import {S3} from "aws-sdk";

const AWS = require('aws-sdk');
const path = require("path");
const fs = require('fs');

export interface S3AdapterOptions {
  accessKeyId?: string,
  secretAccessKey?: string,
  endpoint?: string,
  region?: string,
  bucketName: string
}

export class S3Adapter {
  options: S3AdapterOptions;
  S3: S3;

  isReady = true;

  constructor(options: S3AdapterOptions) {
    this.options = Object.assign(options, process.env);

    if (!this.options.bucketName) {
      this.isReady = false;
    } else {

      let awsConfiguration: S3.Types.ClientConfiguration = {};
      if (!!this.options.accessKeyId && !!this.options.secretAccessKey) {
        awsConfiguration = {
          accessKeyId: this.options.accessKeyId,
          secretAccessKey: this.options.secretAccessKey
        }
      } else {
        console.warn('No AccessKey and SecretAccessKey passed. Implicit authorization from AWS is used.');
      }

      if (!!this.options.endpoint) {
        awsConfiguration.endpoint = this.options.endpoint;
        console.info('Overriding S3 endpoint to ' + awsConfiguration.endpoint);
      }
      if (!!this.options.region) {
        awsConfiguration.region = this.options.region;
        console.info('Region is set to ' + awsConfiguration.region);
      }

      this.S3 = new AWS.S3(awsConfiguration);
    }
  }

  uploadFile(fileName, targetPath) {
    fs.readFile(fileName, (err, data) => {
      if (err) {
        throw err;
      }
      const params = {
        Bucket: this.options.bucketName,
        Key: targetPath,
        Body: data
      };
      this.S3.upload(params, function (s3Err, data) {
        if (s3Err) {
          throw s3Err
        }
      });
    });
  };

  getFile(directory) {
    return new Promise<any>(async (resolve, reject) => {
      this.S3.getObject({
        Bucket: this.options.bucketName,
        Key: directory
      }, (err, data) => {
        if (err) {
          return reject(err);
        }

        resolve(data.Body);
      });
    });
  }

  async fileExists(fileName) {
    const files = await this.listFiles(fileName);

    return files.length > 0;
  }


  async listFiles(directory): Promise<{ size: number, key: string }[]> {
    return new Promise<any>(async (resolve, reject) => {
      this.S3.listObjectsV2({
        Bucket: this.options.bucketName,
        Prefix: directory + '/'
      }, (err, data) => {
        if (err) {
          console.error('Unable to fetch from AWS S3.listObjectsV2.', err);
          return reject(null);
        }
        resolve(data.Contents.map(e => ({key: e.Key, size: e.Size})));

      });
    });
  }

  async downloadDirectory(s3path, localPath) {

    const files = await this.listFiles(s3path);
    let size = 0;
    for (const file of files) {
      size += file.size;
    }

    console.log(`Downloading ${files.length} files (${(size / 1024).toFixed(1)}kb) from distributed cache...`);

    for (const file of files) {
      const content = await this.getFile(file.key);
      let writeFile = localPath + '/' + file.key;
      const writePath = writeFile.substring(0, writeFile.lastIndexOf('/'));

      try {
        fs.mkdirSync(writePath, {recursive: true})
        fs.writeFileSync(writeFile, content)
      } catch (e) {
        console.log(e)
      }
    }
  }

  files = [];

  directoryList(Directory) {
    fs.readdirSync(Directory).forEach(File => {
      const Absolute = path.join(Directory, File);
      if (fs.statSync(Absolute).isDirectory()) {
        return this.directoryList(Absolute);
      } else {
        return this.files.push(Absolute);
      }
    });
  }

  async uploadDir(s3Path, hash) {
    this.files = [];

    this.directoryList(s3Path);

    const uploads = this.files.map(filePath => {
      let bucketPath = filePath.substring(s3Path.length + 1);
      return {Bucket: this.options.bucketName + '/' + hash, Key: bucketPath, Body: fs.readFileSync(filePath)};
    })

    console.log('Files found', uploads.length);

    return Promise.all(uploads.map(upload => {
      return new Promise<any>(async (resolve, reject) => {

        this.S3.putObject(upload, (err, data) => {
          if (err) {
            console.log(err);
            reject(err);
          }
          resolve(upload.Key)
        });
      });
    }))
  };
}