package model

import "time"

// Note holds a text note along with the time the note was taken.
type Note struct {
	Time time.Time `json:"time"`
	Text string    `json:"text"`
}

// NewNote returns a new Note
func NewNote(text string) Note {
	return Note{
		Time: time.Now(),
		Text: text,
	}
}

// Reading holds the glucose and ketone level measurements along with the time the measurements were taken.
type Reading struct {
	Time    time.Time `json:"time"`
	Glucose float64   `json:"glucose"`
	Ketone  float64   `json:"ketone"`
	GKI     float64   `json:"GKI"`
}

// NewReading creates and returns a new Reading instance with the provided glucose and ketone levels, and records
// the current time. The glucose value should be provided in mg/dL, while the ketone level should be in mmol/L.
func NewReading(glucose, ketone float64) Reading {
	var gki float64
	if ketone == 0 {
		gki = 0
	} else {
		gki = (glucose / 18) / ketone
	}

	return Reading{
		Time:    time.Now(),
		Glucose: glucose,
		Ketone:  ketone,
		GKI:     gki,
	}
}

// Record holds a pointer to a Reading or Note.
type Record struct {
	Reading *Reading `json:"reading,omitempty"`
	Note    *Note    `json:"note,omitempty"`
}