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import {
TICKS_PER_SECOND as _TICKS_PER_SECOND,
mediaTimeFromSeconds as _mediaTimeFromSeconds,
mediaTimeToSeconds as _mediaTimeToSeconds,
} from "opencut-wasm";
/**
* Integer-tick time. Mirrors `MediaTime(i64)` in `rust/crates/time/src/media_time.rs`.
*
* `opencut-wasm` exposes `MediaTime` as a bare `number` alias because tsify
* collapses tuple structs. The brand here is the TS-side discipline that
* recovers the invariant: a `MediaTime` is an integer count of ticks, and the
* only legal way to construct one from a fractional `number` is `roundMediaTime`
* (or `mediaTimeFromSeconds`, which rounds inside the wasm boundary).
*
* Reading is free — `MediaTime` is assignable to `number`. Writing is gated —
* a bare `number` is not assignable to `MediaTime`.
*/
export type MediaTime = number & { readonly __mediaTime: unique symbol };
export const TICKS_PER_SECOND = _TICKS_PER_SECOND();
export const ZERO_MEDIA_TIME = 0 as MediaTime;
/**
* Construct a `MediaTime` from a known-integer tick count. Asserts in dev that
* the value is actually an integer; cast in release. Use `roundMediaTime` when
* the input may be fractional.
*/
export function mediaTime({ ticks }: { ticks: number }): MediaTime {
if (process.env.NODE_ENV !== "production" && !Number.isInteger(ticks)) {
throw new Error(
`mediaTime() requires an integer tick count, got ${ticks}. Use roundMediaTime() for fractional values.`,
);
}
return ticks as MediaTime;
}
/**
* Project a fractional value onto the integer-tick lattice.
*
* Rounds half away from zero (`-1.5 → -2`, `1.5 → 2`) and normalises `-0` to
* `0`. The away-from-zero rule matches Rust's `.round()` and avoids the
* `Math.round(-0.5) === -0` quirk that propagates `-0` into stored data.
*/
export function roundMediaTime({ time }: { time: number }): MediaTime {
const roundedMagnitude = Math.round(Math.abs(time));
if (roundedMagnitude === 0) {
return 0 as MediaTime;
}
return (time < 0 ? -roundedMagnitude : roundedMagnitude) as MediaTime;
}
export function mediaTimeFromSeconds({
seconds,
}: {
seconds: number;
}): MediaTime {
const result = _mediaTimeFromSeconds({ seconds });
if (result === undefined) {
throw new Error(
`mediaTimeFromSeconds: rust returned undefined for seconds=${seconds}`,
);
}
return result as MediaTime;
}
export function mediaTimeToSeconds({ time }: { time: MediaTime }): number {
return _mediaTimeToSeconds({ time });
}
/**
* Sum `MediaTime` values. Inputs are integer ticks, so the sum is integer too;
* the cast is a no-op at runtime, only re-establishes the brand for the type
* system.
*/
export function addMediaTime({
a,
b,
}: {
a: MediaTime;
b: MediaTime;
}): MediaTime {
return (a + b) as MediaTime;
}
export function subMediaTime({
a,
b,
}: {
a: MediaTime;
b: MediaTime;
}): MediaTime {
return (a - b) as MediaTime;
}
export function maxMediaTime({
a,
b,
}: {
a: MediaTime;
b: MediaTime;
}): MediaTime {
return (a > b ? a : b) as MediaTime;
}
export function minMediaTime({
a,
b,
}: {
a: MediaTime;
b: MediaTime;
}): MediaTime {
return (a < b ? a : b) as MediaTime;
}
export function clampMediaTime({
time,
min,
max,
}: {
time: MediaTime;
min: MediaTime;
max: MediaTime;
}): MediaTime {
if (time < min) return min;
if (time > max) return max;
return time;
}
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