Add camera zoom and data saver controls

client/src/lib/camera.ts

@@ -0,0 +1,151 @@
+export type CameraQualityPreset = "economy" | "balanced" | "clarity";
+
+export type CameraZoomState = {
+  supported: boolean;
+  min: number;
+  max: number;
+  step: number;
+  current: number;
+  focusMode: string;
+};
+
+type NumericRange = {
+  min: number;
+  max: number;
+  step: number;
+};
+
+function clamp(value: number, min: number, max: number) {
+  return Math.max(min, Math.min(max, value));
+}
+
+function parseNumericRange(value: unknown): NumericRange | null {
+  if (!value || typeof value !== "object") {
+    return null;
+  }
+
+  const candidate = value as { min?: unknown; max?: unknown; step?: unknown };
+  if (typeof candidate.min !== "number" || typeof candidate.max !== "number") {
+    return null;
+  }
+
+  return {
+    min: candidate.min,
+    max: candidate.max,
+    step: typeof candidate.step === "number" && candidate.step > 0 ? candidate.step : 0.1,
+  };
+}
+
+export function getCameraVideoConstraints(
+  facingMode: "user" | "environment",
+  isMobile: boolean,
+  preset: CameraQualityPreset,
+): MediaTrackConstraints {
+  switch (preset) {
+    case "economy":
+      return {
+        facingMode,
+        width: { ideal: isMobile ? 960 : 1280 },
+        height: { ideal: isMobile ? 540 : 720 },
+        frameRate: { ideal: 24, max: 24 },
+      };
+    case "clarity":
+      return {
+        facingMode,
+        width: { ideal: isMobile ? 1280 : 1920 },
+        height: { ideal: isMobile ? 720 : 1080 },
+        frameRate: { ideal: 30, max: 30 },
+      };
+    default:
+      return {
+        facingMode,
+        width: { ideal: isMobile ? 1280 : 1600 },
+        height: { ideal: isMobile ? 720 : 900 },
+        frameRate: { ideal: 30, max: 30 },
+      };
+  }
+}
+
+export function getLiveAnalysisBitrate(preset: CameraQualityPreset, isMobile: boolean) {
+  switch (preset) {
+    case "economy":
+      return isMobile ? 900_000 : 1_100_000;
+    case "clarity":
+      return isMobile ? 1_900_000 : 2_500_000;
+    default:
+      return isMobile ? 1_300_000 : 1_900_000;
+  }
+}
+
+export function readTrackZoomState(track: MediaStreamTrack | null): CameraZoomState {
+  if (!track) {
+    return {
+      supported: false,
+      min: 1,
+      max: 1,
+      step: 0.1,
+      current: 1,
+      focusMode: "auto",
+    };
+  }
+
+  const capabilities = (
+    typeof (track as MediaStreamTrack & { getCapabilities?: () => unknown }).getCapabilities === "function"
+      ? (track as MediaStreamTrack & { getCapabilities: () => unknown }).getCapabilities()
+      : {}
+  ) as Record<string, unknown>;
+  const settings = (
+    typeof (track as MediaStreamTrack & { getSettings?: () => unknown }).getSettings === "function"
+      ? (track as MediaStreamTrack & { getSettings: () => unknown }).getSettings()
+      : {}
+  ) as Record<string, unknown>;
+
+  const zoomRange = parseNumericRange(capabilities.zoom);
+  const focusModes = Array.isArray(capabilities.focusMode)
+    ? capabilities.focusMode.filter((item: unknown): item is string => typeof item === "string")
+    : [];
+  const focusMode = typeof settings.focusMode === "string"
+    ? settings.focusMode
+    : focusModes.includes("continuous")
+      ? "continuous"
+      : focusModes[0] || "auto";
+
+  if (!zoomRange || zoomRange.max - zoomRange.min <= 0.001) {
+    return {
+      supported: false,
+      min: 1,
+      max: 1,
+      step: 0.1,
+      current: 1,
+      focusMode,
+    };
+  }
+
+  const current = typeof settings.zoom === "number"
+    ? clamp(settings.zoom, zoomRange.min, zoomRange.max)
+    : zoomRange.min;
+
+  return {
+    supported: true,
+    min: zoomRange.min,
+    max: zoomRange.max,
+    step: zoomRange.step,
+    current,
+    focusMode,
+  };
+}
+
+export async function applyTrackZoom(track: MediaStreamTrack | null, rawZoom: number) {
+  const currentState = readTrackZoomState(track);
+  if (!track || !currentState.supported) {
+    return currentState;
+  }
+
+  const zoom = clamp(rawZoom, currentState.min, currentState.max);
+  try {
+    await track.applyConstraints({ advanced: [{ zoom }] } as unknown as MediaTrackConstraints);
+  } catch {
+    await track.applyConstraints({ zoom } as unknown as MediaTrackConstraints);
+  }
+  return readTrackZoomState(track);
+}