initial import

crates/g3-config/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "g3-config"
+version = "0.1.0"
+edition = "2021"
+description = "Configuration management for G3 AI coding agent"
+
+[dependencies]
+config = { workspace = true }
+serde = { workspace = true }
+anyhow = { workspace = true }
+thiserror = { workspace = true }
+toml = "0.8"
+shellexpand = "3.0"

crates/g3-config/src/lib.rs

@@ -0,0 +1,103 @@
+use serde::{Deserialize, Serialize};
+use anyhow::Result;
+use std::path::Path;
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct Config {
+    pub providers: ProvidersConfig,
+    pub agent: AgentConfig,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct ProvidersConfig {
+    pub openai: Option<OpenAIConfig>,
+    pub anthropic: Option<AnthropicConfig>,
+    pub default_provider: String,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct OpenAIConfig {
+    pub api_key: String,
+    pub model: String,
+    pub base_url: Option<String>,
+    pub max_tokens: Option<u32>,
+    pub temperature: Option<f32>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct AnthropicConfig {
+    pub api_key: String,
+    pub model: String,
+    pub max_tokens: Option<u32>,
+    pub temperature: Option<f32>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct AgentConfig {
+    pub max_context_length: usize,
+    pub enable_streaming: bool,
+    pub timeout_seconds: u64,
+}
+
+impl Default for Config {
+    fn default() -> Self {
+        Self {
+            providers: ProvidersConfig {
+                openai: None,
+                anthropic: None,
+                default_provider: "openai".to_string(),
+            },
+            agent: AgentConfig {
+                max_context_length: 8192,
+                enable_streaming: true,
+                timeout_seconds: 60,
+            },
+        }
+    }
+}
+
+impl Config {
+    pub fn load(config_path: Option<&str>) -> Result<Self> {
+        let mut settings = config::Config::builder();
+        
+        // Load default configuration
+        settings = settings.add_source(config::Config::try_from(&Config::default())?);
+        
+        // Load from config file if provided
+        if let Some(path) = config_path {
+            if Path::new(path).exists() {
+                settings = settings.add_source(config::File::with_name(path));
+            }
+        } else {
+            // Try to load from default locations
+            let default_paths = [
+                "./g3.toml",
+                "~/.config/g3/config.toml",
+                "~/.g3.toml",
+            ];
+            
+            for path in &default_paths {
+                let expanded_path = shellexpand::tilde(path);
+                if Path::new(expanded_path.as_ref()).exists() {
+                    settings = settings.add_source(config::File::with_name(expanded_path.as_ref()));
+                    break;
+                }
+            }
+        }
+        
+        // Override with environment variables
+        settings = settings.add_source(
+            config::Environment::with_prefix("G3")
+                .separator("_")
+        );
+        
+        let config = settings.build()?.try_deserialize()?;
+        Ok(config)
+    }
+    
+    pub fn save(&self, path: &str) -> Result<()> {
+        let toml_string = toml::to_string_pretty(self)?;
+        std::fs::write(path, toml_string)?;
+        Ok(())
+    }
+}