package datasource

import (
	"context"
	"testing"
	"time"
)

func TestSourceHealthBecomesUnknownWhenStale(t *testing.T) {
	now := time.Date(2026, 8, 1, 12, 0, 0, 0, time.UTC)
	health := SourceHealth{State: HealthHealthy, ObservedAt: now.Add(-2 * time.Minute), ReceivedAt: now, Policy: FreshnessPolicy{MaxAge: time.Minute}}
	if got := health.EffectiveState(now); got != HealthUnknown {
		t.Fatalf("effective state = %q, want unknown", got)
	}
}

func TestCapabilitySetRejectsDuplicateVersions(t *testing.T) {
	set := CapabilitySet{{ID: "inventory", Version: "v1", State: CapabilityEnabled}, {ID: "inventory", Version: "v1", State: CapabilityUnavailable}}
	if err := set.Validate(); err == nil {
		t.Fatal("expected duplicate capability validation error")
	}
}

func TestSourceRejectsUnknownContractAndUnboundedHealth(t *testing.T) {
	now := time.Date(2026, 8, 1, 12, 0, 0, 0, time.UTC)
	source := Source{ID: "source-1", Name: "Prometheus", Type: SourcePrometheus, Enabled: true, Contract: "v2", Health: SourceHealth{State: HealthUnknown, ReceivedAt: now, Policy: FreshnessPolicy{MaxAge: 25 * time.Hour}}}
	if err := source.Validate(now); err == nil {
		t.Fatal("expected source validation error")
	}
}

func TestAdapterContractIsTransportFree(t *testing.T) {
	var adapter Adapter = fakeAdapter{}
	if _, err := adapter.Discover(context.Background()); err != nil {
		t.Fatal(err)
	}
}

type fakeAdapter struct{}

func (fakeAdapter) Discover(context.Context) (DiscoveryResult, error)        { return DiscoveryResult{}, nil }
func (fakeAdapter) Health(context.Context) (SourceHealth, error)             { return SourceHealth{}, nil }
func (fakeAdapter) Inventory(context.Context) (InventoryResult, error)       { return InventoryResult{}, nil }
func (fakeAdapter) MetricsBindings(context.Context) ([]MetricBinding, error) { return nil, nil }
func (fakeAdapter) Events(context.Context) ([]Event, error)                  { return nil, nil }
func (fakeAdapter) Capabilities(context.Context) (CapabilitySet, error)      { return nil, nil }