package controller

import (
	"strings"
	"testing"
	"time"

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

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

type fakeSnapshotter struct {
	snap health.Snapshot
	ok   bool
}

func (f fakeSnapshotter) Snapshot(types.NamespacedName) (health.Snapshot, bool) {
	return f.snap, f.ok
}

// TestReconcile_healthRepresentation covers the reconciler's half of the
// health split: turning the engine's Snapshot into the Healthy condition,
// the latency fields, and ultimately the Ready/Unhealthy phases.
func TestReconcile_healthRepresentation(t *testing.T) {
	t.Parallel()

	probeTime := time.Now()
	freshHash := specHash(managedProxy(), "")
	runningStub := func() *stubProvider {
		return &stubProvider{
			getInst: &provider.Instance{ID: "stub-id-1", IP: "10.1.2.3", State: provider.StateRunning},
		}
	}

	tests := []struct {
		name      string
		proxy     *crawlv1alpha1.Proxy
		stub      *stubProvider
		health    HealthSnapshotter
		wantPhase crawlv1alpha1.ProxyPhase
		verify    func(t *testing.T, r *ProxyReconciler)
	}{
		{
			name:  "running and healthy becomes Ready",
			proxy: managedProxy(withProviderID("stub-id-1"), withSpecHashAnnotation(freshHash)),
			stub:  runningStub(),
			health: fakeSnapshotter{ok: true, snap: health.Snapshot{
				Healthy: true, Latency: 37 * time.Millisecond, LastProbe: probeTime,
			}},
			wantPhase: crawlv1alpha1.PhaseReady,
			verify: func(t *testing.T, r *ProxyReconciler) {
				p := getProxy(t, r)
				assertCondition(t, p, crawlv1alpha1.ConditionHealthy, metav1.ConditionTrue, ReasonProbeSucceeded)
				if p.Status.LatencyMillis != 37 {
					t.Errorf("latencyMillis = %d, want 37", p.Status.LatencyMillis)
				}
				if p.Status.LastHealthCheckTime == nil {
					t.Error("lastHealthCheckTime not set")
				}
			},
		},
		{
			name:  "running but unhealthy becomes Unhealthy",
			proxy: managedProxy(withProviderID("stub-id-1"), withSpecHashAnnotation(freshHash)),
			stub:  runningStub(),
			health: fakeSnapshotter{ok: true, snap: health.Snapshot{
				Healthy: false, LastProbe: probeTime,
				LastError: "CONNECT refused", ConsecutiveFailures: 3,
			}},
			wantPhase: crawlv1alpha1.PhaseUnhealthy,
			verify: func(t *testing.T, r *ProxyReconciler) {
				p := getProxy(t, r)
				assertCondition(t, p, crawlv1alpha1.ConditionHealthy, metav1.ConditionFalse, ReasonProbeFailed)
				cond := apimeta.FindStatusCondition(p.Status.Conditions, crawlv1alpha1.ConditionHealthy)
				if !strings.Contains(cond.Message, "CONNECT refused") {
					t.Errorf("condition message %q does not carry the probe error", cond.Message)
				}
			},
		},
		{
			name:      "no verdict yet stays Provisioning without a Healthy condition",
			proxy:     managedProxy(withProviderID("stub-id-1"), withSpecHashAnnotation(freshHash)),
			stub:      runningStub(),
			health:    fakeSnapshotter{ok: false},
			wantPhase: crawlv1alpha1.PhaseProvisioning,
			verify: func(t *testing.T, r *ProxyReconciler) {
				p := getProxy(t, r)
				if apimeta.FindStatusCondition(p.Status.Conditions, crawlv1alpha1.ConditionHealthy) != nil {
					t.Error("Healthy condition present without an engine verdict")
				}
			},
		},
		{
			name: "external proxy with a healthy verdict becomes Ready",
			proxy: managedProxy(func(p *crawlv1alpha1.Proxy) {
				p.Finalizers = nil
				p.Spec = crawlv1alpha1.ProxySpec{
					Mode:     crawlv1alpha1.ModeExternal,
					Endpoint: &crawlv1alpha1.EndpointSpec{Host: "203.0.113.7"},
				}
			}),
			stub: &stubProvider{},
			health: fakeSnapshotter{ok: true, snap: health.Snapshot{
				Healthy: true, Latency: 5 * time.Millisecond, LastProbe: probeTime,
			}},
			wantPhase: crawlv1alpha1.PhaseReady,
			verify: func(t *testing.T, r *ProxyReconciler) {
				assertCondition(t, getProxy(t, r), crawlv1alpha1.ConditionHealthy, metav1.ConditionTrue, ReasonProbeSucceeded)
			},
		},
		{
			name: "creating a replacement clears the stale Healthy verdict",
			proxy: managedProxy(func(p *crawlv1alpha1.Proxy) {
				p.Status.Conditions = []metav1.Condition{{
					Type: crawlv1alpha1.ConditionHealthy, Status: metav1.ConditionTrue,
					Reason: ReasonProbeSucceeded, LastTransitionTime: metav1.Now(),
				}}
				p.Status.LatencyMillis = 42
				p.Status.LastHealthCheckTime = &metav1.Time{Time: probeTime}
			}),
			stub:      &stubProvider{createID: "stub-id-2"},
			health:    fakeSnapshotter{ok: false},
			wantPhase: crawlv1alpha1.PhaseProvisioning,
			verify: func(t *testing.T, r *ProxyReconciler) {
				p := getProxy(t, r)
				if apimeta.FindStatusCondition(p.Status.Conditions, crawlv1alpha1.ConditionHealthy) != nil {
					t.Error("stale Healthy condition survived instance creation")
				}
				if p.Status.LatencyMillis != 0 || p.Status.LastHealthCheckTime != nil {
					t.Error("stale latency fields survived instance creation")
				}
			},
		},
	}

	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()
			r := newTestReconciler(t, tc.stub, tc.proxy)
			r.Health = tc.health
			if _, err := doReconcile(t, r); err != nil {
				t.Fatalf("Reconcile: %v", err)
			}
			if got := getProxy(t, r).Status.Phase; got != tc.wantPhase {
				t.Errorf("phase = %s, want %s", got, tc.wantPhase)
			}
			tc.verify(t, r)
		})
	}
}

// A nil Health snapshotter must disable representation entirely.
func TestReconcile_nilHealthSnapshotter(t *testing.T) {
	t.Parallel()
	freshHash := specHash(managedProxy(), "")
	r := newTestReconciler(t,
		&stubProvider{getInst: &provider.Instance{ID: "stub-id-1", IP: "10.1.2.3", State: provider.StateRunning}},
		managedProxy(withProviderID("stub-id-1"), withSpecHashAnnotation(freshHash)))

	if _, err := doReconcile(t, r); err != nil {
		t.Fatalf("Reconcile: %v", err)
	}
	p := getProxy(t, r)
	if apimeta.FindStatusCondition(p.Status.Conditions, crawlv1alpha1.ConditionHealthy) != nil {
		t.Error("Healthy condition written with no snapshotter configured")
	}
	if p.Status.Phase != crawlv1alpha1.PhaseProvisioning {
		t.Errorf("phase = %s, want Provisioning", p.Status.Phase)
	}
}