[add] initial commit

app/models/sensor.go

@@ -0,0 +1,124 @@
+package models
+
+import (
+	"database/sql/driver"
+	"errors"
+	"gorm.io/gorm"
+	"strconv"
+	"strings"
+	"time"
+)
+
+type SensorType uint
+
+const (
+	Temperature SensorType = iota + 1 // to allow gorm: not null
+	Humidity
+	Pressure
+	Gas
+	CO2
+)
+
+func (s SensorType) IsValid() bool {
+	switch s {
+	case Temperature, Humidity, Pressure, Gas, CO2:
+		return true
+	default:
+		return false
+	}
+}
+
+type Position struct {
+	X       int  `json:"x"`
+	Y       int  `json:"y"`
+	NotNull bool `json:"-"` // to allow gorm: not null with x/y = 0
+}
+
+type Sensor struct {
+	ID         uint           `json:"id" gorm:"primaryKey"`
+	CreatedAt  time.Time      `json:"-"`
+	UpdatedAt  time.Time      `json:"-"`
+	DeletedAt  gorm.DeletedAt `json:"-" gorm:"index"`
+	Name       string         `json:"name" gorm:"uniqueIndex;not null;default:null"`
+	SensorType SensorType     `json:"sensor_type" gorm:"not null;default:null"`
+	Position   Position       `json:"position" gorm:"not null;default:null"`
+}
+
+type Measurement struct {
+	ID        uint           `json:"id" gorm:"primaryKey"`
+	CreatedAt time.Time      `json:"time"`           // TODO: change to datetime2
+	UpdatedAt time.Time      `json:"-"`              // TODO: remove
+	DeletedAt gorm.DeletedAt `json:"-" gorm:"index"` // TODO: remove
+	SensorID  uint           `json:"sensor_id" gorm:"<-:create;not null;default:null"`
+	Sensor    Sensor         `json:"-"`
+	Value     float64        `json:"value" gorm:"<-:create;default:null"` // TODO on migrate set column NOT NULL
+}
+
+func (s Sensor) IsValid() bool {
+	return s.SensorType.IsValid()
+}
+
+func (p Position) Value() (driver.Value, error) {
+	return strconv.FormatInt(int64(p.X), 10) + "." + strconv.FormatInt(int64(p.Y), 10), nil
+}
+
+func (p *Position) Scan(value interface{}) error {
+	p.X = 0
+	p.Y = 0
+	p.NotNull = true
+	positionString, isString := value.(string)
+	if !isString {
+		return errors.New("invalid scan value")
+	}
+	positionArray := strings.Split(positionString, ".")
+	if len(positionArray) != 2 {
+		return errors.New("invalid string value")
+	}
+	var err error
+	var position int64
+	position, err = strconv.ParseInt(positionArray[0], 10, 32)
+	if err != nil {
+		return errors.New("invalid x value")
+	}
+	p.X = int(position)
+	position, err = strconv.ParseInt(positionArray[1], 10, 32)
+	if err != nil {
+		return errors.New("invalid y value")
+	}
+	p.Y = int(position)
+	return nil
+}
+
+// http -v POST localhost:8080/sensors name="sensor_$RANDOM" sensor_type:=1 position:='{"x":1, "y":2}'
+// http -v POST localhost:8080/sensors name="sensor_$RANDOM" sensor_type:=2
+func (m Model) AddSensor(sensor Sensor) (uint, error) {
+	sensor.ID = 0
+	sensor.Position.NotNull = true
+	if !sensor.SensorType.IsValid() {
+		return 0, errors.New("invalid sensor type")
+	}
+	result := m.app.Db().Create(&sensor)
+	return sensor.ID, result.Error
+}
+
+func (m Model) UpdateSensor(sensor Sensor, txSensor Sensor, tx *gorm.DB) (uint, error) {
+	sensor.ID = txSensor.ID
+	sensor.Position.NotNull = true
+	if !sensor.SensorType.IsValid() {
+		return 0, errors.New("invalid sensor type")
+	}
+	result := tx.Updates(&sensor)
+	return sensor.ID, result.Error
+}
+
+// http -v POST localhost:8080/measurements sensor_id:=3 value:=32
+// http -v GET localhost:8080/measurements/3
+func (m Model) AddMeasurement(measurement Measurement) (uint, error) {
+	measurement.ID = 0
+	err := m.app.Db().First(&Sensor{}, measurement.SensorID).Error
+	if err != nil {
+		return 0, err
+	}
+	result := m.app.Db().Create(&measurement)
+	return measurement.ID, result.Error
+}