From 6a5f50524d301f6f2f6941979af81e7a7e6ba1db Mon Sep 17 00:00:00 2001
From: Frederik Gartenmeister <mustermeiszer@posteo.de>
Date: Wed, 15 Nov 2023 16:14:47 +0100
Subject: [PATCH] wip

---
 runtime/common/src/migrations/balances.rs | 76 +++++++++++++++++++++++
 runtime/common/src/migrations/mod.rs      |  1 +
 2 files changed, 77 insertions(+)
 create mode 100644 runtime/common/src/migrations/balances.rs

diff --git a/runtime/common/src/migrations/balances.rs b/runtime/common/src/migrations/balances.rs
new file mode 100644
index 0000000000..54c210f245
--- /dev/null
+++ b/runtime/common/src/migrations/balances.rs
@@ -0,0 +1,76 @@
+// Copyright 2021 Centrifuge Foundation (centrifuge.io).
+//
+// This file is part of the Centrifuge chain project.
+// Centrifuge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version (see http://www.gnu.org/licenses).
+// Centrifuge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+use frame_support::{traits::OnRuntimeUpgrade, weights::Weight};
+use sp_runtime::DispatchError;
+
+/// All balance information for an account.
+#[derive(Encode, Decode, Clone, PartialEq, Eq, Default, RuntimeDebug, MaxEncodedLen, TypeInfo)]
+pub struct OldAccountData<Balance> {
+	/// Non-reserved part of the balance. There may still be restrictions on
+	/// this, but it is the total pool what may in principle be transferred,
+	/// reserved and used for tipping.
+	///
+	/// This is the only balance that matters in terms of most operations on
+	/// tokens. It alone is used to determine the balance when in the contract
+	/// execution environment.
+	pub free: Balance,
+	/// Balance which is reserved and may not be used at all.
+	///
+	/// This can still get slashed, but gets slashed last of all.
+	///
+	/// This balance is a 'reserve' balance that other subsystems use in order
+	/// to set aside tokens that are still 'owned' by the account holder, but
+	/// which are suspendable. This includes named reserve and unnamed reserve.
+	pub reserved: Balance,
+	/// The amount that `free` may not drop below when withdrawing for *anything
+	/// except transaction fee payment*.
+	pub misc_frozen: Balance,
+	/// The amount that `free` may not drop below when withdrawing specifically
+	/// for transaction fee payment.
+	pub fee_frozen: Balance,
+}
+
+pub struct Migration<T: pallet_balances::Config>(sp_std::marker::PhantomData<T>);
+
+impl<T> OnRuntimeUpgrade for Migration<T>
+where
+	T: pallet_balances::Config,
+{
+	#[cfg(feature = "try-runtime")]
+	fn pre_upgrade() -> Result<Vec<u8>, DispatchError> {
+		// CHECKING DECODING OLD DATASTRUCTURE WITH NEW LAYOUT WORKS:
+		// * Fetch storage from chain with NEW data structure
+		// * Check if fetched accounts matches on-chain storage entries
+
+		// TODO:
+		// * Research whether orml-pallets datastructure also changed
+		// * Research whether we need to migrate locks in orml (maybe first check if
+		//   there exist any. ^^
+
+		let accounts = frame_system::Account::<T>::full_storage_key;
+
+		Ok(Vec::new())
+	}
+
+	fn on_runtime_upgrade() -> Weight {
+		// WE CAN NOT MIGRATE. THIS CODE IS JUST FOR CHECKING IF WE NEED ANYTHING
+		// BESIDES THE LAZY MIGRATION FROM PARITY
+		// See: https://kflabs.slack.com/archives/C05TBFRBL15/p1699956615421249
+		Weight::from_parts(0, 0)
+	}
+
+	#[cfg(feature = "try-runtime")]
+	fn post_upgrade(_: Vec<u8>) -> Result<(), DispatchError> {
+		Ok(())
+	}
+}
diff --git a/runtime/common/src/migrations/mod.rs b/runtime/common/src/migrations/mod.rs
index f0f372bcef..c312a4ea4d 100644
--- a/runtime/common/src/migrations/mod.rs
+++ b/runtime/common/src/migrations/mod.rs
@@ -13,5 +13,6 @@
 //! Centrifuge Runtime-Common Migrations
 
 pub mod asset_registry_xcmv3;
+pub mod balances;
 pub mod nuke;
 pub mod precompile_account_codes;