import { Injectable, Logger } from '@nestjs/common';
import { Patient } from './../studies/entities/patient.entity';
import { Study } from './../studies/entities/study.entity';
import { StudiesService } from './../studies/studies.service';
import { Series } from './../studies/entities/series.entity';
import { Image } from './../studies/entities/image.entity';
import * as dicomParser from '@knopkem/dicom-parser';
import * as fs from 'fs';
import * as rra from 'recursive-readdir-async';
import * as path from 'path';

@Injectable()
export class FilesService {
  constructor(private readonly studiesService: StudiesService) {}
  logger = new Logger('FilesService');

  /**
   * Parse and import a DICOM file
   * @param filename the file path
   * @returns void
   */
  async importDicomFile(filename: string): Promise<void> {
    this.logger.verbose('importing: ' + filename);
    try {
      const data = fs.readFileSync(filename);
      const dataset = dicomParser.parseDicom(data);

      const patient = new Patient();
      patient.patientName = dataset.string('x00100010')!;
      patient.patientId = dataset.string('x00100020')!;
      patient.patientDob = dataset.string('x00100030')!;
      patient.patientSex = dataset.string('x00100040')!;

      const study = new Study();
      study.studyInstanceUid = dataset.string('x0020000d')!;
      study.studyDate = dataset.string('x00080020')!;
      study.studyTime = dataset.string('x00080030')!;
      study.studyId = dataset.string('x00200010')!;
      study.accessionNumber = dataset.string('x00080050')!;
      study.referringPhysicianName = dataset.string('x00080090')!;
      study.studyDescription = dataset.string('x00081030')!;
      study.nameOfPhysicianReadingStudy = dataset.string('x00081060')!;
      study.patientAge = dataset.string('x00101010')!;
      study.patientSize = dataset.string('x00101020')!;
      study.patientWeight = dataset.string('x00101030')!;

      const series = new Series();
      series.seriesInstanceUid = dataset.string('x0020000e')!;
      series.seriesNumber = dataset.string('x00200011')!;
      series.modality = dataset.string('x00080060')!;
      series.seriesDescription = dataset.string('x0008103e')!;
      series.seriesDate = dataset.string('x00080021')!;
      series.seriesTime = dataset.string('x00080031')!;
      series.bodyPartExamined = dataset.string('x00180015')!;
      series.patientPosition = dataset.string('x00185100')!;
      series.protocolName = dataset.string('x00181030')!;

      const image = new Image();
      image.sopInstanceUid = dataset.string('x00080018')!;
      image.sopClassUid = dataset.string('x0008,0016')!;
      image.instanceNumber = dataset.string('x00200013')!;
      image.sliceLocation = dataset.string('x00201041')!;
      image.imageType = dataset.string('x00080008')!;
      image.referencedFrameNumber = dataset.string('x00081160')!;
      image.numberOfFrames = dataset.string('x00280008')!;
      image.rows = dataset.uint16('x00280010')!;
      image.columns = dataset.uint16('x00280011')!;
      image.windowWidth = dataset.string('x00281051')!;
      image.windowCenter = dataset.string('x00281050')!;
      image.photometricInterpretation = dataset.string('x00280004')!;
      image.rescaleSlope = dataset.string('x00281053')!;
      image.rescaleIntercept = dataset.string('x00281052')!;
      image.samplesPerPixel = dataset.uint16('x00280002')!;
      image.pixelSpacing = dataset.string('x00280030')!;
      image.bitsAllocated = dataset.uint16('x00280100')!;
      image.bitsStored = dataset.uint16('x00280101')!;
      image.highBit = dataset.uint16('x00280102')!;
      image.pixelRepresentation = dataset.uint16('x00280103')!;
      image.imagePositionPatient = dataset.string('x00200032')!;
      image.imageOrientationPatient = dataset.string('x00200037')!;
      image.privateFileName = filename.replace(/\\/g, '/');

      return this.studiesService.createFromEntities(patient, study, series, image);
    } catch (error) {
      this.logger.error(error);
    }
  }

  /**
   * Run import of DICOM files from filesystem
   */
  async import() {
    {
      try {
        const directory = path.join(__filename, '../../../import');
        const files = await rra.list(directory);
        for (const file of files) {
          if (!file.isDirectory) {
            await this.importDicomFile(file.fullname);
          }
        }
      } catch (error) {
        this.logger.error(error);
      }
    }
  }
}