type ElSearchQuery = {
  query: {
    bool: {
      should: Array<MultiMatch>
      filter: [
        {
          term: {
            serviceLine: string
          }
        }
      ]
    },
  }
};

type ServiceLine = { serviceId: string, serviceName: string };

type ParoTag = string | { id: number, value: string };

type ProjectSize = '10 hours' | '11-30 hours' | '31-50 hours' | '51+ hours';

interface ParoElasticSearch {
  first: Array<ParoTag>;
  second: Array<ParoTag>;
  neutral: Array<ParoTag>;
  secondLeast: Array<ParoTag>;
  least: Array<ParoTag>;
  primaryServiceLine: ServiceLine;
  secondaryServiceLine: ServiceLine;
  projectSize: ProjectSize;
  queryObj: ElSearchQuery;
  formattedQuery: ElSearchQuery;
}

class ParoElasticSearchQuery implements ParoElasticSearch {

  first: Array<ParoTag>;
  second: Array<ParoTag>;
  neutral: Array<ParoTag>;
  secondLeast: Array<ParoTag>;
  least: Array<ParoTag>;
  primaryServiceLine: ServiceLine;
  secondaryServiceLine: ServiceLine;
  projectSize: ProjectSize;
  queryObj: ElSearchQuery = {
    query: {
      bool: {
        should: [],
        filter: [{
          term: {
            serviceLine: null
          }
        }],
      }
    }
  };

  constructor(private query: ParoElasticSearch) {
    this.first = query.first;
    this.second = query.second;
    this.neutral = query.neutral;
    this.secondLeast = query.secondLeast;
    this.least = query.least;
    this.primaryServiceLine = query.primaryServiceLine;
    this.secondaryServiceLine = query.secondaryServiceLine;
    this.projectSize = query.projectSize;
  }

  private _buildMultiMatch(tag: ParoTag, boost: number): MultiMatch {
    return {
      multi_match: {
        query: (typeof tag === 'string' ? tag : tag.value),
        boost: boost,
        fields: [
          'strengths',
          'projects.tags',
          'projects.company.name',
          'projects.description'
        ]
      }
    };
  }

  private get _formatQueryObject(): ElSearchQuery {

    (this.first || []).map(tag => this.queryObj.query.bool.should.push(this._buildMultiMatch(tag, 5)));
    (this.second || []).map(tag => this.queryObj.query.bool.should.push(this._buildMultiMatch(tag, 4)));
    (this.neutral || []).map(tag => this.queryObj.query.bool.should.push(this._buildMultiMatch(tag, 3)));
    (this.secondLeast || []).map(tag => this.queryObj.query.bool.should.push(this._buildMultiMatch(tag, 2)));
    (this.least || []).map(tag => this.queryObj.query.bool.should.push(this._buildMultiMatch(tag, 1)));

    if (this.primaryServiceLine) {
      const [ primaryServiceLine ] = this.queryObj.query.bool.filter;
      primaryServiceLine.term.serviceLine = this.primaryServiceLine.serviceName;
    }

    if (this.secondaryServiceLine) {
      this.queryObj.query.bool.should.push(this._buildMultiMatch(this.secondaryServiceLine.serviceName, 5));
    }

    if (this.projectSize) {
      this.queryObj.query.bool.should.push(this._buildMultiMatch(this.projectSize, 5));
    }

    return this.queryObj;

  }

  /**
   * returns the formatted elasticsearch query
   */
  get formattedQuery() {
    return this._formatQueryObject;
  }

}