1 files changed, 142 insertions, 0 deletions
diff --git a/src/time.rs b/src/time.rs
new file mode 100644
index 0000000..35e1a86
--- /dev/null
+++ b/src/time.rs
@@ -0,0 +1,142 @@
+use core::{
+	ops::{Add, AddAssign, Sub, SubAssign},
+	time::Duration,
+};
+
+use serde::{Deserialize, Serialize};
+
+use crate::ScriptContext;
+
+mod tortuise {
+
+	#[link(wasm_import_module = "tortuise")]
+	unsafe extern "C" {
+		pub safe fn system_now(context: u64) -> u64;
+		pub safe fn monotonic_now(context: u64) -> u64;
+		pub safe fn delta_time(context: u64) -> u64;
+	}
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
+#[repr(transparent)]
+#[serde(transparent)]
+pub struct SystemTime(u128);
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
+#[repr(transparent)]
+#[serde(transparent)]
+pub struct Instant(u128);
+
+impl ScriptContext {
+	pub fn delta_time(&self) -> Duration {
+		Duration::from_nanos(tortuise::delta_time(self.0))
+	}
+}
+
+impl SystemTime {
+	pub const UNIX_EPOCH: Self = Self(0);
+
+	pub fn now(context: &ScriptContext) -> Self {
+		Self(tortuise::system_now(context.0) as u128)
+	}
+
+	pub fn duration_since(self, earlier: SystemTime) -> Option<Duration> {
+		if self < earlier {
+			return None;
+		}
+
+		Some(Duration::from_nanos_u128(self.0 - earlier.0))
+	}
+
+	pub fn checked_add(self, duration: Duration) -> Option<Self> {
+		Some(Self(self.0.checked_add(duration.as_nanos())?))
+	}
+
+	pub fn checked_sub(self, duration: Duration) -> Option<Self> {
+		Some(Self(self.0.checked_sub(duration.as_nanos())?))
+	}
+}
+
+impl Add<Duration> for SystemTime {
+	type Output = Self;
+
+	fn add(self, rhs: Duration) -> Self::Output {
+		self.checked_add(rhs).unwrap()
+	}
+}
+
+impl AddAssign<Duration> for SystemTime {
+	fn add_assign(&mut self, rhs: Duration) {
+		*self = self.add(rhs);
+	}
+}
+
+impl Sub<Duration> for SystemTime {
+	type Output = Self;
+
+	fn sub(self, rhs: Duration) -> Self::Output {
+		self.checked_sub(rhs).unwrap()
+	}
+}
+
+impl SubAssign<Duration> for SystemTime {
+	fn sub_assign(&mut self, rhs: Duration) {
+		*self = self.sub(rhs)
+	}
+}
+
+impl Instant {
+	pub fn now(context: &ScriptContext) -> Self {
+		Self(tortuise::monotonic_now(context.0) as u128)
+	}
+
+	pub fn duration_since(self, earlier: Instant) -> Option<Duration> {
+		if earlier > self {
+			return None;
+		}
+
+		Some(Duration::from_nanos_u128(self.0 - earlier.0))
+	}
+
+	pub fn elapsed(self, context: &ScriptContext) -> Duration {
+		Self::now(context)
+			.duration_since(self)
+			.unwrap_or(Duration::ZERO)
+	}
+
+	pub fn checked_add(self, duration: Duration) -> Option<Self> {
+		Some(Self(self.0.checked_add(duration.as_nanos())?))
+	}
+
+	pub fn checked_sub(self, duration: Duration) -> Option<Self> {
+		Some(Self(self.0.checked_sub(duration.as_nanos())?))
+	}
+}
+
+impl Add<Duration> for Instant {
+	type Output = Self;
+
+	fn add(self, rhs: Duration) -> Self::Output {
+		self.checked_add(rhs).unwrap()
+	}
+}
+
+impl AddAssign<Duration> for Instant {
+	fn add_assign(&mut self, rhs: Duration) {
+		*self = self.add(rhs);
+	}
+}
+
+impl Sub<Duration> for Instant {
+	type Output = Self;
+
+	fn sub(self, rhs: Duration) -> Self::Output {
+		self.checked_sub(rhs).unwrap()
+	}
+}
+
+impl SubAssign<Duration> for Instant {
+	fn sub_assign(&mut self, rhs: Duration) {
+		*self = self.sub(rhs)
+	}
+}