From 02facb3289aaaceb48dd41989200d3e9d9b64a5d Mon Sep 17 00:00:00 2001
From: tison <wander4096@gmail.com>
Date: Fri, 11 Oct 2024 13:45:53 -0600
Subject: [PATCH] implement integration as a separate crate

Signed-off-by: tison <wander4096@gmail.com>
---
 sqlx-jiff/Cargo.toml      |  3 +-
 sqlx-jiff/src/lib.rs      | 34 ++++++++++++++++++++-
 sqlx-jiff/src/postgres.rs | 62 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 97 insertions(+), 2 deletions(-)

diff --git a/sqlx-jiff/Cargo.toml b/sqlx-jiff/Cargo.toml
index 0b5daa55..67d3837f 100644
--- a/sqlx-jiff/Cargo.toml
+++ b/sqlx-jiff/Cargo.toml
@@ -18,4 +18,5 @@ postgres = ["sqlx/postgres"]
 
 [dependencies]
 jiff = { path = ".." }
-sqlx = { version = "0.8.2" }
+serde = { version = "1.0" }
+sqlx = { version = "0.8" }
diff --git a/sqlx-jiff/src/lib.rs b/sqlx-jiff/src/lib.rs
index e55fad4a..f7ddad00 100644
--- a/sqlx-jiff/src/lib.rs
+++ b/sqlx-jiff/src/lib.rs
@@ -1,2 +1,34 @@
+use std::ops::{Deref, DerefMut};
+use serde::{Deserialize, Serialize};
+
 #[cfg(feature = "postgres")]
-mod postgres;
\ No newline at end of file
+mod postgres;
+
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct Timestamp(pub jiff::Timestamp);
+
+impl From<Timestamp> for jiff::Timestamp {
+    fn from(ts: Timestamp) -> Self {
+        ts.0
+    }
+}
+
+impl From<jiff::Timestamp> for Timestamp {
+    fn from(ts: jiff::Timestamp) -> Self {
+        Self(ts)
+    }
+}
+
+impl Deref for Timestamp {
+    type Target = jiff::Timestamp;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for Timestamp {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
diff --git a/sqlx-jiff/src/postgres.rs b/sqlx-jiff/src/postgres.rs
index e69de29b..61b245f6 100644
--- a/sqlx-jiff/src/postgres.rs
+++ b/sqlx-jiff/src/postgres.rs
@@ -0,0 +1,62 @@
+use std::str::FromStr;
+use sqlx::{Database, Decode, Encode, Postgres, Type};
+use sqlx::encode::IsNull;
+use sqlx::error::BoxDynError;
+use sqlx::postgres::{PgArgumentBuffer, PgHasArrayType, PgTypeInfo, PgValueFormat};
+use sqlx::postgres::types::Oid;
+use jiff::SignedDuration;
+use crate::Timestamp;
+
+impl Type<Postgres> for Timestamp {
+    fn type_info() -> PgTypeInfo {
+        // 1184 => PgType::Timestamptz
+        PgTypeInfo::with_oid(Oid(1184))
+    }
+}
+
+impl PgHasArrayType for Timestamp {
+    fn array_type_info() -> PgTypeInfo {
+        // 1185 => PgType::TimestamptzArray
+        PgTypeInfo::with_oid(Oid(1185))
+    }
+}
+
+impl Encode<'_, Postgres> for Timestamp {
+    fn encode_by_ref(&self, buf: &mut PgArgumentBuffer) -> Result<IsNull, BoxDynError> {
+        // TIMESTAMP is encoded as the microseconds since the epoch
+        let micros = self
+            .0
+            .duration_since(postgres_epoch_timestamp())
+            .as_micros();
+        let micros = i64::try_from(micros)
+            .map_err(|_| format!("Timestamp {} out of range for Postgres: {micros}", self.0))?;
+        Encode::<Postgres>::encode(micros, buf)
+    }
+
+    fn size_hint(&self) -> usize {
+        size_of::<i64>()
+    }
+}
+
+impl<'r> Decode<'r, Postgres> for Timestamp {
+    fn decode(value: <Postgres as Database>::ValueRef<'r>) -> Result<Self, BoxDynError> {
+        Ok(match value.format() {
+            PgValueFormat::Binary => {
+                // TIMESTAMP is encoded as the microseconds since the epoch
+                let us = Decode::<Postgres>::decode(value)?;
+                let ts = postgres_epoch_timestamp().checked_add(SignedDuration::from_micros(us))?;
+                Timestamp(ts)
+            }
+            PgValueFormat::Text => {
+                let s = value.as_str()?;
+                let ts = jiff::Timestamp::from_str(s)?;
+                Timestamp(ts)
+            }
+        })
+    }
+}
+
+fn postgres_epoch_timestamp() -> jiff::Timestamp {
+    jiff::Timestamp::from_str("2000-01-01T00:00:00Z")
+        .expect("2000-01-01T00:00:00Z is a valid timestamp")
+}