chore: lay groundworks for handle registry

src/interfaces/IHandle.cairo

@@ -1,7 +1,7 @@
 use starknet::ContractAddress;
 
 // *************************************************************************
-//                              INTERFACE of FollowNFT 
+//                              INTERFACE of HANDLE NFT 
 // *************************************************************************
 #[starknet::interface]
 pub trait IHandle<TState> {

src/interfaces/IHandleRegistry.cairo

@@ -0,0 +1,17 @@
+use starknet::ContractAddress;
+// *************************************************************************
+//                              INTERFACE OF HANDLE REGISTRY
+// *************************************************************************
+#[starknet::interface]
+pub trait IHandleRegistry<TState> {
+    // *************************************************************************
+    //                              EXTERNALS
+    // *************************************************************************
+    fn link(ref self: TState, handle_id: u256, profile_address: ContractAddress);
+    fn unlink(ref self: TState, handle_id: u256, profile_address: ContractAddress);
+    // *************************************************************************
+    //                              GETTERS
+    // *************************************************************************
+    fn resolve(self: @TState, handle_id: u256) -> ContractAddress;
+    fn get_handle(self: @TState, profile_address: ContractAddress) -> u256;
+}

src/namespaces/handle_registry.cairo

@@ -1 +1,94 @@
+#[starknet::contract]
+mod HandleRegistry {
+    // *************************************************************************
+    //                            IMPORT
+    // *************************************************************************
+    use core::traits::TryInto;
+    use starknet::{ContractAddress, get_caller_address};
+    use karst::interfaces::IHandleRegistry::IHandleRegistry;
 
+    // *************************************************************************
+    //                            STORAGE
+    // *************************************************************************
+    #[storage]
+    struct Storage {
+        hub_address: ContractAddress,
+        handle_address: ContractAddress,
+        handle_to_profile_address: LegacyMap::<u256, ContractAddress>,
+        profile_address_to_handle: LegacyMap::<ContractAddress, u256>,
+    }
+
+    // *************************************************************************
+    //                            EVENTS
+    // *************************************************************************
+    #[event]
+    #[derive(Drop, starknet::Event)]
+    enum Event {
+        Linked: Linked,
+        Unlinked: Unlinked,
+    }
+
+    #[derive(Drop, starknet::Event)]
+    struct HandleLinked {
+        handle_id: u256, 
+        profile_address: ContractAddress,
+        caller: ContractAddress,
+        timestamp: u64
+    }
+
+    #[derive(Drop, starknet::Event)]
+    struct HandleUnlinked {
+        handle_id: u256, 
+        profile_address: ContractAddress,
+        caller: ContractAddress,
+        timestamp: u64
+    }
+
+    // *************************************************************************
+    //                            CONSTRUCTOR
+    // *************************************************************************
+    #[constructor]
+    fn constructor(hub_address: ContractAddress, handle_address: ContractAddress) {
+        self.hub_address.write(hub_address);
+        self.handle_address.write(handle_address);
+    }
+
+    // *************************************************************************
+    //                            EXTERNALS
+    // *************************************************************************
+    #[abi(embed_v0)]
+    impl HandleRegistryImpl of IHandleRegistry<ContractState> {
+        fn link(ref self: ContractState, handle_id: u256, profile_address: ContractAddress) {
+            self._link(handle_id, profile_address);
+        }
+
+        fn unlink(ref self: ContractState, handle_id: u256, profile_address: ContractAddress) {
+            let caller = get_caller_address();
+            self._unlink(handle_id, profile_address, caller);
+        }
+
+        // *************************************************************************
+        //                            GETTERS
+        // *************************************************************************
+        fn resolve(self: @ContractState, handle_id: u256) -> ContractAddress {
+            // TODO
+        }
+
+        fn get_handle(self: @ContractState, profile_address: ContractAddress) -> u256 {
+            // TODO
+        }
+    }
+
+    // *************************************************************************
+    //                            PRIVATE FUNCTIONS
+    // *************************************************************************   
+    impl Private of PrivateTrait {
+        fn _link(ref self: ContractState, handle_id: u256, profile_address: ContractAddress) {
+            // TODO
+        }
+
+        fn _unlink(ref self: ContractState, handle_id: u256, profile_address: ContractAddress) {
+            // TODO
+        }
+    }
+}

src/namespaces/handles.cairo

@@ -185,15 +185,15 @@ mod Handles {
     // *************************************************************************
     #[generate_trait]
     impl Private of PrivateTrait {
-        fn _mint_handle(address: ContractAddress, local_name: felt252) -> u256 {
+        fn _mint_handle(ref self: ContractState, address: ContractAddress, local_name: felt252) -> u256 {
             // TODO
             return 123;
         }
 
-        fn _validate_local_name(local_name: felt252) { // TODO
+        fn _validate_local_name(ref self: ContractState, local_name: felt252) { // TODO
         }
 
-        fn _is_alpha_numeric(char: felt252) -> bool {
+        fn _is_alpha_numeric(self: @ContractState, char: felt252) -> bool {
             // TODO
             return false;
         }