Add live download progress updates

frontend/app/requests/[id]/page.tsx

@@ -3,7 +3,7 @@
 import Image from 'next/image'
 import { useParams, useRouter } from 'next/navigation'
 import { useEffect, useMemo, useState } from 'react'
-import { authFetch, clearToken, getApiBase, getEventStreamToken, getToken } from '../../lib/auth'
+import { authFetch, clearToken, getApiBase, getToken } from '../../lib/auth'
 
 type TimelineHop = {
   service: string
@@ -90,6 +90,14 @@ type ActionHistory = {
   created_at: string
 }
 
+type LiveDownloadProgress = {
+  request_id: string
+  state: string
+  summary: string
+  torrents: Array<Record<string, any>>
+  updated_at: string
+}
+
 const readApiError = async (response: Response, fallback: string) => {
   try {
     const contentType = response.headers.get('content-type') ?? ''
@@ -133,13 +141,45 @@ const formatBytes = (value?: number) => {
 }
 
 const torrentProgress = (torrent: Record<string, any>) => {
-  const supplied = Number(torrent.progressPercent)
-  if (!Number.isNaN(supplied) && supplied >= 0 && supplied <= 100) return Math.round(supplied)
   const progress = Number(torrent.progress)
-  if (!Number.isNaN(progress) && progress >= 0 && progress <= 1) return Math.round(progress * 100)
+  if (!Number.isNaN(progress) && progress >= 0 && progress <= 1) return Math.round(progress * 1000) / 10
+  const supplied = Number(torrent.progressPercent)
+  if (!Number.isNaN(supplied) && supplied >= 0 && supplied <= 100) return Math.round(supplied * 10) / 10
   return null
 }
 
+const formatProgress = (progress: number) => `${progress.toFixed(1).replace(/\.0$/, '')}% complete`
+
+const mergeLiveDownload = (current: Snapshot, live: LiveDownloadProgress): Snapshot => {
+  if (String(current.request_id) !== String(live.request_id)) return current
+  const stageState = live.state === 'completed'
+    ? 'complete'
+    : ['missing', 'error'].includes(live.state)
+      ? 'attention'
+      : 'active'
+  const presentation = current.presentation ?? {}
+  const pipeline = (presentation.pipeline ?? fallbackPipeline(current)).map((stage) =>
+    stage.id === 'download'
+      ? { ...stage, state: stageState, summary: live.summary, visible: true, torrents: live.torrents }
+      : stage
+  )
+  return {
+    ...current,
+    presentation: {
+      ...presentation,
+      download: {
+        ...(presentation.download ?? {}),
+        visible: true,
+        state: live.state,
+        summary: live.summary,
+        torrents: live.torrents,
+        lastSeenAt: live.updated_at,
+      },
+      pipeline,
+    },
+  }
+}
+
 const fallbackStatusLabel = (state: string) => {
   const labels: Record<string, string> = {
     REQUESTED: 'Waiting for approval',
@@ -256,38 +296,84 @@ export default function RequestTimelinePage() {
 
   useEffect(() => {
     if (!getToken() || !requestId) return
-    const baseUrl = getApiBase()
-    let closed = false
-    let source: EventSource | null = null
-    const connect = async () => {
+    let stopped = false
+    const refresh = async () => {
+      if (document.visibilityState === 'hidden') return
       try {
-        const streamToken = await getEventStreamToken()
-        if (closed) return
-        source = new EventSource(
-          `${baseUrl}/events/requests/${encodeURIComponent(requestId)}/stream?stream_token=${encodeURIComponent(streamToken)}`
-        )
-        source.onmessage = (event) => {
-          if (closed) return
-          try {
-            const payload = JSON.parse(event.data)
-            if (payload?.type !== 'request_live' || String(payload.request_id ?? '') !== String(requestId)) return
-            if (isSnapshotPayload(payload.snapshot)) setSnapshot(payload.snapshot)
-            if (Array.isArray(payload.history)) setHistorySnapshots(payload.history)
-            if (Array.isArray(payload.actions)) setHistoryActions(payload.actions)
-          } catch (error) {
-            console.error(error)
+        const response = await authFetch(`${getApiBase()}/requests/${requestId}/snapshot`)
+        if (response.status === 401) {
+          clearToken()
+          router.push('/login')
+          return
+        }
+        if (!response.ok) return
+        const payload = await response.json()
+        if (!stopped && isSnapshotPayload(payload)) setSnapshot(payload)
+      } catch (error) {
+        if (!stopped) console.error(error)
+      }
+    }
+    const timer = window.setInterval(() => void refresh(), 15_000)
+    return () => {
+      stopped = true
+      window.clearInterval(timer)
+    }
+  }, [requestId, router])
+
+  const liveDownloadKey = useMemo(() => {
+    const downloadStage = snapshot?.presentation?.pipeline?.find((stage) => stage.id === 'download')
+    if (!downloadStage?.visible || downloadStage.state !== 'active') return ''
+    return (downloadStage.torrents ?? [])
+      .filter((torrent) => (torrentProgress(torrent) ?? 100) < 100)
+      .map((torrent) => String(torrent.hash ?? torrent.name ?? 'download'))
+      .sort()
+      .join('|')
+  }, [snapshot])
+
+  useEffect(() => {
+    if (!getToken() || !requestId || !liveDownloadKey) return
+    let stopped = false
+    let timer: number | undefined
+    let controller: AbortController | null = null
+    const schedule = () => {
+      if (!stopped) timer = window.setTimeout(() => void refresh(), 2_000)
+    }
+    const refresh = async () => {
+      if (document.visibilityState === 'hidden') {
+        schedule()
+        return
+      }
+      controller = new AbortController()
+      try {
+        const response = await authFetch(`${getApiBase()}/requests/${requestId}/download-progress`, {
+          signal: controller.signal,
+          cache: 'no-store',
+        })
+        if (response.status === 401) {
+          clearToken()
+          router.push('/login')
+          return
+        }
+        if (response.ok) {
+          const payload = await response.json() as LiveDownloadProgress
+          if (!stopped && Array.isArray(payload.torrents)) {
+            setSnapshot((current) => current ? mergeLiveDownload(current, payload) : current)
           }
         }
       } catch (error) {
-        if (!closed) console.error(error)
+        if (!stopped && !(error instanceof DOMException && error.name === 'AbortError')) console.error(error)
+      } finally {
+        controller = null
+        schedule()
       }
     }
-    void connect()
+    timer = window.setTimeout(() => void refresh(), 750)
     return () => {
-      closed = true
-      source?.close()
+      stopped = true
+      if (timer !== undefined) window.clearTimeout(timer)
+      controller?.abort()
     }
-  }, [requestId])
+  }, [liveDownloadKey, requestId, router])
 
   const actionsById = useMemo(
     () => new Map((snapshot?.actions ?? []).map((action) => [action.id, action])),
@@ -519,8 +605,19 @@ export default function RequestTimelinePage() {
                   const progress = torrentProgress(torrent)
                   return (
                     <div className="request-torrent" key={torrent.hash ?? torrent.name}>
-                      <div><strong>{torrent.name ?? 'Download'}</strong><span>{progress === null ? 'Progress unavailable' : `${progress}% complete`}</span></div>
-                      {progress !== null && <div className="request-meter-track"><span style={{ width: `${progress}%` }} /></div>}
+                      <div><strong>{torrent.name ?? 'Download'}</strong><span>{progress === null ? 'Progress unavailable' : formatProgress(progress)}</span></div>
+                      {progress !== null && (
+                        <div
+                          className="request-meter-track is-live-download"
+                          role="progressbar"
+                          aria-label={`${torrent.name ?? 'Download'} progress`}
+                          aria-valuemin={0}
+                          aria-valuemax={100}
+                          aria-valuenow={progress}
+                        >
+                          <span style={{ width: `${progress}%` }} />
+                        </div>
+                      )}
                     </div>
                   )
                 })}