refactor: split audio attachment view into reusable components

web/src/components/MemoMetadata/Attachment/AttachmentListView.tsx

-import { FileAudioIcon, FileIcon, PaperclipIcon } from "lucide-react";
+import { FileIcon, PaperclipIcon } from "lucide-react";
 import { useMemo } from "react";
 import { cn } from "@/lib/utils";
 import type { Attachment } from "@/types/proto/api/v1/attachment_service_pb";
-import { getAttachmentType, getAttachmentUrl } from "@/utils/attachment";
-import { formatFileSize, getFileTypeLabel } from "@/utils/format";
+import { getAttachmentUrl } from "@/utils/attachment";
 import SectionHeader from "../SectionHeader";
 import AttachmentCard from "./AttachmentCard";
+import AudioAttachmentItem from "./AudioAttachmentItem";
+import { getAttachmentMetadata, isImageAttachment, separateAttachments } from "./attachmentViewHelpers";
 
 interface AttachmentListViewProps {
   attachments: Attachment[];
   onImagePreview?: (urls: string[], index: number) => void;
 }
 
-const isImageAttachment = (attachment: Attachment): boolean => getAttachmentType(attachment) === "image/*";
-const isVideoAttachment = (attachment: Attachment): boolean => getAttachmentType(attachment) === "video/*";
-const isAudioAttachment = (attachment: Attachment): boolean => getAttachmentType(attachment) === "audio/*";
-
-const separateAttachments = (attachments: Attachment[]) => {
-  const visual: Attachment[] = [];
-  const audio: Attachment[] = [];
-  const docs: Attachment[] = [];
-
-  for (const attachment of attachments) {
-    if (isImageAttachment(attachment) || isVideoAttachment(attachment)) {
-      visual.push(attachment);
-    } else if (isAudioAttachment(attachment)) {
-      audio.push(attachment);
-    } else {
-      docs.push(attachment);
-    }
-  }
-
-  return { visual, audio, docs };
-};
-
 const DocumentItem = ({ attachment }: { attachment: Attachment }) => {
-  const fileTypeLabel = getFileTypeLabel(attachment.type);
-  const fileSizeLabel = attachment.size ? formatFileSize(Number(attachment.size)) : undefined;
+  const { fileTypeLabel, fileSizeLabel } = getAttachmentMetadata(attachment);
 
   return (
     <div className="flex items-center gap-1 px-1 py-1 rounded text-xs text-muted-foreground hover:text-foreground hover:bg-accent/20 transition-colors whitespace-nowrap">
@@ -62,22 +40,6 @@ const DocumentItem = ({ attachment }: { attachment: Attachment }) => {
   );
 };
 
-const AudioItem = ({ attachment }: { attachment: Attachment }) => {
-  const sourceUrl = getAttachmentUrl(attachment);
-
-  return (
-    <div className="flex flex-col gap-1 px-1 py-1">
-      <div className="flex items-center gap-1 text-xs text-muted-foreground">
-        <FileAudioIcon className="w-3 h-3 shrink-0" />
-        <span className="truncate" title={attachment.filename}>
-          {attachment.filename}
-        </span>
-      </div>
-      <audio src={sourceUrl} controls preload="metadata" className="w-full h-8" />
-    </div>
-  );
-};
-
 interface VisualItemProps {
   attachment: Attachment;
   onImageClick?: (url: string) => void;
@@ -114,9 +76,9 @@ const VisualGrid = ({ attachments, onImageClick }: { attachments: Attachment[];
 );
 
 const AudioList = ({ attachments }: { attachments: Attachment[] }) => (
-  <div className="flex flex-col gap-1">
+  <div className="flex flex-col gap-2">
     {attachments.map((attachment) => (
-      <AudioItem key={attachment.name} attachment={attachment} />
+      <AudioAttachmentItem key={attachment.name} attachment={attachment} />
     ))}
   </div>
 );

web/src/components/MemoMetadata/Attachment/AudioAttachmentItem.tsx

+import { FileAudioIcon, PauseIcon, PlayIcon } from "lucide-react";
+import { useEffect, useRef, useState } from "react";
+import type { Attachment } from "@/types/proto/api/v1/attachment_service_pb";
+import { getAttachmentUrl } from "@/utils/attachment";
+import { formatAudioTime, getAttachmentMetadata } from "./attachmentViewHelpers";
+
+const AUDIO_PLAYBACK_RATES = [1, 1.5, 2] as const;
+
+interface AudioProgressBarProps {
+  attachment: Attachment;
+  currentTime: number;
+  duration: number;
+  progressPercent: number;
+  onSeek: (value: string) => void;
+}
+
+const AudioProgressBar = ({ attachment, currentTime, duration, progressPercent, onSeek }: AudioProgressBarProps) => (
+  <div className="mt-2 flex items-center gap-2.5">
+    <div className="relative flex h-4 min-w-0 flex-1 items-center">
+      <div className="absolute inset-x-0 h-1 rounded-full bg-muted/75" />
+      <div className="absolute left-0 h-1 rounded-full bg-foreground/20" style={{ width: `${Math.min(progressPercent, 100)}%` }} />
+      <input
+        type="range"
+        min={0}
+        max={duration || 1}
+        step={0.1}
+        value={Math.min(currentTime, duration || 0)}
+        onChange={(e) => onSeek(e.target.value)}
+        aria-label={`Seek ${attachment.filename}`}
+        className="relative z-10 h-4 w-full cursor-pointer appearance-none bg-transparent outline-none disabled:cursor-default
+          [&::-webkit-slider-runnable-track]:h-1 [&::-webkit-slider-runnable-track]:rounded-full
+          [&::-webkit-slider-runnable-track]:bg-transparent
+          [&::-webkit-slider-thumb]:mt-[-3px] [&::-webkit-slider-thumb]:size-2 [&::-webkit-slider-thumb]:appearance-none
+          [&::-webkit-slider-thumb]:rounded-full [&::-webkit-slider-thumb]:border [&::-webkit-slider-thumb]:border-border/50
+          [&::-webkit-slider-thumb]:bg-background/95
+          [&::-moz-range-track]:h-1 [&::-moz-range-track]:rounded-full [&::-moz-range-track]:bg-transparent
+          [&::-moz-range-thumb]:size-2 [&::-moz-range-thumb]:rounded-full [&::-moz-range-thumb]:border
+          [&::-moz-range-thumb]:border-border/50 [&::-moz-range-thumb]:bg-background/95"
+        disabled={duration === 0}
+      />
+    </div>
+    <div className="shrink-0 text-[11px] tabular-nums text-muted-foreground">
+      {formatAudioTime(currentTime)} / {duration > 0 ? formatAudioTime(duration) : "--:--"}
+    </div>
+  </div>
+);
+
+const AudioAttachmentItem = ({ attachment }: { attachment: Attachment }) => {
+  const sourceUrl = getAttachmentUrl(attachment);
+  const audioRef = useRef<HTMLAudioElement>(null);
+  const [isPlaying, setIsPlaying] = useState(false);
+  const [currentTime, setCurrentTime] = useState(0);
+  const [duration, setDuration] = useState(0);
+  const [playbackRate, setPlaybackRate] = useState<(typeof AUDIO_PLAYBACK_RATES)[number]>(1);
+  const { fileTypeLabel, fileSizeLabel } = getAttachmentMetadata(attachment);
+  const progressPercent = duration > 0 ? (currentTime / duration) * 100 : 0;
+
+  useEffect(() => {
+    if (!audioRef.current) {
+      return;
+    }
+
+    audioRef.current.playbackRate = playbackRate;
+  }, [playbackRate]);
+
+  const togglePlayback = async () => {
+    const audio = audioRef.current;
+
+    if (!audio) {
+      return;
+    }
+
+    if (audio.paused) {
+      try {
+        await audio.play();
+      } catch {
+        setIsPlaying(false);
+      }
+      return;
+    }
+
+    audio.pause();
+  };
+
+  const handleSeek = (value: string) => {
+    const audio = audioRef.current;
+    const nextTime = Number(value);
+
+    if (!audio || Number.isNaN(nextTime)) {
+      return;
+    }
+
+    audio.currentTime = nextTime;
+    setCurrentTime(nextTime);
+  };
+
+  const handlePlaybackRateChange = () => {
+    const currentRateIndex = AUDIO_PLAYBACK_RATES.findIndex((rate) => rate === playbackRate);
+    const nextRate = AUDIO_PLAYBACK_RATES[(currentRateIndex + 1) % AUDIO_PLAYBACK_RATES.length];
+    setPlaybackRate(nextRate);
+  };
+
+  const handleDuration = (value: number) => {
+    setDuration(Number.isFinite(value) ? value : 0);
+  };
+
+  return (
+    <div className="rounded-xl border border-border/35 bg-background/70 px-2.5 py-2.5">
+      <div className="flex items-start gap-2.5">
+        <div className="mt-0.5 flex size-8 shrink-0 items-center justify-center rounded-lg bg-muted/55 text-muted-foreground">
+          <FileAudioIcon className="size-3.5" />
+        </div>
+
+        <div className="flex min-w-0 flex-1 items-start justify-between gap-3">
+          <div className="min-w-0 flex-1">
+            <div className="truncate text-sm font-medium leading-5 text-foreground" title={attachment.filename}>
+              {attachment.filename}
+            </div>
+            <div className="flex flex-wrap items-center gap-x-1.5 gap-y-0.5 text-xs leading-4 text-muted-foreground">
+              <span>{fileTypeLabel}</span>
+              {fileSizeLabel && (
+                <>
+                  <span className="text-muted-foreground/50">•</span>
+                  <span>{fileSizeLabel}</span>
+                </>
+              )}
+            </div>
+          </div>
+
+          <div className="mt-0.5 flex shrink-0 items-center gap-1">
+            <button
+              type="button"
+              onClick={handlePlaybackRateChange}
+              className="inline-flex h-6 items-center justify-center px-1 text-[11px] font-medium text-muted-foreground transition-colors hover:text-foreground"
+              aria-label={`Playback speed ${playbackRate}x for ${attachment.filename}`}
+            >
+              {playbackRate}x
+            </button>
+            <button
+              type="button"
+              onClick={togglePlayback}
+              className="inline-flex size-6.5 items-center justify-center rounded-md border border-border/45 bg-background/85 text-foreground transition-colors hover:bg-muted/45"
+              aria-label={isPlaying ? `Pause ${attachment.filename}` : `Play ${attachment.filename}`}
+            >
+              {isPlaying ? <PauseIcon className="size-3" /> : <PlayIcon className="size-3 translate-x-[0.5px]" />}
+            </button>
+          </div>
+        </div>
+      </div>
+
+      <AudioProgressBar
+        attachment={attachment}
+        currentTime={currentTime}
+        duration={duration}
+        progressPercent={progressPercent}
+        onSeek={handleSeek}
+      />
+
+      <audio
+        ref={audioRef}
+        src={sourceUrl}
+        preload="metadata"
+        className="hidden"
+        onLoadedMetadata={(e) => handleDuration(e.currentTarget.duration)}
+        onDurationChange={(e) => handleDuration(e.currentTarget.duration)}
+        onTimeUpdate={(e) => setCurrentTime(e.currentTarget.currentTime)}
+        onPlay={() => setIsPlaying(true)}
+        onPause={() => setIsPlaying(false)}
+        onEnded={() => {
+          setIsPlaying(false);
+          setCurrentTime(0);
+        }}
+      />
+    </div>
+  );
+};
+
+export default AudioAttachmentItem;

web/src/components/MemoMetadata/Attachment/attachmentViewHelpers.ts

+import type { Attachment } from "@/types/proto/api/v1/attachment_service_pb";
+import { getAttachmentType } from "@/utils/attachment";
+import { formatFileSize, getFileTypeLabel } from "@/utils/format";
+
+export interface AttachmentGroups {
+  visual: Attachment[];
+  audio: Attachment[];
+  docs: Attachment[];
+}
+
+export interface AttachmentMetadata {
+  fileTypeLabel: string;
+  fileSizeLabel?: string;
+}
+
+export const isImageAttachment = (attachment: Attachment): boolean => getAttachmentType(attachment) === "image/*";
+export const isVideoAttachment = (attachment: Attachment): boolean => getAttachmentType(attachment) === "video/*";
+export const isAudioAttachment = (attachment: Attachment): boolean => getAttachmentType(attachment) === "audio/*";
+
+export const separateAttachments = (attachments: Attachment[]): AttachmentGroups => {
+  const groups: AttachmentGroups = {
+    visual: [],
+    audio: [],
+    docs: [],
+  };
+
+  for (const attachment of attachments) {
+    if (isImageAttachment(attachment) || isVideoAttachment(attachment)) {
+      groups.visual.push(attachment);
+      continue;
+    }
+
+    if (isAudioAttachment(attachment)) {
+      groups.audio.push(attachment);
+      continue;
+    }
+
+    groups.docs.push(attachment);
+  }
+
+  return groups;
+};
+
+export const getAttachmentMetadata = (attachment: Attachment): AttachmentMetadata => ({
+  fileTypeLabel: getFileTypeLabel(attachment.type),
+  fileSizeLabel: attachment.size ? formatFileSize(Number(attachment.size)) : undefined,
+});
+
+export const formatAudioTime = (seconds: number): string => {
+  if (!Number.isFinite(seconds) || seconds < 0) {
+    return "0:00";
+  }
+
+  const rounded = Math.floor(seconds);
+  const hours = Math.floor(rounded / 3600);
+  const minutes = Math.floor((rounded % 3600) / 60);
+  const secs = rounded % 60;
+
+  if (hours > 0) {
+    return `${hours}:${minutes.toString().padStart(2, "0")}:${secs.toString().padStart(2, "0")}`;
+  }
+
+  return `${minutes}:${secs.toString().padStart(2, "0")}`;
+};