package agentsource

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

	"github.com/itworx/pulse/internal/agentstore"
	"github.com/itworx/pulse/internal/datasource"
)

type healthReader map[agentstore.Capability]agentstore.Snapshot

func (r healthReader) Latest(_ context.Context, capability agentstore.Capability) (agentstore.Snapshot, error) {
	snapshot, ok := r[capability]
	if !ok {
		return agentstore.Snapshot{}, agentstore.ErrNoSnapshot
	}
	return snapshot, nil
}

func TestHealthRequiresEveryCapabilityToBeFresh(t *testing.T) {
	now := time.Date(2026, 8, 12, 1, 0, 0, 0, time.UTC)
	reader := healthReader{
		agentstore.CapabilityHost: {
			Capability: agentstore.CapabilityHost, ObservedAt: now.Add(-time.Second), ReceivedAt: now.Add(-time.Second),
		},
		agentstore.CapabilityProcesses: {
			Capability: agentstore.CapabilityProcesses, ObservedAt: now.Add(-2 * time.Second), ReceivedAt: now.Add(-2 * time.Second),
		},
	}
	health, err := Health(context.Background(), reader, []agentstore.Capability{agentstore.CapabilityHost, agentstore.CapabilityProcesses}, Windows{}, now)
	if err != nil {
		t.Fatal(err)
	}
	if health.State != datasource.HealthHealthy || health.LastSuccess != now.Add(-2*time.Second) {
		t.Fatalf("health = %#v", health)
	}

	missing, err := Health(context.Background(), reader, []agentstore.Capability{agentstore.CapabilityHost, agentstore.CapabilityContainers}, Windows{}, now)
	if err != nil {
		t.Fatal(err)
	}
	if missing.State != datasource.HealthUnknown || missing.ReasonCode != ReasonUnavailable {
		t.Fatalf("missing health = %#v", missing)
	}
}

func TestHealthRejectsStaleCapabilityAndPropagatesCancellation(t *testing.T) {
	now := time.Date(2026, 8, 12, 1, 0, 0, 0, time.UTC)
	reader := healthReader{agentstore.CapabilityHost: {
		Capability: agentstore.CapabilityHost, ObservedAt: now.Add(-time.Hour), ReceivedAt: now.Add(-time.Hour),
	}}
	health, err := Health(context.Background(), reader, []agentstore.Capability{agentstore.CapabilityHost}, Windows{}, now)
	if err != nil {
		t.Fatal(err)
	}
	if health.State != datasource.HealthUnknown || health.ReasonCode != ReasonStale {
		t.Fatalf("stale health = %#v", health)
	}

	cancelled, cancel := context.WithCancel(context.Background())
	cancel()
	if _, err := Health(cancelled, reader, []agentstore.Capability{agentstore.CapabilityHost}, Windows{}, now); !errors.Is(err, context.Canceled) {
		t.Fatalf("cancellation error = %v", err)
	}
}