import * as plugins from './plugins.js';
import * as interfaces from './interfaces/index.js';
import { DockerHost } from './classes.host.js';
import { logger } from './logger.js';

/**
 * represents a docker image on the remote docker host
 */
export class DockerImage {
  // STATIC
  public static async getImages(dockerHost: DockerHost) {
    const images: DockerImage[] = [];
    const response = await dockerHost.request('GET', '/images/json');
    for (const imageObject of response.body) {
      images.push(new DockerImage(dockerHost, imageObject));
    }
    return images;
  }

  public static async getImageByName(dockerHost: DockerHost, imageNameArg: string) {
    const images = await this.getImages(dockerHost);
    const result = images.find((image) => {
      if (image.RepoTags) {
        return image.RepoTags.includes(imageNameArg);
      } else {
        return false;
      }
    });
    return result;
  }

  public static async createFromRegistry(
    dockerHostArg: DockerHost,
    optionsArg: {
      creationObject: interfaces.IImageCreationDescriptor
    }
  ): Promise<DockerImage> {
    // lets create a sanatized imageUrlObject
    const imageUrlObject: {
      imageUrl: string;
      imageTag: string;
      imageOriginTag: string;
    } = {
      imageUrl: optionsArg.creationObject.imageUrl,
      imageTag: optionsArg.creationObject.imageTag,
      imageOriginTag: null,
    };
    if (imageUrlObject.imageUrl.includes(':')) {
      const imageUrl = imageUrlObject.imageUrl.split(':')[0];
      const imageTag = imageUrlObject.imageUrl.split(':')[1];
      if (imageUrlObject.imageTag) {
        throw new Error(
          `imageUrl ${imageUrlObject.imageUrl} can't be tagged with ${imageUrlObject.imageTag} because it is already tagged with ${imageTag}`
        );
      } else {
        imageUrlObject.imageUrl = imageUrl;
        imageUrlObject.imageTag = imageTag;
      }
    } else if (!imageUrlObject.imageTag) {
      imageUrlObject.imageTag = 'latest';
    }
    imageUrlObject.imageOriginTag = `${imageUrlObject.imageUrl}:${imageUrlObject.imageTag}`;

    // lets actually create the image
    const response = await dockerHostArg.request(
      'POST',
      `/images/create?fromImage=${encodeURIComponent(
        imageUrlObject.imageUrl
      )}&tag=${encodeURIComponent(imageUrlObject.imageTag)}`
    );
    if (response.statusCode < 300) {
      logger.log('info', `Successfully pulled image ${imageUrlObject.imageUrl} from the registry`);
      const image = await DockerImage.getImageByName(dockerHostArg, imageUrlObject.imageOriginTag);
      return image;
    } else {
      logger.log('error', `Failed at the attempt of creating a new image`);
    }
  }

  /**
   * 
   * @param dockerHostArg
   * @param tarStreamArg
   */
  public static async createFromTarStream(
    dockerHostArg: DockerHost,
    optionsArg: {
      creationObject: interfaces.IImageCreationDescriptor;
      tarStream: plugins.smartstream.stream.Readable;
    }
  ): Promise<DockerImage> {
    // Start the request for importing an image
    const response = await dockerHostArg.requestStreaming(
      'POST',
      '/images/load',
      optionsArg.tarStream
    );

    /**
     * Docker typically returns lines like:
     * {"stream":"Loaded image: myrepo/myimage:latest"}
     *
     * So we will collect those lines and parse out the final image name.
     */
    let rawOutput = '';
    response.on('data', (chunk) => {
      rawOutput += chunk.toString();
    });

    // Wrap the end event in a Promise for easier async/await usage
    await new Promise<void>((resolve, reject) => {
      response.on('end', () => {
        resolve();
      });
      response.on('error', (err) => {
        reject(err);
      });
    });

    // Attempt to parse each line to find something like "Loaded image: ..."
    let loadedImageTag: string | undefined;
    const lines = rawOutput.trim().split('\n').filter(Boolean);

    for (const line of lines) {
      try {
        const jsonLine = JSON.parse(line);
        if (
          jsonLine.stream &&
          (jsonLine.stream.startsWith('Loaded image:') ||
            jsonLine.stream.startsWith('Loaded image ID:'))
        ) {
          // Examples:
          // "Loaded image: your-image:latest"
          // "Loaded image ID: sha256:...."
          loadedImageTag = jsonLine.stream
            .replace('Loaded image: ', '')
            .replace('Loaded image ID: ', '')
            .trim();
        }
      } catch {
        // not valid JSON, ignore
      }
    }

    if (!loadedImageTag) {
      throw new Error(
        `Could not parse the loaded image info from Docker response.\nResponse was:\n${rawOutput}`
      );
    }

    // Now try to look up that image by the "loadedImageTag".
    // Depending on Docker’s response, it might be something like:
    //   "myrepo/myimage:latest"  OR  "sha256:someHash..."
    // If Docker gave you an ID (e.g. "sha256:..."), you may need a separate
    // DockerImage.getImageById method; or if you prefer, you can treat it as a name.
    const newlyImportedImage = await DockerImage.getImageByName(dockerHostArg, loadedImageTag);

    if (!newlyImportedImage) {
      throw new Error(
        `Image load succeeded, but no local reference found for "${loadedImageTag}".`
      );
    }

    logger.log(
      'info',
      `Successfully imported image "${loadedImageTag}".`
    );

    return newlyImportedImage;
  }


  public static async tagImageByIdOrName(
    dockerHost: DockerHost,
    idOrNameArg: string,
    newTagArg: string
  ) {
    const response = await dockerHost.request(
      'POST',
      `/images/${encodeURIComponent(idOrNameArg)}/${encodeURIComponent(newTagArg)}`
    );


  }

  public static async buildImage(dockerHostArg: DockerHost, dockerImageTag) {
    // TODO: implement building an image
  }

  // INSTANCE
  // references
  public dockerHost: DockerHost;

  // properties
  /**
   * the tags for an image
   */
  public Containers: number;
  public Created: number;
  public Id: string;
  public Labels: interfaces.TLabels;
  public ParentId: string;
  public RepoDigests: string[];
  public RepoTags: string[];
  public SharedSize: number;
  public Size: number;
  public VirtualSize: number;

  constructor(dockerHostArg, dockerImageObjectArg: any) {
    this.dockerHost = dockerHostArg;
    Object.keys(dockerImageObjectArg).forEach((keyArg) => {
      this[keyArg] = dockerImageObjectArg[keyArg];
    });
  }

  /**
   * tag an image
   * @param newTag
   */
  public async tagImage(newTag) {
    throw new Error('.tagImage is not yet implemented');
  }

  /**
   * pulls the latest version from the registry
   */
  public async pullLatestImageFromRegistry(): Promise<boolean> {
    const updatedImage = await DockerImage.createFromRegistry(this.dockerHost, {
      creationObject: {
        imageUrl: this.RepoTags[0],
      },
    });
    Object.assign(this, updatedImage);
    // TODO: Compare image digists before and after
    return true;
  }

  // get stuff
  public async getVersion() {
    if (this.Labels && this.Labels.version) {
      return this.Labels.version;
    } else {
      return '0.0.0';
    }
  }

  /**
   * exports an image to a tar ball
   */
  public async exportToTarStream(): Promise<plugins.smartstream.stream.Readable> {
    logger.log('info', `Exporting image ${this.RepoTags[0]} to tar stream.`);
    const response = await this.dockerHost.requestStreaming('GET', `/images/${encodeURIComponent(this.RepoTags[0])}/get`);
    let counter = 0;
    const webduplexStream = new plugins.smartstream.SmartDuplex({
      writeFunction: async (chunk, tools) => {
        if (counter % 1000 === 0)
          console.log(`Got chunk: ${counter}`);
        counter++;
        return chunk;
      }
    });
    response.on('data', (chunk) => {
      if (!webduplexStream.write(chunk)) {
        response.pause();
        webduplexStream.once('drain', () => {
          response.resume();
        })
      };
    });
    response.on('end', () => {
      webduplexStream.end();
    })
    return webduplexStream;
  }
}