from __future__ import annotations
import logging
from typing import Optional

from fastapi import APIRouter, HTTPException, status
from pydantic import BaseModel

logger = logging.getLogger(__name__)
router = APIRouter(prefix='/registry', tags=['registry'])


class AgentInfo(BaseModel):
    name: str
    domain: str
    active: bool
    backend: str = 'ollama'
    last_seen: Optional[str] = None


class BackendOverride(BaseModel):
    agent_name: str
    backend: str  # ollama | claude
    set_by: str
    note: Optional[str] = None


@router.get('/agents', response_model=list[AgentInfo])
async def list_agents():
    from ..app_state import get_agent_registry, get_llm_router
    registry = get_agent_registry()
    llm_router = get_llm_router()
    if registry is None:
        raise HTTPException(status_code=status.HTTP_503_SERVICE_UNAVAILABLE, detail='Registry not ready')
    agents = await registry.get_all()
    result = []
    for agent in agents:
        backend = 'ollama'
        if llm_router:
            try:
                backend = await llm_router.get_backend(agent['name'])
            except Exception:
                pass
        result.append(AgentInfo(
            name=agent['name'],
            domain=agent.get('domain', ''),
            active=agent.get('active', True),
            backend=backend,
            last_seen=agent.get('last_seen'),
        ))
    return result


@router.post('/sync', status_code=status.HTTP_200_OK)
async def sync_registry():
    from ..app_state import get_agent_registry
    registry = get_agent_registry()
    if registry is None:
        raise HTTPException(status_code=status.HTTP_503_SERVICE_UNAVAILABLE, detail='Registry not ready')
    try:
        count = await registry.sync()
        return {'synced': count}
    except Exception as exc:
        logger.error('registry sync failed: %s', exc)
        raise HTTPException(status_code=status.HTTP_500_INTERNAL_SERVER_ERROR, detail=str(exc))


@router.post('/backend', status_code=status.HTTP_200_OK)
async def set_backend_override(req: BackendOverride):
    from ..app_state import get_llm_router
    llm_router = get_llm_router()
    if llm_router is None:
        raise HTTPException(status_code=status.HTTP_503_SERVICE_UNAVAILABLE, detail='LLM router not ready')
    if req.backend not in ('ollama', 'claude'):
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail='backend must be ollama or claude')
    try:
        await llm_router.set_backend_override(
            caller=req.agent_name,
            backend=req.backend,
            set_by=req.set_by,
            note=req.note,
        )
        return {'agent': req.agent_name, 'backend': req.backend}
    except Exception as exc:
        logger.error('set_backend_override failed: %s', exc)
        raise HTTPException(status_code=status.HTTP_500_INTERNAL_SERVER_ERROR, detail=str(exc))


@router.delete('/backend/{agent_name}', status_code=status.HTTP_200_OK)
async def reset_backend_override(agent_name: str):
    from ..app_state import get_llm_router
    llm_router = get_llm_router()
    if llm_router is None:
        raise HTTPException(status_code=status.HTTP_503_SERVICE_UNAVAILABLE, detail='LLM router not ready')
    try:
        await llm_router.reset_backend_override(caller=agent_name)
        return {'agent': agent_name, 'reset': True}
    except Exception as exc:
        raise HTTPException(status_code=status.HTTP_500_INTERNAL_SERVER_ERROR, detail=str(exc))