relic/packages/core/src/helpers/downloadTorrent.js

import humanFormat from "human-format"
import aria2 from "aria2"

function convertSize(size) {
    return `${humanFormat(size, {
        decimals: 2,
    })}B`
}

export default async function downloadTorrent(
    magnet,
    destination,
    {
        onStart,
        onProgress,
        onDone,
        onError,
        taskId,
    } = {}
) {
    let progressInterval = null
    let tickProgress = {
        total: 0,
        transferred: 0,
        speed: 0,

        totalString: "0B",
        transferredString: "0B",
        speedString: "0B/s",
    }

    const client = new aria2({
        host: "localhost",
        port: 6800,
        secure: false,
        secret: "",
        path: "/jsonrpc"
    })

    await client.open()

    let downloadId = await client.call(
        "addUri",
        [magnet],
        {
            dir: destination,
        },
    )

    async function stopDownload() {
        await client.call("remove", downloadId)
        clearInterval(progressInterval)
    }

    await new Promise(async (resolve, reject) => {
        if (typeof onStart === "function") {
            onStart()
        }

        if (taskId) {
            global._relic_eventBus.once(`task:cancel:${taskId}`, stopDownload)
        }

        progressInterval = setInterval(async () => {
            const data = await client.call("tellStatus", downloadId)

            console.log(data)

            if (data.status === "complete") {
                if (Array.isArray(data.followedBy) && data.followedBy[0]) {
                    // replace downloadId
                    downloadId = data.followedBy[0]
                }
            }

            tickProgress.total = parseInt(data.totalLength)
            tickProgress.speed = parseInt(data.downloadSpeed)
            tickProgress.transferred = parseInt(data.completedLength)
            tickProgress.connections = data.connections

            tickProgress.transferredString = convertSize(tickProgress.transferred)
            tickProgress.totalString = convertSize(tickProgress.total)
            tickProgress.speedString = convertSize(tickProgress.speed)

            if (typeof onProgress === "function") {
                onProgress(tickProgress)
            }
        }, 1000)

        client.on("onDownloadStart", async ([{ gid }]) => {
            const data = await client.call("tellStatus", gid)

            console.log(data)

            if (typeof data.following !== "undefined") {
                if (data.following === downloadId) {
                    downloadId = data.gid
                }
            }
        })

        client.on("onBtDownloadComplete", ([{ gid }]) => {
            if (gid !== downloadId) {
                return false
            }

            if (typeof onDone === "function") {
                onDone()
            }

            stopDownload()

            return resolve({
                downloadId,
            })
        })

        client.on("onDownloadError", ([{ gid }]) => {
            if (gid !== downloadId) {
                return false
            }

            stopDownload()

            if (typeof onError === "function") {
                onError()
            }

            return reject()
        })
    })

    await client.call("remove", downloadId)

    if (taskId) {
        global._relic_eventBus.off(`task:cancel:${taskId}`, stopDownload)
    }

    return downloadId
}