Provide coffee details

internal/api/coffee.go

@@ -66,7 +66,7 @@ func CreateCoffee(service *product.Service) func(*gin.Context) {
 			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
 			return
 		}
-		b, err := service.Create(json.Name, json.Price, json.CuppingScore)
+		b, err := service.Create(json.Name, json.Price, json.CuppingScore, &json.Details)
 		if err != nil {
 			log.Println(err)
 			switch {
@@ -85,16 +85,18 @@ func CreateCoffee(service *product.Service) func(*gin.Context) {
 }
 
 type CreateCoffeeRequest struct {
-	Name         string  `form:"name" json:"name" binding:"required"`
-	Price        float64 `form:"price" json:"price" binding:"required"`
-	CuppingScore *int    `form:"cupping_score" json:"cupping_score,omitempty"`
+	Name         string                `form:"name" json:"name" binding:"required"`
+	Price        float64               `form:"price" json:"price" binding:"required"`
+	CuppingScore *int                  `form:"cupping_score" json:"cupping_score,omitempty"`
+	Details      product.CoffeeDetails `form:"info" json:"info"`
 }
 
 type CoffeeInfo struct {
-	ID           string  `json:"id"`
-	Name         string  `json:"name"`
-	Price        float64 `json:"price"`
-	CuppingScore int     `json:"cupping_score"`
+	ID           string                `json:"id"`
+	Name         string                `json:"name"`
+	Price        float64               `json:"price"`
+	CuppingScore int                   `json:"cupping_score"`
+	Details      product.CoffeeDetails `json:"info"`
 }
 
 func allToCoffeeInfo(list []product.Coffee) ([]CoffeeInfo, error) {
@@ -116,5 +118,10 @@ func toCoffeeInfo(b *product.Coffee) (CoffeeInfo, error) {
 	if b == nil {
 		return CoffeeInfo{}, errors.New("beverage is nil")
 	}
-	return CoffeeInfo{ID: b.AggregateID, Name: b.Type, Price: b.Price(), CuppingScore: b.CoffeeValue().Value}, nil
+	d := toCoffeeDetails(b.Details())
+	return CoffeeInfo{ID: b.AggregateID, Name: b.Type, Price: b.Price(), CuppingScore: b.CoffeeValue().Value, Details: d}, nil
+}
+
+func toCoffeeDetails(d product.Details) product.CoffeeDetails {
+	return product.CoffeeDetails{Origin: d.Origin, Description: d.Description, Misc: d.Misc}
 }

internal/product/coffee.go

@@ -10,11 +10,12 @@ import (
 
 // Coffee is the actual representation of the black gold.
 type Coffee struct {
-	AggregateID string
-	Type        string
-	price       float64
-	cva         CuppingScore
-	events      []event.Event
+	AggregateID string        // The ID to identify the coffee in the system
+	Type        string        // What type of coffee it is, e.g. black coffee, espresso, ...
+	price       float64       // The current price of the coffee in €, e.g. 0.50 for 50 cents
+	cva         CuppingScore  // The coffee value assessment result, currently the CuppingScore
+	details     Details       // A more detailed description about the coffee
+	events      []event.Event // Uncommitted events of the aggregate
 }
 
 // CoffeeValue provides the assessed Value of the current coffee.
@@ -89,6 +90,49 @@ func (e CvaProvided) Occurred() time.Time {
 	return e.OccurredOn
 }
 
+// Details enables a containerised description with more detail of a Coffee.
+type Details struct {
+	Origin      string            `json:"origin"`      // The country the coffee has been produced
+	Description string            `json:"description"` // Some detailed description about the coffee
+	RoastHouse  string            `json:"roast_house"` // The location the coffee has been roasted
+	Misc        map[string]string `json:"misc"`        // An unstructured collection of key:values to provide more details
+}
+
+func (c *Coffee) Details() Details {
+	return c.details
+}
+
+// UpdateDetails sets some more detailed information for the current Coffee.
+func (c *Coffee) UpdateDetails(details Details) error {
+	e := NewDetailsUpdated(c.AggregateID, details)
+	if err := c.apply(e); err != nil {
+		return errors.Join(fmt.Errorf("could not update details for %s [id: %s]", c.Type, c.AggregateID), err)
+	}
+	return nil
+}
+
+type DetailsUpdated struct {
+	ID         string
+	Details    Details
+	OccurredOn time.Time
+}
+
+func (e DetailsUpdated) AggregateID() string {
+	return e.ID
+}
+
+func (e DetailsUpdated) Type() string {
+	return "DetailsUpdated"
+}
+
+func (e DetailsUpdated) Occurred() time.Time {
+	return e.OccurredOn
+}
+
+func NewDetailsUpdated(id string, details Details) DetailsUpdated {
+	return DetailsUpdated{ID: id, Details: details, OccurredOn: time.Now()}
+}
+
 // ChangePrice updates the price of the current Coffee.
 //
 // Only values greater or equal zero are allowed.
@@ -135,6 +179,10 @@ func (c *Coffee) apply(e event.Event) error {
 		if err := c.applyCva(theEvent); err != nil {
 			return err
 		}
+	case DetailsUpdated:
+		if err := c.applyDetails(theEvent); err != nil {
+			return err
+		}
 	default:
 		return fmt.Errorf("cannot apply event: unknown event '%T'", e)
 	}
@@ -170,6 +218,12 @@ func (c *Coffee) applyCva(e CvaProvided) error {
 	return nil
 }
 
+func (c *Coffee) applyDetails(e DetailsUpdated) error {
+	c.details = e.Details
+	c.events = append(c.events, e)
+	return nil
+}
+
 type CoffeeCreated struct {
 	ID           string
 	BeverageType string

internal/product/coffee_test.go

@@ -96,3 +96,28 @@ func TestCVA(t *testing.T) {
 		return
 	}
 }
+
+func TestDetails(t *testing.T) {
+	c, _ := NewCoffee("Black Coffee", 0.25)
+	c.Clear()
+
+	d := Details{"Kirinyaga County", "Kenianischer Waldkaffee", "", nil}
+
+	err := c.UpdateDetails(d)
+
+	if err != nil {
+		t.Errorf("UpdateDetails() error = %v", err)
+	}
+
+	if !(c.Details().Origin == "Kirinyaga County") {
+		t.Errorf("Details should have been Kirinyaga County")
+	}
+
+	switch c.Events()[0].(type) {
+	case DetailsUpdated:
+		break
+	default:
+		t.Errorf("Events() should have returned a DetailsUpdated, but returned %v", c.Events()[0])
+	}
+
+}

internal/product/service.go

@@ -85,14 +85,29 @@ func convert(entry storage.EventEntry) (event.Event, error) {
 			return nil, err
 		}
 		return evnt, nil
+	case "DetailsUpdated":
+		evnt, err := toDetailsUpdated(entry)
+		if err != nil {
+			return nil, err
+		}
+		return evnt, nil
 	default:
 		return nil, fmt.Errorf("unknown event type '%s'", entry.EventType)
 	}
 }
 
+func toDetailsUpdated(entry storage.EventEntry) (DetailsUpdated, error) {
+	e := DetailsUpdated{}
+	err := json.Unmarshal(entry.EventData, &e)
+	if err != nil {
+		return e, fmt.Errorf("failed to unmarshal expected DetailsUpdated event data: %w", err)
+	}
+	return e, nil
+}
+
 var InvalidPropertyError = errors.New("invalid property")
 
-func (s *Service) Create(name string, price float64, score *int) (*Coffee, error) {
+func (s *Service) Create(name string, price float64, score *int, details *CoffeeDetails) (*Coffee, error) {
 	b, err := NewCoffee(name, price)
 	if err != nil {
 		return nil, fmt.Errorf("%w: %s", InvalidPropertyError, err.Error())
@@ -104,6 +119,18 @@ func (s *Service) Create(name string, price float64, score *int) (*Coffee, error
 		return nil, fmt.Errorf("%w: %s", InvalidPropertyError, err.Error())
 	}
 
+	// Details are optional
+	if details != nil {
+		d := Details{
+			Origin:      details.Origin,
+			Description: details.Description,
+			RoastHouse:  details.RoastHouse,
+			Misc:        details.Misc}
+		if err = b.UpdateDetails(d); err != nil {
+			return nil, fmt.Errorf("%w: %s", InvalidPropertyError, err.Error())
+		}
+	}
+
 	entries := make([]storage.EventEntry, 0)
 	for _, e := range b.Events() {
 		entry, err := toEventEntry(e)
@@ -139,6 +166,12 @@ func toEventEntry(event event.Event) (storage.EventEntry, error) {
 			return storage.EventEntry{}, err
 		}
 		return storage.EventEntry{AggregateID: t.AggregateID(), Date: t.OccurredOn, EventType: "CvaProvided", EventData: data}, nil
+	case DetailsUpdated:
+		data, err := json.Marshal(t)
+		if err != nil {
+			return storage.EventEntry{}, err
+		}
+		return storage.EventEntry{AggregateID: t.AggregateID(), Date: t.OccurredOn, EventType: "DetailsUpdated", EventData: data}, nil
 	default:
 		return storage.EventEntry{}, fmt.Errorf("unknown event type: %T", t)
 	}
@@ -167,3 +200,10 @@ func toCvaProvided(entry storage.EventEntry) (event.Event, error) {
 	}
 	return e, nil
 }
+
+type CoffeeDetails struct {
+	Origin      string            `json:"origin"`
+	Description string            `json:"description"`
+	RoastHouse  string            `json:"roast_house"`
+	Misc        map[string]string `json:"misc"`
+}