implement AppContext, add Note type, add menu

README.md

@@ -22,3 +22,11 @@ Reading data will be saved to `$HOME/.ketotrack/readings.json`.
 go build
 mv ketotrack $HOME/.local/bin
 ```
+
+## Refactoring Notes
+- [X] Create `Record` and `Note` struct types
+- [X] Add `GKI` field to `Reading` struct type
+- [X] Encapsulate application data with an `AppContext` struct that holds a `Records` slice
+  - [X] `LoadRecords`, `SaveRecords`, `AddReading`, `AddNote` receiver methods
+- [X] Add interactive menu for adding either a `Note` or a `Record`
+- [ ] Standardize method names for getting user input to `handleNewNote` and `handleNewReading`

main.go

@@ -12,7 +12,7 @@ import (
 	"time"
 )
 
-var readingsFilename string
+var recordsFilename string
 
 func init() {
 	// Get user's homeDir directory
@@ -33,7 +33,19 @@ func init() {
 	}
 
 	// Set data file path for readings
-	readingsFilename = filepath.Join(ketotrackDir, "readings.json")
+	recordsFilename = filepath.Join(ketotrackDir, "records.json")
+}
+
+// Record holds a pointer to a Reading or Note.
+type Record struct {
+	Reading *Reading `json:"reading,omitempty"`
+	Note    *Note    `json:"note,omitempty"`
+}
+
+// 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"`
 }
 
 // Reading holds the glucose and ketone level measurements along with the time the measurements were taken.
@@ -41,89 +53,109 @@ 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,
 	}
 }
 
-// GKI calculates and returns the Glucose Ketone Index of the reading.
-// The Glucose Ketone Index helps determine the efficiency of glucose and ketone levels within the body. It is
-// calculated as (glucose level in mg/dL / 18) divided by the ketone level.
-func (r Reading) GKI() (float64, error) {
-	if r.Ketone == 0 {
-		return 0, errors.New("ketone level must not be zero to calculate GKI")
-	}
-	return (r.Glucose / 18) / r.Ketone, nil
+// AppContext is the application data store that holds Records
+type AppContext struct {
+	Records []Record
 }
 
-func main() {
-	// Take a new reading from the user
-	reading, err := getReading()
+// LoadRecords will load records from file
+func (ctx *AppContext) LoadRecords(filename string) error {
+	data, err := os.ReadFile(filename)
 	if err != nil {
-		fmt.Println(err.Error())
-		return
+		return err
+	}
+	return json.Unmarshal(data, &ctx.Records)
 }
 
-	// Calculate GKI
-	gki, err := reading.GKI()
-	if err != nil {
-		fmt.Println(err.Error())
-		fmt.Println("You are not in ketosis.")
-		return
-	}
-	fmt.Printf("\nYour GKI is: %0.2f\n", gki)
-
-	// Display level of ketosis
-	switch {
-	case gki <= 1:
-		fmt.Println("You're in the highest level of ketosis.")
-	case gki < 3:
-		fmt.Println("You're in a high therapeutic level of ketosis.")
-	case gki < 6:
-		fmt.Println("You're in a moderate level of ketosis.")
-	case gki <= 9:
-		fmt.Println("You're in a low level of ketosis.")
-	default:
-		fmt.Println("You are not in ketosis.")
-	}
-
-	// Save latest reading to readings file
-	readings, _ := loadReadingsFromFile(readingsFilename)
-	readings = append(readings, reading)
-	err = saveReadingsToFile(readingsFilename, readings)
-	if err != nil {
-		fmt.Printf("error saving data: %s\n", err.Error())
-	}
-}
-
-func saveReadingsToFile(filename string, data []Reading) error {
-	jsonData, err := json.Marshal(data)
+// SaveRecords will save records to a file
+func (ctx *AppContext) SaveRecords(filename string) error {
+	jsonData, err := json.Marshal(ctx.Records)
 	if err != nil {
 		return err
 	}
 	return os.WriteFile(filename, jsonData, 0660)
 }
 
-func loadReadingsFromFile(filename string) ([]Reading, error) {
-	data, err := os.ReadFile(filename)
-	if err != nil {
-		return nil, err
+// AddReading will add a Reading to the AppContext
+func (ctx *AppContext) AddReading(reading Reading) {
+	ctx.Records = append(ctx.Records, Record{Reading: &reading})
 }
 
-	var readings []Reading
-	err = json.Unmarshal(data, &readings)
-	if err != nil {
-		return nil, err
+// AddNote will a add a Note to the AppContext
+func (ctx *AppContext) AddNote(note Note) {
+	ctx.Records = append(ctx.Records, Record{Note: &note})
 }
 
-	return readings, nil
+func main() {
+	var appCtx AppContext
+
+	err := appCtx.LoadRecords(recordsFilename)
+	if err != nil {
+		fmt.Printf("Error loading records: %s\n", err)
+	}
+
+	// Display menu
+	choice, err := getUserInput("1. Enter new reading\n2. Enter new note\n3. Exit\nYour choice")
+	switch choice {
+	case "1":
+		// Take a new reading from the user
+		reading, err := getReading()
+		if err != nil {
+			fmt.Printf("Error getting reading: %s\n", err)
+		} else {
+			// Display GKI and level of ketosis
+			fmt.Printf("\nYour GKI is: %0.2f\n", reading.GKI)
+			switch {
+			case reading.GKI <= 1:
+				fmt.Println("You're in the highest level of ketosis.")
+			case reading.GKI < 3:
+				fmt.Println("You're in a high therapeutic level of ketosis.")
+			case reading.GKI < 6:
+				fmt.Println("You're in a moderate level of ketosis.")
+			case reading.GKI <= 9:
+				fmt.Println("You're in a low level of ketosis.")
+			default:
+				fmt.Println("You are not in ketosis.")
+			}
+			appCtx.AddReading(reading)
+		}
+	case "2":
+		noteText, err := getUserInput("Enter your note text: ")
+		if err != nil {
+			fmt.Println("Error getting note: %s\n", err)
+		} else {
+			appCtx.AddNote(Note{
+				Time: time.Now(),
+				Text: noteText,
+			})
+		}
+	default:
+		fmt.Println("Quitting...")
+	}
+
+	// Save Records before exiting
+	err = appCtx.SaveRecords(recordsFilename)
 }
 
 func getReading() (Reading, error) {