import asyncio

from app import jobs
from app.commands import CommandSpec
from app.jobs import default_conda_env_for_job
from app.main import _job_with_progress
from app.schemas import JobCreate


async def _stream_text(response) -> str:
    chunks = []
    async for chunk in response.body_iterator:
        chunks.append(chunk.decode("utf-8") if isinstance(chunk, bytes) else chunk)
    return "".join(chunks)


def test_mmseg_jobs_use_mmseg_conda_env_by_default():
    assert default_conda_env_for_job("mmseg.train") == "seg_mmcv"
    assert default_conda_env_for_job("segmodel.train") == "seg_smp"


def test_build_task_sets_cuda_visible_devices(tmp_path, monkeypatch):
    def fake_build_module_task(job_type, params, conda_env):
        return CommandSpec(["python", "-c", "print('ok')"], tmp_path, "fake task")

    monkeypatch.setattr(jobs, "build_module_task", fake_build_module_task)
    spec = jobs._build_task(JobCreate(type="mock.echo", params={}, gpus=[2, 0]))

    assert spec.env["CUDA_VISIBLE_DEVICES"] == "2,0"


def test_build_task_uses_requested_conda_env(tmp_path, monkeypatch):
    captured = {}

    def fake_build_module_task(job_type, params, conda_env):
        captured["conda_env"] = conda_env
        return CommandSpec(["python", "-c", "print('ok')"], tmp_path, "fake task")

    monkeypatch.setattr(jobs, "build_module_task", fake_build_module_task)
    jobs._build_task(JobCreate(type="segmodel.train", params={}, conda_env="seg_custom"))

    assert captured["conda_env"] == "seg_custom"


def test_job_progress_reports_log_size(tmp_path):
    log_path = tmp_path / "job.log"
    log_path.write_text("line one\nline two\n", encoding="utf-8")
    job = {"id": "job1", "status": "running", "log_path": str(log_path)}

    enriched = _job_with_progress(job, include_log_tail=True)

    assert enriched["log_size"] == log_path.stat().st_size
    assert enriched["log_tail"] == "line one\nline two\n"


def test_job_events_respect_log_offset(tmp_path, monkeypatch):
    from app import main

    log_path = tmp_path / "job.log"
    old_chunk = "old chunk\n"
    log_path.write_text(old_chunk + "new chunk\n", encoding="utf-8")

    def fake_get_job(job_id):
        return {"id": job_id, "status": "success", "log_path": str(log_path)}

    monkeypatch.setattr(main.db, "get_job", fake_get_job)
    response = asyncio.run(main.api_job_events("job1", offset=len(old_chunk.encode("utf-8"))))
    text = asyncio.run(_stream_text(response))

    assert response.media_type == "text/event-stream"
    assert "new chunk" in text
    assert "old chunk" not in text