feat: enhance session/conversation (#162)

* feat: enhance session/conversation

* updates

* updates

* cut version v0.9.0-rc2

* add .session name completion

1 files changed, 159 insertions, 0 deletions

diff --git a/src/config/session.rs b/src/config/session.rs
new file mode 100644
index 0000000..95b01ef
--- /dev/null
+++ b/src/config/session.rs
@@ -0,0 +1,159 @@
+use super::message::{num_tokens_from_messages, Message, MessageRole};
+use super::role::Role;
+
+use anyhow::{bail, Context, Result};
+use serde::{Deserialize, Serialize};
+use std::fs::{self, read_to_string};
+use std::path::Path;
+
+pub const TEMP_SESSION_NAME: &str = "temp";
+
+#[derive(Debug, Clone, Deserialize, Serialize)]
+pub struct Session {
+    pub path: Option<String>,
+    pub model: String,
+    pub tokens: usize,
+    pub messages: Vec<Message>,
+    #[serde(skip)]
+    pub dirty: bool,
+    #[serde(skip)]
+    pub role: Option<Role>,
+    #[serde(skip)]
+    pub name: String,
+}
+
+impl Session {
+    pub fn new(name: &str, model: &str, role: Option<Role>) -> Self {
+        let mut value = Self {
+            path: None,
+            model: model.to_string(),
+            tokens: 0,
+            messages: vec![],
+            dirty: false,
+            role,
+            name: name.to_string(),
+        };
+        value.update_tokens();
+        value
+    }
+
+    pub fn load(name: &str, path: &Path) -> Result<Self> {
+        let content = read_to_string(path)
+            .with_context(|| format!("Failed to load session {} at {}", name, path.display()))?;
+        let mut session: Self =
+            serde_yaml::from_str(&content).with_context(|| format!("Invalid sesion {}", name))?;
+
+        session.name = name.to_string();
+        session.path = Some(path.display().to_string());
+
+        Ok(session)
+    }
+
+    pub fn info(&self) -> Result<String> {
+        self.guard_save()?;
+        let output = serde_yaml::to_string(&self)
+            .with_context(|| format!("Unable to show info about session {}", &self.name))?;
+        Ok(output)
+    }
+
+    pub fn update_role(&mut self, role: Option<Role>) -> Result<()> {
+        self.guard_empty()?;
+        self.role = role;
+        self.update_tokens();
+        Ok(())
+    }
+
+    pub fn save(&mut self, session_path: &Path) -> Result<()> {
+        if !self.should_save() {
+            return Ok(());
+        }
+        self.dirty = false;
+        let content = serde_yaml::to_string(&self)
+            .with_context(|| format!("Failed to serde session {}", self.name))?;
+        fs::write(session_path, content).with_context(|| {
+            format!(
+                "Failed to write session {} to {}",
+                self.name,
+                session_path.display()
+            )
+        })?;
+        Ok(())
+    }
+
+    pub fn should_save(&self) -> bool {
+        !self.is_empty() && self.dirty
+    }
+
+    pub fn guard_save(&self) -> Result<()> {
+        if self.path.is_none() {
+            bail!("Not found session '{}'", self.name)
+        }
+        Ok(())
+    }
+
+    pub fn guard_empty(&self) -> Result<()> {
+        if !self.is_empty() {
+            bail!("Cannot perform this action in session")
+        }
+        Ok(())
+    }
+
+    pub fn is_temp(&self) -> bool {
+        self.name == TEMP_SESSION_NAME
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.messages.is_empty()
+    }
+
+    pub fn update_tokens(&mut self) {
+        self.tokens = num_tokens_from_messages(&self.build_emssages(""));
+    }
+
+    #[allow(clippy::unnecessary_wraps)]
+    pub fn add_message(&mut self, input: &str, output: &str) -> Result<()> {
+        let mut need_add_msg = true;
+        if self.messages.is_empty() {
+            if let Some(role) = self.role.as_ref() {
+                self.messages.extend(role.build_messages(input));
+                need_add_msg = false;
+            }
+        }
+        if need_add_msg {
+            self.messages.push(Message {
+                role: MessageRole::User,
+                content: input.to_string(),
+            });
+        }
+        self.messages.push(Message {
+            role: MessageRole::Assistant,
+            content: output.to_string(),
+        });
+        self.tokens = num_tokens_from_messages(&self.messages);
+        self.dirty = true;
+        Ok(())
+    }
+
+    pub fn echo_messages(&self, content: &str) -> String {
+        let messages = self.build_emssages(content);
+        serde_yaml::to_string(&messages).unwrap_or_else(|_| "Unable to echo message".into())
+    }
+
+    pub fn build_emssages(&self, content: &str) -> Vec<Message> {
+        let mut messages = self.messages.clone();
+        let mut need_add_msg = true;
+        if messages.is_empty() {
+            if let Some(role) = self.role.as_ref() {
+                messages = role.build_messages(content);
+                need_add_msg = false;
+            }
+        };
+        if need_add_msg {
+            messages.push(Message {
+                role: MessageRole::User,
+                content: content.into(),
+            });
+        }
+        messages
+    }
+}