Add data types for pipeline routing, add route for OpenAI

We just had a simple if-else for pipeline routing. Instead, let's add a
data type that includes the paths and optionally a `target_url`. We can
use that to add a routing for OpenAI which we'll use for testing the
Copilot provider.

In the future we can make the routings pluggable.

src/codegate/providers/copilot/mapping.py

@@ -1,4 +1,6 @@
-from typing import List
+from dataclasses import dataclass
+from enum import Enum
+from typing import List, Optional
 
 from pydantic import BaseModel, HttpUrl
 from pydantic_settings import BaseSettings
@@ -43,3 +45,26 @@ class CoPilotMappings(BaseSettings):
 VALIDATED_ROUTES: List[CopilotProxyRoute] = [
     CopilotProxyRoute(path=path, target=target) for path, target in mappings.PROXY_ROUTES
 ]
+
+
+class PipelineType(Enum):
+    FIM = "fim"
+    CHAT = "chat"
+
+
+@dataclass
+class PipelineRoute:
+    path: str
+    pipeline_type: PipelineType
+    target_url: Optional[str] = None
+
+
+PIPELINE_ROUTES = [
+    PipelineRoute(
+        path="v1/chat/completions",
+        # target_url="https://api.openai.com/v1/chat/completions",
+        pipeline_type=PipelineType.CHAT,
+    ),
+    PipelineRoute(path="v1/engines/copilot-codex/completions", pipeline_type=PipelineType.FIM),
+    PipelineRoute(path="chat/completions", pipeline_type=PipelineType.CHAT),
+]

src/codegate/providers/copilot/provider.py

@@ -15,7 +15,7 @@
 from codegate.pipeline.factory import PipelineFactory
 from codegate.pipeline.output import OutputPipelineInstance
 from codegate.pipeline.secrets.manager import SecretsManager
-from codegate.providers.copilot.mapping import VALIDATED_ROUTES
+from codegate.providers.copilot.mapping import PIPELINE_ROUTES, VALIDATED_ROUTES, PipelineType
 from codegate.providers.copilot.pipeline import (
     CopilotChatPipeline,
     CopilotFimPipeline,
@@ -153,12 +153,18 @@ def __init__(self, loop: asyncio.AbstractEventLoop):
         self.context_tracking: Optional[PipelineContext] = None
 
     def _select_pipeline(self, method: str, path: str) -> Optional[CopilotPipeline]:
-        if method == "POST" and path == "v1/engines/copilot-codex/completions":
-            logger.debug("Selected CopilotFimStrategy")
-            return CopilotFimPipeline(self.pipeline_factory)
-        if method == "POST" and path == "chat/completions":
-            logger.debug("Selected CopilotChatStrategy")
-            return CopilotChatPipeline(self.pipeline_factory)
+        if method != "POST":
+            logger.debug("Not a POST request, no pipeline selected")
+            return None
+
+        for route in PIPELINE_ROUTES:
+            if path == route.path:
+                if route.pipeline_type == PipelineType.FIM:
+                    logger.debug("Selected FIM pipeline")
+                    return CopilotFimPipeline(self.pipeline_factory)
+                elif route.pipeline_type == PipelineType.CHAT:
+                    logger.debug("Selected CHAT pipeline")
+                    return CopilotChatPipeline(self.pipeline_factory)
 
         logger.debug("No pipeline selected")
         return None