refactor(casting): extract useCastPlayerProgress hook

hooks/useCastPlayerProgress.ts

@@ -0,0 +1,160 @@
+import type { BaseItemDto } from "@jellyfin/sdk/lib/generated-client";
+import { type RefObject, useEffect, useRef, useState } from "react";
+import { MediaPlayerState, type MediaStatus } from "react-native-google-cast";
+import { type SharedValue, useSharedValue } from "react-native-reanimated";
+import { useTrickplay } from "@/hooks/useTrickplay";
+
+interface TrickplayTime {
+  hours: number;
+  minutes: number;
+  seconds: number;
+}
+
+interface UseCastPlayerProgressParams {
+  /** Raw Chromecast media status, or null when no session. */
+  mediaStatus: MediaStatus | null;
+  /** Full item fetched from Jellyfin, used to derive trickplay data. */
+  fetchedItem: BaseItemDto | null;
+  /** Total media duration, in seconds. */
+  duration: number;
+}
+
+type TrickplayReturn = ReturnType<typeof useTrickplay>;
+
+interface UseCastPlayerProgressResult {
+  /** Shared value tracking the slider progress, in milliseconds. */
+  sliderProgress: SharedValue<number>;
+  /** Shared value for the slider minimum, in milliseconds. */
+  sliderMin: SharedValue<number>;
+  /** Shared value for the slider maximum, in milliseconds. */
+  sliderMax: SharedValue<number>;
+  /** Mutable ref flag set true while the user is scrubbing. */
+  isScrubbing: RefObject<boolean>;
+  /** Trickplay time display state for the bubble. */
+  trickplayTime: TrickplayTime;
+  /** Updates the trickplay time display state. */
+  setTrickplayTime: (time: TrickplayTime) => void;
+  /** Current scrub percentage (0-1), used to position the trickplay bubble. */
+  scrubPercentage: number;
+  /** Updates the scrub percentage. */
+  setScrubPercentage: (value: number) => void;
+  /** Current playback progress, in seconds (live-updating). */
+  progress: number;
+  /** Live-updating playback position, in seconds. */
+  liveProgress: number;
+  /** Last stable playback position (seconds), for resuming across reloads. */
+  resumePositionRef: RefObject<number>;
+  /** Current trickplay image URL/coordinates, or null. */
+  trickPlayUrl: TrickplayReturn["trickPlayUrl"];
+  /** Computes the trickplay URL for a given progress in ticks. */
+  calculateTrickplayUrl: TrickplayReturn["calculateTrickplayUrl"];
+  /** Parsed trickplay metadata, or null. */
+  trickplayInfo: TrickplayReturn["trickplayInfo"];
+}
+
+/**
+ * Progress/slider/trickplay cluster for the casting player.
+ * Owns the slider shared values, scrub state, live-progress interpolation,
+ * resume-position tracking, and trickplay preview.
+ */
+export function useCastPlayerProgress({
+  mediaStatus,
+  fetchedItem,
+  duration,
+}: UseCastPlayerProgressParams): UseCastPlayerProgressResult {
+  // Shared values for progress slider (must be initialized before any early returns)
+  const sliderProgress = useSharedValue(0);
+  const sliderMin = useSharedValue(0);
+  const sliderMax = useSharedValue(100);
+  const isScrubbing = useRef(false);
+
+  // Trickplay time display
+  const [trickplayTime, setTrickplayTime] = useState({
+    hours: 0,
+    minutes: 0,
+    seconds: 0,
+  });
+
+  // Track scrub percentage for trickplay bubble positioning
+  const [scrubPercentage, setScrubPercentage] = useState(0);
+
+  // Live progress tracking - update every second
+  const [liveProgress, setLiveProgress] = useState(0);
+  const lastSyncPositionRef = useRef(0);
+  const lastSyncTimestampRef = useRef(Date.now());
+
+  // Last stable playback position (seconds), for resuming across reloads.
+  const resumePositionRef = useRef(0);
+
+  useEffect(() => {
+    // Sync refs whenever mediaStatus provides a new position
+    if (mediaStatus?.streamPosition !== undefined) {
+      lastSyncPositionRef.current = mediaStatus.streamPosition;
+      lastSyncTimestampRef.current = Date.now();
+      setLiveProgress(mediaStatus.streamPosition);
+    }
+
+    // Update every second when playing, deriving from last sync point
+    const interval = setInterval(() => {
+      if (
+        mediaStatus?.playerState === MediaPlayerState.PLAYING &&
+        mediaStatus?.streamPosition !== undefined
+      ) {
+        const elapsed = (Date.now() - lastSyncTimestampRef.current) / 1000;
+        setLiveProgress(lastSyncPositionRef.current + elapsed);
+      } else if (mediaStatus?.streamPosition !== undefined) {
+        // Sync with actual position when paused/buffering
+        setLiveProgress(mediaStatus.streamPosition);
+      }
+    }, 1000);
+
+    return () => clearInterval(interval);
+  }, [mediaStatus?.playerState, mediaStatus?.streamPosition]);
+
+  // Track the last stable position so a reload mid-switch resumes correctly.
+  useEffect(() => {
+    const pos = mediaStatus?.streamPosition ?? 0;
+    if (mediaStatus?.playerState === MediaPlayerState.PLAYING && pos > 0) {
+      resumePositionRef.current = pos;
+    }
+  }, [mediaStatus?.streamPosition, mediaStatus?.playerState]);
+
+  // Derive state from raw Chromecast hooks
+  const progress = liveProgress; // Use live-updating progress
+
+  // Trickplay for seeking preview - use fetched item with full data
+  const { trickPlayUrl, calculateTrickplayUrl, trickplayInfo } = useTrickplay(
+    fetchedItem ?? null,
+  );
+
+  // Update slider max when duration changes
+  useEffect(() => {
+    if (duration > 0) {
+      sliderMax.value = duration * 1000; // Convert to milliseconds
+    }
+  }, [duration, sliderMax]);
+
+  // Update slider progress when not scrubbing
+  useEffect(() => {
+    if (!isScrubbing.current && progress > 0) {
+      sliderProgress.value = progress * 1000; // Convert to milliseconds
+    }
+  }, [progress, sliderProgress]);
+
+  return {
+    sliderProgress,
+    sliderMin,
+    sliderMax,
+    isScrubbing,
+    trickplayTime,
+    setTrickplayTime,
+    scrubPercentage,
+    setScrubPercentage,
+    progress,
+    liveProgress,
+    resumePositionRef,
+    trickPlayUrl,
+    calculateTrickplayUrl,
+    trickplayInfo,
+  };
+}