chore: fitgen's mesgdef: simplify builder and only create array as ne…

…eded (#40)

internal/cmd/fitgen/profile/mesgdef/builder.go

@@ -80,7 +80,6 @@ func (b *mesgdefBuilder) Build() ([]builder.Data, error) {
 				Name:          strutil.ToTitle(mesg.Fields[i].Name),
 				String:        field.Name,
 				Type:          transformType(field.Type, field.Array),
-				InvalidValue:  b.baseTypeInvalid(strutil.ToTitle(b.baseTypeMapByProfileType[field.Type]), field.Array),
 				AssignedValue: b.transformValue(field.Num, field.Type, field.Array),
 				Comment:       field.Comment,
 			}
@@ -105,13 +104,9 @@ func (b *mesgdefBuilder) Build() ([]builder.Data, error) {
 			}
 
 			fields = append(fields, f)
-			if strings.HasPrefix(f.InvalidValue, "basetype") {
+			if strings.HasPrefix(f.Type, "basetype") {
 				imports["github.com/muktihari/fit/profile/basetype"] = struct{}{}
 			}
-
-			if strings.HasPrefix(f.InvalidValue, "math") {
-				imports["math"] = struct{}{}
-			}
 		}
 
 		data := Data{
@@ -133,26 +128,6 @@ func (b *mesgdefBuilder) Build() ([]builder.Data, error) {
 	return dataBuilders, nil
 }
 
-func (b *mesgdefBuilder) baseTypeInvalid(_type, array string) string {
-	if strings.ToLower(_type) == "bool" {
-		return "false"
-	}
-
-	if array == "" {
-		if strings.HasPrefix(_type, "Float32") {
-			return fmt.Sprintf("math.Float32frombits(basetype.%sInvalid)", _type)
-		}
-
-		if strings.HasPrefix(_type, "Float64") {
-			return fmt.Sprintf("math.Float64frombits(basetype.%sInvalid)", _type)
-		}
-
-		return fmt.Sprintf("basetype.%sInvalid", _type)
-	}
-
-	return "nil"
-}
-
 func transformType(name, array string) string {
 	isBaseType := make(map[string]string)
 	for _, bt := range basetype.List() {

internal/cmd/fitgen/profile/mesgdef/mesgdef.tmpl

@@ -38,17 +38,18 @@ func New{{ .Name }}(mesg proto.Message) *{{ .Name }} {
 		return nil
 	}
 
-	vals := [256]any{ // Mark all values as invalid, replace only when specified.
+	vals := [...]any{ // nil value will be converted to its corresponding invalid value by typeconv.
 		{{ range .Fields -}}
-			{{ .Num }}: {{ .InvalidValue }}, /* {{ .Name }} */
+			{{ .Num }}: nil, /* {{ .Name }} */
 		{{ end -}}
 	}
 
 	for i := range mesg.Fields {
-		if mesg.Fields[i].Value == nil {
-			continue // keep the invalid value
+		field := &mesg.Fields[i]
+		if field.Num >= byte(len(vals)) {
+			continue
 		}
-		vals[mesg.Fields[i].Num] = mesg.Fields[i].Value
+		vals[field.Num] = field.Value
 	}
 
 	return &{{ .Name }}{
@@ -75,18 +76,22 @@ func (m {{ .Name }}) PutMessage(mesg *proto.Message) {
 		return
 	}
 
-	vals := [256]any{
+	vals := [...]any{
 		{{ range .Fields -}}
 			{{ .Num }}: m.{{ .Name }},
 		{{ end -}}
 	}
 
 	for i := range mesg.Fields {
-		mesg.Fields[i].Value = vals[mesg.Fields[i].Num]
+		field := &mesg.Fields[i]
+		if field.Num >= byte(len(vals)) {
+			continue
+		}
+		field.Value = vals[field.Num]
 	}
 
-	{{- if and (not (eq .Name "FileId")) (not (eq .Name "DeveloperDataId")) (not (eq .Name "FieldDescription"))  }}
+	{{ if and (not (eq .Name "FileId")) (not (eq .Name "DeveloperDataId")) (not (eq .Name "FieldDescription"))  }}
 	mesg.DeveloperFields = m.DeveloperFields
-	{{ end }}
+	{{ end -}}
 }
 {{ end }}