huskies: merge 867

server/src/pipeline_state/apply.rs

@@ -97,3 +97,28 @@ pub fn apply_transition_str(
 ) -> Result<TransitionFired, String> {
     apply_transition(story_id, event, content_transform).map_err(|e| e.to_string())
 }
+
+/// Freeze a story at its current stage.
+///
+/// Transitions the story to `Stage::Frozen { resume_to: current_stage }` and
+/// writes `resume_to_stage` into the front matter so the projection layer can
+/// reconstruct the full typed stage on subsequent reads.
+pub fn transition_to_frozen(story_id: &str) -> Result<TransitionFired, ApplyError> {
+    let item = read_typed(story_id)?.ok_or_else(|| ApplyError::NotFound(story_id.to_string()))?;
+    let resume_dir = item.stage.dir_name().to_string();
+    let transform = move |content: &str| -> String {
+        crate::io::story_metadata::set_front_matter_field(content, "resume_to_stage", &resume_dir)
+    };
+    apply_transition(story_id, PipelineEvent::Freeze, Some(&transform))
+}
+
+/// Unfreeze a story, restoring it to the stage it was in before freezing.
+///
+/// Transitions `Stage::Frozen { resume_to }` back to `resume_to` and removes
+/// the `resume_to_stage` field from the front matter.
+pub fn transition_to_unfrozen(story_id: &str) -> Result<TransitionFired, ApplyError> {
+    let transform = |content: &str| -> String {
+        crate::io::story_metadata::clear_front_matter_field_in_content(content, "resume_to_stage")
+    };
+    apply_transition(story_id, PipelineEvent::Unfreeze, Some(&transform))
+}