collapses config into one library

internal/config/envconfig.go

@@ -0,0 +1,111 @@
+package config
+
+import (
+	"fmt"
+	"reflect"
+	"strconv"
+	"strings"
+)
+
+type StructInfo struct {
+	Name         string
+	Alt          string
+	Key          string
+	Field        reflect.Value
+	Tags         reflect.StructTag
+	Type         reflect.Type
+	DefaultValue interface{}
+}
+
+func getStructInfo(spec interface{}) ([]StructInfo, error) {
+	s := reflect.ValueOf(spec)
+
+	if s.Kind() != reflect.Pointer {
+		return []StructInfo{}, fmt.Errorf("getStructInfo() was sent a %s instead of a pointer to a struct.\n", s.Kind())
+	}
+
+	s = s.Elem()
+	if s.Kind() != reflect.Struct {
+		return []StructInfo{}, fmt.Errorf("getStructInfo() was sent a %s instead of a struct.\n", s.Kind())
+	}
+	typeOfSpec := s.Type()
+
+	infos := make([]StructInfo, 0, s.NumField())
+	for i := 0; i < s.NumField(); i++ {
+		f := s.Field(i)
+		ftype := typeOfSpec.Field(i)
+
+		ignored, _ := strconv.ParseBool(ftype.Tag.Get("ignored"))
+		if !f.CanSet() || ignored {
+			continue
+		}
+
+		for f.Kind() == reflect.Pointer {
+			if f.IsNil() {
+				if f.Type().Elem().Kind() != reflect.Struct {
+					break
+				}
+				f.Set(reflect.New(f.Type().Elem()))
+			}
+			f = f.Elem()
+		}
+
+		info := StructInfo{
+			Name:  ftype.Name,
+			Alt:   strings.ToUpper(ftype.Tag.Get("env")),
+			Key:   ftype.Name,
+			Field: f,
+			Tags:  ftype.Tag,
+			Type:  ftype.Type,
+		}
+		if info.Alt != "" {
+			info.Key = info.Alt
+		}
+		info.Key = strings.ToUpper(info.Key)
+		if ftype.Tag.Get("default") != "" {
+			v, err := typeConversion(ftype.Type.String(), ftype.Tag.Get("default"))
+			if err != nil {
+				return []StructInfo{}, err
+			}
+			info.DefaultValue = v
+		}
+		infos = append(infos, info)
+	}
+	return infos, nil
+}
+
+func typeConversion(t, v string) (interface{}, error) {
+	switch t {
+	case "string":
+		return v, nil
+	case "int":
+		return strconv.ParseInt(v, 10, 0)
+	case "int8":
+		return strconv.ParseInt(v, 10, 8)
+	case "int16":
+		return strconv.ParseInt(v, 10, 16)
+	case "int32":
+		return strconv.ParseInt(v, 10, 32)
+	case "int64":
+		return strconv.ParseInt(v, 10, 64)
+	case "uint":
+		return strconv.ParseUint(v, 10, 0)
+	case "uint16":
+		return strconv.ParseUint(v, 10, 16)
+	case "uint32":
+		return strconv.ParseUint(v, 10, 32)
+	case "uint64":
+		return strconv.ParseUint(v, 10, 64)
+	case "float32":
+		return strconv.ParseFloat(v, 32)
+	case "float64":
+		return strconv.ParseFloat(v, 64)
+	case "complex64":
+		return strconv.ParseComplex(v, 64)
+	case "complex128":
+		return strconv.ParseComplex(v, 128)
+	case "bool":
+		return strconv.ParseBool(v)
+	}
+	return nil, fmt.Errorf("Unable to identify type.")
+}