import time
from datetime import datetime, timezone

from fastapi import APIRouter, Depends
from sqlalchemy import text
from sqlalchemy.orm import Session

from app.database import get_db
from app.schemas import HealthCheck, HealthResponse

router = APIRouter(tags=['health'])
START_TIME = time.time()


def build_health(db: Session) -> HealthResponse:
    db_check: HealthCheck
    try:
        t0 = time.perf_counter()
        db.execute(text("SELECT 1"))
        latency_ms = round((time.perf_counter() - t0) * 1000, 2)
        db_check = HealthCheck(status='pass', latency_ms=latency_ms, detail='sqlite ok')
    except Exception as exc:
        db_check = HealthCheck(status='fail', detail=str(exc))
    overall = 'pass' if db_check.status == 'pass' else 'fail'
    return HealthResponse(
        status=overall,
        service='netmapper-backend',
        version='0.1.0',
        time=datetime.now(timezone.utc),
        uptime_s=round(time.time() - START_TIME, 2),
        checks={'db': db_check},
    )


@router.get('/live', response_model=HealthResponse)
def live(db: Session = Depends(get_db)) -> HealthResponse:
    return build_health(db)


@router.get('/ready', response_model=HealthResponse)
def ready(db: Session = Depends(get_db)) -> HealthResponse:
    return build_health(db)


@router.get('/health', response_model=HealthResponse)
def health(db: Session = Depends(get_db)) -> HealthResponse:
    return build_health(db)