From 570a7e94d0f71287e4960c5306e07ce4cd85d125 Mon Sep 17 00:00:00 2001
From: Phoebe Goldman <phoebe@goldman-tribe.org>
Date: Mon, 17 Jul 2023 10:03:00 -0400
Subject: [PATCH 1/2] [SDK] Functions for saving and loading `Credentials`
 to/from disk

---
 Cargo.lock                 | 10 ++++++++
 crates/sdk/Cargo.toml      |  1 +
 crates/sdk/src/identity.rs | 47 +++++++++++++++++++++++++++++++++++++-
 3 files changed, 57 insertions(+), 1 deletion(-)

diff --git a/Cargo.lock b/Cargo.lock
index 0a3903b86a..4a07f7b04b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1753,6 +1753,15 @@ dependencies = [
  "digest",
 ]
 
+[[package]]
+name = "home"
+version = "0.5.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5444c27eef6923071f7ebcc33e3444508466a76f7a2b93da00ed6e19f30c1ddb"
+dependencies = [
+ "windows-sys 0.48.0",
+]
+
 [[package]]
 name = "hostname"
 version = "0.3.1"
@@ -4137,6 +4146,7 @@ dependencies = [
  "base64 0.21.2",
  "futures",
  "futures-channel",
+ "home",
  "http",
  "im",
  "log",
diff --git a/crates/sdk/Cargo.toml b/crates/sdk/Cargo.toml
index c7f03d6ba1..d137434727 100644
--- a/crates/sdk/Cargo.toml
+++ b/crates/sdk/Cargo.toml
@@ -22,3 +22,4 @@ futures-channel = "0.3"
 anymap = "0.12"
 im = "15.1"
 base64 = "0.21"
+home = "0.5"
diff --git a/crates/sdk/src/identity.rs b/crates/sdk/src/identity.rs
index 21a68cf8f4..7577063ef9 100644
--- a/crates/sdk/src/identity.rs
+++ b/crates/sdk/src/identity.rs
@@ -1,6 +1,7 @@
 use crate::callbacks::CallbackId;
 use crate::global_connection::try_with_credential_store;
-use anyhow::{anyhow, Result};
+use crate::sats::bsatn;
+use anyhow::{anyhow, Context, Result};
 use spacetimedb_lib::de::Deserialize;
 use spacetimedb_lib::ser::Serialize;
 // TODO: impl ser/de for `Identity`, `Token`, `Credentials` so that clients can stash them
@@ -167,3 +168,47 @@ pub fn credentials() -> Result<Credentials> {
     try_with_credential_store(|cred_store| cred_store.credentials().ok_or(anyhow!("Credentials not yet received")))
         .and_then(|inner| inner)
 }
+
+const CREDS_FILE: &str = "credentials";
+
+/// Load a saved `Credentials` from a file within `~/dirname`, if one exists.
+///
+/// `dirname` is treated as a directory in the user's home directory.
+/// If it contains a file named `credentials`,
+/// that file is treated as a BSATN-encoded `Credentials`, deserialized and returned.
+///
+/// Returns `Ok(None)` if the directory or the credentials file does not exist.
+/// Returns `Err` when IO or deserialization fails.
+pub fn load_credentials(dirname: &str) -> Result<Option<Credentials>> {
+    let mut path = home::home_dir().with_context(|| "Determining user home directory to compute credentials path")?;
+    path.push(dirname);
+    path.push(CREDS_FILE);
+
+    match std::fs::read(&path) {
+        Err(e) if e.kind() == std::io::ErrorKind::NotFound => Ok(None),
+        Err(e) => Err(e).with_context(|| "Reading BSATN-encoded credentials from file")?,
+        Ok(file_contents) => bsatn::from_slice::<Credentials>(&file_contents)
+            .with_context(|| "Deserializing credentials")
+            .map(Some),
+    }
+}
+
+/// Stores a `Credentials` to a file within `~/dirname`, to be later loaded with [`load_credentials`].
+///
+/// `dirname` is treated as a directory in the user's home directory.
+/// The directory is created if it does not already exists.
+/// A file within it named `credentials` is created or replaced,
+/// containing `creds` encoded as BSATN.
+///
+/// Returns `Err` when IO or serialization fails.
+pub fn save_credentials(dirname: &str, creds: &Credentials) -> Result<()> {
+    let creds_bytes = bsatn::to_vec(creds).with_context(|| "Serializing credentials")?;
+
+    let mut path = home::home_dir().with_context(|| "Determining user home directory to compute credentials path")?;
+    path.push(dirname);
+
+    std::fs::create_dir_all(&path).with_context(|| "Creating credentials directory")?;
+
+    path.push(CREDS_FILE);
+    std::fs::write(&path, creds_bytes).with_context(|| "Writing credentials to file")
+}

From cb5ad1269fb0b597d3d02090e7c9d5bb0bb37de3 Mon Sep 17 00:00:00 2001
From: Boppy <no-reply@boppygames.gg>
Date: Mon, 17 Jul 2023 14:51:38 -0500
Subject: [PATCH 2/2] Added import

---
 crates/sdk/src/identity.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/crates/sdk/src/identity.rs b/crates/sdk/src/identity.rs
index b16529214d..fe000639c3 100644
--- a/crates/sdk/src/identity.rs
+++ b/crates/sdk/src/identity.rs
@@ -3,6 +3,7 @@ use crate::global_connection::with_credential_store;
 use anyhow::{anyhow, Context, Result};
 use spacetimedb_lib::de::Deserialize;
 use spacetimedb_lib::ser::Serialize;
+use spacetimedb_sats::bsatn;
 // TODO: impl ser/de for `Identity`, `Token`, `Credentials` so that clients can stash them
 //       to disk and use them to re-connect.