Add logout, only login if not already logged in (#91)

Also:
- Ensures that a key is generated as soon as a user registers!
- Ensures that "atuin key" will generate a key if needed, and doesn't
  double base64 encode data

And a few other little fixes :)

Resolves #85
Resolves #86

7 files changed, 62 insertions, 14 deletions

diff --git a/atuin-client/src/encryption.rs b/atuin-client/src/encryption.rs
index 9cb8d3ea..ecb8a0c7 100644
--- a/atuin-client/src/encryption.rs
+++ b/atuin-client/src/encryption.rs
@@ -24,23 +24,30 @@ pub struct EncryptedHistory {
     pub nonce: secretbox::Nonce,
 }
 
+pub fn new_key(settings: &Settings) -> Result<secretbox::Key> {
+    let path = settings.key_path.as_str();
+
+    let key = secretbox::gen_key();
+    let encoded = encode_key(key.clone())?;
+
+    let mut file = File::create(path)?;
+    file.write_all(encoded.as_bytes())?;
+
+    Ok(key)
+}
+
 // Loads the secret key, will create + save if it doesn't exist
 pub fn load_key(settings: &Settings) -> Result<secretbox::Key> {
     let path = settings.key_path.as_str();
 
-    if PathBuf::from(path).exists() {
+    let key = if PathBuf::from(path).exists() {
         let key = std::fs::read_to_string(path)?;
-        let key = decode_key(key)?;
-        Ok(key)
+        decode_key(key)?
     } else {
-        let key = secretbox::gen_key();
-        let encoded = encode_key(key.clone())?;
+        new_key(settings)?
+    };
 
-        let mut file = File::create(path)?;
-        file.write_all(encoded.as_bytes())?;
-
-        Ok(key)
-    }
+    Ok(key)
 }
 
 pub fn load_encoded_key(settings: &Settings) -> Result<String> {
diff --git a/atuin-client/src/settings.rs b/atuin-client/src/settings.rs
index 9057eca2..1d7e9a5f 100644
--- a/atuin-client/src/settings.rs
+++ b/atuin-client/src/settings.rs
@@ -83,7 +83,9 @@ impl Settings {
     }
 
     pub fn should_sync(&self) -> Result<bool> {
-        if !self.auto_sync {
+        let session_path = atuin_common::utils::data_dir().join("session");
+
+        if !self.auto_sync || !session_path.exists() {
             return Ok(false);
         }
 
diff --git a/docs/sync.md b/docs/sync.md
index 78510526..81e8b598 100644
--- a/docs/sync.md
+++ b/docs/sync.md
@@ -53,3 +53,9 @@ If you want to login to a new machine, you will require your encryption key
 ```
 atuin login -u <USERNAME> -p <PASSWORD> -k <KEY>
 ```
+
+## Logout
+
+```
+atuin logout
+```
diff --git a/src/command/login.rs b/src/command/login.rs
index eacb2105..9a144580 100644
--- a/src/command/login.rs
+++ b/src/command/login.rs
@@ -22,6 +22,16 @@ pub struct Cmd {
 
 impl Cmd {
     pub fn run(&self, settings: &Settings) -> Result<()> {
+        let session_path = atuin_common::utils::data_dir().join("session");
+
+        if session_path.exists() {
+            println!(
+                "You are already logged in! Please run 'atuin logout' if you wish to login again"
+            );
+
+            return Ok(());
+        }
+
         let session = api_client::login(
             settings.sync_address.as_str(),
             self.username.as_str(),
@@ -34,7 +44,7 @@ impl Cmd {
 
         let key_path = settings.key_path.as_str();
         let mut file = File::create(key_path)?;
-        file.write_all(&base64::decode(self.key.clone())?)?;
+        file.write_all(self.key.as_bytes())?;
 
         println!("Logged in!");
 
diff --git a/src/command/logout.rs b/src/command/logout.rs
new file mode 100644
index 00000000..ec7d8dcb
--- /dev/null
+++ b/src/command/logout.rs
@@ -0,0 +1,12 @@
+use std::fs::remove_file;
+
+pub fn run() {
+    let session_path = atuin_common::utils::data_dir().join("session");
+
+    if session_path.exists() {
+        remove_file(session_path.as_path()).expect("Failed to remove session file");
+        println!("You have logged out!");
+    } else {
+        println!("You are not logged in");
+    }
+}
diff --git a/src/command/mod.rs b/src/command/mod.rs
index 161c99d9..6050c4eb 100644
--- a/src/command/mod.rs
+++ b/src/command/mod.rs
@@ -13,6 +13,7 @@ mod history;
 mod import;
 mod init;
 mod login;
+mod logout;
 mod register;
 mod search;
 mod server;
@@ -83,6 +84,9 @@ pub enum AtuinCmd {
     #[structopt(about = "login to the configured server")]
     Login(login::Cmd),
 
+    #[structopt(about = "log out")]
+    Logout,
+
     #[structopt(about = "register with the configured server")]
     Register(register::Cmd),
 
@@ -136,6 +140,10 @@ impl AtuinCmd {
 
             Self::Sync { force } => sync::run(&client_settings, force, &mut db).await,
             Self::Login(l) => l.run(&client_settings),
+            Self::Logout => {
+                logout::run();
+                Ok(())
+            }
             Self::Register(r) => register::run(
                 &client_settings,
                 r.username.as_str(),
@@ -143,8 +151,8 @@ impl AtuinCmd {
                 r.password.as_str(),
             ),
             Self::Key => {
-                let key = std::fs::read(client_settings.key_path.as_str())?;
-                println!("{}", base64::encode(key));
+                let key = atuin_client::encryption::load_key(&client_settings)?;
+                println!("{}", atuin_client::encryption::encode_key(key)?);
                 Ok(())
             }
 
diff --git a/src/command/register.rs b/src/command/register.rs
index acf9b1a3..7c38f483 100644
--- a/src/command/register.rs
+++ b/src/command/register.rs
@@ -27,5 +27,8 @@ pub fn run(settings: &Settings, username: &str, email: &str, password: &str) ->
     let mut file = File::create(path)?;
     file.write_all(session.session.as_bytes())?;
 
+    // Create a new key, and save it to disk
+    let _key = atuin_client::encryption::new_key(settings)?;
+
     Ok(())
 }