Add an extensions API to the collaboration server (#7807)

This PR adds a REST API to the collab server for searching and
downloading extensions. Previously, we had implemented this API in
zed.dev directly, but this implementation is better, because we use the
collab database to store the download counts for extensions.

Release Notes:

- N/A

---------

Co-authored-by: Marshall Bowers <elliott.codes@gmail.com>
Co-authored-by: Marshall <marshall@zed.dev>
Co-authored-by: Conrad <conrad@zed.dev>

crates/collab/src/db.rs

@@ -1,12 +1,8 @@
-#[cfg(test)]
-pub mod tests;
-
-#[cfg(test)]
-pub use tests::TestDb;
-
 mod ids;
 mod queries;
 mod tables;
+#[cfg(test)]
+pub mod tests;
 
 use crate::{executor::Executor, Error, Result};
 use anyhow::anyhow;
@@ -25,7 +21,7 @@ use sea_orm::{
     FromQueryResult, IntoActiveModel, IsolationLevel, JoinType, QueryOrder, QuerySelect, Statement,
     TransactionTrait,
 };
-use serde::{Deserialize, Serialize};
+use serde::{ser::Error as _, Deserialize, Serialize, Serializer};
 use sqlx::{
     migrate::{Migrate, Migration, MigrationSource},
     Connection,
@@ -40,13 +36,17 @@ use std::{
     sync::Arc,
     time::Duration,
 };
-pub use tables::*;
+use time::{format_description::well_known::iso8601, PrimitiveDateTime};
 use tokio::sync::{Mutex, OwnedMutexGuard};
 
+#[cfg(test)]
+pub use tests::TestDb;
+
 pub use ids::*;
 pub use queries::contributors::ContributorSelector;
 pub use sea_orm::ConnectOptions;
 pub use tables::user::Model as User;
+pub use tables::*;
 
 /// Database gives you a handle that lets you access the database.
 /// It handles pooling internally.
@@ -717,3 +717,42 @@ pub struct WorktreeSettingsFile {
     pub path: String,
     pub content: String,
 }
+
+pub struct NewExtensionVersion {
+    pub name: String,
+    pub version: semver::Version,
+    pub description: String,
+    pub authors: Vec<String>,
+    pub repository: String,
+    pub published_at: PrimitiveDateTime,
+}
+
+#[derive(Debug, Serialize, PartialEq)]
+pub struct ExtensionMetadata {
+    pub id: String,
+    pub name: String,
+    pub version: String,
+    pub authors: Vec<String>,
+    pub repository: String,
+    #[serde(serialize_with = "serialize_iso8601")]
+    pub published_at: PrimitiveDateTime,
+    pub download_count: u64,
+}
+
+pub fn serialize_iso8601<S: Serializer>(
+    datetime: &PrimitiveDateTime,
+    serializer: S,
+) -> Result<S::Ok, S::Error> {
+    const SERDE_CONFIG: iso8601::EncodedConfig = iso8601::Config::DEFAULT
+        .set_year_is_six_digits(false)
+        .set_time_precision(iso8601::TimePrecision::Second {
+            decimal_digits: None,
+        })
+        .encode();
+
+    datetime
+        .assume_utc()
+        .format(&time::format_description::well_known::Iso8601::<SERDE_CONFIG>)
+        .map_err(S::Error::custom)?
+        .serialize(serializer)
+}