From 7097775a4a73e869caf913b5809699975a6a70ca Mon Sep 17 00:00:00 2001
From: greg <greg.shuflin@protonmail.com>
Date: Thu, 6 Jun 2019 22:21:50 -0700
Subject: [PATCH] :help command working

---
 schala-repl/src/repl/command_tree.rs |  7 ++++--
 schala-repl/src/repl/help.rs         | 36 +++++++++++++++++-----------
 schala-repl/src/repl/mod.rs          |  2 +-
 3 files changed, 28 insertions(+), 17 deletions(-)

diff --git a/schala-repl/src/repl/command_tree.rs b/schala-repl/src/repl/command_tree.rs
index d1ceda5..30c612b 100644
--- a/schala-repl/src/repl/command_tree.rs
+++ b/schala-repl/src/repl/command_tree.rs
@@ -54,14 +54,17 @@ impl CommandTree {
       CommandTree::Top(_) => ""
     }
   }
-  pub fn get_children(&self) -> Vec<&str> {
+  pub fn get_children(&self) -> &Vec<CommandTree> {
     use CommandTree::*;
     match self {
       Terminal { children, .. } |
       NonTerminal { children, .. } |
-      Top(children) => children.iter().map(|x| x.get_cmd()).collect()
+      Top(children) => children
     }
   }
+  pub fn get_subcommands(&self) -> Vec<&str> {
+    self.get_children().iter().map(|x| x.get_cmd()).collect()
+  }
 
   pub fn perform(&self, repl: &mut Repl, arguments: &Vec<&str>) -> InterpreterDirectiveOutput {
     let mut dir_pointer: &CommandTree = self;
diff --git a/schala-repl/src/repl/help.rs b/schala-repl/src/repl/help.rs
index e14af5c..1e51cad 100644
--- a/schala-repl/src/repl/help.rs
+++ b/schala-repl/src/repl/help.rs
@@ -1,31 +1,39 @@
 use std::fmt::Write as FmtWrite;
 
 use super::{Repl, InterpreterDirectiveOutput};
-use crate::repl::command_tree::CommandTree;
 
 pub fn help(repl: &mut Repl, arguments: &[&str]) -> InterpreterDirectiveOutput {
-  let mut buf = String::new();
-  let directives = match repl.get_directives() {
-    CommandTree::Top(children) => children,
-    _ => panic!("Top-level CommandTree not Top")
-  };
-
   match arguments {
-    [] =>  return global_help(repl, &directives),
-    _ => {
-      writeln!(buf, "Command-specific help not available yet").unwrap();
+    [] =>  return global_help(repl),
+    commands => {
+      let dirs = repl.get_directives();
+      let mut directive_list = dirs.get_children();
+      let mut matched_directive = None;
+      for cmd in commands {
+        let found = directive_list.iter().find(|directive| directive.get_cmd() == *cmd);
+        if let Some(dir) = found {
+            directive_list = dir.get_children();
+        }
+
+        matched_directive = found;
+      }
+
+      Some(if let Some(dir) = matched_directive {
+        format!("{}", dir.get_help())
+      } else {
+        format!("Last command not found")
+      })
     }
-  };
-  Some(buf)
+  }
 }
 
-fn global_help(repl: &mut Repl, directives: &Vec<CommandTree>) -> InterpreterDirectiveOutput {
+fn global_help(repl: &mut Repl) -> InterpreterDirectiveOutput {
   let mut buf = String::new();
 
   writeln!(buf, "MetaInterpreter options").unwrap();
   writeln!(buf, "-----------------------").unwrap();
 
-  for directive in directives {
+  for directive in repl.get_directives().get_children() {
     let trailer = " ";
     writeln!(buf, "{}{}- {}", directive.get_cmd(), trailer, directive.get_help()).unwrap();
   }
diff --git a/schala-repl/src/repl/mod.rs b/schala-repl/src/repl/mod.rs
index 1070d7a..e8d7073 100644
--- a/schala-repl/src/repl/mod.rs
+++ b/schala-repl/src/repl/mod.rs
@@ -220,7 +220,7 @@ impl<T: Terminal> Completer<T> for TabCompleteHandler {
             _ => false
           };
           let word = if top { word.get(1..).unwrap() } else { word };
-          for cmd in command_tree.map(|x| x.get_children()).unwrap_or(vec![]).into_iter() {
+          for cmd in command_tree.map(|x| x.get_subcommands()).unwrap_or(vec![]).into_iter() {
             if cmd.starts_with(word) {
               completions.push(Completion {
                 completion: format!("{}{}", if top { ":" } else { "" }, cmd),