Bridge-Multi/src-angular/app/core/services/download.service.ts

import { EventEmitter, Injectable, NgZone } from '@angular/core'

import _ from 'lodash'
import { ChartData } from 'src-shared/interfaces/search.interface'
import { removeStyleTags } from 'src-shared/UtilFunctions'

import { DownloadProgress } from '../../../../src-shared/interfaces/download.interface'

@Injectable({
	providedIn: 'root',
})
export class DownloadService {

	public downloadCountChanges = new EventEmitter<number>()
	public downloads: DownloadProgress[] = []

	constructor(zone: NgZone) {
		window.electron.on.downloadQueueUpdate(download => zone.run(() => {
			const downloadIndex = this.downloads.findIndex(d => d.md5 === download.md5)
			if (download.type === 'cancel') {
				this.downloads = this.downloads.filter(d => d.md5 !== this.downloads[downloadIndex]?.md5)
			} else if (downloadIndex === -1) {
				this.downloads.push(download)
			} else {
				_.assign(this.downloads[downloadIndex], download)
			}
		}))
	}

	get downloadCount() {
		return this.downloads.length
	}

	get completedCount() {
		return this.downloads.filter(download => download.type === 'done').length
	}

	get totalDownloadingPercent() {
		let total = 0
		let count = 0
		for (const download of this.downloads) {
			if (!download.stale) {
				total += download.percent ?? 0
				count++
			}
		}
		if (this.anyErrorsExist && total === 0) { return null }
		return count ? total / count : 0
	}

	get anyErrorsExist() {
		return this.downloads.find(download => download.type === 'error') ? true : false
	}

	addDownload(chart: ChartData) {
		if (!this.downloads.find(d => d.md5 === chart.md5)) { // Don't download something twice
			if (this.downloads.every(d => d.type === 'done')) { // Reset overall progress bar if it finished
				this.downloads.forEach(d => d.stale = true)
			}
			const chartName = `${removeStyleTags(chart.artist ?? 'Unknown Artist')
				} - ${removeStyleTags(chart.name ?? 'Unknown Name')
				} (${removeStyleTags(chart.charter ?? 'Unknown Charter')})`
			this.downloads.push({
				md5: chart.md5,
				chartName,
				header: 'Waiting for other downloads to finish...',
				body: '',
				percent: 0,
				type: 'good',
				isPath: false,
			})
			window.electron.emit.download({ action: 'add', md5: chart.md5, chartName })
		}
		this.downloadCountChanges.emit(this.downloadCount)
	}

	cancelDownload(md5: string) {
		window.electron.emit.download({ action: 'remove', md5 })
		this.downloadCountChanges.emit(this.downloadCount - 1)
	}

	cancelAllCompleted() {
		for (const download of this.downloads) {
			if (download.type === 'done') {
				window.electron.emit.download({ action: 'remove', md5: download.md5 })
			}
		}
		this.downloads = this.downloads.filter(d => d.type !== 'done')
		this.downloadCountChanges.emit(this.downloadCount)
	}

	retryDownload(md5: string) {
		const chartDownload = this.downloads.find(d => d.md5 === md5)
		if (chartDownload) {
			chartDownload.type = 'good'
			chartDownload.header = 'Waiting to retry...'
			chartDownload.body = ''
			chartDownload.isPath = false
			chartDownload.percent = 0

			window.electron.emit.download({ action: 'retry', md5 })
		}
	}
}