package decoder

import (
	"context"
	"encoding/json"
	"os"
	"testing"
	"time"

	"github.com/AFASystems/presence/internal/pkg/common/appcontext"
	"github.com/AFASystems/presence/internal/pkg/model"
	"github.com/segmentio/kafka-go"
)

// TestIntegration_DecoderEndToEnd tests the complete decoder flow
func TestIntegration_DecoderEndToEnd(t *testing.T) {
	if testing.Short() {
		t.Skip("Skipping integration test in short mode")
	}

	// Check if Kafka is available
	kafkaURL := os.Getenv("KAFKA_URL")
	if kafkaURL == "" {
		kafkaURL = "localhost:9092"
	}

	// Create test topics
	rawTopic := "test-rawbeacons-" + time.Now().Format("20060102150405")
	alertTopic := "test-alertbeacons-" + time.Now().Format("20060102150405")

	// Setup
	appState := appcontext.NewAppState()
	parserRegistry := &model.ParserRegistry{}

	// Register a test parser
	config := model.Config{
		Name:       "integration-test-parser",
		Prefix:     "02",
		Length:     2,
		MinLength:  2,
		MaxLength:  20,
	}
	parserRegistry.Register("integration-test-parser", config)

	// Create Kafka writer
	writer := kafka.NewWriter(kafka.WriterConfig{
		Brokers: []string{kafkaURL},
		Topic:   alertTopic,
	})
	defer writer.Close()

	// Create Kafka reader to verify messages
	reader := kafka.NewReader(kafka.ReaderConfig{
		Brokers: []string{kafkaURL},
		Topic:   alertTopic,
		GroupID: "test-group-" + time.Now().Format("20060102150405"),
	})
	defer reader.Close()

	// Create a test beacon advertisement
	adv := model.BeaconAdvertisement{
		ID:   "integration-test-beacon",
		Data: "020106", // Valid hex data
	}

	// Process the beacon
	err := decodeBeacon(adv, appState, writer, parserRegistry)
	if err != nil {
		t.Logf("Decode beacon returned error (may be expected if no parser matches): %v", err)
	}

	// Give Kafka time to propagate
	time.Sleep(1 * time.Second)

	// Verify event was stored in appState
	event, exists := appState.GetBeaconEvent("integration-test-beacon")
	if exists {
		t.Logf("Event stored in appState: %+v", event)
	}
}

// TestIntegration_ParserRegistryOperations tests parser registry with real Kafka
func TestIntegration_ParserRegistryOperations(t *testing.T) {
	if testing.Short() {
		t.Skip("Skipping integration test in short mode")
	}

	kafkaURL := os.Getenv("KAFKA_URL")
	if kafkaURL == "" {
		kafkaURL = "localhost:9092"
	}

	alertTopic := "test-alertbeacons-registry-" + time.Now().Format("20060102150405")

	// Setup
	appState := appcontext.NewAppState()
	parserRegistry := &model.ParserRegistry{}

	writer := kafka.NewWriter(kafka.WriterConfig{
		Brokers: []string{kafkaURL},
		Topic:   alertTopic,
	})
	defer writer.Close()

	// Test parser registration through Kafka message flow
	parserMsg := model.KafkaParser{
		ID:   "add",
		Name: "kafka-test-parser",
		Config: model.Config{
			Name:       "kafka-test-parser",
			Prefix:     "02",
			Length:     2,
			MinLength:  2,
			MaxLength:  20,
		},
	}

	// Simulate parser registry update
	switch parserMsg.ID {
	case "add":
		config := parserMsg.Config
		parserRegistry.Register(config.Name, config)
	case "delete":
		parserRegistry.Unregister(parserMsg.Name)
	case "update":
		config := parserMsg.Config
		parserRegistry.Register(config.Name, config)
	}

	// Verify parser was registered
	if len(parserRegistry.ParserList) != 1 {
		t.Errorf("Expected 1 parser in registry, got %d", len(parserRegistry.ParserList))
	}

	if _, exists := parserRegistry.ParserList["kafka-test-parser"]; !exists {
		t.Error("Parser should exist in registry")
	}
}

// TestIntegration_MultipleBeaconsSequential tests processing multiple beacons
func TestIntegration_MultipleBeaconsSequential(t *testing.T) {
	if testing.Short() {
		t.Skip("Skipping integration test in short mode")
	}

	kafkaURL := os.Getenv("KAFKA_URL")
	if kafkaURL == "" {
		kafkaURL = "localhost:9092"
	}

	alertTopic := "test-alertbeacons-multi-" + time.Now().Format("20060102150405")

	// Setup
	appState := appcontext.NewAppState()
	parserRegistry := &model.ParserRegistry{}

	// Register parser
	config := model.Config{
		Name:       "multi-test-parser",
		Prefix:     "02",
		Length:     2,
		MinLength:  2,
		MaxLength:  20,
	}
	parserRegistry.Register("multi-test-parser", config)

	writer := kafka.NewWriter(kafka.WriterConfig{
		Brokers: []string{kafkaURL},
		Topic:   alertTopic,
	})
	defer writer.Close()

	reader := kafka.NewReader(kafka.ReaderConfig{
		Brokers:  []string{kafkaURL},
		Topic:    alertTopic,
		GroupID:  "test-group-multi-" + time.Now().Format("20060102150405"),
		MinBytes: 10e3,
		MaxBytes: 10e6,
	})
	defer reader.Close()

	// Process multiple beacons
	beacons := []model.BeaconAdvertisement{
		{ID: "beacon-1", Data: "020106"},
		{ID: "beacon-2", Data: "020107"},
		{ID: "beacon-3", Data: "020108"},
	}

	for _, adv := range beacons {
		err := decodeBeacon(adv, appState, writer, parserRegistry)
		if err != nil {
			t.Logf("Processing beacon %s returned error: %v", adv.ID, err)
		}
	}

	// Give Kafka time to propagate
	time.Sleep(2 * time.Second)

	// Verify events in appState
	for _, adv := range beacons {
		event, exists := appState.GetBeaconEvent(adv.ID)
		if exists {
			t.Logf("Event for %s: %+v", adv.ID, event)
		}
	}
}

// TestIntegration_EventDeduplication tests that duplicate events are not published
func TestIntegration_EventDeduplication(t *testing.T) {
	if testing.Short() {
		t.Skip("Skipping integration test in short mode")
	}

	kafkaURL := os.Getenv("KAFKA_URL")
	if kafkaURL == "" {
		kafkaURL = "localhost:9092"
	}

	alertTopic := "test-alertbeacons-dedup-" + time.Now().Format("20060102150405")

	// Setup
	appState := appcontext.NewAppState()
	parserRegistry := &model.ParserRegistry{}

	// Register parser
	config := model.Config{
		Name:       "dedup-test-parser",
		Prefix:     "02",
		Length:     2,
		MinLength:  2,
		MaxLength:  20,
	}
	parserRegistry.Register("dedup-test-parser", config)

	writer := kafka.NewWriter(kafka.WriterConfig{
		Brokers: []string{kafkaURL},
		Topic:   alertTopic,
	})
	defer writer.Close()

	reader := kafka.NewReader(kafka.ReaderConfig{
		Brokers: []string{kafkaURL},
		Topic:   alertTopic,
		GroupID: "test-group-dedup-" + time.Now().Format("20060102150405"),
	})
	defer reader.Close()

	// Create identical beacon advertisement
	adv := model.BeaconAdvertisement{
		ID:   "dedup-test-beacon",
		Data: "020106",
	}

	// Process first time
	err := decodeBeacon(adv, appState, writer, parserRegistry)
	if err != nil {
		t.Logf("First processing returned error: %v", err)
	}

	// Process second time with identical data
	err = decodeBeacon(adv, appState, writer, parserRegistry)
	if err != nil {
		t.Logf("Second processing returned error: %v", err)
	}

	// Give Kafka time to propagate
	time.Sleep(1 * time.Second)

	// Try to read from Kafka - should have at most 1 message due to deduplication
	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
	defer cancel()

	messageCount := 0
	for {
		msg, err := reader.ReadMessage(ctx)
		if err != nil {
			break
		}

		messageCount++
		t.Logf("Read message %d: %s", messageCount, string(msg.Value))

		if messageCount > 1 {
			t.Error("Expected at most 1 message due to deduplication, got more")
			break
		}
	}

	t.Logf("Total messages read: %d", messageCount)
}

// TestIntegration_AppStatePersistence tests that events persist in AppState
func TestIntegration_AppStatePersistence(t *testing.T) {
	if testing.Short() {
		t.Skip("Skipping integration test in short mode")
	}

	kafkaURL := os.Getenv("KAFKA_URL")
	if kafkaURL == "" {
		kafkaURL = "localhost:9092"
	}

	alertTopic := "test-alertbeacons-persist-" + time.Now().Format("20060102150405")

	// Setup
	appState := appcontext.NewAppState()
	parserRegistry := &model.ParserRegistry{}

	config := model.Config{
		Name:       "persist-test-parser",
		Prefix:     "02",
		Length:     2,
		MinLength:  2,
		MaxLength:  20,
	}
	parserRegistry.Register("persist-test-parser", config)

	writer := kafka.NewWriter(kafka.WriterConfig{
		Brokers: []string{kafkaURL},
		Topic:   alertTopic,
	})
	defer writer.Close()

	// Process beacon
	adv := model.BeaconAdvertisement{
		ID:   "persist-test-beacon",
		Data: "020106",
	}

	err := decodeBeacon(adv, appState, writer, parserRegistry)
	if err != nil {
		t.Logf("Processing returned error: %v", err)
	}

	// Verify event persists in AppState
	event, exists := appState.GetBeaconEvent("persist-test-beacon")
	if !exists {
		t.Error("Event should exist in AppState after processing")
	} else {
		t.Logf("Event persisted: ID=%s, Type=%s, Battery=%d",
			event.ID, event.Type, event.Battery)

		// Verify event can be serialized to JSON
		jsonData, err := event.ToJSON()
		if err != nil {
			t.Errorf("Failed to serialize event to JSON: %v", err)
		} else {
			t.Logf("Event JSON: %s", string(jsonData))
		}
	}
}

// TestIntegration_ParserUpdateFlow tests updating parsers during runtime
func TestIntegration_ParserUpdateFlow(t *testing.T) {
	if testing.Short() {
		t.Skip("Skipping integration test in short mode")
	}

	kafkaURL := os.Getenv("KAFKA_URL")
	if kafkaURL == "" {
		kafkaURL = "localhost:9092"
	}

	alertTopic := "test-alertbeacons-update-" + time.Now().Format("20060102150405")

	// Setup
	appState := appcontext.NewAppState()
	parserRegistry := &model.ParserRegistry{}

	writer := kafka.NewWriter(kafka.WriterConfig{
		Brokers: []string{kafkaURL},
		Topic:   alertTopic,
	})
	defer writer.Close()

	// Initial parser config
	config1 := model.Config{
		Name:       "update-test-parser",
		Prefix:     "02",
		Length:     2,
		MinLength:  2,
		MaxLength:  20,
	}
	parserRegistry.Register("update-test-parser", config1)

	// Process with initial config
	adv := model.BeaconAdvertisement{
		ID:   "update-test-beacon",
		Data: "020106",
	}

	err := decodeBeacon(adv, appState, writer, parserRegistry)
	t.Logf("First processing: %v", err)

	// Update parser config
	config2 := model.Config{
		Name:       "update-test-parser",
		Prefix:     "03",
		Length:     3,
		MinLength:  3,
		MaxLength:  25,
	}
	parserRegistry.Register("update-test-parser", config2)

	// Process again with updated config
	adv2 := model.BeaconAdvertisement{
		ID:   "update-test-beacon-2",
		Data: "030107",
	}

	err = decodeBeacon(adv2, appState, writer, parserRegistry)
	t.Logf("Second processing with updated parser: %v", err)

	// Verify parser still exists
	if _, exists := parserRegistry.ParserList["update-test-parser"]; !exists {
		t.Error("Parser should exist after update")
	}
}