import uuid
from typing import Any

import pytest
from httpx import AsyncClient

from app.config import settings
from app.services import events


async def new_case(client: AsyncClient) -> str:
    r = await client.post(
        "/api/cases",
        json={"name": f"s-{uuid.uuid4()}", "vcf_uri": "gs://bucket/x.vcf.gz", "assembly": "GRCh37"},
    )
    assert r.status_code == 201, r.text
    return r.json()["id"]


@pytest.mark.usefixtures("db")
async def test_local_without_nextflow_fails_fast_with_instructions(
    client: AsyncClient, monkeypatch: pytest.MonkeyPatch
) -> None:
    monkeypatch.setattr(settings, "pubsub_topic", None)
    monkeypatch.setattr(events.shutil, "which", lambda _: None)
    case_id = await new_case(client)

    r = await client.post(f"/api/cases/{case_id}/annotate")
    assert r.status_code == 202
    job = r.json()
    assert job["status"] == "failed"
    assert "make annotate" in job["log"]
    assert job["finished_at"] is not None


class FakeStdout:
    """Stands in for asyncio's StreamReader: async-iterates the process output."""

    def __init__(self, lines: list[bytes]) -> None:
        self._lines = lines

    def __aiter__(self) -> "FakeStdout":
        return self

    async def __anext__(self) -> bytes:
        if not self._lines:
            raise StopAsyncIteration
        return self._lines.pop(0)


class FakeProcess:
    def __init__(self, returncode: int, output: bytes = b"", lines: list[bytes] | None = None) -> None:
        self.returncode = returncode
        self.pid = 4242
        self.stdout = FakeStdout(lines if lines is not None else ([output] if output else []))

    async def wait(self) -> int:
        return self.returncode


@pytest.mark.usefixtures("db")
async def test_local_run_is_watched_and_a_crash_marks_the_job_failed(
    client: AsyncClient, monkeypatch: pytest.MonkeyPatch
) -> None:
    monkeypatch.setattr(settings, "pubsub_topic", None)
    monkeypatch.setattr(events.shutil, "which", lambda _: "/usr/bin/nextflow")
    launched: dict[str, Any] = {}

    async def fake_exec(*cmd: str, **kw: Any) -> FakeProcess:
        launched["cmd"], launched["env"] = cmd, kw["env"]
        return FakeProcess(1, b"ERROR ~ VEP cache not found")

    monkeypatch.setattr(events.asyncio, "create_subprocess_exec", fake_exec)
    case_id = await new_case(client)

    r = await client.post(f"/api/cases/{case_id}/annotate")
    assert r.status_code == 202
    await events.drain()

    job = (await client.get(f"/api/jobs/{r.json()['id']}")).json()
    assert job["status"] == "failed"
    assert "VEP cache not found" in job["log"]
    # The DB password travels in the environment, never on the command line.
    assert settings.database_url not in " ".join(launched["cmd"])
    assert launched["env"]["DATABASE_URL"] == settings.database_url
    assert launched["cmd"][launched["cmd"].index("--assembly") + 1] == "GRCh37"


class FakeFuture:
    def __init__(self, result: str | Exception) -> None:
        self._result = result

    def result(self, timeout: float | None = None) -> str:
        if isinstance(self._result, Exception):
            raise self._result
        return self._result


class FakePublisher:
    def __init__(self, result: str | Exception) -> None:
        self.result = result
        self.published: list[tuple[str, bytes]] = []

    def topic_path(self, project: str, topic: str) -> str:
        return f"projects/{project}/topics/{topic}"

    def publish(self, topic: str, data: bytes) -> FakeFuture:
        self.published.append((topic, data))
        return FakeFuture(self.result)


@pytest.mark.usefixtures("db")
async def test_pubsub_publishes_to_the_full_topic_path(
    client: AsyncClient, monkeypatch: pytest.MonkeyPatch
) -> None:
    publisher = FakePublisher("msg-123")
    monkeypatch.setattr(settings, "pubsub_topic", "vcf-uploaded")
    monkeypatch.setattr(settings, "gcp_project", "my-proj")
    monkeypatch.setattr(events, "_publisher", lambda: publisher)
    case_id = await new_case(client)

    r = await client.post(f"/api/cases/{case_id}/annotate")
    job = r.json()
    assert (job["status"], job["workflow_ref"]) == ("running", "pubsub:msg-123")
    [(topic, data)] = publisher.published
    assert topic == "projects/my-proj/topics/vcf-uploaded"
    assert b'"assembly": "GRCh37"' in data and job["id"].encode() in data


@pytest.mark.usefixtures("db")
async def test_pubsub_failure_marks_the_job_failed(
    client: AsyncClient, monkeypatch: pytest.MonkeyPatch
) -> None:
    monkeypatch.setattr(settings, "pubsub_topic", "vcf-uploaded")
    monkeypatch.setattr(settings, "gcp_project", "my-proj")
    monkeypatch.setattr(events, "_publisher", lambda: FakePublisher(RuntimeError("403 denied")))
    case_id = await new_case(client)

    job = (await client.post(f"/api/cases/{case_id}/annotate")).json()
    assert job["status"] == "failed"
    assert "403 denied" in job["log"]


@pytest.mark.usefixtures("db")
async def test_the_pipeline_gets_its_own_database_url(
    client: AsyncClient, monkeypatch: pytest.MonkeyPatch
) -> None:
    """The loader runs in a container, where the API's own localhost URL would point at itself."""
    monkeypatch.setattr(settings, "pubsub_topic", None)
    monkeypatch.setattr(settings, "cloudrun_job", None)
    monkeypatch.setattr(
        settings, "pipeline_database_url", "postgresql+asyncpg://u:p@host.docker.internal:5432/db"
    )
    monkeypatch.setattr(events.shutil, "which", lambda _: "/usr/bin/nextflow")
    launched: dict[str, Any] = {}

    async def fake_exec(*cmd: str, **kw: Any) -> FakeProcess:
        launched["env"] = kw["env"]
        return FakeProcess(0, b"")

    monkeypatch.setattr(events.asyncio, "create_subprocess_exec", fake_exec)
    case_id = await new_case(client)

    await client.post(f"/api/cases/{case_id}/annotate")
    await events.drain()
    assert launched["env"]["DATABASE_URL"] == "postgresql+asyncpg://u:p@host.docker.internal:5432/db"


@pytest.mark.usefixtures("db")
async def test_progress_is_recorded_while_the_pipeline_runs(
    client: AsyncClient, monkeypatch: pytest.MonkeyPatch
) -> None:
    """The UI needs something better than "running" for two minutes."""
    monkeypatch.setattr(settings, "pubsub_topic", None)
    monkeypatch.setattr(settings, "cloudrun_job", None)
    monkeypatch.setattr(events.shutil, "which", lambda _: "/usr/bin/nextflow")

    async def fake_exec(*cmd: str, **kw: Any) -> FakeProcess:
        return FakeProcess(0, lines=[
            b"[PIPELINE] main.nf | profile=docker\n",
            b"[PROCESS f2/5c13bd] NORMALISE (tiny)\n",
            b"[PROCESS cc/d62082] VEP (tiny)\n",
        ])

    monkeypatch.setattr(events.asyncio, "create_subprocess_exec", fake_exec)
    case_id = await new_case(client)

    r = await client.post(f"/api/cases/{case_id}/annotate")
    await events.drain()

    job = (await client.get(f"/api/jobs/{r.json()['id']}")).json()
    assert "VEP (tiny)" in job["log"]
    assert job["status"] == "running"  # the loader is what marks it succeeded


@pytest.mark.usefixtures("db")
async def test_progress_never_overwrites_a_finished_job(client: AsyncClient) -> None:
    from app.db import SessionLocal
    from app.models import Case, Job, JobStatus

    async with SessionLocal() as s:
        case = Case(name=f"c-{uuid.uuid4()}", vcf_uri="gs://bucket/x.vcf.gz", assembly="GRCh38")
        job = Job(case=case, status=JobStatus.succeeded)
        s.add_all([case, job])
        await s.commit()
        job_id = job.id

    await events._record_progress(job_id, "[PROCESS 1/a] VEP (late)")

    job_json = (await client.get(f"/api/jobs/{job_id}")).json()
    assert job_json["status"] == "succeeded"
    assert job_json["log"] is None