feat: support PaLM (#209)

1 files changed, 135 insertions, 0 deletions

diff --git a/src/client/palm.rs b/src/client/palm.rs
new file mode 100644
index 0000000..87b60d1
--- /dev/null
+++ b/src/client/palm.rs
@@ -0,0 +1,135 @@
+use super::{PaLMClient, Client, ExtraConfig, Model, PromptType, SendData, TokensCountFactors, send_message_as_streaming};
+
+use crate::{config::GlobalConfig, render::ReplyHandler, utils::PromptKind};
+
+use anyhow::{anyhow, bail, Result};
+use async_trait::async_trait;
+use reqwest::{Client as ReqwestClient, RequestBuilder};
+use serde::Deserialize;
+use serde_json::{json, Value};
+
+const API_BASE: &str = "https://generativelanguage.googleapis.com/v1beta2";
+
+const MODELS: [(&str, usize, &str); 1] = [("chat-bison-001", 4096, "/models/chat-bison-001")];
+
+const TOKENS_COUNT_FACTORS: TokensCountFactors = (3, 8);
+
+#[derive(Debug, Clone, Deserialize, Default)]
+pub struct PaLMConfig {
+    pub name: Option<String>,
+    pub api_key: Option<String>,
+    pub extra: Option<ExtraConfig>,
+}
+
+#[async_trait]
+impl Client for PaLMClient {
+    fn config(&self) -> (&GlobalConfig, &Option<ExtraConfig>) {
+        (&self.global_config, &self.config.extra)
+    }
+
+    async fn send_message_inner(&self, client: &ReqwestClient, data: SendData) -> Result<String> {
+        let builder = self.request_builder(client, data)?;
+        send_message(builder).await
+    }
+
+    async fn send_message_streaming_inner(
+        &self,
+        client: &ReqwestClient,
+        handler: &mut ReplyHandler,
+        data: SendData,
+    ) -> Result<()> {
+        let builder = self.request_builder(client, data)?;
+        send_message_as_streaming(builder, handler, send_message).await
+    }
+}
+
+impl PaLMClient {
+    config_get_fn!(api_key, get_api_key);
+
+    pub const PROMPTS: [PromptType<'static>; 1] =
+        [("api_key", "API Key:", true, PromptKind::String)];
+
+    pub fn list_models(local_config: &PaLMConfig, client_index: usize) -> Vec<Model> {
+        let client_name = Self::name(local_config);
+        MODELS
+            .into_iter()
+            .map(|(name, max_tokens, _)| {
+                Model::new(client_index, client_name, name)
+                    .set_max_tokens(Some(max_tokens))
+                    .set_tokens_count_factors(TOKENS_COUNT_FACTORS)
+            })
+            .collect()
+    }
+
+    fn request_builder(&self, client: &ReqwestClient, data: SendData) -> Result<RequestBuilder> {
+        let api_key = self.get_api_key()?;
+
+        let body = build_body(data, self.model.llm_name.clone());
+
+        let model = self.model.llm_name.clone();
+        let (_, _, endpoint) = MODELS
+            .iter()
+            .find(|(v, _, _)| v == &model)
+            .ok_or_else(|| anyhow!("Miss Model '{}' in {}", model, self.model.client_name))?;
+
+        let url = format!("{API_BASE}{endpoint}:generateMessage?key={}", api_key);
+
+        let builder = client.post(url).json(&body);
+
+        Ok(builder)
+    }
+}
+
+async fn send_message(builder: RequestBuilder) -> Result<String> {
+    let data: Value = builder.send().await?.json().await?;
+    check_error(&data)?;
+
+    let output = data["candidates"][0]["content"]
+        .as_str()
+        .ok_or_else(|| anyhow!("Unexpected response {data}"))?;
+
+    Ok(output.to_string())
+}
+
+fn check_error(data: &Value) -> Result<()> {
+    if let Some(error) = data["error"].as_object() {
+        if let Some(message) = error["message"].as_str() {
+            bail!("{message}");
+        } else {
+            bail!("Request failed. {}", data);
+        }
+    }
+    Ok(())
+}
+
+fn build_body(data: SendData, _model: String) -> Value {
+    let SendData {
+        mut messages,
+        temperature,
+        ..
+    } = data;
+
+    let mut context = None;
+    if messages[0].role.is_system() {
+        let message = messages.remove(0);
+        context = Some(message.content);
+    }
+    
+    let messages: Vec<Value> = messages.into_iter().map(|v| json!({ "content": v.content })).collect();
+
+    let mut prompt = json!({ "messages": messages });
+
+    if let Some(context) = context {
+        prompt["context"] = context.into();
+    };
+
+    let mut body = json!({
+        "prompt": prompt,
+    });
+
+    if let Some(temperature) = temperature {
+        body["temperature"] = (temperature / 2.0).into();
+    }
+
+    body
+}