import uuid
from datetime import UTC, datetime

from fastapi import APIRouter, HTTPException, status
from sqlalchemy import select
from sqlalchemy.exc import IntegrityError

from app.db import SessionDep
from app.models import Job, JobStatus, Sample
from app.schemas import JobOut, SampleCreate, SampleOut
from app.services import events

router = APIRouter()


@router.get("", response_model=list[SampleOut])
async def list_samples(session: SessionDep):
    result = await session.scalars(select(Sample).order_by(Sample.created_at.desc()))
    return result.all()


@router.post("", response_model=SampleOut, status_code=status.HTTP_201_CREATED)
async def create_sample(payload: SampleCreate, session: SessionDep):
    sample = Sample(**payload.model_dump())
    session.add(sample)
    try:
        await session.commit()
    except IntegrityError:  # samples.name is unique
        await session.rollback()
        raise HTTPException(409, f"a sample named {payload.name!r} already exists") from None
    await session.refresh(sample)
    return sample


@router.get("/{sample_id}/jobs", response_model=list[JobOut])
async def list_jobs(sample_id: uuid.UUID, session: SessionDep):
    result = await session.scalars(
        select(Job).where(Job.sample_id == sample_id).order_by(Job.created_at.desc())
    )
    return result.all()


@router.post("/{sample_id}/annotate", response_model=JobOut, status_code=status.HTTP_202_ACCEPTED)
async def annotate(sample_id: uuid.UUID, session: SessionDep):
    sample = await session.get(Sample, sample_id)
    if sample is None:
        raise HTTPException(404, "sample not found")
    # Commit `running` before launching: a local run that dies instantly is marked failed by its
    # watcher, and a later status write here would overwrite that.
    job = Job(sample_id=sample.id, status=JobStatus.running)
    session.add(job)
    await session.commit()
    try:
        job.workflow_ref = await events.launch(job.id, sample.vcf_uri, sample.assembly)
    except events.LaunchError as e:
        job.status = JobStatus.failed
        job.log = str(e)
        job.finished_at = datetime.now(UTC)
    await session.commit()
    await session.refresh(job)
    return job