package eventbus

import (
	"context"
	"time"
)

// EventType 事件类型
type EventType string

const (
	// 生产事件
	EventLoad             EventType = "LOAD"
	EventUnload           EventType = "UNLOAD"
	EventExchange         EventType = "EXCHANGE"
	EventScan             EventType = "SCAN"
	EventMark             EventType = "MARK"
	EventReplenish        EventType = "REPLENISH"
	EventMachineStart     EventType = "MACHINE_START"
	EventMachineDone      EventType = "MACHINE_DONE"
	EventInspectionResult EventType = "INSPECTION_RESULT"
	EventJobCompleted     EventType = "JOB_COMPLETED"
	EventJobScrapped      EventType = "JOB_SCRAPPED"
	EventJobDischarged    EventType = "JOB_DISCHARGED"

	// 工单生命周期事件
	EventOrderStarted   EventType = "ORDER_STARTED"
	EventOrderPaused    EventType = "ORDER_PAUSED"
	EventOrderResumed   EventType = "ORDER_RESUMED"
	EventOrderCancelled EventType = "ORDER_CANCELLED"
	EventOrderCompleted EventType = "ORDER_COMPLETED"

	// 托盘生命周期事件
	EventPalletCompleted EventType = "PALLET_COMPLETED"

	// MOM 对接事件
	EventMomReportSuccess EventType = "MOM_REPORT_SUCCESS"
	EventMomReportFailure EventType = "MOM_REPORT_FAILURE"
	EventMomAgvRequest    EventType = "MOM_AGV_ENTRY_REQUESTED"

	EventTempSlotChanged EventType = "TEMP_SLOT_CHANGED"

	// 报警事件
	EventAlarmRaised EventType = "ALARM_RAISED"
	EventAlarmAcked  EventType = "ALARM_ACKED"

	// 人工交互事件
	EventManualActionCreated  EventType = "MANUAL_ACTION_CREATED"
	EventManualActionResolved EventType = "MANUAL_ACTION_RESOLVED"

	// 设备事件
	EventEquipmentAvailabilityChanged EventType = "EQUIPMENT_AVAILABILITY_CHANGED"

	// 连接状态事件
	EventConnectionStatusUpdated EventType = "CONNECTION_STATUS_UPDATED"

	// 装配线操作日志事件（工单/工件/操作步骤/人员可追溯）
	EventBomSaved          EventType = "BOM_SAVED"
	EventMaterialRequested EventType = "MATERIAL_REQUESTED"
	EventPlcProcessSent    EventType = "PLC_PROCESS_SENT"
	EventTorqueReported    EventType = "TORQUE_REPORTED"
	EventScanReported      EventType = "SCAN_REPORTED"
	EventSemiFlow          EventType = "SEMI_FLOW"
	EventAgvTaskCreated    EventType = "AGV_TASK_CREATED"

	EventAll EventType = "*"
)

// EntityType 实体类型
type EntityType string

const (
	EntityJob      EntityType = "job"
	EntityTempSlot EntityType = "temp_slot"
)

// Event 事件
type Event struct {
	ID            string         `json:"id"`
	Type          EventType      `json:"type"`
	Source        string         `json:"source"`
	EntityType    string         `json:"entityType,omitempty"`
	EntityID      string         `json:"entityId,omitempty"`
	EntityVersion int64          `json:"entityVersion,omitempty"`
	Timestamp     time.Time      `json:"timestamp"`
	Payload       map[string]any `json:"payload"`
}

// EventHandler 事件处理器
type EventHandler func(ctx context.Context, event Event) error

// Subscription 事件订阅
type Subscription interface {
	Unsubscribe()
}

// Bus 事件总线接口
type Bus interface {
	Publish(ctx context.Context, event Event) error
	Subscribe(eventType EventType, handler EventHandler) Subscription
	SubscribeAll(handler EventHandler) Subscription
	Start(ctx context.Context) error
	Stop() error
	Close() error
}

type handlerEntry struct {
	id      uint64
	handler EventHandler
}