package link

import (
	"context"
	"encoding/json"
	"errors"
	"io"
	"log"
	"testing"
	"time"
)

// heldControl is a merge announcement that records how it was settled.
type heldControl struct {
	body              []byte
	took, held, drops int
}

func (c *heldControl) Kind() string                         { return "source-moved" }
func (c *heldControl) Body() []byte                         { return c.body }
func (c *heldControl) Subject() string                      { return "" }
func (c *heldControl) Redelivered() bool                    { return false }
func (c *heldControl) HeldFor() time.Duration               { return 0 }
func (c *heldControl) Answer(context.Context, []byte) error { return nil }
func (c *heldControl) Took() error                          { c.took++; return nil }
func (c *heldControl) Hold(time.Duration) error             { c.held++; return nil }
func (c *heldControl) Drop() error                          { c.drops++; return nil }

type sourceMover struct {
	Upgrader
	answer error
}

func (s sourceMover) SourceMoved(context.Context, SourceMoved) error { return s.answer }

// **A merge is acknowledged only after the controller recorded it** (novox/hq ADR 0407 decision 3, issue 1092): an
// answer of "not now" — the plan it belongs to could not be saved, the bus away, the lease lost — leaves the announcement
// unacknowledged, held to be handed over again; only an answer that is not "not now" settles it.
func TestAMergeTheControllerCouldNotRecordIsHeldAndNotAcknowledged(t *testing.T) {
	body, err := json.Marshal(SourceMoved{Owner: "novox", Repo: "mesh-catalog", Base: "main", Commit: "c1"})
	if err != nil {
		t.Fatal(err)
	}
	s := &Server{log: log.New(io.Discard, "", 0)}
	for name, tc := range map[string]struct {
		answer     error
		took, held int
	}{
		"recorded":              {nil, 1, 0},
		"not now":               {errors.Join(ErrTryAgain, errors.New("the plan is not saved")), 0, 1},
		"an answer, not a wait": {errors.New("the mesh could not act on it"), 1, 0},
	} {
		s.upgrader = sourceMover{answer: tc.answer}
		m := &heldControl{body: body}
		s.sourceMoved(context.Background(), m)
		if m.took != tc.took || m.held != tc.held || m.drops != 0 {
			t.Errorf("%s: acknowledged %d times and held %d times, want %d and %d", name, m.took, m.held, tc.took, tc.held)
		}
	}
}