package tracing

import (
	"context"
	"fmt"
	"time"

	"go.opentelemetry.io/otel/attribute"
	"go.uber.org/zap"

	"tyapi-server/internal/application/user/dto/commands"
	"tyapi-server/internal/domains/user/entities"
	"tyapi-server/internal/shared/interfaces"
)

// ServiceWrapper 服务包装器，提供自动追踪能力
type ServiceWrapper struct {
	tracer *Tracer
	logger *zap.Logger
}

// NewServiceWrapper 创建服务包装器
func NewServiceWrapper(tracer *Tracer, logger *zap.Logger) *ServiceWrapper {
	return &ServiceWrapper{
		tracer: tracer,
		logger: logger,
	}
}

// TraceServiceCall 追踪服务调用的通用方法
func (w *ServiceWrapper) TraceServiceCall(
	ctx context.Context,
	serviceName, methodName string,
	fn func(context.Context) error,
) error {
	// 创建span名称
	spanName := fmt.Sprintf("%s.%s", serviceName, methodName)

	// 开始追踪
	ctx, span := w.tracer.StartSpan(ctx, spanName)
	defer span.End()

	// 添加基础属性
	w.tracer.AddSpanAttributes(span,
		attribute.String("service.name", serviceName),
		attribute.String("service.method", methodName),
		attribute.String("service.type", "business"),
	)

	// 记录开始时间
	startTime := time.Now()

	// 执行原始方法
	err := fn(ctx)

	// 计算执行时间
	duration := time.Since(startTime)
	w.tracer.AddSpanAttributes(span,
		attribute.Int64("service.duration_ms", duration.Milliseconds()),
	)

	// 标记慢方法
	if duration > 100*time.Millisecond {
		w.tracer.AddSpanAttributes(span,
			attribute.Bool("service.slow_method", true),
		)
		w.logger.Warn("慢方法检测",
			zap.String("service", serviceName),
			zap.String("method", methodName),
			zap.Duration("duration", duration),
			zap.String("trace_id", w.tracer.GetTraceID(ctx)),
		)
	}

	// 处理错误
	if err != nil {
		w.tracer.SetSpanError(span, err)
		w.logger.Error("服务方法执行失败",
			zap.String("service", serviceName),
			zap.String("method", methodName),
			zap.Error(err),
			zap.String("trace_id", w.tracer.GetTraceID(ctx)),
		)
	} else {
		w.tracer.SetSpanSuccess(span)
	}

	return err
}

// TracedUserService 自动追踪的用户服务包装器
type TracedUserService struct {
	service interfaces.UserService
	wrapper *ServiceWrapper
}

// NewTracedUserService 创建带追踪的用户服务
func NewTracedUserService(service interfaces.UserService, wrapper *ServiceWrapper) interfaces.UserService {
	return &TracedUserService{
		service: service,
		wrapper: wrapper,
	}
}

func (t *TracedUserService) Name() string {
	return "user-service"
}

func (t *TracedUserService) Initialize(ctx context.Context) error {
	return t.wrapper.TraceServiceCall(ctx, "user", "initialize", t.service.Initialize)
}

func (t *TracedUserService) HealthCheck(ctx context.Context) error {
	return t.service.HealthCheck(ctx) // 不追踪健康检查
}

func (t *TracedUserService) Shutdown(ctx context.Context) error {
	return t.wrapper.TraceServiceCall(ctx, "user", "shutdown", t.service.Shutdown)
}

func (t *TracedUserService) Register(ctx context.Context, req *commands.RegisterUserCommand) (*entities.User, error) {
	var result *entities.User
	var err error

	traceErr := t.wrapper.TraceServiceCall(ctx, "user", "register", func(ctx context.Context) error {
		result, err = t.service.Register(ctx, req)
		return err
	})

	if traceErr != nil {
		return nil, traceErr
	}

	return result, err
}

func (t *TracedUserService) LoginWithPassword(ctx context.Context, req *commands.LoginWithPasswordCommand) (*entities.User, error) {
	var result *entities.User
	var err error

	traceErr := t.wrapper.TraceServiceCall(ctx, "user", "login_password", func(ctx context.Context) error {
		result, err = t.service.LoginWithPassword(ctx, req)
		return err
	})

	if traceErr != nil {
		return nil, traceErr
	}

	return result, err
}

func (t *TracedUserService) LoginWithSMS(ctx context.Context, req *commands.LoginWithSMSCommand) (*entities.User, error) {
	var result *entities.User
	var err error

	traceErr := t.wrapper.TraceServiceCall(ctx, "user", "login_sms", func(ctx context.Context) error {
		result, err = t.service.LoginWithSMS(ctx, req)
		return err
	})

	if traceErr != nil {
		return nil, traceErr
	}

	return result, err
}

func (t *TracedUserService) ChangePassword(ctx context.Context, userID string, req *commands.ChangePasswordCommand) error {
	return t.wrapper.TraceServiceCall(ctx, "user", "change_password", func(ctx context.Context) error {
		return t.service.ChangePassword(ctx, userID, req)
	})
}

func (t *TracedUserService) GetByID(ctx context.Context, id string) (*entities.User, error) {
	var result *entities.User
	var err error

	traceErr := t.wrapper.TraceServiceCall(ctx, "user", "get_by_id", func(ctx context.Context) error {
		result, err = t.service.GetByID(ctx, id)
		return err
	})

	if traceErr != nil {
		return nil, traceErr
	}

	return result, err
}