From 734826a2cd178d51f110da0176196aae783482ea Mon Sep 17 00:00:00 2001
From: Matthias Beyer <mail@beyermatthias.de>
Date: Fri, 30 Sep 2016 15:32:48 +0200
Subject: [PATCH] Add initial readline backend implementation

---
 libimaginteraction/src/readline.rs | 123 +++++++++++++++++++++++++++++
 1 file changed, 123 insertions(+)
 create mode 100644 libimaginteraction/src/readline.rs

diff --git a/libimaginteraction/src/readline.rs b/libimaginteraction/src/readline.rs
new file mode 100644
index 00000000..de2a1e95
--- /dev/null
+++ b/libimaginteraction/src/readline.rs
@@ -0,0 +1,123 @@
+//
+// imag - the personal information management suite for the commandline
+// Copyright (C) 2015, 2016 Matthias Beyer <mail@beyermatthias.de> and contributors
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; version
+// 2.1 of the License.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+//
+
+use error::InteractionErrorKind as IEK;
+use error::MapErrInto;
+
+use toml::Value;
+
+use rustyline::{Config, Editor};
+
+pub struct Readline {
+    editor: Editor,
+    history_file: PathBuf,
+    prompt: String,
+}
+
+impl Readline {
+
+    pub fn new(rt: &Runtime) -> Result<Readline> {
+        let cfg = try!(rt.config().ok_or(IEK::NoConfigError));
+
+        let c = cfg.config();
+        let histfile     = try!(c.lookup("ui.cli.readline_history_file").ok_or(IEK::ConfigError));
+        let histsize     = try!(c.lookup("ui.cli.readline_history_size").ok_or(IEK::ConfigError));
+        let histigndups  = try!(c.lookup("ui.cli.readline_history_ignore_dups").ok_or(IEK::ConfigError));
+        let histignspace = try!(c.lookup("ui.cli.readline_history_ignore_space").ok_or(IEK::ConfigError));
+        let prompt       = try!(c.lookup("ui.cli.readline_prompt").ok_or(IEK::ConfigError));
+
+        let histfile = try!(match histfile {
+            Value::String(s) => PathBuf::from(s),
+            _ => Err(IEK::ConfigTypeError.into_error())
+                .map_err_into(IEK::ConfigError)
+                .map_err_into(IEK::ReadlineError)
+        });
+
+        let histsize = try!(match histsize {
+            Value::Integer(i) => i,
+            _ => Err(IEK::ConfigTypeError.into_error())
+                .map_err_into(IEK::ConfigError)
+                .map_err_into(IEK::ReadlineError)
+        });
+
+        let histigndups = try!(match histigndups {
+            Value::Boolean(b) => b,
+            _ => Err(IEK::ConfigTypeError.into_error())
+                .map_err_into(IEK::ConfigError)
+                .map_err_into(IEK::ReadlineError)
+        });
+
+        let histignspace = try!(match histignspace {
+            Value::Boolean(b) => b,
+            _ => Err(IEK::ConfigTypeError.into_error())
+                .map_err_into(IEK::ConfigError)
+                .map_err_into(IEK::ReadlineError)
+        });
+
+        let prompt = try!(match prompt {
+            Value::String(s) => s,
+            _ => Err(IEK::ConfigTypeError.into_error())
+                .map_err_into(IEK::ConfigError)
+                .map_err_into(IEK::ReadlineError)
+        });
+
+        let config = Config::builder().
+            .max_history_size(histsize)
+            .history_ignore_dups(histigndups)
+            .history_ignore_space(histignspace)
+            .build();
+
+        let mut editor = Editor::new(config);
+        let _ = try!(editor.load_history(&histfile).map_err_into(ReadlineError));
+
+        Ok(Readline {
+            editor: editor,
+            history_file: histfile,
+            prompt: prompt,
+        })
+    }
+
+    pub fn read_line(&mut self) -> Result<Option<String>> {
+        use rustyline::ReadlineError;
+        use libimagutil::warn_result::*;
+
+        match self.editor.readline(&self.prompt) {
+            Ok(line) => {
+                self.editor.add_history_line(&line);
+                self.editor
+                    .save_history(&self.history_file)
+                    .map_warn_err_str(|e| format!("Could not save history file {} -> {:?}",
+                                                  self.history_file.display(), e));
+                return line;
+            },
+            Err(ReadlineError::Interrupted) => {
+                info!("CTRL-C");
+                Ok(None)
+            },
+            Err(ReadlineError::Eof) => {
+                info!("CTRL-D");
+                Ok(None)
+            },
+            Err(err) => Err(err).map_err_into(ReadlineError),
+
+        }
+    }
+
+}
+