Refactor ActionRunJob parsing into a reusable function (#35623)

Use a helper method around the jobparser for parsing a single job
structure from an ActionRunJob

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

models/actions/run_job.go

@@ -14,6 +14,7 @@ import (
 	"code.gitea.io/gitea/modules/timeutil"
 	"code.gitea.io/gitea/modules/util"
 
+	"github.com/nektos/act/pkg/jobparser"
 	"xorm.io/builder"
 )
 
@@ -99,6 +100,24 @@ func (job *ActionRunJob) LoadAttributes(ctx context.Context) error {
 	return job.Run.LoadAttributes(ctx)
 }
 
+// ParseJob parses the job structure from the ActionRunJob.WorkflowPayload
+func (job *ActionRunJob) ParseJob() (*jobparser.Job, error) {
+	// job.WorkflowPayload is a SingleWorkflow created from an ActionRun's workflow, which exactly contains this job's YAML definition.
+	// Ideally it shouldn't be called "Workflow", it is just a job with global workflow fields + trigger
+	parsedWorkflows, err := jobparser.Parse(job.WorkflowPayload)
+	if err != nil {
+		return nil, fmt.Errorf("job %d single workflow: unable to parse: %w", job.ID, err)
+	} else if len(parsedWorkflows) != 1 {
+		return nil, fmt.Errorf("job %d single workflow: not single workflow", job.ID)
+	}
+	_, workflowJob := parsedWorkflows[0].Job()
+	if workflowJob == nil {
+		// it shouldn't happen, and since the callers don't check nil, so return an error instead of nil
+		return nil, util.ErrorWrap(util.ErrNotExist, "job %d single workflow: payload doesn't contain a job", job.ID)
+	}
+	return workflowJob, nil
+}
+
 func GetRunJobByID(ctx context.Context, id int64) (*ActionRunJob, error) {
 	var job ActionRunJob
 	has, err := db.GetEngine(ctx).Where("id=?", id).Get(&job)