import {Injectable} from '@angular/core';
import {Observable} from 'rxjs';
import {map} from 'rxjs/operators';
import {BodyMeasuresSection, IntegerValueWithUnitEnum, OverallAssessmentSection} from '@nspop/gm-web-facade-api';
import {DataCardService} from '../api/data-card.service';

export interface MeasurementMidwife {
  bodyMeasuresSection?: BodyMeasuresSection;
  overallAssessmentSection?: OverallAssessmentSection;
  calculatedWeight?: number | undefined;
}

@Injectable({
  providedIn: 'root'
})
export class MeasurementService {
  public midwifeMeasurements$: Observable<MeasurementMidwife[]> = this.dataCardService.activeDataCard$.pipe(
    map((dataCard) => {
      const measurement: MeasurementMidwife = {
        bodyMeasuresSection: dataCard?.bodyMeasuresSection,
        overallAssessmentSection: dataCard?.overallAssessmentSection,
        calculatedWeight: this.calculateWeight(dataCard?.bodyMeasuresSection)
      };
      return [measurement];
    })
  );

  constructor(private dataCardService: DataCardService) {
  }

  public calculateWeight(bodyMeasuresSection?: BodyMeasuresSection): number | undefined  {
    const bodyHeightMeters: number | undefined = this.calculateHeightMeters(bodyMeasuresSection?.bodyHeight);
    const bodyMassIndex: number | undefined  = bodyMeasuresSection?.bodyMassIndex?.value;
    console.log(`measurementService calculateHeight() for bodyHeight: ${bodyHeightMeters} & bodyMassIndex ${bodyMassIndex}`);
    if (bodyHeightMeters && bodyMassIndex){
      return +(bodyMassIndex * bodyHeightMeters * bodyHeightMeters).toFixed(2);
    }
    return undefined;
  }

  private calculateHeightMeters(bodyHeight: IntegerValueWithUnitEnum | undefined): number | undefined {
    if (!bodyHeight) { return undefined; }
    else if (bodyHeight.unit === 'cm' && bodyHeight.value)
    {
      return bodyHeight.value / 100;
    }
    return bodyHeight.value;
  }
}