import { Readable } from 'stream'

import { Injectable, OnModuleInit } from '@nestjs/common'
import { debug, Debugger } from 'debug'
import { storage } from 'firebase-admin'
import { nanoid } from 'nanoid'

import { Firebender } from '../firebender'

@Injectable()
export class StorageService implements OnModuleInit {
  private debug: Debugger = debug(`http:${this.constructor.name}`)
  private firebender: Firebender

  onModuleInit(): void {
    this.firebender = new Firebender()
  }

  async upload(filePath: string, file: Buffer, contentType: string): Promise<string> {
    const bucketFile = storage(this.firebender.firebaseAdmin)
      .bucket()
      .file(filePath)

    return new Promise((resolve, reject) => {
      this.getStreamFromBuffer(file)
        .pipe(bucketFile.createWriteStream({ contentType }))
        .on('error', err => reject(err))
        .on('finish', async () => {
          await bucketFile.makePublic()

          resolve(bucketFile.publicUrl())
        })
    })
  }

  async getFile(filePath: string): Promise<Buffer> {
    const id = nanoid()

    this.debug.extend('request')(JSON.stringify({ id, type: 'get_file', body: { filePath } }))

    const [file] = await storage(this.firebender.firebaseAdmin)
      .bucket()
      .file(filePath)
      .download()

    this.debug.extend('response')(JSON.stringify({ id, type: 'get_file', response: 'ok' }))

    return file
  }

  async moveFile(fromPath: string, toPath: string): Promise<void> {
    const id = nanoid()

    this.debug.extend('request')(JSON.stringify({ id, type: 'move_file', body: { fromPath, toPath } }))

    await storage(this.firebender.firebaseAdmin)
      .bucket()
      .file(fromPath)
      .move(toPath)

    this.debug.extend('response')(JSON.stringify({ id, type: 'get_file', response: 'ok' }))
  }

  private getStreamFromBuffer(buffer: Buffer): Readable {
    const stream = new Readable()

    stream.push(buffer)
    stream.push(null)

    return stream
  }
}