type Log struct {
	ID			uint			`gorm:"primaryKey"`
	Name		string			`gorm:"not null"`
	Notes		string	
	LogType		string			`gorm:"not null"`
	Date		Datetime.Time	`gorm:"type:date;default:CURRENT_DATE"not null`
	Duration	float64			`gorm:"not null"` // in hours
	VisibiltyID uint			`gorm:"not null"`
	Visibility	Taxonomy		`gorm:"constraint:OnUpdate:CASCADE,OnDelete:CASCADE;not null"`
}

type _LogMetadata struct {
	ID	uint	`gorm:"primaryKey"`
	LogID uint	`gorm:"not null"`
	Log	Log		`gorm:"foreignKey:LogID;constraint:OnUpdate:CASCADE,OnDelete:CASCADE;not null"`
}

type _FieldWorkLog struct {
	_LogMetadata
	WorkedAreaPercentage	float64	`gorm:"not null"`
	MachineID				uint	`gorm:"not null"`
	Machine					Machine	`gorm:"constraint:OnUpdate:CASCADE,OnDelete:CASCADE;not null"`
}

type SeedingLog struct {
	_FieldWorkLog
	SeedID			uint		`gorm:"not null"`
	Seed			Seed		`gorm:"constraint:OnUpdate:CASCADE,OnDelete:CASCADE;not null"`
	TechniqueID 	uint		`gorm:"not null"`
	Technique		Taxonomy	`gorm:"constraint:OnUpdate:CASCADE,OnDelete:CASCADE;not null"`
	Amount			float64		`gorm:"not null"` // in units/ha
	ConditionsID 	uint		`gorm:"not null"`
	Conditions		Taxonomy	`gorm:"constraint:OnUpdate:CASCADE,OnDelete:CASCADE;not null"`
}

type FertilizingLog struct {
	_FieldWorkLog
	FertilizerID	uint		`gorm:"not null"`
	Fertilizer		Fertilizer	`gorm:"constraint:OnUpdate:CASCADE,OnDelete:CASCADE;not null"`
	Amount			float64		`gorm:"not null"` // in units/ha
}