// Allocations is used to list the allocations for an evaluation
func (e *Eval) Allocations(args *structs.EvalSpecificRequest,
	reply *structs.EvalAllocationsResponse) error {
	if done, err := e.srv.forward("Eval.Allocations", args, args, reply); done {
		return err
	}
	defer metrics.MeasureSince([]string{"nomad", "eval", "allocations"}, time.Now())

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

			// Convert to a stub
			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
			e.srv.setQueryMeta(&reply.QueryMeta)
			return nil
		}}
	return e.srv.blockingRPC(&opts)
}

func (s *HTTPServer) evalAllocations(resp http.ResponseWriter, req *http.Request, evalID string) (interface{}, error) {
	if req.Method != "GET" {
		return nil, CodedError(405, ErrInvalidMethod)
	}

	args := structs.EvalSpecificRequest{
		EvalID: evalID,
	}
	if s.parse(resp, req, &args.Region, &args.QueryOptions) {
		return nil, nil
	}

	var out structs.EvalAllocationsResponse
	if err := s.agent.RPC("Eval.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
}