(refs #533)Add remove user checking for the last one administrator.

src/main/scala/gitbucket/core/controller/AccountController.scala

@@ -155,7 +155,7 @@ trait AccountControllerBase extends AccountManagementControllerBase {
   get("/:userName/_edit")(oneselfOnly {
     val userName = params("userName")
     getAccountByUserName(userName).map { x =>
-      html.edit(x, flash.get("info"))
+      html.edit(x, flash.get("info"), flash.get("error"))
     } getOrElse NotFound
   })
 
@@ -178,7 +178,11 @@ trait AccountControllerBase extends AccountManagementControllerBase {
   get("/:userName/_delete")(oneselfOnly {
     val userName = params("userName")
 
-    getAccountByUserName(userName, true).foreach { account =>
+    getAccountByUserName(userName, true).map { account =>
+      if(isLastAdministrator(userName)){
+        flash += "error" -> "Account can't be removed because this is the last administrator."
+        redirect(s"/${userName}/_edit")
+      } else {
 //      // Remove repositories
 //      getRepositoryNamesOfUser(userName).foreach { repositoryName =>
 //        deleteRepository(userName, repositoryName)
@@ -187,14 +191,12 @@ trait AccountControllerBase extends AccountManagementControllerBase {
 //        FileUtils.deleteDirectory(getTemporaryDir(userName, repositoryName))
 //      }
 //      // Remove from GROUP_MEMBER, COLLABORATOR and REPOSITORY
-//      removeUserRelatedData(userName)
-
-      removeUserRelatedData(userName)
-      updateAccount(account.copy(isRemoved = true))
-    }
-
-    session.invalidate
-    redirect("/")
+        removeUserRelatedData(userName)
+        updateAccount(account.copy(isRemoved = true))
+        session.invalidate
+        redirect("/")
+      }
+    } getOrElse NotFound
   })
 
   get("/:userName/_ssh")(oneselfOnly {

src/main/scala/gitbucket/core/service/AccountService.scala

@@ -97,6 +97,12 @@ trait AccountService {
       Accounts filter (_.removed === false.bind) sortBy(_.userName) list
     }
 
+  def isLastAdministrator(userName: String)(implicit s: Session): Boolean = {
+    getAccountByUserName(userName).collect { case account if account.isAdmin =>
+      (Accounts filter (_.removed === false.bind) filter (_.isAdmin === true.bind) map (_.userName.length)).first == 1
+    } getOrElse false
+  }
+
   def createAccount(userName: String, password: String, fullName: String, mailAddress: String, isAdmin: Boolean, url: Option[String])
                    (implicit s: Session): Unit =
     Accounts insert Account(

src/main/twirl/gitbucket/core/account/edit.scala.html

@@ -1,4 +1,4 @@
-@(account: gitbucket.core.model.Account, info: Option[Any])(implicit context: gitbucket.core.controller.Context)
+@(account: gitbucket.core.model.Account, info: Option[Any], error: Option[Any])(implicit context: gitbucket.core.controller.Context)
 @import gitbucket.core.util.LDAPUtil
 @import context._
 @import gitbucket.core.view.helpers._
@@ -6,6 +6,7 @@
 <div class="container body">
   @menu("profile", settings.ssh){
     @helper.html.information(info)
+    @helper.html.error(error)
     @if(LDAPUtil.isDummyMailAddress(account)){<div class="alert alert-danger">Please register your mail address.</div>}
     <form action="@url(account.userName)/_edit" method="POST" validate="true">
       <div class="panel panel-default">