feat: add generate license

license.go

@@ -1 +1,59 @@
 package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"path/filepath"
+	"strings"
+)
+
+const (
+	templatesPath = "templates"
+)
+
+// map template name with filename
+var templates = map[string]templateInfo{
+	"MIT": {
+		filename: "mit",
+		args: []string{
+			"[year]",
+			"[fullname]",
+		},
+	},
+}
+
+type templateInfo struct {
+	filename string
+	args     []string
+}
+
+func generateLicense(name string, values map[string]string) (string, error) {
+	if name == "" {
+		return "", fmt.Errorf("empty license name")
+	}
+
+	templateInfo, ok := templates[name]
+	if !ok {
+		return "", fmt.Errorf("not support license %s", name)
+	}
+
+	// Read template
+	path := filepath.Join(templatesPath, templateInfo.filename)
+	templateRaw, err := ioutil.ReadFile(path)
+	if err != nil {
+		return "", fmt.Errorf("failed to read file %s: %w", path, err)
+	}
+
+	// Replace template
+	template := string(templateRaw)
+	for _, arg := range templateInfo.args {
+		value, ok := values[arg]
+		if !ok {
+			return "", fmt.Errorf("missing arg %s", arg)
+		}
+
+		template = strings.ReplaceAll(template, arg, value)
+	}
+
+	return template, nil
+}