1 files changed, 47 insertions, 0 deletions
diff --git a/srv/api/chat.go b/srv/api/chat.go
index 84fffde..55d9d02 100644
--- a/srv/api/chat.go
+++ b/srv/api/chat.go
@@ -4,6 +4,8 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"strings"
+	"unicode"
 
 	"github.com/mediocregopher/blog.mediocregopher.com/srv/chat"
 )
@@ -39,3 +41,48 @@ func (a *api) chatHistoryHandler() http.Handler {
 		})
 	})
 }
+
+func (a *api) getUserID(r *http.Request) (chat.UserID, error) {
+	name := r.PostFormValue("name")
+	if l := len(name); l == 0 {
+		return chat.UserID{}, errors.New("name is required")
+	} else if l > 16 {
+		return chat.UserID{}, errors.New("name too long")
+	}
+
+	nameClean := strings.Map(func(r rune) rune {
+		if !unicode.IsPrint(r) {
+			return -1
+		}
+		return r
+	}, name)
+
+	if nameClean != name {
+		return chat.UserID{}, errors.New("name contains invalid characters")
+	}
+
+	password := r.PostFormValue("password")
+	if l := len(password); l == 0 {
+		return chat.UserID{}, errors.New("password is required")
+	} else if l > 128 {
+		return chat.UserID{}, errors.New("password too long")
+	}
+
+	return a.params.UserIDCalculator.Calculate(name, password), nil
+}
+
+func (a *api) getUserIDHandler() http.Handler {
+	return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
+		userID, err := a.getUserID(r)
+		if err != nil {
+			badRequest(rw, r, err)
+			return
+		}
+
+		jsonResult(rw, r, struct {
+			UserID chat.UserID `json:"userID"`
+		}{
+			UserID: userID,
+		})
+	})
+}