Add job status update in service layer

Signed-off-by: Lee Smet <lee.smet@hotmail.com>

src/models/job.rs

@@ -28,7 +28,7 @@ pub struct Job {
     status: JobStatus,
 }
 
-#[derive(Clone, Serialize, Deserialize)]
+#[derive(Clone, Serialize, Deserialize, PartialEq, Eq, Debug)]
 pub enum JobStatus {
     Dispatched,
     WaitingForPrerequisites,
@@ -56,4 +56,7 @@ impl Job {
     pub fn script_type(&self) -> ScriptType {
         self.script_type.clone()
     }
+    pub fn status(&self) -> JobStatus {
+        self.status.clone()
+    }
 }

src/service.rs

@@ -1,9 +1,27 @@
 use crate::dag::{build_flow_dag, DagResult, FlowDag};
-use crate::models::{Actor, Context, Flow, Job, Message, Runner};
+use crate::models::{Actor, Context, Flow, Job, JobStatus, Message, Runner};
 use crate::storage::RedisDriver;
 
 pub type BoxError = Box<dyn std::error::Error + Send + Sync>;
 
+#[derive(Debug)]
+struct InvalidJobStatusTransition {
+    from: JobStatus,
+    to: JobStatus,
+}
+
+impl std::fmt::Display for InvalidJobStatusTransition {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "Invalid job status transition: {:?} -> {:?}",
+            self.from, self.to
+        )
+    }
+}
+
+impl std::error::Error for InvalidJobStatusTransition {}
+
 pub struct AppService {
     redis: RedisDriver,
 }
@@ -82,6 +100,56 @@ impl AppService {
         Ok(job)
     }
 
+    /// Update a job status with transition validation.
+    /// Allowed transitions:
+    /// - Dispatched -> WaitingForPrerequisites | Started | Error
+    /// - WaitingForPrerequisites -> Started | Error
+    /// - Started -> Finished | Error
+    /// - Finished, Error -> terminal (no transitions)
+    /// If the new status equals the current status, this is a no-op.
+    pub async fn update_job_status(
+        &self,
+        context_id: u32,
+        caller_id: u32,
+        id: u32,
+        new_status: JobStatus,
+    ) -> Result<(), BoxError> {
+        let job = self.redis.load_job(context_id, caller_id, id).await?;
+        let current = job.status();
+
+        if new_status == current {
+            // Idempotent: don't touch storage if no change
+            return Ok(());
+        }
+
+        let allowed = match current {
+            JobStatus::Dispatched => matches!(
+                new_status,
+                JobStatus::WaitingForPrerequisites | JobStatus::Started | JobStatus::Error
+            ),
+            JobStatus::WaitingForPrerequisites => matches!(
+                new_status,
+                JobStatus::Started | JobStatus::Error
+            ),
+            JobStatus::Started => matches!(
+                new_status,
+                JobStatus::Finished | JobStatus::Error
+            ),
+            JobStatus::Finished | JobStatus::Error => false,
+        };
+
+        if !allowed {
+            return Err(Box::new(InvalidJobStatusTransition {
+                from: current,
+                to: new_status,
+            }));
+        }
+
+        self.redis
+            .update_job_status(context_id, caller_id, id, new_status)
+            .await?;
+        Ok(())
+    }
     // -----------------------------
     // Message
     // -----------------------------