import { DockerfileService, DockerfileInfo } from './dockerfile.service';
import { Injectable } from 'angular-ts-decorators';


@Injectable(DockerfileService.name)
export class DockerfileServiceImpl implements DockerfileService {

  constructor(private DataFileService: any, private Config: any, private FileReaderFactory: () => FileReader) {

  }

  public extractDockerfile(file: any): Promise<DockerfileInfoImpl | string> {
    return new Promise((resolve, reject) => {
      // TODO: Replace callbacks with promises
    });
  }

  public getDockerfile(file: any,
                       success: (dockerfile: DockerfileInfoImpl) => void,
                       failure: (error: Event | string) => void): void {
    var reader: FileReader = this.FileReaderFactory();
    reader.onload = (event: any) => {
      this.DataFileService.readDataArrayAsPossibleArchive(event.target.result,
        (files: any[]) => {
          this.processFiles(files, success, failure);
        },
        () => {
          // Not an archive. Read directly as a single file.
          this.processFile(event.target.result, success, failure);
      });
    };

    reader.onerror = failure;
    reader.readAsArrayBuffer(file);
  }

  private processFile(dataArray: any,
                      success: (dockerfile: DockerfileInfoImpl) => void,
                      failure: (error: ErrorEvent | string) => void): void {
    this.DataFileService.arrayToString(dataArray, (contents: string) => {
      var result: DockerfileInfoImpl | null = DockerfileInfoImpl.forData(contents, this.Config);
      if (result == null) {
        failure('File chosen is not a valid Dockerfile');
      }
      else {
        success(result);
      }
    });
  }

  private processFiles(files: any[],
                       success: (dockerfile: DockerfileInfoImpl) => void,
                       failure: (error: ErrorEvent | string) => void): void {
    var found: boolean = false;
    files.forEach((file) => {
      if (file['name'] == 'Dockerfile') {
        this.DataFileService.blobToString(file.toBlob(), (contents: string) => {
          var result: DockerfileInfoImpl | null = DockerfileInfoImpl.forData(contents, this.Config);
          if (result == null) {
            failure('Dockerfile inside archive is not a valid Dockerfile');
          }
          else {
            success(result);
          }
        });
        found = true;
      }
    });

    if (!found) {
      failure('No Dockerfile found in root of archive');
    }
  }
}


export class DockerfileInfoImpl implements DockerfileInfo {

  constructor(private contents: string, private config: any) {

  }

  public static forData(contents: string, config: any): DockerfileInfoImpl | null {
    var dockerfileInfo: DockerfileInfoImpl = null;
    if (contents.indexOf('FROM ') != -1) {
      dockerfileInfo = new DockerfileInfoImpl(contents, config);
    }

    return dockerfileInfo;
  }

  public getRegistryBaseImage(): string | null {
    var baseImage = this.getBaseImage();
    if (!baseImage) {
      return null;
    }

    if (baseImage.indexOf(this.config.getDomain() + '/') != 0) {
      return null;
    }

    return baseImage.substring(this.config.getDomain().length + 1);
  }

  public getBaseImage(): string | null {
    const imageAndTag = this.getBaseImageAndTag();
    if (!imageAndTag) {
      return null;
    }

    // Note, we have to handle a few different cases here:
    // 1) someimage
    // 2) someimage:tag
    // 3) host:port/someimage
    // 4) host:port/someimage:tag
    const lastIndex: number = imageAndTag.lastIndexOf(':');
    if (lastIndex == -1) {
      return imageAndTag;
    }

    // Otherwise, check if there is a / in the portion after the split point. If so,
    // then the latter is part of the path (and not a tag).
    const afterColon: string = imageAndTag.substring(lastIndex + 1);
    if (afterColon.indexOf('/') != -1) {
      return imageAndTag;
    }

    return imageAndTag.substring(0, lastIndex);
  }

  public getBaseImageAndTag(): string | null {
    var baseImageAndTag: string = null;

    const fromIndex: number = this.contents.indexOf('FROM ');
    if (fromIndex != -1) {
      var newlineIndex: number = this.contents.indexOf('\n', fromIndex);
      if (newlineIndex == -1) {
        newlineIndex = this.contents.length;
      }

      baseImageAndTag = this.contents.substring(fromIndex + 'FROM '.length, newlineIndex).trim();
    }

    return baseImageAndTag;
  }
}