From f1ca1c9186bed805327d561cda9b22ff5121a85d Mon Sep 17 00:00:00 2001
From: Nicole Lemaster Slattengren <nlslatt@sandia.gov>
Date: Fri, 17 Sep 2021 15:14:48 -0700
Subject: [PATCH] #1359: LB: add function for printing lb-specific args

---
 .../balance/lb_invoke/lb_manager.cc           | 34 +++++++++++++++++++
 .../collection/balance/lb_invoke/lb_manager.h |  8 +++++
 2 files changed, 42 insertions(+)

diff --git a/src/vt/vrt/collection/balance/lb_invoke/lb_manager.cc b/src/vt/vrt/collection/balance/lb_invoke/lb_manager.cc
index f466c31b7a..620f51925e 100644
--- a/src/vt/vrt/collection/balance/lb_invoke/lb_manager.cc
+++ b/src/vt/vrt/collection/balance/lb_invoke/lb_manager.cc
@@ -262,6 +262,40 @@ void LBManager::startLB(PhaseType phase, LBType lb) {
   runLB(base_proxy, phase);
 }
 
+void LBManager::printLBArgsHelp(LBType lb) {
+  if (theContext()->getNode() == 0) {
+    fmt::print("\nLB arguments for {}:\n\n", lb_names_[lb]);
+
+    std::unordered_map<std::string, std::string> help;
+
+    switch (lb) {
+    case LBType::HierarchicalLB:
+      help = std::move(lb::HierarchicalLB::getInputKeysWithHelp());
+      break;
+    case LBType::GreedyLB:
+      help = std::move(lb::GreedyLB::getInputKeysWithHelp());
+      break;
+    case LBType::RotateLB:
+      help = std::move(lb::RotateLB::getInputKeysWithHelp());
+      break;
+    case LBType::TemperedLB:
+      help = std::move(lb::TemperedLB::getInputKeysWithHelp());
+      break;
+    case LBType::RandomLB:
+      help = std::move(lb::RandomLB::getInputKeysWithHelp());
+      break;
+    default:
+      fmt::print("Documentation has not been provided for this LB.\n\n");
+      break;
+    }
+
+    for (auto &arg_help : help) {
+      fmt::print("Argument: {}\n", arg_help.first);
+      fmt::print("{}\n", arg_help.second);
+    }
+  }
+}
+
 void LBManager::startup() {
   thePhase()->registerHookCollective(phase::PhaseHook::EndPostMigration, []{
     auto const phase = thePhase()->getCurrentPhase();
diff --git a/src/vt/vrt/collection/balance/lb_invoke/lb_manager.h b/src/vt/vrt/collection/balance/lb_invoke/lb_manager.h
index 8964fb0e77..c8294a905a 100644
--- a/src/vt/vrt/collection/balance/lb_invoke/lb_manager.h
+++ b/src/vt/vrt/collection/balance/lb_invoke/lb_manager.h
@@ -133,6 +133,14 @@ struct LBManager : runtime::component::Component<LBManager> {
    */
   void startLB(PhaseType phase, LBType lb);
 
+  /**
+   * \internal
+   * \brief Print documentation for LB args for the chosen LB
+   *
+   * \param[in] lb the load balancer to query
+   */
+  static void printLBArgsHelp(LBType lb);
+
 protected:
   /**
    * \internal