package realtime

import (
	"context"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"time"

	"github.com/alicebob/miniredis/v2"
	"github.com/redis/go-redis/v9"

	"lingniu-vehicle-ingest/go/vehicle-gateway/internal/envelope"
)

func TestRepositoryUpdatesMergedAndProtocolSnapshots(t *testing.T) {
	repo, closeFn := newTestRepository(t)
	defer closeFn()
	ctx := context.Background()

	if err := repo.Update(ctx, envelope.FrameEnvelope{
		Protocol:     envelope.ProtocolJT808,
		VIN:          "VIN001",
		EventTimeMS:  1000,
		ReceivedAtMS: 1100,
		Fields: map[string]any{
			envelope.FieldLongitude:      121.1,
			envelope.FieldTotalMileageKM: 10.5,
		},
	}); err != nil {
		t.Fatalf("Update() error = %v", err)
	}
	if err := repo.Update(ctx, envelope.FrameEnvelope{
		Protocol:     envelope.ProtocolGB32960,
		VIN:          "VIN001",
		EventTimeMS:  900,
		ReceivedAtMS: 1200,
		Fields: map[string]any{
			envelope.FieldLongitude: 120.0,
			envelope.FieldLatitude:  30.5,
		},
	}); err != nil {
		t.Fatalf("Update() error = %v", err)
	}

	merged, err := repo.GetMerged(ctx, "VIN001")
	if err != nil {
		t.Fatalf("GetMerged() error = %v", err)
	}
	if merged.Fields[envelope.FieldLongitude] != 121.1 {
		t.Fatalf("older longitude overwrote newer value: %#v", merged.Fields)
	}
	if merged.Fields[envelope.FieldLatitude] != 30.5 {
		t.Fatalf("new latitude missing: %#v", merged.Fields)
	}
	protocol, err := repo.GetProtocol(ctx, "VIN001", envelope.ProtocolJT808)
	if err != nil {
		t.Fatalf("GetProtocol() error = %v", err)
	}
	if protocol.Fields[envelope.FieldTotalMileageKM] != 10.5 {
		t.Fatalf("protocol snapshot = %#v", protocol)
	}
}

func TestRepositoryOnlineStatus(t *testing.T) {
	repo, closeFn := newTestRepository(t)
	defer closeFn()
	ctx := context.Background()

	status, err := repo.IsOnline(ctx, "VIN001")
	if err != nil {
		t.Fatalf("IsOnline() error = %v", err)
	}
	if status.Online {
		t.Fatal("empty vin should be offline")
	}

	if err := repo.Update(ctx, envelope.FrameEnvelope{
		Protocol:     envelope.ProtocolJT808,
		VIN:          "VIN001",
		EventTimeMS:  1000,
		ReceivedAtMS: 1100,
		Fields:       map[string]any{envelope.FieldSpeedKMH: 12.3},
	}); err != nil {
		t.Fatalf("Update() error = %v", err)
	}
	status, err = repo.IsOnline(ctx, "VIN001")
	if err != nil {
		t.Fatalf("IsOnline() error = %v", err)
	}
	if !status.Online || status.LastSeenMS != 1100 {
		t.Fatalf("online status = %#v", status)
	}
}

func TestRepositoryUpdatesPhoneOnlyVehicleKey(t *testing.T) {
	repo, closeFn := newTestRepository(t)
	defer closeFn()
	ctx := context.Background()

	if err := repo.Update(ctx, envelope.FrameEnvelope{
		Protocol:     envelope.ProtocolJT808,
		Phone:        "013307811170",
		EventTimeMS:  1000,
		ReceivedAtMS: 1100,
		Fields: map[string]any{
			envelope.FieldSpeedKMH:       23.0,
			envelope.FieldTotalMileageKM: 10003.7,
		},
	}); err != nil {
		t.Fatalf("Update() error = %v", err)
	}

	vehicleKey := "JT808:013307811170"
	merged, err := repo.GetMerged(ctx, vehicleKey)
	if err != nil {
		t.Fatalf("GetMerged() error = %v", err)
	}
	if merged.VehicleKey != vehicleKey || merged.VIN != "" {
		t.Fatalf("unexpected identity: %#v", merged)
	}
	if merged.Fields[envelope.FieldTotalMileageKM] != 10003.7 {
		t.Fatalf("merged fields = %#v", merged.Fields)
	}
	status, err := repo.IsOnline(ctx, vehicleKey)
	if err != nil {
		t.Fatalf("IsOnline() error = %v", err)
	}
	if !status.Online || status.VehicleKey != vehicleKey {
		t.Fatalf("online status = %#v", status)
	}
}

func TestRepositoryDoesNotOverwritePositiveMileageWithZero(t *testing.T) {
	repo, closeFn := newTestRepository(t)
	defer closeFn()
	ctx := context.Background()

	if err := repo.Update(ctx, envelope.FrameEnvelope{
		Protocol:     envelope.ProtocolJT808,
		VIN:          "VIN001",
		EventTimeMS:  1000,
		ReceivedAtMS: 1100,
		Fields: map[string]any{
			envelope.FieldTotalMileageKM: 12345.6,
		},
	}); err != nil {
		t.Fatalf("Update() error = %v", err)
	}
	if err := repo.Update(ctx, envelope.FrameEnvelope{
		Protocol:     envelope.ProtocolJT808,
		VIN:          "VIN001",
		EventTimeMS:  2000,
		ReceivedAtMS: 2100,
		Fields: map[string]any{
			envelope.FieldSpeedKMH:       22.0,
			envelope.FieldTotalMileageKM: 0,
		},
	}); err != nil {
		t.Fatalf("Update() error = %v", err)
	}

	merged, err := repo.GetMerged(ctx, "VIN001")
	if err != nil {
		t.Fatalf("GetMerged() error = %v", err)
	}
	if merged.Fields[envelope.FieldTotalMileageKM] != 12345.6 {
		t.Fatalf("zero mileage overwrote positive value: %#v", merged.Fields)
	}
	if merged.Fields[envelope.FieldSpeedKMH] != 22.0 {
		t.Fatalf("new speed should still merge: %#v", merged.Fields)
	}
}

func TestHandlerReturnsMergedSnapshot(t *testing.T) {
	repo, closeFn := newTestRepository(t)
	defer closeFn()
	if err := repo.Update(context.Background(), envelope.FrameEnvelope{
		Protocol:     envelope.ProtocolJT808,
		VIN:          "VIN001",
		EventTimeMS:  1000,
		ReceivedAtMS: 1100,
		Fields:       map[string]any{envelope.FieldSpeedKMH: 12.3},
	}); err != nil {
		t.Fatalf("Update() error = %v", err)
	}

	req := httptest.NewRequest(http.MethodGet, "/api/realtime/vehicles/VIN001", nil)
	rec := httptest.NewRecorder()
	NewHandler(repo).ServeHTTP(rec, req)
	if rec.Code != http.StatusOK {
		t.Fatalf("status = %d body=%s", rec.Code, rec.Body.String())
	}
	if !stringsContains(rec.Body.String(), `"vin":"VIN001"`) {
		t.Fatalf("unexpected body: %s", rec.Body.String())
	}
}

func TestHandlerReturnsPhoneOnlyVehicleKeySnapshot(t *testing.T) {
	repo, closeFn := newTestRepository(t)
	defer closeFn()
	if err := repo.Update(context.Background(), envelope.FrameEnvelope{
		Protocol:     envelope.ProtocolJT808,
		Phone:        "013307811170",
		EventTimeMS:  1000,
		ReceivedAtMS: 1100,
		Fields:       map[string]any{envelope.FieldSpeedKMH: 12.3},
	}); err != nil {
		t.Fatalf("Update() error = %v", err)
	}

	req := httptest.NewRequest(http.MethodGet, "/api/realtime/vehicles/JT808:013307811170", nil)
	rec := httptest.NewRecorder()
	NewHandler(repo).ServeHTTP(rec, req)
	if rec.Code != http.StatusOK {
		t.Fatalf("status = %d body=%s", rec.Code, rec.Body.String())
	}
	if !stringsContains(rec.Body.String(), `"vehicle_key":"JT808:013307811170"`) {
		t.Fatalf("unexpected body: %s", rec.Body.String())
	}
}

func newTestRepository(t *testing.T) (*Repository, func()) {
	t.Helper()
	server, err := miniredis.Run()
	if err != nil {
		t.Fatalf("miniredis.Run() error = %v", err)
	}
	client := redis.NewClient(&redis.Options{Addr: server.Addr()})
	return NewRepository(client, Config{OnlineTTL: time.Minute}), func() {
		_ = client.Close()
		server.Close()
	}
}

func stringsContains(value string, pattern string) bool {
	return strings.Contains(value, pattern)
}