"""Endpoints for inspecting and testing the external LLM hookup.

The LLM is not hosted here — the user supplies a base URL + model + key.
"""
from __future__ import annotations

from fastapi import APIRouter, HTTPException
from pydantic import BaseModel

from api.lib.llm import (
    LLMConfig,
    LLMError,
    chat_complete,
    from_settings,
    list_models,
    ping,
)


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


class LLMConfigIn(BaseModel):
    base_url: str
    api_key: str = ""
    # model is optional here so /llm/models can be called before a model is picked
    model: str = ""
    timeout: int = 120
    max_tokens: int = 1000
    temperature: float = 0.3
    extra_headers: dict[str, str] = {}


class LLMStatus(BaseModel):
    configured: bool
    base_url: str | None = None
    model: str | None = None


class ChatIn(BaseModel):
    config: LLMConfigIn | None = None
    messages: list[dict]


@router.get("/config", response_model=LLMStatus)
async def get_status():
    cfg = from_settings()
    if cfg is None:
        return LLMStatus(configured=False)
    return LLMStatus(configured=True, base_url=cfg.base_url, model=cfg.model)


@router.post("/test")
async def test_connection(cfg: LLMConfigIn | None = None):
    """Send a tiny ping to verify the endpoint accepts our requests."""
    config = LLMConfig(**cfg.model_dump()) if cfg else from_settings()
    if config is None:
        raise HTTPException(
            status_code=400,
            detail="No LLM config in body and none configured in environment",
        )
    try:
        reply = ping(config)
    except LLMError as e:
        raise HTTPException(status_code=502, detail=str(e))
    return {"ok": True, "model": config.model, "reply": reply}


@router.post("/models")
async def models(cfg: LLMConfigIn | None = None):
    """List available models from the configured (or supplied) endpoint."""
    config = LLMConfig(**cfg.model_dump()) if cfg else from_settings()
    if config is None:
        raise HTTPException(
            status_code=400,
            detail="No LLM config in body and none configured in environment",
        )
    try:
        items = list_models(config)
    except LLMError as e:
        raise HTTPException(status_code=502, detail=str(e))
    return {"models": items, "count": len(items)}


@router.post("/chat")
async def chat(body: ChatIn):
    """Pass-through chat endpoint — useful for sanity-testing prompts."""
    config = LLMConfig(**body.config.model_dump()) if body.config else from_settings()
    if config is None:
        raise HTTPException(status_code=400, detail="No LLM config supplied")
    try:
        reply = chat_complete(config, body.messages)
    except LLMError as e:
        raise HTTPException(status_code=502, detail=str(e))
    return {"reply": reply, "model": config.model}