// Allocations is used to list the allocations for a job
func (j *Job) Allocations(args *structs.JobSpecificRequest,
	reply *structs.JobAllocationsResponse) error {
	if done, err := j.srv.forward("Job.Allocations", args, args, reply); done {
		return err
	}
	defer metrics.MeasureSince([]string{"nomad", "job", "allocations"}, time.Now())

	// Setup the blocking query
	opts := blockingOptions{
		queryOpts: &args.QueryOptions,
		queryMeta: &reply.QueryMeta,
		watch:     watch.NewItems(watch.Item{AllocJob: args.JobID}),
		run: func() error {
			// Capture the allocations
			snap, err := j.srv.fsm.State().Snapshot()
			if err != nil {
				return err
			}
			allocs, err := snap.AllocsByJob(args.JobID)
			if err != nil {
				return err
			}

			// Convert to stubs
			if len(allocs) > 0 {
				reply.Allocations = make([]*structs.AllocListStub, 0, len(allocs))
				for _, alloc := range allocs {
					reply.Allocations = append(reply.Allocations, alloc.Stub())
				}
			}

			// Use the last index that affected the allocs table
			index, err := snap.Index("allocs")
			if err != nil {
				return err
			}
			reply.Index = index

			// Set the query response
			j.srv.setQueryMeta(&reply.QueryMeta)
			return nil

		}}
	return j.srv.blockingRPC(&opts)
}

func (s *HTTPServer) jobAllocations(resp http.ResponseWriter, req *http.Request,
	jobName string) (interface{}, error) {
	if req.Method != "GET" {
		return nil, CodedError(405, ErrInvalidMethod)
	}
	args := structs.JobSpecificRequest{
		JobID: jobName,
	}
	if s.parse(resp, req, &args.Region, &args.QueryOptions) {
		return nil, nil
	}

	var out structs.JobAllocationsResponse
	if err := s.agent.RPC("Job.Allocations", &args, &out); err != nil {
		return nil, err
	}

	setMeta(resp, &out.QueryMeta)
	if out.Allocations == nil {
		out.Allocations = make([]*structs.AllocListStub, 0)
	}
	return out.Allocations, nil
}