package providerhealth

import (
	"strings"
	"testing"
	"time"
	"unicode/utf8"

	apimeta "k8s.io/apimachinery/pkg/api/meta"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"

	crawlv1alpha1 "gitea.home.hrajfrisbee.cz/kacerr/egress-proxies-operator/api/v1alpha1"
	"gitea.home.hrajfrisbee.cz/kacerr/egress-proxies-operator/internal/provider"
)

func readyAt(name string, at time.Time) crawlv1alpha1.ProviderTarget {
	return crawlv1alpha1.ProviderTarget{Name: name, Ready: true, Reason: provider.ReasonReachable, LastTransitionTime: metav1.NewTime(at)}
}

func TestBuildStatus(t *testing.T) {
	t.Parallel()
	tests := []struct {
		name             string
		prev             crawlv1alpha1.ProviderHealthStatus
		result           Result
		wantStatus       metav1.ConditionStatus
		wantReason       string
		wantMessage      string
		wantTargetsReady string
		// wantTransitions is each target's lastTransitionTime, in order.
		wantTransitions []time.Time
	}{
		{
			name:             "all ready",
			result:           Result{Type: "kvm", Supported: true, Targets: []provider.TargetStatus{up("nas1"), up("nas2")}, CheckedAt: t1},
			wantStatus:       metav1.ConditionTrue,
			wantReason:       reasonAllTargetsReady,
			wantMessage:      "2 of 2 targets ready",
			wantTargetsReady: "2/2",
			wantTransitions:  []time.Time{t1, t1},
		},
		{
			name:             "one target down",
			result:           Result{Type: "kvm", Supported: true, Targets: []provider.TargetStatus{up("nas1"), down("nas2", provider.ReasonUnreachable)}, CheckedAt: t1},
			wantStatus:       metav1.ConditionFalse,
			wantReason:       reasonTargetsNotReady,
			wantMessage:      "nas2: Unreachable",
			wantTargetsReady: "1/2",
			wantTransitions:  []time.Time{t1, t1},
		},
		{
			name: "only a flip moves a target's transition time",
			prev: crawlv1alpha1.ProviderHealthStatus{Targets: []crawlv1alpha1.ProviderTarget{readyAt("nas1", t0), readyAt("nas2", t0)}},
			result: Result{Type: "kvm", Supported: true, CheckedAt: t1,
				Targets: []provider.TargetStatus{up("nas1"), down("nas2", provider.ReasonTimeout)}},
			wantStatus:       metav1.ConditionFalse,
			wantReason:       reasonTargetsNotReady,
			wantMessage:      "nas2: Timeout",
			wantTargetsReady: "1/2",
			wantTransitions:  []time.Time{t0, t1},
		},
		{
			name:       "no checker",
			result:     Result{Type: "gcp", CheckedAt: t1},
			wantStatus: metav1.ConditionUnknown,
			wantReason: reasonChecksNotImplemented,
		},
		{
			name:             "nothing to check",
			result:           Result{Type: "kvm", Supported: true, CheckedAt: t1},
			wantStatus:       metav1.ConditionUnknown,
			wantReason:       reasonNoTargets,
			wantTargetsReady: "0/0",
		},
	}
	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()
			got := buildStatus(tc.prev, tc.result)

			cond := apimeta.FindStatusCondition(got.Conditions, crawlv1alpha1.ConditionReady)
			if cond == nil || cond.Status != tc.wantStatus || cond.Reason != tc.wantReason {
				t.Fatalf("Ready = %+v, want %s/%s", cond, tc.wantStatus, tc.wantReason)
			}
			if tc.wantMessage != "" && cond.Message != tc.wantMessage {
				t.Errorf("Ready message = %q, want %q", cond.Message, tc.wantMessage)
			}
			if got.TargetsReady != tc.wantTargetsReady {
				t.Errorf("targetsReady = %q, want %q", got.TargetsReady, tc.wantTargetsReady)
			}
			if got.Type != tc.result.Type || got.LastCheckTime == nil || !got.LastCheckTime.Time.Equal(t1) {
				t.Errorf("type/lastCheckTime = %q/%v, want %q/%s", got.Type, got.LastCheckTime, tc.result.Type, t1)
			}
			if len(got.Targets) != len(tc.wantTransitions) {
				t.Fatalf("got %d targets, want %d", len(got.Targets), len(tc.wantTransitions))
			}
			for i, want := range tc.wantTransitions {
				if lt := got.Targets[i].LastTransitionTime.Time; !lt.Equal(want) {
					t.Errorf("target %s lastTransitionTime = %s, want %s", got.Targets[i].Name, lt, want)
				}
			}
		})
	}
}

func TestBuildStatus_conditionKeepsTransitionWhileUnchanged(t *testing.T) {
	t.Parallel()
	first := buildStatus(crawlv1alpha1.ProviderHealthStatus{},
		Result{Type: "kvm", Supported: true, Targets: []provider.TargetStatus{up("nas1")}, CheckedAt: t0})
	firstCond := apimeta.FindStatusCondition(first.Conditions, crawlv1alpha1.ConditionReady)

	second := buildStatus(first, Result{Type: "kvm", Supported: true, Targets: []provider.TargetStatus{up("nas1")}, CheckedAt: t1})

	cond := apimeta.FindStatusCondition(second.Conditions, crawlv1alpha1.ConditionReady)
	if !cond.LastTransitionTime.Time.Equal(t0) {
		t.Errorf("Ready lastTransitionTime = %s, want %s from the first round", cond.LastTransitionTime, t0)
	}
	if !firstCond.LastTransitionTime.Time.Equal(t0) || len(first.Conditions) != 1 {
		t.Errorf("buildStatus modified the previous status: %+v", first.Conditions)
	}
}

func TestBuildStatus_truncatesLongMessages(t *testing.T) {
	t.Parallel()
	long := strings.Repeat("é", 3000)
	got := buildStatus(crawlv1alpha1.ProviderHealthStatus{}, Result{Type: "kvm", Supported: true, CheckedAt: t1,
		Targets: []provider.TargetStatus{{Name: "nas1", Reason: provider.ReasonUnreachable, Message: long}}})

	if n := utf8.RuneCountInString(got.Targets[0].Message); n != maxMessageLen {
		t.Errorf("message has %d characters, want %d", n, maxMessageLen)
	}
	if !strings.HasSuffix(got.Targets[0].Message, "…") {
		t.Error("truncated message does not end with an ellipsis")
	}
}