feat: add generate token function

model/function.go

@@ -0,0 +1,52 @@
+package model
+
+import (
+	"errors"
+	"github.com/weloe/token-go/util"
+	"sync"
+)
+
+type GenerateFunc func() (string, error)
+
+type GenerateTokenFunc struct {
+	fns *sync.Map
+}
+
+func (g *GenerateTokenFunc) Exec(tokenForm string) (string, error) {
+	handlerFunc, err := g.GetFunction(tokenForm)
+	if err != nil {
+		return "", err
+	}
+	s, err := handlerFunc()
+	if err != nil {
+		return "", nil
+	}
+	return s, nil
+}
+
+func (g *GenerateTokenFunc) GetFunction(tokenForm string) (GenerateFunc, error) {
+	value, ok := g.fns.Load(tokenForm)
+	if !ok {
+		return nil, errors.New("GetFunction() failed: load func error")
+	}
+	if value == nil {
+		return nil, errors.New("GetFunction() failed: func doesn't exist")
+	}
+	handlerFunc := value.(GenerateFunc)
+	return handlerFunc, nil
+}
+
+func LoadFunctionMap() GenerateTokenFunc {
+	fm := &GenerateTokenFunc{fns: &sync.Map{}}
+	fm.AddFunc("uuid", util.GenerateUUID)
+	fm.AddFunc("uuid-simple", util.GenerateSimpleUUID)
+	fm.AddFunc("random-string32", util.GenerateRandomString32)
+	fm.AddFunc("random-string64", util.GenerateRandomString64)
+	fm.AddFunc("random-string128", util.GenerateRandomString128)
+
+	return *fm
+}
+
+func (g *GenerateTokenFunc) AddFunc(key string, f GenerateFunc) {
+	g.fns.LoadOrStore(key, f)
+}