package audit

import (
	"context"
	"sync"
	"time"
)

// 审计事件
type Event struct {
	EventID     string         `json:"event_id,omitempty"`
	TenantID    int64          `json:"tenant_id"`
	ObjectType  string         `json:"object_type"`
	ObjectID    int64          `json:"object_id"`
	Action      string         `json:"action"`
	BeforeState map[string]any `json:"before_state,omitempty"`
	AfterState  map[string]any `json:"after_state,omitempty"`
	RequestID   string         `json:"request_id,omitempty"`
	ResultCode  string         `json:"result_code"`
	ClientIP    string         `json:"client_ip,omitempty"`
	CreatedAt   time.Time      `json:"created_at"`
}

// 审计存储接口
type AuditStore interface {
	Emit(ctx context.Context, event Event)
	Query(ctx context.Context, filter EventFilter) ([]Event, error)
}

// 事件过滤器
type EventFilter struct {
	TenantID   int64
	ObjectType string
	ObjectID   int64
	Action     string
	StartDate  string
	EndDate    string
	Limit      int
}

// 内存审计存储
type MemoryAuditStore struct {
	mu     sync.RWMutex
	events []Event
	nextID int64
}

func NewMemoryAuditStore() *MemoryAuditStore {
	return &MemoryAuditStore{
		events: make([]Event, 0),
		nextID: 1,
	}
}

func (s *MemoryAuditStore) Emit(ctx context.Context, event Event) {
	s.mu.Lock()
	defer s.mu.Unlock()

	event.EventID = generateEventID()
	event.CreatedAt = time.Now()
	s.events = append(s.events, event)
}

func (s *MemoryAuditStore) Query(ctx context.Context, filter EventFilter) ([]Event, error) {
	s.mu.RLock()
	defer s.mu.RUnlock()

	var result []Event
	for _, event := range s.events {
		if filter.TenantID > 0 && event.TenantID != filter.TenantID {
			continue
		}
		if filter.ObjectType != "" && event.ObjectType != filter.ObjectType {
			continue
		}
		if filter.ObjectID > 0 && event.ObjectID != filter.ObjectID {
			continue
		}
		if filter.Action != "" && event.Action != filter.Action {
			continue
		}
		result = append(result, event)
	}

	// 限制返回数量
	if filter.Limit > 0 && len(result) > filter.Limit {
		result = result[:filter.Limit]
	}

	return result, nil
}

func generateEventID() string {
	return time.Now().Format("20060102150405") + "-evt"
}