From ebcdc25e90489db922a7a9c8177f8576aa106ed9 Mon Sep 17 00:00:00 2001
From: Aravinth Manivannan <realaravinth@batsense.net>
Date: Tue, 23 Jul 2024 17:43:14 +0530
Subject: [PATCH] feat: implement Aggregate for LineItem aggregate

---
 src/ordering/domain/add_line_item_command.rs |  3 +
 src/ordering/domain/line_item_aggregate.rs   | 97 ++++++++++++++++++++
 2 files changed, 100 insertions(+)

diff --git a/src/ordering/domain/add_line_item_command.rs b/src/ordering/domain/add_line_item_command.rs
index d059735..16cc2b9 100644
--- a/src/ordering/domain/add_line_item_command.rs
+++ b/src/ordering/domain/add_line_item_command.rs
@@ -64,6 +64,8 @@ pub struct AddLineItemCommand {
 
 #[cfg(test)]
 mod tests {
+    use time::macros::datetime;
+
     use crate::utils::uuid::tests::UUID;
 
     use super::*;
@@ -78,6 +80,7 @@ mod tests {
             UnvalidatedAddLineItemCommandBuilder::default()
                 .product_name(product_name.into())
                 .adding_by(adding_by)
+                .sale_time(datetime!(1970-01-01 0:00 UTC))
                 .quantity(quantity.clone())
                 .product_id(product_id)
                 .build()
diff --git a/src/ordering/domain/line_item_aggregate.rs b/src/ordering/domain/line_item_aggregate.rs
index b0f4fc4..29efd76 100644
--- a/src/ordering/domain/line_item_aggregate.rs
+++ b/src/ordering/domain/line_item_aggregate.rs
@@ -10,6 +10,10 @@ use serde::{Deserialize, Serialize};
 use time::OffsetDateTime;
 use uuid::Uuid;
 
+use crate::ordering::{
+    application::services::{errors::*, *},
+    domain::{commands::*, events::*},
+};
 use crate::types::quantity::Quantity;
 
 #[derive(
@@ -26,6 +30,19 @@ pub struct LineItem {
     deleted: bool,
 }
 
+impl Default for LineItem {
+    fn default() -> Self {
+        Self {
+            sale_time: OffsetDateTime::now_utc(),
+            product_name: String::default(),
+            product_id: Default::default(),
+            line_item_id: Default::default(),
+            quantity: Default::default(),
+            deleted: false,
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use crate::{
@@ -49,3 +66,83 @@ mod tests {
         }
     }
 }
+
+#[async_trait]
+impl Aggregate for LineItem {
+    type Command = OrderingCommand;
+    type Event = OrderingEvent;
+    type Error = OrderingError;
+    type Services = std::sync::Arc<dyn OrderingServicesInterface>;
+
+    // This identifier should be unique to the system.
+    fn aggregate_type() -> String {
+        "ordering.line_item".to_string()
+    }
+
+    // The aggregate logic goes here. Note that this will be the _bulk_ of a CQRS system
+    // so expect to use helper functions elsewhere to keep the code clean.
+    async fn handle(
+        &self,
+        command: Self::Command,
+        services: &Self::Services,
+    ) -> Result<Vec<Self::Event>, Self::Error> {
+        match command {
+            OrderingCommand::AddLineItem(cmd) => {
+                let res = services.add_line_item().add_line_item(cmd).await?;
+                Ok(vec![OrderingEvent::LineItemAdded(res)])
+            }
+            OrderingCommand::UpdateLineItem(cmd) => {
+                unimplemented!()
+            }
+            OrderingCommand::DeleteLineItem(cmd) => {
+                unimplemented!()
+            } //    _ => Ok(Vec::default()),
+        }
+    }
+
+    fn apply(&mut self, event: Self::Event) {
+        match event {
+            OrderingEvent::LineItemAdded(e) => *self = e.line_item().clone(),
+            OrderingEvent::LineItemUpdated(e) => *self = e.new_line_item().clone(),
+            OrderingEvent::LineItemDeleted(e) => *self = e.line_item().clone(),
+            //            _ => (),
+        }
+    }
+}
+
+#[cfg(test)]
+mod aggregate_tests {
+    use std::sync::Arc;
+
+    use add_line_item_service::tests::mock_add_line_item_service;
+    use cqrs_es::test::TestFramework;
+
+    use super::*;
+
+    use crate::tests::bdd::*;
+
+    use crate::ordering::domain::{
+        add_line_item_command::*,
+        line_item_added_event::tests::get_added_line_item_event_from_command,
+    };
+
+    type LineItemTestFramework = TestFramework<LineItem>;
+
+    #[test]
+    fn test_create_product() {
+        let cmd = AddLineItemCommand::get_cmd();
+        let expected = get_added_line_item_event_from_command(&cmd);
+        let expected = OrderingEvent::LineItemAdded(expected);
+
+        let mut services = MockOrderingServicesInterface::new();
+        services
+            .expect_add_line_item()
+            .times(IS_CALLED_ONLY_ONCE.unwrap())
+            .return_const(mock_add_line_item_service(IS_CALLED_ONLY_ONCE, cmd.clone()));
+
+        LineItemTestFramework::with(Arc::new(services))
+            .given_no_previous_events()
+            .when(OrderingCommand::AddLineItem(cmd))
+            .then_expect_events(vec![expected]);
+    }
+}