feat: lite deep researcher implementation

src/config/loader.py

@@ -0,0 +1,49 @@
+import os
+import yaml
+from typing import Dict, Any
+
+
+def replace_env_vars(value: str) -> str:
+    """Replace environment variables in string values."""
+    if not isinstance(value, str):
+        return value
+    if value.startswith("$"):
+        env_var = value[1:]
+        return os.getenv(env_var, value)
+    return value
+
+
+def process_dict(config: Dict[str, Any]) -> Dict[str, Any]:
+    """Recursively process dictionary to replace environment variables."""
+    result = {}
+    for key, value in config.items():
+        if isinstance(value, dict):
+            result[key] = process_dict(value)
+        elif isinstance(value, str):
+            result[key] = replace_env_vars(value)
+        else:
+            result[key] = value
+    return result
+
+
+_config_cache: Dict[str, Dict[str, Any]] = {}
+
+
+def load_yaml_config(file_path: str) -> Dict[str, Any]:
+    """Load and process YAML configuration file."""
+    # 如果文件不存在，返回{}
+    if not os.path.exists(file_path):
+        return {}
+
+    # 检查缓存中是否已存在配置
+    if file_path in _config_cache:
+        return _config_cache[file_path]
+
+    # 如果缓存中不存在，则加载并处理配置
+    with open(file_path, "r") as f:
+        config = yaml.safe_load(f)
+    processed_config = process_dict(config)
+
+    # 将处理后的配置存入缓存
+    _config_cache[file_path] = processed_config
+    return processed_config