package check

import (
	"context"
	"errors"
	"strings"
	"testing"
	"time"

	"git.novox.be/novox/mesh-sdk/go/delivery"
)

func assignerOn(instance string, online bool) PresenceEvent {
	key, _ := delivery.PresencePartKey(delivery.AssignerModule, instance)
	return PresenceEvent{Key: key, Online: online}
}

func compEvent(t *testing.T, v delivery.CompositionVerdict) CompositionEvent {
	t.Helper()
	data, err := delivery.EncodeCompositionVerdict(v)
	if err != nil {
		t.Fatal(err)
	}
	return CompositionEvent{Value: data}
}

var passed = delivery.CompositionVerdict{Group: "feat/x", Heads: "0123456789ab", State: delivery.CompositionPass, SDK: "x", Machines: []string{"g14"}}

// 1297/B3d: with no assigner online, the wait answers ErrAssignerNotRunning as soon as both watches handed what stands.
func TestNoAssignerAnswersAtOnce(t *testing.T) {
	presence, comps := make(chan PresenceEvent, 4), make(chan CompositionEvent, 4)
	presence <- assignerOn("novox", false)
	presence <- PresenceEvent{Settled: true}
	comps <- CompositionEvent{Settled: true}
	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
	defer cancel()
	if _, err := AwaitComposition(ctx, presence, comps); !errors.Is(err, ErrAssignerNotRunning) {
		t.Fatalf("answered %v, want the assigner not running", err)
	}
}

// 1297/B3d: with the assigner online it waits for the key, past a composition that waits, and answers the verdict.
func TestAnOnlineAssignerIsWaitedFor(t *testing.T) {
	presence, comps := make(chan PresenceEvent, 4), make(chan CompositionEvent, 4)
	presence <- assignerOn("novox", true)
	presence <- PresenceEvent{Settled: true}
	comps <- CompositionEvent{Settled: true}
	done := make(chan error, 1)
	var got delivery.CompositionVerdict
	go func() {
		var err error
		got, err = AwaitComposition(context.Background(), presence, comps)
		done <- err
	}()
	comps <- compEvent(t, delivery.CompositionVerdict{Group: "feat/x", Heads: "0123456789ab", State: delivery.CompositionWaits, Words: "w"})
	select {
	case err := <-done:
		t.Fatalf("answered before the composition was written: %v", err)
	case <-time.After(50 * time.Millisecond):
	}
	comps <- compEvent(t, passed)
	if err := <-done; err != nil || got.State != delivery.CompositionPass {
		t.Fatalf("answered %+v, %v", got, err)
	}
	// And the last instance going offline during a wait ends it as not running.
	presence2, comps2 := make(chan PresenceEvent, 4), make(chan CompositionEvent, 4)
	presence2 <- assignerOn("novox", true)
	presence2 <- PresenceEvent{Settled: true}
	comps2 <- CompositionEvent{Settled: true}
	presence2 <- assignerOn("novox", false)
	if _, err := AwaitComposition(context.Background(), presence2, comps2); !errors.Is(err, ErrAssignerNotRunning) {
		t.Errorf("the assigner going offline answered %v", err)
	}
}

// 1297/B3d: a passing check with no assigner says at once, loud, that its composition is not judged; never a pass of it.
func TestAPassingCheckWithNoAssignerSaysTheCompositionIsNotJudged(t *testing.T) {
	b := newBench(t)
	b.ex.Compositions = &fakeCompositions{err: ErrAssignerNotRunning}
	v := b.judge(t, caseOf(t, pullOf(repoA, 7, head1))).Verdict
	if v.Composition == nil || v.Composition.State != delivery.CompositionNotRun || v.Composition.Words != delivery.AssignerNotRunning {
		t.Fatalf("composition = %+v", v.Composition)
	}
	if words := compositionWords(v.Composition, 0); words != "composition not judged: the assigner is not running" {
		t.Errorf("the line says %q", words)
	}
}

// 1297/B3d: the assigner starting writes the composition later, and the checker takes it into the verdict that said it
// was not judged, writing the status again; a failed one fails the check.
func TestTheAssignerStartingBringsTheComposition(t *testing.T) {
	for _, comp := range []delivery.CompositionVerdict{passed,
		{Group: "feat/x", Heads: "", State: delivery.CompositionFail, SDK: "x", Machine: "g14", Words: "g14 runs web, which the change removes"}} {
		ch, cs := checkerWithNotJudged(t)
		comp.Heads = cs.HeadsHash
		ch.Composed(context.Background(), comp)
		raw, _, _, _ := ch.Verdicts.Get(context.Background(), cs.Key)
		v, err := delivery.DecodeVerdict(raw)
		if err != nil || v.Composition == nil || v.Composition.State != comp.State {
			t.Fatalf("after the composition came, the verdict is %+v, %v", v, err)
		}
		if comp.State == delivery.CompositionFail && (v.State != delivery.VerdictFail || v.Failed.Machine != "g14") {
			t.Errorf("a failed composition left the verdict %+v", v)
		}
		owed := ch.Owed.(*memKV)
		keys, _ := owed.Keys(context.Background())
		if len(keys) == 0 {
			t.Fatal("no status was written again")
		}
		data, _, _, _ := owed.Get(context.Background(), keys[0])
		o, _ := delivery.DecodeCheckerOwed(data)
		if !strings.Contains(o.Text, "composition passed") && !strings.Contains(o.Text, "g14 runs web") {
			t.Errorf("the status's line says %q", o.Text)
		}
	}
}

// checkerWithNotJudged is a checker holding a candidate whose passing verdict said its composition was not judged.
func checkerWithNotJudged(t *testing.T) (*Checker, *Case) {
	t.Helper()
	cs := caseOf(t, pullOf(repoA, 7, head1))
	raw := candidateOf(t, cs.Group, pullOf(repoA, 7, head1))
	ch := &Checker{Verdicts: newMemKV(), Owed: newMemKV(), Trunks: fixedTrunks{cs.Trunk}}
	ckey, _ := delivery.CandidatesKey(cs.Group)
	ch.init()
	c, err := delivery.DecodeCandidate(raw)
	if err != nil {
		t.Fatal(err)
	}
	ch.known[ckey] = c
	if got := CaseOf(c, ch.heads()); got == nil || got.Key != cs.Key {
		t.Fatalf("the case is %+v, want %s", got, cs.Key)
	}
	v := delivery.Verdict{Group: cs.Group, Heads: cs.Heads, State: delivery.VerdictPass,
		Levels:      map[string]delivery.LevelResult{delivery.LevelUnit: {Run: 1}, delivery.LevelIntegration: {Run: 1}},
		Composition: &delivery.Composition{State: delivery.CompositionNotRun, Words: delivery.AssignerNotRunning}}
	data, err := delivery.EncodeVerdict(v)
	if err != nil {
		t.Fatal(err)
	}
	if _, err := ch.Verdicts.Create(context.Background(), cs.Key, data); err != nil {
		t.Fatal(err)
	}
	return ch, cs
}

type fixedTrunks struct{ heads map[string]string }

func (f fixedTrunks) Heads() map[string]string { return f.heads }