import { createId } from '@paralleldrive/cuid2'
import { spawn } from 'child_process';
import { ua0 } from '@futureporn/scout/ua.js'
import { PassThrough, pipeline, Readable } from 'stream';
import prettyBytes from 'pretty-bytes';
import { Upload } from "@aws-sdk/lib-storage";
import { S3Client } from "@aws-sdk/client-s3";
import 'dotenv/config'


export interface RecordArgs {
  filename?: string;
  channel: string;
  s3Client: S3Client;
  bucket: string;
  date?: string;
  inputStream: Readable;
}

interface MakeS3ClientOptions {
  accessKeyId: string;
  secretAccessKey: string;
  region: string;
  endpoint: string
}

interface getFFmpegDownloadOptions {
  url: string;
}

export default class Record {
  readonly id: string;
  private s3Client: S3Client;
  private uploadStream: PassThrough;
  private ticker?: NodeJS.Timeout;
  inputStream: Readable;
  counter: number;
  bucket: string;
  keyName: string;
  datestamp: string;
  filename?: string;
  channel: string;
  date?: string;

  constructor({ inputStream, channel, s3Client, bucket }: RecordArgs) {
    if (!inputStream) throw new Error('Record constructor was missing inputStream.');
    if (!bucket) throw new Error('Record constructor was missing bucket.');
    if (!channel) throw new Error('Record constructer was missing channel!');
    if (!s3Client) throw new Error('Record constructer was missing s3Client');
    this.inputStream = inputStream
    this.id = createId()
    this.s3Client = s3Client
    this.bucket = bucket
    this.channel = channel
    this.counter = 0
    this.datestamp = new Date().toISOString()
    this.keyName = `${this.datestamp}-${channel}-${createId()}.ts`
    this.uploadStream = new PassThrough()
  }

  makeProgressTicker() {
    this.ticker = setInterval(() => {
      console.log(`[progress] ${this.counter} bytes (aggregate) (${prettyBytes(this.counter)}) have passed through the pipeline.`)
    }, 1000 * 30)
  }


  static makeS3Client({ 
    accessKeyId, 
    secretAccessKey,
    region,
    endpoint
  }: MakeS3ClientOptions): S3Client {
    const client = new S3Client({
      endpoint,
      region,
      credentials: {
        accessKeyId,
        secretAccessKey
      }
    })
    return client
  }

  static getFFmpegDownload({ url }: getFFmpegDownloadOptions): Readable {
    

    const ffmpegProc = spawn('ffmpeg', [
      '-headers', `"User-Agent: ${ua0}"`, 
      '-i', url, 
      '-c:v', 'copy',
      '-c:a', 'copy',
      '-movflags', 'faststart',
      '-y',
      '-f', 'mpegts', 
      '-loglevel', 'quiet',
      'pipe:1'
    ], {
      // ignoring stderr is important because if not, ffmpeg will fill that buffer and node will hang
      stdio: ['pipe', 'pipe', 'ignore']
    })
    return ffmpegProc.stdout

  }
  
  
  async uploadToS3() {
  
    const target = {
      Bucket: this.bucket,
      Key: this.keyName,
      // We do this to keep TS happy. Body expects a Readable, not a ReadableStream nor a NodeJS.ReadableStream
      // Body: new Readable().wrap(this.uploadStream)
      Body: this.uploadStream
    }
    
    // greets https://stackoverflow.com/a/70159394/1004931
    try {
      const parallelUploads3 = new Upload({
        client: this.s3Client,
        partSize: 1024 * 1024 * 5,
        queueSize: 1,
        leavePartsOnError: false,
        params: target,
      });
  
  
      parallelUploads3.on("httpUploadProgress", (progress) => {
        console.log(progress)
        if (progress?.loaded) {
          console.log(`loaded ${progress.loaded} bytes (${prettyBytes(progress.loaded)})`);
        } else {
          console.log(`httpUploadProgress ${JSON.stringify(progress, null, 2)}`)
        }
      });
  
      await parallelUploads3.done();
  
    } catch (e) {
      if (e instanceof Error) {
        console.error(`while uploading a file to s3, we encountered an error`)
        throw new Error(e.message);
      } else {
        throw new Error(`error of some sort ${JSON.stringify(e, null, 2)}`)
      }
    }
  }



  async start() {
    
    this.makeProgressTicker()

    // streams setup
    this.uploadStream.on('data', (data) => {
      this.counter += data.length
    })


    // stream pipeline setup
    pipeline(
      this.inputStream,
      this.uploadStream,
      (err) => {
        if (err) {
          console.error(`pipeline errored.`)
          console.error(err)
        } else {
          console.log('pipeline succeeded.')
        }
      }
    )

    await this.uploadToS3()
    clearInterval(this.ticker)

    return {
      id: this.id,
      keyName: this.keyName,
      channel: this.channel
    }
  }

  async stop() {
    throw new Error('@todo please implement')
  }
}