api: Add go files

I know this is a huge commit, but I can't be bothered to check
this in part by part.

api/smtp_templates.go

@@ -0,0 +1,49 @@
+package main
+
+import (
+	"fmt"
+	"html/template"
+)
+
+var headerTemplate *template.Template
+
+type headerPlugs struct {
+	FromAddress string
+	ToName      string
+	ToAddress   string
+	Subject     string
+}
+
+var templates map[string]*template.Template
+
+func loadTemplates() error {
+	var err error
+	headerTemplate, err = template.New("header").Parse(`MIME-Version: 1.0
+Content-Type: text/html; charset=UTF-8
+From: {{.FromAddress}}
+To: {{.ToName}} <{{.ToAddress}}>
+Subject: {{.Subject}}
+
+`)
+	if err != nil {
+		logger.Fatalf("cannot parse header template: %v", err)
+		return errorMalformedTemplate
+	}
+
+	names := []string{"confirm-hex"}
+
+	templates = make(map[string]*template.Template)
+
+	logger.Infof("loading templates: %v", names)
+	for _, name := range names {
+		var err error
+		templates[name] = template.New(name)
+		templates[name], err = template.ParseFiles(fmt.Sprintf("email/%s.html", name))
+		if err != nil {
+			logger.Fatalf("cannot parse %s.html: %v\n", name, err)
+			return errorMalformedTemplate
+		}
+	}
+
+	return nil
+}