuery(allQueries).then(function(data): any {
      if (!data || !data.results) {
        return [];
      }

      var seriesList = [];
      for (i = 0; i < data.results.length; i++) {
        var result = data.results[i];
        if (!result || !result.series) { continue; }

        var target = queryTargets[i];
        var alias = target.alias;
        if (alias) {
          alias = templateSrv.replace(target.alias, options.scopedVars);
        }

        var influxSeries = new InfluxSeries({ series: data.results[i].series, alias: alias });

        switch (target.resultFormat) {
          case 'table': {
            seriesList.push(influxSeries.getTable());
            break;
          }
          default: {
            var timeSeries = influxSeries.getTimeSeries();
            for (y = 0; y < timeSeries.length; y++) {
              seriesList.push(timeSeries[y]);
            }
            break;
          }
        }
      }

      return { data: seriesList };
    });
  };

  this.annotationQuery = function(options) {
    if (!options.annotation.query) {
      return $q.reject({message: 'Query missing in annotation definition'});
    }

    var timeFilter = getTimeFilter({rangeRaw: options.rangeRaw});
    var query = options.annotation.query.replace('$timeFilter', timeFilter);
    query = templateSrv.replace(query);

    return this._seriesQuery(query).then(function(data) {
      if (!data || !data.results || !data.results[0]) {
        throw { message: 'No results in response from InfluxDB' };
      }
      return new InfluxSeries({series: data.results[0].series, annotation: options.annotation}).getAnnotations();
    });
  };

  this.metricFindQuery = function (query) {
    var interpolated;
    try {
      interpolated = templateSrv.replace(query, null, 'regex');
    } catch (err) {
      return $q.reject(err);
    }

    return this._seriesQuery(interpolated).then((results) => {
      if (!results || results.results.length === 0) { return []; }

      var influxResults = results.results[0];
      if (!influxResults.series) {
        return [];
      }

      var series = influxResults.series[0];
      return _.map(series.values, (value) => {
        if (_.isArray(value)) {
          return { text: this.getValueBasedOnInfluxVersion(value) };
        } else {
          return { text: value };
        }
      });
    });
  };

  this.getValueBasedOnInfluxVersion = function(value) {
    //influxdb 0.10.0 sends the value in first position
    //influxdb 0.11.0 sends the value in second position
    return value[1] || value[0];
  };

  this._seriesQuery = function(query) {
    return this._influxRequest('GET', '/query', {q: query, epoch: 'ms'});
  };

  this.testDatasource = function() {
    return this.metricFindQuery('SHOW MEASUREMENTS LIMIT 1').then(function () {
      return { status: "success", message: "Data source is working", title: "Success" };
    });
  };

  this._influxRequest = function(method, url, data) {
    var self = this;

    var currentUrl = self.urls.shift();
    self.urls.push(currentUrl);

    var params: any = {
      u: self.username,
      p: self.password,
    };

    if (self.database) {
      params.db = self.database;
    }

    if (method === 'GET') {
      _.extend(params, data);
      data = null;
    }

    var options: any = {
      method: method,
      url:    currentUrl + url,
      params: params,
      data:   data,
      precision: "ms",
      inspect: { type: 'influxdb' },
    };

    options.headers = options.headers || {};
    if (self.basicAuth) {
      options.headers.Authorization = self.basicAuth;
    }

    return backendSrv.datasourceRequest(options).then(function(result) {
      return result.data;
    }, function(err) {
      if (err.status !== 0 || err.status >= 300) {
        if (err.data && err.data.error) {
          throw { message: 'InfluxDB Error Response: ' + err.data.error, data: err.data, config: err.config };
        } else {
          throw { message: 'InfluxDB Error: ' + err.message, data: err.data, config: err.config };
        }
      }
    });
  };

  function getTimeFilter(options) {
    var from = getInfluxTime(options.rangeRaw.from, false);
    var until = getInfluxTime(options.rangeRaw.to, true);
    var fromIsAbsolute = from[from.length-1] === 's';

    if (until === 'now()' && !fromIsAbsolute) {
      return 'time > ' + from;
    }

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

  function getInfluxTime(date, roundUp) {
    if (_.isString(date)) {
      if (date === 'now') {
        return 'now()';
      }

      var parts = /^now-(\d+)([d|h|m|s])$/.exec(date);
      if (parts) {
        var amount = parseInt(parts[1]);
        var unit = parts[2];
        return 'now() - ' + amount + unit;
      }
      date = dateMath.parse(date, roundUp);
    }
    return (date.valueOf() / 1000).toFixed(0) + 's';
  }
}