1 files changed, 118 insertions, 0 deletions
diff --git a/pkg/motd/motd.go b/pkg/motd/motd.go
new file mode 100644
index 0000000..db21025
--- /dev/null
+++ b/pkg/motd/motd.go
@@ -0,0 +1,118 @@
+package motd
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"log"
+	"os"
+	"time"
+)
+
+const TimeString = "02 Jan 06 15:04 -0700" // RFC822 with numeric zone
+const ExampleFile = "motd-example.json"
+
+func ParseFile(f string) (Messages, error) {
+	jsonFile, err := os.Open(f)
+	if err != nil {
+		panic(err)
+	}
+	defer jsonFile.Close()
+	byteVal, err := ioutil.ReadAll(jsonFile)
+	if err != nil {
+		panic(err)
+	}
+	return getFromJSON(byteVal)
+}
+
+func getFromJSON(b []byte) (Messages, error) {
+	var m Messages
+	json.Unmarshal(b, &m)
+	return m, nil
+}
+
+type Messages struct {
+	Messages []Message `json:"motd"`
+}
+
+func (m *Messages) Length() int {
+	return len(m.Messages)
+}
+
+type Message struct {
+	Begin    string          `json:"begin"`
+	End      string          `json:"end"`
+	Type     string          `json:"type"`
+	Platform string          `json:"platform"`
+	Urgency  string          `json:"urgency"`
+	Text     []LocalizedText `json:"text"`
+}
+
+func (m *Message) IsValid() bool {
+	valid := (m.IsValidBegin() && m.IsValidEnd() &&
+		m.IsValidType() && m.IsValidPlatform() && m.IsValidUrgency() &&
+		m.HasLocalizedText())
+	return valid
+}
+
+func (m *Message) IsValidBegin() bool {
+	_, err := time.Parse(TimeString, m.Begin)
+	if err != nil {
+		log.Println(err)
+		return false
+	}
+	return true
+}
+
+func (m *Message) IsValidEnd() bool {
+	endTime, err := time.Parse(TimeString, m.End)
+	if err != nil {
+		log.Println(err)
+		return false
+	}
+	beginTime, err := time.Parse(TimeString, m.Begin)
+	if err != nil {
+		log.Println(err)
+		return false
+	}
+	if !beginTime.Before(endTime) {
+		log.Println("begin ts should be before end")
+		return false
+	}
+	return true
+}
+
+func (m *Message) IsValidType() bool {
+	switch m.Type {
+	case "once", "daily":
+		return true
+	default:
+		return false
+	}
+}
+
+func (m *Message) IsValidPlatform() bool {
+	switch m.Platform {
+	case "windows", "linux", "osx", "all":
+		return true
+	default:
+		return false
+	}
+}
+
+func (m *Message) IsValidUrgency() bool {
+	switch m.Urgency {
+	case "normal", "critical":
+		return true
+	default:
+		return false
+	}
+}
+
+func (m *Message) HasLocalizedText() bool {
+	return len(m.Text) > 0
+}
+
+type LocalizedText struct {
+	Lang string `json:"lang"`
+	Str  string `json:"str"`
+}