From b0477c36f60e9843fd5042326d70081eefb07ba2 Mon Sep 17 00:00:00 2001
From: daa <andrey.dubravin@gmail.com>
Date: Tue, 17 Oct 2017 21:34:49 +0300
Subject: [PATCH] Check vim-plug loaded

---
 src/nvim.rs                 | 11 +++++++++--
 src/plug_manager/manager.rs | 24 +++++++++++++++---------
 src/plug_manager/ui.rs      | 33 +++++++++++++++++++++++++--------
 3 files changed, 49 insertions(+), 19 deletions(-)

diff --git a/src/nvim.rs b/src/nvim.rs
index d9287bc..4290f69 100644
--- a/src/nvim.rs
+++ b/src/nvim.rs
@@ -505,17 +505,24 @@ fn call(
     Ok(repaint_mode)
 }
 
-pub trait ErrorReport {
+pub trait ErrorReport<T> {
     fn report_err(&self, nvim: &mut NeovimApi);
+
+    fn ok_and_report(&self, nvim: &mut NeovimApi) -> Option<&T>;
 }
 
-impl<T> ErrorReport for result::Result<T, CallError> {
+impl<T> ErrorReport<T> for result::Result<T, CallError> {
     fn report_err(&self, _: &mut NeovimApi) {
         if let Err(ref err) = *self {
             println!("{}", err);
             //nvim.report_error(&err_msg).expect("Error report error :)");
         }
     }
+
+    fn ok_and_report(&self, nvim: &mut NeovimApi) -> Option<&T> {
+        self.report_err(nvim);
+        self.as_ref().ok()
+    }
 }
 
 #[derive(Clone, Debug)]
diff --git a/src/plug_manager/manager.rs b/src/plug_manager/manager.rs
index fe9a93c..24d295e 100644
--- a/src/plug_manager/manager.rs
+++ b/src/plug_manager/manager.rs
@@ -1,19 +1,17 @@
 use std::rc::Rc;
 use std::cell::{RefCell, RefMut};
 
-use neovim_lib::{Neovim, NeovimApi, Value};
+use neovim_lib::{Neovim, NeovimApi};
 
-use nvim::NeovimClient;
+use nvim::{NeovimClient, ErrorReport};
 
 pub struct Manager {
-   nvim: Option<Rc<RefCell<NeovimClient>>>,
+    nvim: Option<Rc<RefCell<NeovimClient>>>,
 }
 
 impl Manager {
     pub fn new() -> Self {
-        Manager { 
-            nvim: None,
-        }
+        Manager { nvim: None }
     }
 
     pub fn initialize(&mut self, nvim: Rc<RefCell<NeovimClient>>) {
@@ -31,10 +29,18 @@ impl Manager {
 
     pub fn get_state(&self) -> State {
         if let Some(mut nvim) = self.nvim() {
-            nvim.command("exists('g:loaded_plug')");
+            let loaded_plug = nvim.eval("exists('g:loaded_plug')");
+            loaded_plug
+                .ok_and_report(&mut *nvim)
+                .and_then(|loaded_plug| loaded_plug.as_i64())
+                .map_or(State::Unknown, |loaded_plug| if loaded_plug > 0 {
+                    State::AlreadyLoaded
+                } else {
+                    State::Unknown
+                })
+        } else {
+            State::Unknown
         }
-        
-        State::Unknown
     }
 }
 
diff --git a/src/plug_manager/ui.rs b/src/plug_manager/ui.rs
index c5903f7..e3d1dd0 100644
--- a/src/plug_manager/ui.rs
+++ b/src/plug_manager/ui.rs
@@ -3,15 +3,13 @@ use gtk::prelude::*;
 
 use super::manager;
 
-pub struct Ui <'a> {
+pub struct Ui<'a> {
     manager: &'a manager::Manager,
 }
 
-impl <'a> Ui <'a> {
+impl<'a> Ui<'a> {
     pub fn new(manager: &'a manager::Manager) -> Ui<'a> {
-        Ui {
-            manager,
-        }
+        Ui { manager }
     }
 
     pub fn show<T: IsA<gtk::Window>>(&self, parent: &T) {
@@ -27,9 +25,24 @@ impl <'a> Ui <'a> {
         let content = dlg.get_content_area();
         let tabs = gtk::Notebook::new();
 
-        let get_plugins = gtk::Box::new(gtk::Orientation::Vertical, 0);
-        let get_plugins_lbl = gtk::Label::new("Get Plugins");
-        tabs.append_page(&get_plugins, Some(&get_plugins_lbl));
+        match self.get_state() {
+            manager::State::AlreadyLoaded => {
+                let get_plugins = gtk::Box::new(gtk::Orientation::Vertical, 0);
+                let warn_lbl = gtk::Label::new(
+                    "Plug manager already loaded.\n\
+                                               NeovimGtk manages plugins using vim-plug as backend.\n\
+                                               To allow NeovimGtk manage plugins please disable vim-plug in your configuration",
+                );
+                get_plugins.add(&warn_lbl);
+                let get_plugins_lbl = gtk::Label::new("Help");
+                tabs.append_page(&get_plugins, Some(&get_plugins_lbl));
+            }
+            manager::State::Unknown => {
+                let get_plugins = gtk::Box::new(gtk::Orientation::Vertical, 0);
+                let get_plugins_lbl = gtk::Label::new("Get Plugins");
+                tabs.append_page(&get_plugins, Some(&get_plugins_lbl));
+            }
+        }
 
         let plugins = gtk::Box::new(gtk::Orientation::Vertical, 0);
         let plugins_lbl = gtk::Label::new("Plugins");
@@ -49,4 +62,8 @@ impl <'a> Ui <'a> {
 
         dlg.destroy();
     }
+
+    fn get_state(&self) -> manager::State {
+        self.manager.get_state()
+    }
 }