"""AI router: model listing and chat completions via OpenRouter."""
from fastapi import APIRouter, Depends, HTTPException, status

from ..dependencies import get_current_user
from ..models.ai import ChatRequest, ChatResponse, ModelInfo
from ..services import openrouter

router = APIRouter(prefix="/ai", tags=["ai"])


@router.get("/models", response_model=list[ModelInfo])
async def get_models(_: dict = Depends(get_current_user)) -> list[ModelInfo]:
    """List available AI models from OpenRouter."""
    try:
        raw = await openrouter.list_models()
    except Exception as exc:
        raise HTTPException(
            status_code=status.HTTP_502_BAD_GATEWAY,
            detail=f"OpenRouter error: {exc}",
        )
    return [
        ModelInfo(
            id=m.get("id", ""),
            name=m.get("name", m.get("id", "")),
            context_length=m.get("context_length"),
            pricing=m.get("pricing"),
        )
        for m in raw
    ]


@router.post("/chat", response_model=ChatResponse)
async def chat(
    body: ChatRequest,
    _: dict = Depends(get_current_user),
) -> ChatResponse:
    """Send a chat completion request through OpenRouter."""
    try:
        result = await openrouter.chat_completion(
            model=body.model,
            messages=[m.model_dump() for m in body.messages],
            temperature=body.temperature,
            max_tokens=body.max_tokens,
        )
    except Exception as exc:
        raise HTTPException(
            status_code=status.HTTP_502_BAD_GATEWAY,
            detail=f"OpenRouter error: {exc}",
        )

    try:
        choice = result["choices"][0]
        return ChatResponse(
            id=result["id"],
            model=result.get("model", body.model),
            content=choice["message"]["content"],
            usage=result.get("usage"),
        )
    except (KeyError, IndexError) as exc:
        raise HTTPException(
            status_code=status.HTTP_502_BAD_GATEWAY,
            detail=f"Unexpected response format from OpenRouter: {exc}",
        )