package eventbus

import (
	"context"
	"errors"
	"testing"

	amqp "github.com/rabbitmq/amqp091-go"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"go.uber.org/zap"
	"go.uber.org/zap/zapcore"
	"go.uber.org/zap/zaptest/observer"
)

// TestPublish_DisabledBusLogsWarnAndReturnsError verifies the "EventBus
// disabled" path emits a WARN with message-size context and still returns
// an EventBusUnavailableError so callers that care can notice.
func TestPublish_DisabledBusLogsWarnAndReturnsError(t *testing.T) {
	core, observed := observer.New(zapcore.WarnLevel)
	eb := &RabbitMQEventBus{
		config:    &RabbitMQConfig{Enable: false},
		logger:    zap.New(core),
		IsEnabled: false,
	}

	err := eb.Publish(context.Background(), "veza.events", "track.uploaded", false, false, amqp.Publishing{
		Body: []byte(`{"track_id":"abc"}`),
	})

	var unavail *EventBusUnavailableError
	require.True(t, errors.As(err, &unavail), "disabled bus must return EventBusUnavailableError")

	entries := observed.All()
	require.Len(t, entries, 1)
	assert.Equal(t, zapcore.WarnLevel, entries[0].Level)
	assert.Contains(t, entries[0].Message, "disabled")

	// Verify structured context so dashboards can group drops by
	// exchange+routing_key.
	fields := map[string]interface{}{}
	for _, f := range entries[0].Context {
		fields[f.Key] = f
	}
	assert.Contains(t, fields, "exchange")
	assert.Contains(t, fields, "routing_key")
	assert.Contains(t, fields, "payload_bytes")
}

// TestPublish_NilLoggerIsAllowed guards against the legacy callers that
// construct an EventBus without a logger — the method must stay panic-free.
func TestPublish_NilLoggerIsAllowed(t *testing.T) {
	eb := &RabbitMQEventBus{
		config:    &RabbitMQConfig{Enable: false},
		logger:    nil,
		IsEnabled: false,
	}
	assert.NotPanics(t, func() {
		_ = eb.Publish(context.Background(), "x", "y", false, false, amqp.Publishing{Body: []byte("hi")})
	})
}