feat: replace iot adapter with mqtt command pipeline

backend/iot-server/internal/protocol/payload.go

@@ -0,0 +1,155 @@
+package protocol
+
+import (
+	"encoding/binary"
+	"fmt"
+)
+
+const (
+	MainBasicInfo  = byte(0x01)
+	MainRuntime    = byte(0x20)
+	MainQuery      = byte(0x30)
+	MainSetting    = byte(0x40)
+	MainRealtime   = byte(0x50)
+	MainHistorical = byte(0x60)
+	SubValve       = byte(0x0A)
+)
+
+// DataBlock 是主标识下的一个子标识数据块。
+type DataBlock struct {
+	SubID byte
+	Data  []byte
+}
+
+type RealtimeData struct {
+	Sensors    []SensorReading    `json:"sensors,omitempty"`
+	Events     []EventReading     `json:"events,omitempty"`
+	IO         []IOReading        `json:"io,omitempty"`
+	Parameters []ParameterReading `json:"parameters,omitempty"`
+}
+type SensorReading struct {
+	Number     uint32 `json:"number"`
+	SensorType byte   `json:"sensor_type"`
+	Object     uint16 `json:"object"`
+	Value      int16  `json:"value"`
+	Unit       byte   `json:"unit"`
+	Decimal    byte   `json:"decimal"`
+	Status     byte   `json:"status"`
+}
+type EventReading struct {
+	Type   uint16 `json:"type"`
+	Number uint32 `json:"number"`
+	Value  int16  `json:"value"`
+}
+type IOReading struct {
+	Type   uint16 `json:"type"`
+	Number uint32 `json:"number"`
+	Status byte   `json:"status"`
+}
+type ParameterReading struct {
+	Code  byte  `json:"code"`
+	Value int16 `json:"value"`
+}
+
+// EncodePayload 按“主标识、块数量、子标识、定长数据”编码。
+// 由于厂商协议没有携带块长度，本函数用于已知命令；上行解析由业务标识专用解析器完成。
+func EncodePayload(mainID byte, blocks ...DataBlock) ([]byte, error) {
+	if len(blocks) > 255 {
+		return nil, fmt.Errorf("数据块数量超过 255")
+	}
+	result := []byte{mainID, byte(len(blocks))}
+	for _, block := range blocks {
+		result = append(result, block.SubID)
+		result = append(result, block.Data...)
+	}
+	result = append(result, 0x00)
+	return result, nil
+}
+
+// ValveCommand 编码 0x40/0x0A 电磁阀控制；0x01 关闭，0xA0 开启。
+func ValveCommand(controller, loop, component byte, open bool) ([]byte, error) {
+	action := byte(0x01)
+	if open {
+		action = 0xA0
+	}
+	return EncodePayload(MainSetting, DataBlock{SubID: SubValve, Data: []byte{controller, loop, component, action}})
+}
+
+// DecodeRealtime 解析协议 0x50 的传感器、事件、IO 和 AI 阀参数定长数据块。
+func DecodeRealtime(payload []byte) (RealtimeData, error) {
+	var result RealtimeData
+	if len(payload) < 3 || payload[0] != MainRealtime {
+		return result, fmt.Errorf("不是实时数据包")
+	}
+	offset := 2
+	for blockIndex := 0; blockIndex < int(payload[1]); blockIndex++ {
+		if offset >= len(payload) {
+			return result, fmt.Errorf("实时数据块被截断")
+		}
+		subID := payload[offset]
+		offset++
+		switch subID {
+		case 0x01:
+			count, next, err := readCount(payload, offset, 12)
+			if err != nil {
+				return result, err
+			}
+			offset = next
+			for range count {
+				item := payload[offset : offset+12]
+				result.Sensors = append(result.Sensors, SensorReading{Number: binary.BigEndian.Uint32(item[0:4]), SensorType: item[4], Object: binary.BigEndian.Uint16(item[5:7]), Value: int16(binary.BigEndian.Uint16(item[7:9])), Unit: item[9], Decimal: item[10], Status: item[11]})
+				offset += 12
+			}
+		case 0x02:
+			count, next, err := readCount(payload, offset, 8)
+			if err != nil {
+				return result, err
+			}
+			offset = next
+			for range count {
+				item := payload[offset : offset+8]
+				result.Events = append(result.Events, EventReading{Type: binary.BigEndian.Uint16(item[0:2]), Number: binary.BigEndian.Uint32(item[2:6]), Value: int16(binary.BigEndian.Uint16(item[6:8]))})
+				offset += 8
+			}
+		case 0x03:
+			count, next, err := readCount(payload, offset, 7)
+			if err != nil {
+				return result, err
+			}
+			offset = next
+			for range count {
+				item := payload[offset : offset+7]
+				result.IO = append(result.IO, IOReading{Type: binary.BigEndian.Uint16(item[0:2]), Number: binary.BigEndian.Uint32(item[2:6]), Status: item[6]})
+				offset += 7
+			}
+		case 0x04:
+			if offset >= len(payload) {
+				return result, fmt.Errorf("参数块被截断")
+			}
+			count := int(payload[offset])
+			offset++
+			if offset+count*3 > len(payload) {
+				return result, fmt.Errorf("参数块长度无效")
+			}
+			for range count {
+				result.Parameters = append(result.Parameters, ParameterReading{Code: payload[offset], Value: int16(binary.BigEndian.Uint16(payload[offset+1 : offset+3]))})
+				offset += 3
+			}
+		default:
+			return result, fmt.Errorf("未知实时数据子标识 0x%02X", subID)
+		}
+	}
+	return result, nil
+}
+
+func readCount(payload []byte, offset, recordSize int) (int, int, error) {
+	if offset+2 > len(payload) {
+		return 0, offset, fmt.Errorf("数据块数量被截断")
+	}
+	count := int(binary.BigEndian.Uint16(payload[offset : offset+2]))
+	offset += 2
+	if offset+count*recordSize > len(payload) {
+		return 0, offset, fmt.Errorf("数据块记录长度无效")
+	}
+	return count, offset, nil
+}