from fastapi import APIRouter, Depends
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.config import settings
from app.core.dependencies import get_current_admin, get_current_user
from app.database import get_db
from app.models import AppSetting
from app.models.user import User
from app.schemas.schemas import SettingUpdate, SettingsResponse

router = APIRouter()


@router.get("", response_model=SettingsResponse)
async def get_settings(
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """Return current effective settings (env + DB overrides)."""
    # DB overrides take precedence over env vars
    overrides: dict[str, str] = {}
    result = await db.execute(select(AppSetting))
    for row in result.scalars().all():
        overrides[row.key] = row.value

    return SettingsResponse(
        llm_provider=overrides.get("llm_provider", settings.LLM_PROVIDER),
        llm_model=overrides.get("llm_model", _current_model(overrides.get("llm_provider", settings.LLM_PROVIDER))),
        congress_poll_interval_minutes=int(overrides.get("congress_poll_interval_minutes", settings.CONGRESS_POLL_INTERVAL_MINUTES)),
        newsapi_enabled=bool(settings.NEWSAPI_KEY),
        pytrends_enabled=settings.PYTRENDS_ENABLED,
    )


@router.put("")
async def update_setting(
    body: SettingUpdate,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_admin),
):
    """Update a runtime setting."""
    ALLOWED_KEYS = {"llm_provider", "llm_model", "congress_poll_interval_minutes"}
    if body.key not in ALLOWED_KEYS:
        from fastapi import HTTPException
        raise HTTPException(status_code=400, detail=f"Allowed setting keys: {ALLOWED_KEYS}")

    existing = await db.get(AppSetting, body.key)
    if existing:
        existing.value = body.value
    else:
        db.add(AppSetting(key=body.key, value=body.value))
    await db.commit()
    return {"key": body.key, "value": body.value}


@router.post("/test-llm")
async def test_llm_connection(
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_admin),
):
    """Ping the configured LLM provider with a minimal request."""
    import asyncio
    prov_row = await db.get(AppSetting, "llm_provider")
    model_row = await db.get(AppSetting, "llm_model")
    provider_name = prov_row.value if prov_row else settings.LLM_PROVIDER
    model_name = model_row.value if model_row else None
    try:
        return await asyncio.to_thread(_ping_provider, provider_name, model_name)
    except Exception as exc:
        return {"status": "error", "detail": str(exc)}


_PING = "Reply with exactly three words: Connection test successful."


def _ping_provider(provider_name: str, model_name: str | None) -> dict:
    if provider_name == "openai":
        from openai import OpenAI
        model = model_name or settings.OPENAI_MODEL
        client = OpenAI(api_key=settings.OPENAI_API_KEY)
        resp = client.chat.completions.create(
            model=model,
            messages=[{"role": "user", "content": _PING}],
            max_tokens=20,
        )
        reply = resp.choices[0].message.content.strip()
        return {"status": "ok", "provider": "openai", "model": model, "reply": reply}

    if provider_name == "anthropic":
        import anthropic
        model = model_name or settings.ANTHROPIC_MODEL
        client = anthropic.Anthropic(api_key=settings.ANTHROPIC_API_KEY)
        resp = client.messages.create(
            model=model,
            max_tokens=20,
            messages=[{"role": "user", "content": _PING}],
        )
        reply = resp.content[0].text.strip()
        return {"status": "ok", "provider": "anthropic", "model": model, "reply": reply}

    if provider_name == "gemini":
        import google.generativeai as genai
        model = model_name or settings.GEMINI_MODEL
        genai.configure(api_key=settings.GEMINI_API_KEY)
        resp = genai.GenerativeModel(model_name=model).generate_content(_PING)
        reply = resp.text.strip()
        return {"status": "ok", "provider": "gemini", "model": model, "reply": reply}

    if provider_name == "ollama":
        import requests as req
        model = model_name or settings.OLLAMA_MODEL
        resp = req.post(
            f"{settings.OLLAMA_BASE_URL}/api/generate",
            json={"model": model, "prompt": _PING, "stream": False},
            timeout=30,
        )
        resp.raise_for_status()
        reply = resp.json().get("response", "").strip()
        return {"status": "ok", "provider": "ollama", "model": model, "reply": reply}

    raise ValueError(f"Unknown provider: {provider_name}")


@router.get("/llm-models")
async def list_llm_models(
    provider: str,
    current_user: User = Depends(get_current_admin),
):
    """Fetch available models directly from the provider's API."""
    import asyncio
    handlers = {
        "openai": _list_openai_models,
        "anthropic": _list_anthropic_models,
        "gemini": _list_gemini_models,
        "ollama": _list_ollama_models,
    }
    fn = handlers.get(provider)
    if not fn:
        return {"models": [], "error": f"Unknown provider: {provider}"}
    try:
        return await asyncio.to_thread(fn)
    except Exception as exc:
        return {"models": [], "error": str(exc)}


def _list_openai_models() -> dict:
    from openai import OpenAI
    if not settings.OPENAI_API_KEY:
        return {"models": [], "error": "OPENAI_API_KEY not configured"}
    client = OpenAI(api_key=settings.OPENAI_API_KEY)
    all_models = client.models.list().data
    CHAT_PREFIXES = ("gpt-", "o1", "o3", "o4", "chatgpt-")
    EXCLUDE = ("realtime", "audio", "tts", "whisper", "embedding", "dall-e", "instruct")
    filtered = sorted(
        [m.id for m in all_models
         if any(m.id.startswith(p) for p in CHAT_PREFIXES)
         and not any(x in m.id for x in EXCLUDE)],
        reverse=True,
    )
    return {"models": [{"id": m, "name": m} for m in filtered]}


def _list_anthropic_models() -> dict:
    import requests as req
    if not settings.ANTHROPIC_API_KEY:
        return {"models": [], "error": "ANTHROPIC_API_KEY not configured"}
    resp = req.get(
        "https://api.anthropic.com/v1/models",
        headers={
            "x-api-key": settings.ANTHROPIC_API_KEY,
            "anthropic-version": "2023-06-01",
        },
        timeout=10,
    )
    resp.raise_for_status()
    data = resp.json()
    return {
        "models": [
            {"id": m["id"], "name": m.get("display_name", m["id"])}
            for m in data.get("data", [])
        ]
    }


def _list_gemini_models() -> dict:
    import google.generativeai as genai
    if not settings.GEMINI_API_KEY:
        return {"models": [], "error": "GEMINI_API_KEY not configured"}
    genai.configure(api_key=settings.GEMINI_API_KEY)
    models = [
        {"id": m.name.replace("models/", ""), "name": m.display_name}
        for m in genai.list_models()
        if "generateContent" in m.supported_generation_methods
    ]
    return {"models": sorted(models, key=lambda x: x["id"])}


def _list_ollama_models() -> dict:
    import requests as req
    try:
        resp = req.get(f"{settings.OLLAMA_BASE_URL}/api/tags", timeout=5)
        resp.raise_for_status()
        tags = resp.json().get("models", [])
        return {"models": [{"id": m["name"], "name": m["name"]} for m in tags]}
    except Exception as exc:
        return {"models": [], "error": f"Ollama unreachable: {exc}"}


def _current_model(provider: str) -> str:
    if provider == "openai":
        return settings.OPENAI_MODEL
    elif provider == "anthropic":
        return settings.ANTHROPIC_MODEL
    elif provider == "gemini":
        return settings.GEMINI_MODEL
    elif provider == "ollama":
        return settings.OLLAMA_MODEL
    return "unknown"