1 files changed, 125 insertions, 0 deletions
diff --git a/src/repo/token.rs b/src/repo/token.rs
new file mode 100644
index 0000000..e7eb273
--- /dev/null
+++ b/src/repo/token.rs
@@ -0,0 +1,125 @@
+use chrono::TimeDelta;
+use sqlx::{sqlite::Sqlite, SqliteConnection, Transaction};
+use uuid::Uuid;
+
+use super::login::{self, Login};
+use crate::clock::DateTime;
+
+pub trait Provider {
+    fn tokens(&mut self) -> Tokens;
+}
+
+impl<'c> Provider for Transaction<'c, Sqlite> {
+    fn tokens(&mut self) -> Tokens {
+        Tokens(self)
+    }
+}
+
+pub struct Tokens<'t>(&'t mut SqliteConnection);
+
+impl<'c> Tokens<'c> {
+    /// Issue a new token for an existing login. The issued_at timestamp will
+    /// be used to control expiry, until the token is actually used.
+    pub async fn issue(
+        &mut self,
+        login: &login::Id,
+        issued_at: DateTime,
+    ) -> Result<String, sqlx::Error> {
+        let secret = Uuid::new_v4().to_string();
+
+        let secret = sqlx::query_scalar!(
+            r#"
+                insert
+                into token (secret, login, issued_at, last_used_at)
+                values ($1, $2, $3, $3)
+                returning secret as "secret!"
+            "#,
+            secret,
+            login,
+            issued_at,
+        )
+        .fetch_one(&mut *self.0)
+        .await?;
+
+        Ok(secret)
+    }
+
+    /// Revoke a token by its secret.
+    pub async fn revoke(&mut self, secret: &str) -> Result<(), sqlx::Error> {
+        sqlx::query!(
+            r#"
+                delete
+                from token
+                where secret = $1
+                returning 1 as "found: u32"
+            "#,
+            secret,
+        )
+        .fetch_one(&mut *self.0)
+        .await?;
+
+        Ok(())
+    }
+
+    /// Expire and delete all tokens that haven't been used within the expiry
+    /// interval (right now, 7 days) prior to `expire_at`. Tokens that are in
+    /// use within that period will be retained.
+    pub async fn expire(&mut self, expire_at: DateTime) -> Result<(), sqlx::Error> {
+        // Somewhat arbitrarily, expire after 7 days.
+        let expired_issue_at = expire_at - TimeDelta::days(7);
+        sqlx::query!(
+            r#"
+                delete
+                from token
+                where last_used_at < $1
+            "#,
+            expired_issue_at,
+        )
+        .execute(&mut *self.0)
+        .await?;
+
+        Ok(())
+    }
+
+    /// Validate a token by its secret, retrieving the associated Login record.
+    /// Will return [None] if the token is not valid. The token's last-used
+    /// timestamp will be set to `used_at`.
+    pub async fn validate(
+        &mut self,
+        secret: &str,
+        used_at: DateTime,
+    ) -> Result<Option<Login>, sqlx::Error> {
+        // I would use `update … returning` to do this in one query, but
+        // sqlite3, as of this writing, does not allow an update's `returning`
+        // clause to reference columns from tables joined into the update. Two
+        // queries is fine, but it feels untidy.
+        sqlx::query!(
+            r#"
+                update token
+                set last_used_at = $1
+                where secret = $2
+            "#,
+            used_at,
+            secret,
+        )
+        .execute(&mut *self.0)
+        .await?;
+
+        let login = sqlx::query_as!(
+            Login,
+            r#"
+                select
+                    login.id as "id: login::Id",
+                    name
+                from login
+                join token on login.id = token.login
+                where token.secret = $1
+            "#,
+            secret,
+        )
+        .fetch_optional(&mut *self.0)
+        .await?;
+
+        Ok(login)
+    }
+}