"""
User-level settings: AI provider configuration.
"""
from __future__ import annotations

from fastapi import APIRouter, Depends, HTTPException
from pydantic import BaseModel
from sqlalchemy import update
from sqlalchemy.ext.asyncio import AsyncSession

from app.core.security import decrypt_field, encrypt_field
from app.dependencies import get_current_user, get_db
from app.db.models.user import User

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

SUPPORTED_PROVIDERS = {"anthropic", "openai"}


class AiSettingsResponse(BaseModel):
    provider: str | None
    has_api_key: bool
    base_url: str | None
    model: str | None


class AiSettingsSave(BaseModel):
    provider: str
    api_key: str = ""
    base_url: str = ""
    model: str = ""


@router.get("/ai", response_model=AiSettingsResponse)
async def get_ai_settings(user: User = Depends(get_current_user)):
    return AiSettingsResponse(
        provider=user.ai_provider,
        has_api_key=bool(user.ai_api_key_enc),
        base_url=user.ai_base_url,
        model=user.ai_model,
    )


@router.put("/ai", response_model=AiSettingsResponse)
async def save_ai_settings(
    body: AiSettingsSave,
    db: AsyncSession = Depends(get_db),
    user: User = Depends(get_current_user),
):
    if body.provider not in SUPPORTED_PROVIDERS:
        raise HTTPException(status_code=400, detail=f"Unsupported provider. Choose: {', '.join(SUPPORTED_PROVIDERS)}")

    values: dict = {
        "ai_provider": body.provider,
        "ai_base_url": body.base_url.rstrip("/") or None,
        "ai_model": body.model.strip() or None,
    }

    if body.api_key.strip():
        values["ai_api_key_enc"] = encrypt_field(body.api_key.strip())
    elif not user.ai_api_key_enc:
        raise HTTPException(status_code=400, detail="api_key is required when no key is saved yet")

    await db.execute(update(User).where(User.id == user.id).values(**values))
    await db.commit()
    return AiSettingsResponse(
        provider=body.provider,
        has_api_key=True,
        base_url=values["ai_base_url"],
        model=values["ai_model"],
    )


@router.delete("/ai", status_code=204)
async def clear_ai_settings(
    db: AsyncSession = Depends(get_db),
    user: User = Depends(get_current_user),
):
    await db.execute(
        update(User)
        .where(User.id == user.id)
        .values(ai_provider=None, ai_api_key_enc=None, ai_base_url=None, ai_model=None)
    )
    await db.commit()