package telemetry

import (
	"context"
	"sync"
	"testing"
	"time"

	"go.opentelemetry.io/otel"
	sdkmetric "go.opentelemetry.io/otel/sdk/metric"
	sdktrace "go.opentelemetry.io/otel/sdk/trace"

	"code.nochebuena.dev/go/logz"
)

// stubLogger captures Info/Warn/Error calls for test assertions.
type stubLogger struct {
	mu   sync.Mutex
	logs []stubLog
}

type stubLog struct {
	level string
	msg   string
	args  []any
}

func (s *stubLogger) Info(msg string, args ...any) {
	s.mu.Lock()
	defer s.mu.Unlock()
	s.logs = append(s.logs, stubLog{"info", msg, args})
}

func (s *stubLogger) Warn(msg string, args ...any) {
	s.mu.Lock()
	defer s.mu.Unlock()
	s.logs = append(s.logs, stubLog{"warn", msg, args})
}

func (s *stubLogger) Error(msg string, err error, args ...any) {
	s.mu.Lock()
	defer s.mu.Unlock()
	s.logs = append(s.logs, stubLog{"error", msg, args})
}

func (s *stubLogger) Debug(msg string, args ...any) {
	s.mu.Lock()
	defer s.mu.Unlock()
	s.logs = append(s.logs, stubLog{"debug", msg, args})
}

func (s *stubLogger) With(args ...any) logz.Logger        { return s }
func (s *stubLogger) WithContext(ctx context.Context) logz.Logger { return s }

func (s *stubLogger) find(msg string) (stubLog, bool) {
	s.mu.Lock()
	defer s.mu.Unlock()
	for _, l := range s.logs {
		if l.msg == msg {
			return l, true
		}
	}
	return stubLog{}, false
}

func consoleCfg() ConsoleConfig {
	return ConsoleConfig{
		ServiceName:    "test-svc",
		ServiceVersion: "0.0.1",
		Environment:    "test",
	}
}

func TestNewConsole_ShutdownCallable(t *testing.T) {
	logger := &stubLogger{}
	ctx := context.Background()

	shutdown, err := NewConsole(ctx, logger, consoleCfg())
	if err != nil {
		t.Fatalf("NewConsole: %v", err)
	}
	if shutdown == nil {
		t.Fatal("shutdown is nil")
	}
	shutCtx, cancel := context.WithTimeout(ctx, 200*time.Millisecond)
	defer cancel()
	if err := shutdown(shutCtx); err != nil {
		t.Errorf("shutdown: %v", err)
	}
}

func TestNewConsole_SetsGlobalTracerProvider(t *testing.T) {
	logger := &stubLogger{}
	ctx := context.Background()

	shutdown, err := NewConsole(ctx, logger, consoleCfg())
	if err != nil {
		t.Fatalf("NewConsole: %v", err)
	}
	t.Cleanup(func() {
		shutCtx, cancel := context.WithTimeout(ctx, 200*time.Millisecond)
		defer cancel()
		_ = shutdown(shutCtx)
	})

	tp := otel.GetTracerProvider()
	if _, ok := tp.(*sdktrace.TracerProvider); !ok {
		t.Errorf("expected *sdktrace.TracerProvider, got %T", tp)
	}
}

func TestNewConsole_SetsGlobalMeterProvider(t *testing.T) {
	logger := &stubLogger{}
	ctx := context.Background()

	shutdown, err := NewConsole(ctx, logger, consoleCfg())
	if err != nil {
		t.Fatalf("NewConsole: %v", err)
	}
	t.Cleanup(func() {
		shutCtx, cancel := context.WithTimeout(ctx, 200*time.Millisecond)
		defer cancel()
		_ = shutdown(shutCtx)
	})

	mp := otel.GetMeterProvider()
	if _, ok := mp.(*sdkmetric.MeterProvider); !ok {
		t.Errorf("expected *sdkmetric.MeterProvider, got %T", mp)
	}
}

func TestNewConsole_ExportsSpan(t *testing.T) {
	logger := &stubLogger{}
	ctx := context.Background()

	shutdown, err := NewConsole(ctx, logger, consoleCfg())
	if err != nil {
		t.Fatalf("NewConsole: %v", err)
	}
	defer func() {
		shutCtx, cancel := context.WithTimeout(ctx, 200*time.Millisecond)
		defer cancel()
		_ = shutdown(shutCtx)
	}()

	tracer := otel.Tracer("test")
	_, span := tracer.Start(ctx, "test-span")
	span.End() // WithSyncer exports synchronously on End

	if _, ok := logger.find("otel: span"); !ok {
		t.Error("expected logger to receive 'otel: span' after span.End()")
	}
}

func TestNewConsole_ExportsMetric(t *testing.T) {
	logger := &stubLogger{}
	ctx := context.Background()

	shutdown, err := NewConsole(ctx, logger, consoleCfg())
	if err != nil {
		t.Fatalf("NewConsole: %v", err)
	}

	meter := otel.Meter("test")
	counter, err := meter.Int64Counter("test.counter")
	if err != nil {
		t.Fatalf("Int64Counter: %v", err)
	}
	counter.Add(ctx, 1)

	// Force export by shutting down — PeriodicReader flushes on shutdown.
	shutCtx, cancel := context.WithTimeout(ctx, 2*time.Second)
	defer cancel()
	if err := shutdown(shutCtx); err != nil {
		t.Errorf("shutdown: %v", err)
	}

	if _, ok := logger.find("otel: metric"); !ok {
		t.Error("expected logger to receive 'otel: metric' after shutdown flush")
	}
}