package service

import (
	"context"
	"encoding/json"
	"net/http"
	"tailly_back_v2/internal/domain"
	"tailly_back_v2/internal/repository"
	"time"
)

type AuditService interface {
	LogEvent(
		ctx context.Context,
		action string,
		entityType string,
		entityID *int,
		r *http.Request,
		status string,
		metadata interface{},
	) error
	GetEvents(ctx context.Context, filter domain.AuditFilter) ([]*domain.AuditLog, error)
	ExportEvents(ctx context.Context, filter domain.AuditFilter) ([]byte, error)
}

type auditService struct {
	auditRepo repository.AuditRepository
}

func NewAuditService(auditRepo repository.AuditRepository) AuditService {
	return &auditService{
		auditRepo: auditRepo,
	}
}

func (s *auditService) LogEvent(
	ctx context.Context,
	action string,
	entityType string,
	entityID *int,
	r *http.Request,
	status string,
	metadata interface{},
) error {
	var userID *int
	if ctxUserID, ok := ctx.Value("userID").(int); ok {
		userID = &ctxUserID
	}

	metadataJSON, err := json.Marshal(metadata)
	if err != nil {
		return err
	}

	ip := r.Header.Get("X-Forwarded-For")
	if ip == "" {
		ip = r.RemoteAddr
	}

	log := &domain.AuditLog{
		UserID:     userID,
		Action:     action,
		EntityType: entityType,
		EntityID:   entityID,
		IPAddress:  ip,
		UserAgent:  r.UserAgent(),
		Metadata:   string(metadataJSON),
		Status:     status,
		CreatedAt:  time.Now(),
	}

	return s.auditRepo.Save(ctx, log)
}

func (s *auditService) GetEvents(ctx context.Context, filter domain.AuditFilter) ([]*domain.AuditLog, error) {
	if filter.Limit == 0 {
		filter.Limit = 50
	}
	return s.auditRepo.Get(ctx, filter)
}

func (s *auditService) ExportEvents(ctx context.Context, filter domain.AuditFilter) ([]byte, error) {
	logs, err := s.auditRepo.Get(ctx, filter)
	if err != nil {
		return nil, err
	}

	return json.Marshal(logs)
}