// media/job/attachment-ingest.js
// Copyright (C) 2022 DTP Technologies, LLC
// License: Apache-2.0

'use strict';

const path = require('path');
const fs = require('fs');
const sharp = require('sharp');

const ATTACHMENT_IMAGE_HEIGHT = 540;

const mongoose = require('mongoose');
const { response } = require('express');
const Attachment = mongoose.model('Attachment');

const { SiteWorkerProcess } = require(path.join(__dirname, '..', '..', '..', '..', 'lib', 'site-lib'));

class AttachmentIngestJob extends SiteWorkerProcess {

  static get COMPONENT ( ) {
    return {
      name: 'attachmentIngestJob',
      slug: 'attachment-ingest-job',
    };
  }

  constructor (worker) {
    super(worker, AttachmentIngestJob.COMPONENT);
    this.processors = {
      processAttachmentSharp: this.processAttachmentSharp.bind(this),
      processAttachmentFFMPEG: this.processAttachmentFFMPEG.bind(this),
    };
  }

  async start ( ) {
    await super.start();

    this.queue = await this.getJobQueue('media');

    this.log.info('registering job processor', { queue: this.queue.name, name: 'attachment-ingest' });
    this.queue.process('attachment-ingest', 1, this.processAttachmentIngest.bind(this));
  }

  async stop ( ) {
    await super.stop();
  }

  async processAttachmentIngest (job) {
    const { attachment: attachmentService } = this.dtp.services;

    const { attachmentId } = job.data;
    this.log.info('received attachment-ingest job', { id: job.id, attachmentId });

    try {
      job.data.attachment = await attachmentService.getById(attachmentId, { withOriginal: true });

      await this.resetAttachment(job);
      await this.fetchAttachmentFile(job);
      await this.processors[job.data.processor](job);

      //TODO: emit a completion event which should cause a refresh of the
      // creator's view to display the processed attachment

    } catch (error) {
      this.log.error('failed to process attachment for ingest', { attachmentId: job.data.attachmentId, error });
      throw error;
    } finally {
      if (job.data.workPath) {
        this.log.info('removing attachment work path');
        await fs.promises.rmdir(job.data.workPath, { recursive: true, force: true });
        delete job.data.workPath;
      }
    }
  }

  async fetchAttachmentFile (job) {
    const { minio: minioService } = this.dtp.services;
    try {
      const { attachment } = job.data;

      job.data.workPath = path.join(
        process.env.DTP_ATTACHMENT_WORK_PATH,
        AttachmentIngestJob.COMPONENT.slug,
        attachment._id.toString(),
      );
  
      this.jobLog(job, 'creating work directory', { worthPath: job.data.workPath });
      await fs.promises.mkdir(job.data.workPath, { recursive: true });

      switch (attachment.original.mime) {
        case 'image/jpeg':
          job.data.origFilePath = path.join(job.data.workPath, `${attachment._id}.jpg`);
          job.data.procFilePath = path.join(job.data.workPath, `${attachment._id}.proc.jpg`);
          job.data.processor = 'processAttachmentSharp';
          job.data.sharpFormat = 'jpeg';
          job.data.sharpFormatParameters = { quality: 85 };
          break;
  
        case 'image/png':
          job.data.origFilePath = path.join(job.data.workPath, `${attachment._id}.png`);
          job.data.procFilePath = path.join(job.data.workPath, `${attachment._id}.proc.png`);
          job.data.processor = 'processAttachmentSharp';
          job.data.sharpFormat = 'png';
          job.data.sharpFormatParameters = { compression: 9 };
          break;
  
        case 'image/gif':
          job.data.origFilePath = path.join(job.data.workPath, `${attachment._id}.gif`);
          job.data.procFilePath = path.join(job.data.workPath, `${attachment._id}.proc.mp4`);
          job.data.processor = 'processAttachmentFFMPEG';
          break;
  
        case 'image/webp': // process as PNG
          job.data.origFilePath = path.join(job.data.workPath, `${attachment._id}.webp`);
          job.data.procFilePath = path.join(job.data.workPath, `${attachment._id}.proc.png`);
          job.data.processor = 'processAttachmentSharp';
          job.data.sharpFormat = 'png';
          job.data.sharpFormatParameters = { compression: 9 };
          break;
  
        default:
          throw new Error(`unsupported attachment type: ${attachment.original.mime}`);
      }

      this.jobLog(job, 'fetching attachment original file', {
        attachmentId: attachment._id,
        mime: attachment.original.mime,
        size: attachment.original.size,
        worthPath: job.data.origFilePath,
      });
      await minioService.downloadFile({
        bucket: attachment.original.bucket,
        key: attachment.original.key,
        filePath: job.data.origFilePath,
      });
    } catch (error) {
      this.log.error('failed to fetch attachment file', { attachmentId: job.data.attachmentId, error });
      throw error;
    }
  }

  async resetAttachment (job) {
    const { minio: minioService } = this.dtp.services;
    const { attachment } = job.data;

    const updateOp = { $set: { status: 'processing' } };

    if (attachment.encoded) {
      this.log.info('removing existing encoded attachment file', { file: attachment.encoded });
      await minioService.removeObject(attachment.encoded.bucket, attachment.encoded.key);
      delete attachment.encoded;
      updateOp.$unset = { encoded: '' };
    }
    
    await Attachment.updateOne({ _id: attachment._id }, updateOp);
  }

  async processAttachmentSharp (job) {
    const { attachment: attachmentService, minio: minioService } = this.dtp.services;
    const { attachment } = job.data;
    const attachmentId = attachment._id;

    const sharpImage = sharp(job.data.origFilePath);
    const metadata = await sharpImage.metadata();
    this.log.info('attachment metadata from Sharp', { attachmentId, metadata });

    let chain = sharpImage
      .clone()
      .toColorspace('srgb')
      .resize({ height: ATTACHMENT_IMAGE_HEIGHT });
    chain = chain[job.data.sharpFormat](job.data.sharpFormatParameters);
    await chain.toFile(job.data.procFilePath);

    job.data.outFileStat = await fs.promises.stat(job.data.procFilePath);

    const bucket = process.env.MINIO_ATTACHMENT_BUCKET;
    const key = attachmentService.getAttachmentKey(attachment, 'processed');

    const response = await minioService.uploadFile({
      bucket,
      key,
      filePath: job.data.procFilePath,
      metadata: {
        'Content-Type': `image/${job.data.sharpFormat}`,
        'Content-Length': job.data.outFileStat.size,
      },
    });

    await Attachment.updateOne(
      { _id: job.data.attachment._id },
      {
        $set: {
          status: 'live',
          encoded: {
            bucket,
            key,
            mime: `image/${job.data.sharpFormat}`,
            size: job.data.outFileStat.size,
            etag: response.etag,
          },
        },
      },
    );
  }

  async processAttachmentFFMPEG (job) {
    const {
      attachment: attachmentService,
      media: mediaService,
      minio: minioService,
    } = this.dtp.services;

    const { attachment } = job.data;
    const codecVideo = (process.env.DTP_GPU_ACCELERATION === 'enabled') ? 'h264_nvenc' : 'libx264';

    // generate the encoded attachment
    // Output height is 100 lines by [aspect] width with width and height being
    // padded to be divisible by 2. The video stream is given a bit rate of
    // 128Kbps, and the media is flagged for +faststart. Audio is stripped if
    // present.

    const ffmpegArgs = [
      '-y', '-i', job.data.origFilePath,
      '-vf', `scale=-1:${ATTACHMENT_IMAGE_HEIGHT},pad=ceil(iw/2)*2:ceil(ih/2)*2`,
      '-pix_fmt', 'yuv420p',
      '-c:v', codecVideo,
      '-b:v', '128k',
      '-movflags', '+faststart',
      '-an',
      job.data.procFilePath,
    ];

    this.log.debug('transcoding attachment', { ffmpegArgs });
    await mediaService.ffmpeg(ffmpegArgs);

    job.data.outFileStat = await fs.promises.stat(job.data.procFilePath);

    const bucket = process.env.MINIO_VIDEO_BUCKET;
    const key = attachmentService.getAttachmentKey(attachment, 'processed');

    this.jobLog(job, 'uploading processed media file');
    const response = await minioService.uploadFile({
      bucket, key,
      filePath: job.data.procFilePath,
      metadata: {
        'Content-Type': 'video/mp4',
        'Content-Length': job.data.outFileStat.size,
      },
    });

    await Attachment.updateOne(
      { _id: attachment._id },
      {
        $set: {
          status: 'live',
          encoded: {
            bucket,
            key,
            mime: 'video/mp4',
            size: job.data.outFileStat.size,
            etag: response.etag,
          },
        },
      },
    );
  }
}

module.exports = AttachmentIngestJob;