import { from, Subject, Subscription } from 'rxjs'
import { concatMap, map, switchMap, tap } from 'rxjs/operators'
import { Component, OnDestroy, OnInit } from '@angular/core'
import { ComponentPagination, hasMoreItems, ScreenService, User, UserService } from '@app/core'
import { Account, AccountService, Video, VideoChannel, VideoChannelService, VideoService } from '@app/shared/shared-main'
import { VideoSortField } from '@shared/models'

@Component({
  selector: 'my-account-video-channels',
  templateUrl: './account-video-channels.component.html',
  styleUrls: [ './account-video-channels.component.scss' ]
})
export class AccountVideoChannelsComponent implements OnInit, OnDestroy {
  account: Account
  videoChannels: VideoChannel[] = []
  videos: { [id: number]: Video[] } = {}

  channelPagination: ComponentPagination = {
    currentPage: 1,
    itemsPerPage: 2,
    totalItems: null
  }

  videosPagination: ComponentPagination = {
    currentPage: 1,
    itemsPerPage: 12,
    totalItems: null
  }
  videosSort: VideoSortField = '-publishedAt'

  onChannelDataSubject = new Subject<any>()

  userMiniature: User

  private accountSub: Subscription

  constructor (
    private accountService: AccountService,
    private videoChannelService: VideoChannelService,
    private videoService: VideoService,
    private screenService: ScreenService,
    private userService: UserService
  ) { }

  ngOnInit () {
    // Parent get the account for us
    this.accountSub = this.accountService.accountLoaded
        .subscribe(account => {
          this.account = account

          this.loadMoreChannels()
        })

    this.userService.getAnonymousOrLoggedUser()
      .subscribe(user => this.userMiniature = user)
  }

  ngOnDestroy () {
    if (this.accountSub) this.accountSub.unsubscribe()
  }

  loadMoreChannels () {
    this.videoChannelService.listAccountVideoChannels(this.account, this.channelPagination)
      .pipe(
        tap(res => this.channelPagination.totalItems = res.total),
        switchMap(res => from(res.data)),
        concatMap(videoChannel => {
          return this.videoService.getVideoChannelVideos(videoChannel, this.videosPagination, this.videosSort)
            .pipe(map(data => ({ videoChannel, videos: data.data })))
        })
      )
      .subscribe(({ videoChannel, videos }) => {
        this.videoChannels.push(videoChannel)

        this.videos[videoChannel.id] = videos

        this.onChannelDataSubject.next([ videoChannel ])
      })
  }

  getVideosOf (videoChannel: VideoChannel) {
    const numberOfVideos = this.screenService.getNumberOfAvailableMiniatures()

    // 2 rows
    return this.videos[ videoChannel.id ].slice(0, numberOfVideos * 2)
  }

  onNearOfBottom () {
    if (!hasMoreItems(this.channelPagination)) return

    this.channelPagination.currentPage += 1

    this.loadMoreChannels()
  }

  getVideoChannelLink (videoChannel: VideoChannel) {
    return [ '/video-channels', videoChannel.nameWithHost ]
  }
}