fix: handle session and confirm flow discrepancy in surcharge details (#2696)

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

crates/router/src/core/utils.rs

@@ -1,10 +1,18 @@
 use std::{marker::PhantomData, str::FromStr};
 
-use api_models::enums::{DisputeStage, DisputeStatus};
+use api_models::{
+    enums::{DisputeStage, DisputeStatus},
+    payment_methods::{SurchargeDetailsResponse, SurchargeMetadata},
+};
 #[cfg(feature = "payouts")]
 use common_utils::{crypto::Encryptable, pii::Email};
-use common_utils::{errors::CustomResult, ext_traits::AsyncExt};
+use common_utils::{
+    errors::CustomResult,
+    ext_traits::{AsyncExt, Encode},
+};
 use error_stack::{report, IntoReport, ResultExt};
+use euclid::enums as euclid_enums;
+use redis_interface::errors::RedisError;
 use router_env::{instrument, tracing};
 use uuid::Uuid;
 
@@ -1073,3 +1081,65 @@ pub fn get_flow_name<F>() -> RouterResult<String> {
         .attach_printable("Flow stringify failed")?
         .to_string())
 }
+
+pub async fn persist_individual_surcharge_details_in_redis(
+    state: &AppState,
+    merchant_account: &domain::MerchantAccount,
+    surcharge_metadata: &SurchargeMetadata,
+) -> RouterResult<()> {
+    if !surcharge_metadata.is_empty_result() {
+        let redis_conn = state
+            .store
+            .get_redis_conn()
+            .change_context(errors::ApiErrorResponse::InternalServerError)
+            .attach_printable("Failed to get redis connection")?;
+        let redis_key = SurchargeMetadata::get_surcharge_metadata_redis_key(
+            &surcharge_metadata.payment_attempt_id,
+        );
+
+        let mut value_list = Vec::with_capacity(surcharge_metadata.get_surcharge_results_size());
+        for (key, value) in surcharge_metadata
+            .get_individual_surcharge_key_value_pairs()
+            .into_iter()
+        {
+            value_list.push((
+                key,
+                Encode::<SurchargeDetailsResponse>::encode_to_string_of_json(&value)
+                    .change_context(errors::ApiErrorResponse::InternalServerError)
+                    .attach_printable("Failed to encode to string of json")?,
+            ));
+        }
+        let intent_fulfillment_time = merchant_account
+            .intent_fulfillment_time
+            .unwrap_or(consts::DEFAULT_FULFILLMENT_TIME);
+        redis_conn
+            .set_hash_fields(&redis_key, value_list, Some(intent_fulfillment_time))
+            .await
+            .change_context(errors::ApiErrorResponse::InternalServerError)
+            .attach_printable("Failed to write to redis")?;
+    }
+    Ok(())
+}
+
+pub async fn get_individual_surcharge_detail_from_redis(
+    state: &AppState,
+    payment_method: &euclid_enums::PaymentMethod,
+    payment_method_type: &euclid_enums::PaymentMethodType,
+    card_network: Option<euclid_enums::CardNetwork>,
+    payment_attempt_id: &str,
+) -> CustomResult<SurchargeDetailsResponse, RedisError> {
+    let redis_conn = state
+        .store
+        .get_redis_conn()
+        .attach_printable("Failed to get redis connection")?;
+    let redis_key = SurchargeMetadata::get_surcharge_metadata_redis_key(payment_attempt_id);
+    let value_key = SurchargeMetadata::get_surcharge_details_redis_hashset_key(
+        payment_method,
+        payment_method_type,
+        card_network.as_ref(),
+    );
+
+    redis_conn
+        .get_hash_field_and_deserialize(&redis_key, &value_key, "SurchargeDetailsResponse")
+        .await
+}