phi_agent/config/
llm.rs

1use anyhow::{Result, anyhow};
2
3const DEFAULT_MODEL: &str = "copilot";
4const DEFAULT_BASE_URL: &str = "https://api.openai.com/v1";
5
6/// Resolved LLM configuration.
7#[derive(Clone, Debug)]
8pub struct LlmConfig {
9    /// API key for the LLM provider.
10    pub api_key: String,
11    /// Model name (e.g. `"opus"`, `"gpt-4o"`).
12    pub model: String,
13    /// Base URL for the LLM API endpoint.
14    pub base_url: String,
15}
16
17/// Resolve LLM configuration (API key, model, base_url).
18///
19/// Priority: CLI arg > environment variable (.env) > default
20pub fn resolve_llm_config(model: Option<&str>, base_url: Option<&str>) -> Result<LlmConfig> {
21    let api_key = super::optional_env("LLM_API_KEY")
22        .or_else(|| super::optional_env("OPENAI_API_KEY"))
23        .ok_or_else(|| anyhow!("Missing environment variable LLM_API_KEY. Please configure it in .env."))?;
24
25    let resolved_model = model
26        .map(|s| s.to_string())
27        .or_else(|| super::optional_env("LLM_MODEL"))
28        .or_else(|| super::optional_env("OPENAI_MODEL"))
29        .unwrap_or_else(|| DEFAULT_MODEL.to_string());
30
31    let resolved_base_url = base_url
32        .map(|s| s.to_string())
33        .or_else(|| super::optional_env("LLM_BASE_URL"))
34        .or_else(|| super::optional_env("OPENAI_BASE_URL"))
35        .unwrap_or_else(|| DEFAULT_BASE_URL.to_string());
36
37    Ok(LlmConfig { api_key, model: resolved_model, base_url: resolved_base_url })
38}
39
40#[cfg(test)]
41mod tests {
42    use super::*;
43
44    struct EnvGuard {
45        keys: Vec<&'static str>,
46        saved: Vec<Option<String>>,
47    }
48
49    impl EnvGuard {
50        fn new(keys: &[&'static str]) -> Self {
51            let saved: Vec<Option<String>> = keys.iter().map(|k| std::env::var(k).ok()).collect();
52            for k in keys {
53                unsafe { std::env::remove_var(k) };
54            }
55            Self { keys: keys.to_vec(), saved }
56        }
57    }
58
59    impl Drop for EnvGuard {
60        fn drop(&mut self) {
61            for (i, k) in self.keys.iter().enumerate() {
62                unsafe { std::env::remove_var(k) };
63                if let Some(ref v) = self.saved[i] {
64                    unsafe { std::env::set_var(k, v) };
65                }
66            }
67        }
68    }
69
70    /// All env-var tests run sequentially in one function to avoid races.
71    #[test]
72    fn test_env_var_resolution_chain() {
73        let vars = &["LLM_API_KEY", "OPENAI_API_KEY", "LLM_MODEL", "OPENAI_MODEL", "LLM_BASE_URL", "OPENAI_BASE_URL"];
74        let _guard = EnvGuard::new(vars);
75
76        let set = |k: &str, v: &str| unsafe { std::env::set_var(k, v) };
77        let rm = |k: &str| unsafe { std::env::remove_var(k) };
78
79        // 1. Error when no API key set at all
80        assert!(resolve_llm_config(None, None).is_err());
81
82        // 2. LLM_API_KEY only
83        set("LLM_API_KEY", "sk-llm");
84        let cfg = resolve_llm_config(None, None).unwrap();
85        assert_eq!(cfg.api_key, "sk-llm");
86        assert_eq!(cfg.model, DEFAULT_MODEL);
87        rm("LLM_API_KEY");
88
89        // 3. OPENAI_API_KEY fallback
90        set("OPENAI_API_KEY", "sk-openai");
91        let cfg = resolve_llm_config(None, None).unwrap();
92        assert_eq!(cfg.api_key, "sk-openai");
93        rm("OPENAI_API_KEY");
94
95        // 4. LLM_API_KEY preferred over OPENAI_API_KEY
96        set("LLM_API_KEY", "sk-llm");
97        set("OPENAI_API_KEY", "sk-openai");
98        let cfg = resolve_llm_config(None, None).unwrap();
99        assert_eq!(cfg.api_key, "sk-llm");
100        rm("LLM_API_KEY");
101        rm("OPENAI_API_KEY");
102
103        // 5. CLI model arg takes priority over env
104        set("LLM_API_KEY", "sk-test");
105        set("LLM_MODEL", "env-model");
106        let cfg = resolve_llm_config(Some("cli-model"), None).unwrap();
107        assert_eq!(cfg.model, "cli-model");
108        rm("LLM_MODEL");
109
110        // 6. LLM_MODEL env var
111        set("LLM_MODEL", "gpt-4");
112        let cfg = resolve_llm_config(None, None).unwrap();
113        assert_eq!(cfg.model, "gpt-4");
114        rm("LLM_MODEL");
115
116        // 7. OPENAI_MODEL fallback
117        set("OPENAI_MODEL", "gpt-3.5");
118        let cfg = resolve_llm_config(None, None).unwrap();
119        assert_eq!(cfg.model, "gpt-3.5");
120        rm("OPENAI_MODEL");
121
122        // 8. DEFAULT_MODEL when nothing set
123        let cfg = resolve_llm_config(None, None).unwrap();
124        assert_eq!(cfg.model, DEFAULT_MODEL);
125
126        // 9. CLI base_url takes priority
127        set("LLM_BASE_URL", "https://env.example.com/v1");
128        let cfg = resolve_llm_config(None, Some("https://cli.example.com/v1")).unwrap();
129        assert_eq!(cfg.base_url, "https://cli.example.com/v1");
130        rm("LLM_BASE_URL");
131
132        // 10. LLM_BASE_URL env var
133        set("LLM_BASE_URL", "https://llm.example.com/v1");
134        let cfg = resolve_llm_config(None, None).unwrap();
135        assert_eq!(cfg.base_url, "https://llm.example.com/v1");
136        rm("LLM_BASE_URL");
137
138        // 11. DEFAULT_BASE_URL fallback
139        let cfg = resolve_llm_config(None, None).unwrap();
140        assert_eq!(cfg.base_url, DEFAULT_BASE_URL);
141
142        // 12. Empty env var treated as unset
143        set("LLM_MODEL", "");
144        let cfg = resolve_llm_config(None, None).unwrap();
145        assert_eq!(cfg.model, DEFAULT_MODEL);
146        rm("LLM_MODEL");
147
148        // 13. OPENAI_BASE_URL fallback
149        set("OPENAI_BASE_URL", "https://openai.example.com/v1");
150        let cfg = resolve_llm_config(None, None).unwrap();
151        assert_eq!(cfg.base_url, "https://openai.example.com/v1");
152        rm("OPENAI_BASE_URL");
153
154        set("LLM_API_KEY", "sk-test");
155        // ── guard drops here, original env vars restored ──
156    }
157
158    #[test]
159    fn test_llm_config_debug_clone() {
160        let cfg = LlmConfig {
161            api_key: "sk-test".into(),
162            model: "gpt-4".into(),
163            base_url: "https://api.openai.com/v1".into(),
164        };
165        let cloned = cfg.clone();
166        assert_eq!(cloned.api_key, "sk-test");
167        assert_eq!(cloned.model, "gpt-4");
168        // LlmConfig is Debug — verify it doesn't panic
169        let _ = format!("{:?}", cfg);
170    }
171}
phi_agent/config/llm.rs

phi_agent/config/
llm.rs
