init,llm gateway & import_analyse

app/providers/base.py

@@ -0,0 +1,44 @@
+from __future__ import annotations
+
+from abc import ABC, abstractmethod
+from typing import Any
+
+import httpx
+
+from app.exceptions import ProviderConfigurationError
+from app.models import LLMRequest, LLMResponse
+
+
+class LLMProviderClient(ABC):
+    """Base class for provider-specific chat completion clients."""
+
+    name: str
+    api_key_env: str | None = None
+    supports_stream: bool = False
+
+    def __init__(self, api_key: str | None):
+        if self.api_key_env and not api_key:
+            raise ProviderConfigurationError(
+                f"Provider '{self.name}' requires environment variable '{self.api_key_env}'."
+            )
+        self.api_key = api_key or ""
+
+    @abstractmethod
+    async def chat(
+        self, request: LLMRequest, client: httpx.AsyncClient
+    ) -> LLMResponse:
+        """Execute a chat completion call."""
+
+    @staticmethod
+    def merge_payload(base: dict[str, Any], extra: dict[str, Any] | None) -> dict[str, Any]:
+        """Merge provider payload with optional extra params, ignoring None values."""
+        merged = {k: v for k, v in base.items() if v is not None}
+        if extra:
+            merged.update({k: v for k, v in extra.items() if v is not None})
+        return merged
+
+    def ensure_stream_supported(self, stream_requested: bool) -> None:
+        if stream_requested and not self.supports_stream:
+            raise ProviderConfigurationError(
+                f"Provider '{self.name}' does not support streaming mode."
+            )