Add evaluate_state api

src/api.rs

@@ -1413,6 +1413,26 @@ pub fn refuse_state(init_commitment: String, merkle_root_hex: String) -> ApiResu
     add_validation_token(init_commitment, merkle_root_hex, false)
 }
 
+#[wasm_bindgen]
+pub fn evaluate_state(init_commitment: String, previous_state: Option<String>, state: String) -> ApiResult<ApiReturn> {
+    let prev_state: Option<ProcessState> = if let Some(s) = previous_state { Some(serde_json::from_str(&s)?) } else { None };
+    let process_state: ProcessState = serde_json::from_str(&state)?;
+
+    process_state.is_valid(prev_state.as_ref())?;
+
+    let clear_pcd = process_state.decrypt_pcd()?;
+    let roles = clear_pcd.extract_roles()?;
+
+    // We create a commit msg with the valid state
+    let outpoint: OutPoint = OutPoint::from_str(&init_commitment)?;
+    let commit_msg = CommitMessage::new_update_commitment(outpoint, process_state.pcd_commitment, roles);
+
+    Ok(ApiReturn {
+        commit_to_send: Some(commit_msg),
+        ..Default::default()
+    })
+}
+
 fn add_validation_token(init_commitment: String, merkle_root_hex: String, approval: bool) -> ApiResult<ApiReturn> {
     let mut merkle_root = [0u8; 32];
     let pcd_commitment_vec = Vec::from_hex(&merkle_root_hex)?;
@@ -1440,11 +1460,17 @@ fn add_validation_token(init_commitment: String, merkle_root_hex: String, approv
     let sp_wallet = local_device.get_wallet();
     let proof = Proof::new(message_hash, sp_wallet.get_client().get_spend_key().try_into()?);
 
+    // we copy the state before modifying it
+    let previous_state = update_state.clone();
+
     update_state.validation_tokens.push(proof);
 
+    let new_state = update_state.clone();
+
     let updated_process = UpdatedProcess {
         commitment_tx: OutPoint::from_str(&init_commitment)?,
         current_process: process.clone(),
+        modified_state: Some((previous_state, new_state)),
         ..Default::default()
     };