ghostfolio/apps/api/src/models/rules/currency-cluster-risk/current-investment.ts

import { Rule } from '@ghostfolio/api/models/rule';
import type { ExchangeRateDataService } from '@ghostfolio/api/services/exchange-rate-data/exchange-rate-data.service';
import type { I18nService } from '@ghostfolio/api/services/i18n/i18n.service';
import type {
  PortfolioPosition,
  RuleSettings
} from '@ghostfolio/common/interfaces';

export class CurrencyClusterRiskCurrentInvestment extends Rule<Settings> {
  private holdings: PortfolioPosition[];
  private i18nService: I18nService;

  public constructor({
    exchangeRateDataService,
    holdings,
    i18nService,
    languageCode
  }: {
    exchangeRateDataService: ExchangeRateDataService;
    holdings: PortfolioPosition[];
    i18nService: I18nService;
    languageCode: string;
  }) {
    super({
      exchangeRateDataService,
      languageCode,
      key: 'CurrencyClusterRiskCurrentInvestment'
    });

    this.holdings = holdings;
    this.i18nService = i18nService;
  }

  public evaluate(ruleSettings: Settings) {
    const holdingsGroupedByCurrency = this.groupCurrentHoldingsByAttribute(
      this.holdings,
      'assetProfile.currency',
      ruleSettings.baseCurrency
    );

    let maxItem = holdingsGroupedByCurrency[0];
    let totalValue = 0;

    holdingsGroupedByCurrency.forEach((groupItem) => {
      // Calculate total value
      totalValue += groupItem.value;

      // Find maximum
      if (groupItem.value > maxItem.value) {
        maxItem = groupItem;
      }
    });

    const maxValueRatio = maxItem?.value / totalValue || 0;

    if (maxValueRatio > ruleSettings.thresholdMax) {
      return {
        evaluation: this.i18nService.getTranslation({
          id: 'rule.currencyClusterRiskCurrentInvestment.false',
          languageCode: this.getLanguageCode(),
          placeholders: {
            currency: maxItem.groupKey as string,
            maxValueRatio: (maxValueRatio * 100).toPrecision(3),
            thresholdMax: ruleSettings.thresholdMax * 100
          }
        }),
        value: false
      };
    }

    return {
      evaluation: this.i18nService.getTranslation({
        id: 'rule.currencyClusterRiskCurrentInvestment.true',
        languageCode: this.getLanguageCode(),
        placeholders: {
          currency: maxItem.groupKey as string,
          maxValueRatio: (maxValueRatio * 100).toPrecision(3),
          thresholdMax: ruleSettings.thresholdMax * 100
        }
      }),
      value: true
    };
  }

  public getConfiguration() {
    return {
      threshold: {
        max: 1,
        min: 0,
        step: 0.01,
        unit: '%'
      },
      thresholdMax: true
    };
  }

  public getName() {
    return this.i18nService.getTranslation({
      id: 'rule.currencyClusterRiskCurrentInvestment',
      languageCode: this.getLanguageCode()
    });
  }
}

interface Settings extends RuleSettings {
  baseCurrency: string;
  thresholdMax: number;
}