import {
  MetricSupplierResult,
  MetricValue,
} from '@atlassian/forge-graphql-types';
import isValidDateString from '../helpers/isValidDate';

class MetricSupplierError extends Error {}

export enum MetricSupplierValidationErrors {
  METRIC_VALUES_NOT_PROVIDED = "Can't get metric values",
  INVALID_DATE = 'Invalid date',
}

/*
    Builder class for constructing a response object for
    compass:metricSupplier Forge modules.
*/

export class MetricSupplierResponse {
  metricValues: MetricValue[];

  error: string;

  public build(): MetricSupplierResult {
    this.validate();
    return {
      metricValues: this.metricValues,
      error: this.error,
    };
  }

  public addMetricValues(
    metricValues: MetricValue[] | null,
  ): MetricSupplierResponse {
    if (metricValues === null) {
      this.error = MetricSupplierValidationErrors.METRIC_VALUES_NOT_PROVIDED;
      return this;
    }

    this.metricValues = metricValues;
    return this;
  }

  private validate(): void {
    try {
      if (this.error) {
        return;
      }
      this.validateTimestamps();
    } catch (error) {
      this.error = error.message;
      this.metricValues = undefined;
    }
  }

  private validateTimestamps(): void | never {
    if (!this.metricValues.length) {
      return;
    }

    this.metricValues.forEach((value) => {
      const validDate = isValidDateString(value.timestamp);
      if (!validDate) {
        throw new MetricSupplierError(
          MetricSupplierValidationErrors.INVALID_DATE,
        );
      }
    });
  }
}