app/backend/tests/api/routes/test_runs.py

"""The stage cache, from the side that needs a database.

The pipeline half — what a hit restores and what a key is made of — is in
`tests/flow/test_runs.py`, which runs without one.
"""

import csv
import json
from datetime import UTC, datetime, timedelta

import pytest
from sqlmodel import Session, col, select

from fluksio.core.config import settings
from fluksio.core.db import engine as db_engine
from fluksio.flow.artifacts import ArtifactStore
from fluksio.flow.controller import FlowController
from fluksio.flow.messages import DType, MessageSpec
from fluksio.flow.pipeline import NodeOutcome
from fluksio.flow.runs import (
    OUTPUT_CAP,
    RunCache,
    RunRejected,
    RunService,
    _cacheable,
    new_run_id,
    resolve_references,
    seed_values,
)
from fluksio.flow.schemas import FlowDef, FlowInput, NodeDef
from fluksio.flow.store import FlowStore
from fluksio.models import Run, RunArtifact, RunMetric, RunNode


def test_a_run_cache_finds_what_an_earlier_run_recorded(tmp_path):
    """The run history is the cache; there is no second store to keep."""
    store = ArtifactStore(tmp_path / "artifacts")
    reference = store.put([b"payload"], name="data.bin")
    plain, with_artifact, collected = "k-plain", "k-artifact", "k-collected"
    with Session(db_engine) as session:
        session.add(
            RunNode(
                run_id="cache-1",
                node="study.a",
                status="ok",
                cache_key=plain,
                outputs=json.dumps({"study.loss": 1.5}),
            )
        )
        session.add(
            RunNode(
                run_id="cache-2",
                node="study.b",
                status="ok",
                cache_key=with_artifact,
                outputs=json.dumps({"study.data": reference}),
            )
        )
        session.add(
            RunNode(
                run_id="cache-3",
                node="study.c",
                status="ok",
                cache_key=collected,
                outputs=json.dumps(
                    {"study.data": {**reference, "digest": "sha256:" + "1" * 64}}
                ),
            )
        )
        session.commit()

    cache = RunCache(store)
    hit = cache.lookup(plain)
    assert hit is not None and hit.outputs == {"study.loss": 1.5}
    # Where its series is, so a run reusing it can read the curve back.
    assert hit.metrics_run == "cache-1"
    found = cache.lookup(with_artifact)
    assert found is not None and found.outputs == {"study.data": reference}
    # Its bytes have gone from the store, so the reference names nothing a
    # restored run could open. That is a miss, not a broken run.
    assert cache.lookup(collected) is None
    assert cache.lookup("never-seen") is None
    assert cache.lookup("") is None


def test_what_may_be_stored_as_a_cache_entry():
    """A row carries a key and its outputs together, or neither."""
    ok = NodeOutcome(
        node="study.a", ok=True, cache_key="k", output_values={"study.loss": 1.0}
    )
    assert _cacheable(ok) == '{"study.loss":1.0}'
    # A node that published nothing is still an answer worth reusing.
    assert _cacheable(ok.model_copy(update={"output_values": None})) == "null"
    # Not cacheable: it failed, it has no key, or it returned too much.
    assert _cacheable(ok.model_copy(update={"ok": False})) is None
    assert _cacheable(ok.model_copy(update={"cache_key": ""})) is None
    big = {"study.data": "x" * (OUTPUT_CAP + 1)}
    assert _cacheable(ok.model_copy(update={"output_values": big})) is None


# -----------------------------------------------------------------------------
# Naming an artifact from outside the process that made it
#
# A python caller passes the reference it holds. A shell holds nothing, so the
# same input also takes `@run:<id>.<output>` or a bare digest, resolved here
# rather than in each client.
# -----------------------------------------------------------------------------


def artifact_flow() -> FlowDef:
    """A flow taking a dataset somebody else's run produced."""
    dataset = MessageSpec(name="dataset", dtype=DType.ARTIFACT)
    return FlowDef(
        name="study",
        mode="batch",
        inputs=[FlowInput(spec=dataset)],
        nodes=[NodeDef(id="train", requires=[dataset])],
    )


@pytest.fixture
def made_artifact():
    """A finished run with one artifact, as a later run would find it."""
    digest = "sha256:" + "a1" * 32
    reference = {
        "digest": digest,
        "size": 12,
        "media_type": "text/csv",
        "name": "cities.csv",
    }
    run_id = new_run_id()
    with Session(db_engine) as session:
        session.add(
            Run(
                id=run_id,
                flow="prepare",
                status="ok",
                result={"dataset": reference},
                created_at=datetime.now(UTC),
            )
        )
        session.add(
            RunArtifact(
                run_id=run_id,
                name="prepare.dataset",
                filename="cities.csv",
                node="load",
                digest=digest,
                size=12,
            )
        )
        session.commit()
    yield run_id, reference
    with Session(db_engine) as session:
        session.delete(session.get(RunArtifact, (run_id, "prepare.dataset")))
        session.delete(session.get(Run, run_id))
        session.commit()


def test_a_run_reference_resolves_to_what_that_run_produced(made_artifact):
    run_id, reference = made_artifact
    resolved = resolve_references(
        artifact_flow(), {"dataset": f"@run:{run_id}.dataset"}
    )

    # The producer's own reference, whatever type it made it — the row beside
    # it is the fallback, not the first answer.
    assert resolved["dataset"] == reference


def test_the_artifact_row_answers_with_the_name_the_node_gave_the_file(made_artifact):
    """Bytes the flow never declared as an output are reachable through the row."""
    run_id, reference = made_artifact
    with Session(db_engine) as session:
        run = session.get(Run, run_id)
        run.result = {}
        session.add(run)
        session.commit()

    resolved = resolve_references(
        artifact_flow(), {"dataset": f"@run:{run_id}.dataset"}
    )

    assert resolved["dataset"]["digest"] == reference["digest"]
    # The file name, not the message it happened to leave on.
    assert resolved["dataset"]["name"] == "cities.csv"


def test_a_bare_digest_resolves_to_the_bytes_under_it(made_artifact):
    _run_id, reference = made_artifact
    resolved = resolve_references(artifact_flow(), {"dataset": reference["digest"]})

    assert resolved["dataset"]["digest"] == reference["digest"]
    assert resolved["dataset"]["size"] == 12


def test_a_resolved_reference_passes_the_input_check(made_artifact):
    run_id, _reference = made_artifact
    flow = artifact_flow()
    resolved = resolve_references(flow, {"dataset": f"@run:{run_id}.dataset"})

    assert "study.dataset" in seed_values(flow, resolved)


def test_an_output_a_run_never_made_says_what_it_did(made_artifact):
    run_id, _reference = made_artifact
    with pytest.raises(RunRejected, match="prepare.dataset"):
        resolve_references(artifact_flow(), {"dataset": f"@run:{run_id}.weights"})


def test_a_reference_to_no_run_at_all_is_refused():
    with pytest.raises(RunRejected, match="no run"):
        resolve_references(artifact_flow(), {"dataset": "@run:nothing.dataset"})


def test_an_unknown_digest_is_refused():
    with pytest.raises(RunRejected, match="nothing here"):
        resolve_references(artifact_flow(), {"dataset": "sha256:" + "b2" * 32})


def test_a_reference_passed_whole_is_left_alone(made_artifact):
    """A python caller already has the object, and hands it over as one."""
    _run_id, reference = made_artifact
    assert resolve_references(artifact_flow(), {"dataset": reference}) == {
        "dataset": reference
    }


def chaining_flow() -> FlowDef:
    """A flow taking a json config and a label another run worked out."""
    meta = MessageSpec(name="meta", dtype=DType.JSON)
    label = MessageSpec(name="label", dtype=DType.STR)
    return FlowDef(
        name="study",
        mode="batch",
        inputs=[FlowInput(spec=meta), FlowInput(spec=label)],
        nodes=[NodeDef(id="train", requires=[meta, label])],
    )


@pytest.fixture
def made_config():
    """A finished run whose result is an object, not bytes."""
    meta = {"rows": 256, "source": "builtin"}
    run_id = new_run_id()
    with Session(db_engine) as session:
        session.add(
            Run(
                id=run_id,
                flow="generate",
                status="ok",
                result={"meta": meta, "label": "run-7"},
                created_at=datetime.now(UTC),
            )
        )
        session.commit()
    yield run_id, meta
    with Session(db_engine) as session:
        session.delete(session.get(Run, run_id))
        session.commit()


def test_a_json_input_may_name_a_run_s_output(made_config):
    """The gap this closes: chaining without pasting the object into a shell."""
    run_id, meta = made_config
    flow = chaining_flow()
    resolved = resolve_references(flow, {"meta": f"@run:{run_id}.meta"})

    assert resolved["meta"] == meta
    # And it is the value's own type from here on, so the input check passes.
    assert seed_values(flow, resolved)["study.meta"] == meta


def test_the_spelling_is_reserved_on_a_text_input_too(made_config):
    run_id, _meta = made_config
    resolved = resolve_references(chaining_flow(), {"label": f"@run:{run_id}.label"})

    assert resolved["label"] == "run-7"


def test_text_that_names_nothing_is_still_left_alone(made_config):
    """Only the two spellings are read as names; everything else is a value."""
    _run_id, _meta = made_config
    params = {"label": "@run-of-the-mill", "meta": {"rows": 1}}
    assert resolve_references(chaining_flow(), params) == params


def test_the_overview_counts_a_flow_the_list_page_would_not_reach(
    client, superuser_token_headers
):
    """The list caps at 500 newest; the flow rail needs whole counts."""
    with Session(db_engine) as session:
        for index in range(3):
            session.add(
                Run(
                    id=f"ov-{index}",
                    flow="overviewed",
                    status="ok" if index else "running",
                    created_at=datetime(2026, 1, 1 + index, tzinfo=UTC),
                )
            )
        session.commit()

    rows = client.get(
        f"{settings.API_V1_STR}/runs/overview", headers=superuser_token_headers
    ).json()
    row = next(r for r in rows if r["flow"] == "overviewed")

    assert (row["runs"], row["running"], row["queued"]) == (3, 1, 0)


def test_a_running_run_reports_how_long_it_has_been_going(
    client, superuser_token_headers
):
    """A duration is only written at the end; until then, time since it began."""
    with Session(db_engine) as session:
        session.add(
            Run(
                id="in-flight",
                flow="timed",
                status="running",
                created_at=datetime.now(UTC),
                started_at=datetime.now(UTC) - timedelta(seconds=30),
            )
        )
        session.commit()

    rows = client.get(
        f"{settings.API_V1_STR}/runs",
        headers=superuser_token_headers,
        params={"flow": "timed"},
    ).json()

    assert rows[0]["duration_ms"] >= 30_000


def test_a_run_records_which_caller_asked_for_it(
    client, superuser_token_headers, monkeypatch
):
    """The dashboard, the CLI and the SDK are told apart by what they send.

    Client-supplied, so the vocabulary is closed: a column nobody can write
    free text into is one a table can group by.
    """
    seen: dict[str, object] = {}

    class Recorder:
        def submit(self, name, **kwargs):
            seen.update(kwargs)
            return Run(
                id="cause-1",
                flow=name,
                cause=str(kwargs["cause"]),
                created_at=datetime.now(UTC),
            )

    monkeypatch.setattr(client.app.state, "run_service", Recorder())
    url = f"{settings.API_V1_STR}/runs/flows/demo"

    answer = client.post(url, headers=superuser_token_headers, json={"cause": "cli"})
    assert answer.status_code == 202
    assert (seen["cause"], answer.json()["cause"]) == ("cli", "cli")

    # Nothing said still means the dashboard, which is the only caller that
    # does not name itself.
    client.post(url, headers=superuser_token_headers, json={})
    assert seen["cause"] == "api"

    refused = client.post(
        url, headers=superuser_token_headers, json={"cause": "somewhere else"}
    )
    assert refused.status_code == 422


class _Unusable:
    """Anything reaching this is something a deduplicated submit should not do."""

    def __getattr__(self, name):
        raise AssertionError(f"a repeated submit must not reach {name}")


def test_a_repeated_submit_returns_the_run_it_already_made():
    """The key is the answer to "did my first attempt land?".

    Answered before the flow is even read: a caller retrying a submit it never
    got a reply to is owed that run, whatever has been published since.
    """
    service = RunService(controller=_Unusable(), queue=_Unusable())
    with Session(db_engine) as session:
        session.add(
            Run(
                id="dedup-1",
                flow="study",
                status="running",
                idempotency_key="key-abc",
                created_at=datetime.now(UTC),
            )
        )
        session.commit()

    again = service.submit("study", {"lr": 0.1}, idempotency_key="key-abc")

    assert again.id == "dedup-1"


class _OneFlow:
    """A controller that has exactly one flow and no engine behind it."""

    def __init__(self, flow):
        self.store = self
        self._flow = flow

    def read_flow(self, name, draft=False):
        return self._flow

    def head(self):
        return ""


class _Collect:
    def __init__(self):
        self.items = []

    def add(self, item):
        self.items.append(item)


def test_a_run_records_the_inputs_it_actually_starts_from():
    """An input left out takes its declared value, and the row says so.

    `params = {}` could not tell a run that took every default from one
    submitted with those same numbers spelled out — and an export of the
    first had a blank cell where its `lr` should be.
    """
    flow = FlowDef(
        name="study",
        mode="batch",
        inputs=[
            FlowInput(spec=MessageSpec(name="lr", dtype=DType.FLOAT), initial=0.01),
            FlowInput(spec=MessageSpec(name="epochs", dtype=DType.INT)),
        ],
    )
    service = RunService(controller=_OneFlow(flow), queue=_Collect())
    made = []
    try:
        defaulted = service.submit("study", {"epochs": 5})
        made.append(defaulted.id)
        assert defaulted.params == {"lr": 0.01, "epochs": 5}

        # Spelling out the declared value is the same run, and now reads as it.
        spelled = service.submit("study", {"lr": 0.01, "epochs": 5})
        made.append(spelled.id)
        assert spelled.params_digest == defaulted.params_digest
    finally:
        with Session(db_engine) as session:
            for run in session.exec(select(Run).where(col(Run.id).in_(made))).all():
                session.delete(run)
            session.commit()


def test_the_seed_is_recorded_the_same_way_however_it_arrived():
    """One field an export should not have to coalesce two columns for.

    `--seed 1` fills the run's own column; a flow declaring a `seed` input
    fills the parameter. Both are the seed the run used, so both are written.
    """
    flow = FlowDef(
        name="seeded",
        mode="batch",
        inputs=[FlowInput(spec=MessageSpec(name="seed", dtype=DType.INT), initial=42)],
    )
    service = RunService(controller=_OneFlow(flow), queue=_Collect())
    made = []
    try:
        passed = service.submit("seeded", {}, seed=1)
        made.append(passed.id)
        assert (passed.seed, passed.params) == (1, {"seed": 1})

        # Nothing passed: the declared value is the seed it ran with, and the
        # run-level column says so rather than staying empty.
        defaulted = service.submit("seeded", {})
        made.append(defaulted.id)
        assert (defaulted.seed, defaulted.params) == (42, {"seed": 42})

        # A parameter still outranks the run's own seed, as it always has —
        # and the column follows it rather than reporting the one that lost.
        both = service.submit("seeded", {"seed": 7}, seed=1)
        made.append(both.id)
        assert (both.seed, both.params) == (7, {"seed": 7})
    finally:
        with Session(db_engine) as session:
            for run in session.exec(select(Run).where(col(Run.id).in_(made))).all():
                session.delete(run)
            session.commit()


DRAFT_SOURCE = "def process():\n    return {'answer': 'draft'}\n"
PUBLISHED_SOURCE = "def process():\n    return {'answer': 'published'}\n"


def test_a_draft_run_executes_the_draft(tmp_path):
    """The flag was checked at submit and forgotten by the time it ran.

    Which made trying an edit before publishing it impossible from anywhere:
    the submit validated the working copy and the driver then executed what
    was published, and the two only agree when there is no draft.
    """
    flow = FlowDef(
        name="study",
        mode="batch",
        outputs=["answer"],
        nodes=[
            NodeDef(
                id="answer",
                provides=[MessageSpec(name="answer", dtype=DType.STR)],
            )
        ],
    )
    store = FlowStore(tmp_path / "flows")
    store.write_flow(flow)
    store.write_node_source("study", "answer", PUBLISHED_SOURCE)
    store.write_node_source("study", "answer", DRAFT_SOURCE, draft=True)

    service = RunService(controller=FlowController(store), queue=_Collect())
    made = []
    try:
        for draft, expected in ((True, "draft"), (False, "published")):
            run = service.submit("study", {}, draft=draft)
            made.append(run.id)
            assert run.draft is draft
            service._drive(run.id)
            with Session(db_engine) as session:
                stored = session.get(Run, run.id)
                assert stored.status == "ok", stored.status_reason
                assert stored.result == {"answer": expected}
    finally:
        with Session(db_engine) as session:
            for run in session.exec(select(Run).where(col(Run.id).in_(made))).all():
                session.delete(run)
            for node in session.exec(
                select(RunNode).where(col(RunNode.run_id).in_(made))
            ).all():
                session.delete(node)
            session.commit()


def test_a_retry_is_a_new_run_that_names_the_one_it_repeats():
    """The way back from a run an engine restart interrupted.

    Re-issuing the whole sweep is the blunt version; this keeps the group, so
    what was missing is filled in rather than run twice.
    """
    flow = FlowDef(
        name="study",
        mode="batch",
        inputs=[
            FlowInput(spec=MessageSpec(name="lr", dtype=DType.FLOAT), initial=0.01)
        ],
    )
    queue = _Collect()
    service = RunService(controller=_OneFlow(flow), queue=queue)
    made = []
    with Session(db_engine) as session:
        session.add(
            Run(
                id="abandoned-1",
                flow="study",
                status="abandoned",
                params={"lr": 0.3},
                group_id="sweep-9",
                draft=True,
                created_at=datetime.now(UTC),
            )
        )
        session.add(
            Run(
                id="going-1",
                flow="study",
                status="running",
                created_at=datetime.now(UTC),
            )
        )
        session.commit()
    try:
        again = service.retry("abandoned-1", actor="someone@example.com")
        made.append(again.id)
        assert again.parent_id == "abandoned-1"
        assert (again.params, again.group_id, again.cause) == (
            {"lr": 0.3},
            "sweep-9",
            "retry",
        )
        # What it was a run of comes with it: retrying a run of the working
        # copy that silently ran the published one would say nothing at all.
        assert again.draft is True
        assert queue.items[-1].run_id == again.id

        # A run that has not finished is cancelled, not retried.
        with pytest.raises(RunRejected):
            service.retry("going-1")
        with pytest.raises(RunRejected):
            service.retry("never-existed")
    finally:
        with Session(db_engine) as session:
            for run in session.exec(
                select(Run).where(col(Run.id).in_([*made, "abandoned-1", "going-1"]))
            ).all():
                session.delete(run)
            session.commit()


def test_runs_left_queued_are_woken_by_the_next_engine():
    """The row is the record, and the work item is not part of its transaction.

    An in-memory queue loses the item with the process and a stream item
    nobody claimed is nobody's, so without this a run submitted just before a
    restart waits for an engine that will never be told about it.
    """
    queue = _Collect()
    service = RunService(controller=_Unusable(), queue=queue)
    with Session(db_engine) as session:
        session.add(
            Run(
                id="orphan-1",
                flow="study",
                status="queued",
                created_at=datetime.now(UTC),
            )
        )
        session.add(
            Run(
                id="finished-1",
                flow="study",
                status="ok",
                created_at=datetime.now(UTC),
            )
        )
        session.commit()
    try:
        service._requeue_queued()
        assert [item.run_id for item in queue.items] == ["orphan-1"]
        assert queue.items[0].flow == "study"
    finally:
        with Session(db_engine) as session:
            for run in session.exec(
                select(Run).where(col(Run.id).in_(["orphan-1", "finished-1"]))
            ).all():
                session.delete(run)
            session.commit()


def test_a_key_nobody_used_submits_normally(
    client, superuser_token_headers, monkeypatch
):
    """The route carries the key through; without one nothing changes."""
    seen: dict[str, object] = {}

    class Recorder:
        def submit(self, name, **kwargs):
            seen.update(kwargs)
            return Run(id="keyed-1", flow=name, created_at=datetime.now(UTC))

    monkeypatch.setattr(client.app.state, "run_service", Recorder())
    answer = client.post(
        f"{settings.API_V1_STR}/runs/flows/demo",
        headers=superuser_token_headers,
        json={"idempotency_key": "key-xyz"},
    )

    assert answer.status_code == 202
    assert seen["idempotency_key"] == "key-xyz"


def test_overview_is_not_read_as_a_run_id(client, superuser_token_headers):
    """`/overview` is declared before `/{run_id}`, which would swallow it."""
    answer = client.get(
        f"{settings.API_V1_STR}/runs/overview", headers=superuser_token_headers
    )

    assert answer.status_code == 200
    assert isinstance(answer.json(), list)


# -----------------------------------------------------------------------------
# Deleting a run
#
# The route owns the four statements; what these guard is that it takes the
# children with it and refuses a run the driver is still writing to.
# -----------------------------------------------------------------------------


@pytest.fixture
def deletable_run():
    """One finished run with a node, a number and an artifact row hanging off it."""
    run_id = "del-1"
    with Session(db_engine) as session:
        session.add(
            Run(id=run_id, flow="deleted", status="ok", created_at=datetime.now(UTC))
        )
        session.add(RunNode(run_id=run_id, node="deleted.a", status="ok"))
        session.add(RunMetric(run_id=run_id, name="deleted.loss", step=0, value=1.0))
        session.add(
            RunArtifact(
                run_id=run_id,
                name="deleted.out",
                filename="out.bin",
                node="a",
                digest="d" * 64,
                size=7,
            )
        )
        session.commit()
    yield run_id
    with Session(db_engine) as session:
        run = session.get(Run, run_id)
        if run is not None:
            session.delete(run)
            session.commit()


def test_deleting_a_run_takes_its_children_with_it(
    client, superuser_token_headers, deletable_run
):
    """No foreign key cascades here, so the route has to do it itself."""
    answer = client.delete(
        f"{settings.API_V1_STR}/runs/{deletable_run}", headers=superuser_token_headers
    )

    assert answer.status_code == 204
    with Session(db_engine) as session:
        assert session.get(Run, deletable_run) is None
        for table in (RunNode, RunMetric, RunArtifact):
            left = session.exec(
                select(table).where(col(table.run_id) == deletable_run)
            ).all()
            assert left == [], f"{table.__name__} rows outlived the run"


def test_deleting_a_run_that_is_not_there_is_a_404(client, superuser_token_headers):
    answer = client.delete(
        f"{settings.API_V1_STR}/runs/nope-1", headers=superuser_token_headers
    )

    assert answer.status_code == 404


def test_a_running_run_is_refused_rather_than_raced(client, superuser_token_headers):
    """The driver writes its nodes back at the end; they would have no run."""
    run_id = "del-live"
    with Session(db_engine) as session:
        session.add(
            Run(
                id=run_id,
                flow="deleted",
                status="running",
                created_at=datetime.now(UTC),
            )
        )
        session.commit()
    try:
        answer = client.delete(
            f"{settings.API_V1_STR}/runs/{run_id}", headers=superuser_token_headers
        )

        assert answer.status_code == 409
        assert "Cancel it" in answer.json()["detail"]
        with Session(db_engine) as session:
            assert session.get(Run, run_id) is not None
    finally:
        with Session(db_engine) as session:
            run = session.get(Run, run_id)
            if run is not None:
                session.delete(run)
                session.commit()


# -----------------------------------------------------------------------------
# A cached node's curve
#
# A hit replays no emissions, so the series stays in the run that recorded it
# and the run reusing it points there. Reading either one answers the same.
# -----------------------------------------------------------------------------


@pytest.fixture
def reused_run():
    """A run of `quick` whose node was restored from a run of `train`."""
    with Session(db_engine) as session:
        made = datetime.now(UTC)
        session.add(Run(id="src-1", flow="train", status="ok", created_at=made))
        session.add(Run(id="reuse-1", flow="quick", status="ok", created_at=made))
        session.add(RunNode(run_id="src-1", node="train.fit", status="ok"))
        session.add(
            RunNode(
                run_id="reuse-1",
                node="quick.fit",
                status="cached",
                cached_from="src-1",
            )
        )
        for step, value in enumerate([3.0, 2.0, 1.0]):
            session.add(
                RunMetric(
                    run_id="src-1",
                    name="train.loss",
                    step=step,
                    node="train.fit",
                    value=value,
                )
            )
        session.commit()
    yield
    with Session(db_engine) as session:
        for row in session.exec(select(RunMetric)).all():
            session.delete(row)
        for row in session.exec(select(RunNode)).all():
            session.delete(row)
        for run_id in ("src-1", "reuse-1"):
            run = session.get(Run, run_id)
            if run is not None:
                session.delete(run)
        session.commit()


@pytest.mark.usefixtures("reused_run")
def test_a_cached_node_answers_with_the_curve_it_was_restored_from(
    client, superuser_token_headers
):
    points = client.get(
        f"{settings.API_V1_STR}/runs/reuse-1/metrics",
        headers=superuser_token_headers,
    ).json()

    # Named for the flow that asked, not the one that recorded it.
    assert [point["name"] for point in points] == ["quick.loss"] * 3
    assert [point["value"] for point in points] == [3.0, 2.0, 1.0]

    named = client.get(
        f"{settings.API_V1_STR}/runs/reuse-1/metrics",
        params={"name": "quick.loss"},
        headers=superuser_token_headers,
    ).json()
    assert len(named) == 3


@pytest.mark.usefixtures("reused_run")
def test_a_curve_whose_run_is_gone_is_empty_rather_than_an_error(
    client, superuser_token_headers
):
    """Deleting a flow deletes its runs; what pointed at one is left holding it."""
    with Session(db_engine) as session:
        session.delete(session.get(Run, "src-1"))
        session.commit()

    answer = client.get(
        f"{settings.API_V1_STR}/runs/reuse-1/metrics",
        headers=superuser_token_headers,
    )
    assert answer.status_code == 200
    assert answer.json() == []


def _metric(run_id: str, name: str, step: int, value: float, ts: float) -> RunMetric:
    return RunMetric(run_id=run_id, name=name, step=step, value=value, ts=ts)


@pytest.fixture
def plotted():
    """A run with a loss curve and an epoch counter beside it."""
    run_id = new_run_id()
    with Session(db_engine) as session:
        session.add(
            Run(id=run_id, flow="study", status="ok", created_at=datetime.now(UTC))
        )
        for step, (loss, epoch) in enumerate([(1.0, 10.0), (0.5, 20.0), (0.25, 30.0)]):
            session.add(_metric(run_id, "study.loss", step, loss, 100.0 + step * 5))
            session.add(_metric(run_id, "study.epoch", step, epoch, 100.0 + step * 5))
        session.commit()
    yield run_id
    with Session(db_engine) as session:
        for row in session.exec(
            select(RunMetric).where(col(RunMetric.run_id) == run_id)
        ).all():
            session.delete(row)
        session.delete(session.get(Run, run_id))
        session.commit()


def test_the_metric_names_of_a_selection_are_exact(
    client, superuser_token_headers, plotted
):
    """Names are flow-qualified, so this is what says which spellings exist.

    Read over the whole selection rather than off the newest run that measured
    anything, which is what missed a name only an older run ever wrote — here,
    the older run's `study.grad` against the newer one's two.
    """
    older = new_run_id()
    with Session(db_engine) as session:
        session.add(
            Run(
                id=older,
                flow="study",
                status="ok",
                created_at=datetime.now(UTC) - timedelta(hours=1),
            )
        )
        session.add(_metric(older, "study.grad", 0, 0.1, 50.0))
        session.commit()

    try:
        both = client.get(
            f"{settings.API_V1_STR}/runs/metrics/names",
            params={"ids": f"{plotted},{older}"},
            headers=superuser_token_headers,
        )
        assert both.status_code == 200
        assert both.json() == ["study.epoch", "study.grad", "study.loss"]

        # The same question by filter rather than by name.
        assert client.get(
            f"{settings.API_V1_STR}/runs/metrics/names",
            params={"flow": "study"},
            headers=superuser_token_headers,
        ).json() == ["study.epoch", "study.grad", "study.loss"]

        # A selection that recorded nothing has nothing to offer, which is not
        # an error: a run opened before its first reading is the ordinary case.
        assert (
            client.get(
                f"{settings.API_V1_STR}/runs/metrics/names",
                params={"ids": "no-such-run"},
                headers=superuser_token_headers,
            ).json()
            == []
        )
    finally:
        with Session(db_engine) as session:
            for row in session.exec(
                select(RunMetric).where(col(RunMetric.run_id) == older)
            ).all():
                session.delete(row)
            session.delete(session.get(Run, older))
            session.commit()


def test_a_comparison_is_plotted_against_the_step_by_default(
    client, superuser_token_headers, plotted
):
    answer = client.get(
        f"{settings.API_V1_STR}/runs/series/compare",
        params={"ids": plotted, "metric": "study.loss"},
        headers=superuser_token_headers,
    ).json()

    assert answer["x"] == "step"
    assert answer["lines"][0]["points"] == [[0.0, 1.0], [1.0, 0.5], [2.0, 0.25]]


def test_time_is_measured_from_this_runs_own_first_reading(
    client, superuser_token_headers, plotted
):
    """Runs started hours apart still lie on top of each other."""
    answer = client.get(
        f"{settings.API_V1_STR}/runs/series/compare",
        params={"ids": plotted, "metric": "study.loss", "x": "time"},
        headers=superuser_token_headers,
    ).json()

    assert answer["x"] == "time"
    assert answer["lines"][0]["points"] == [[0.0, 1.0], [5.0, 0.5], [10.0, 0.25]]


def test_one_metric_can_be_plotted_against_another(
    client, superuser_token_headers, plotted
):
    answer = client.get(
        f"{settings.API_V1_STR}/runs/series/compare",
        params={"ids": plotted, "metric": "study.loss", "x": "study.epoch"},
        headers=superuser_token_headers,
    ).json()

    assert answer["lines"][0]["points"] == [[10.0, 1.0], [20.0, 0.5], [30.0, 0.25]]


def test_a_step_the_x_metric_never_reached_is_left_out(
    client, superuser_token_headers, plotted
):
    """The join is on the step, which is the only thing two series share."""
    with Session(db_engine) as session:
        session.add(_metric(plotted, "study.loss", 3, 0.1, 120.0))
        session.commit()

    answer = client.get(
        f"{settings.API_V1_STR}/runs/series/compare",
        params={"ids": plotted, "metric": "study.loss", "x": "study.epoch"},
        headers=superuser_token_headers,
    ).json()

    assert [point[0] for point in answer["lines"][0]["points"]] == [10.0, 20.0, 30.0]


def test_a_run_records_the_code_it_started_with_not_the_code_it_was_queued_with():
    """A sweep queues every run at once and the tree moves while it waits.

    `_restamp` is what runs at claim time, so the digest the record keeps is
    the one the run actually executed.
    """
    service = RunService(controller=_Unusable(), queue=_Unusable())
    with Session(db_engine) as session:
        session.add(
            Run(
                id="stamp-1",
                flow="study",
                status="queued",
                code_digest="at-submit",
                created_at=datetime.now(UTC),
            )
        )
        session.commit()
        run = session.get(Run, "stamp-1")

    assert service._restamp(run, "at-claim") == "at-claim"

    with Session(db_engine) as session:
        assert session.get(Run, "stamp-1").code_digest == "at-claim"


def test_a_tree_that_did_not_move_is_not_written_again():
    service = RunService(controller=_Unusable(), queue=_Unusable())
    with Session(db_engine) as session:
        session.add(
            Run(
                id="stamp-2",
                flow="study",
                status="queued",
                code_digest="same",
                created_at=datetime.now(UTC),
            )
        )
        session.commit()
        run = session.get(Run, "stamp-2")

    assert service._restamp(run, "same") == "same"


# -----------------------------------------------------------------------------
# Export
#
# Two tables an analysis reads: the long one a curve is plotted from, and the
# wide one arms are compared in. Both carry the run id on every row.
# -----------------------------------------------------------------------------


@pytest.fixture
def exported():
    """Two runs of one flow: two curves each, and records on both sides.

    The numbers a node returns are usually inside a record rather than at the
    top of the result, so the fixture is shaped the way a real one is.
    """
    made = datetime.now(UTC)
    with Session(db_engine) as session:
        for index, (lr, acc) in enumerate([(0.1, 0.5), (0.01, 0.25)]):
            run_id = f"exp-{index}"
            session.add(
                Run(
                    id=run_id,
                    flow="export-study",
                    status="ok",
                    params={
                        "lr": lr,
                        "epochs": 10,
                        "config": {"model": "mlp", "depth": index + 1},
                    },
                    result={
                        "acc": acc,
                        "note": "n/a",
                        "final_metrics": {"train_loss": acc * 2},
                        "test_metrics": {"known": {"perfect": 1.0}},
                    },
                    created_at=made + timedelta(seconds=index),
                )
            )
            for name in ("study.loss", "study.val"):
                for step in range(4):
                    session.add(_metric(run_id, name, step, float(step), 100.0 + step))
        session.commit()
    yield ["exp-0", "exp-1"]
    with Session(db_engine) as session:
        for run_id in ("exp-0", "exp-1"):
            for row in session.exec(
                select(RunMetric).where(col(RunMetric.run_id) == run_id)
            ).all():
                session.delete(row)
            run = session.get(Run, run_id)
            if run is not None:
                session.delete(run)
        session.commit()


def _lines(answer) -> list[dict]:
    return [json.loads(line) for line in answer.text.splitlines() if line]


def test_an_export_strides_each_series_and_names_its_run(
    client, superuser_token_headers, exported
):
    """Every second point of every curve — not every second row of all of them."""
    answer = client.get(
        f"{settings.API_V1_STR}/runs/export/metrics",
        params={"ids": ",".join(exported), "stride": 2, "format": "jsonl"},
        headers=superuser_token_headers,
    )

    assert answer.status_code == 200
    rows = _lines(answer)
    assert {row["run"] for row in rows} == set(exported)
    curves: dict[tuple[str, str], list[int]] = {}
    for row in rows:
        curves.setdefault((row["run"], row["name"]), []).append(row["step"])
    assert len(curves) == 4
    assert all(steps == [0, 2] for steps in curves.values())


def test_an_exported_run_row_carries_every_recorded_input(
    client, superuser_token_headers, exported
):
    """Every input is a column, so the schema does not move with the selection."""

    def export(**extra):
        answer = client.get(
            f"{settings.API_V1_STR}/runs/export/runs",
            params={"ids": ",".join(exported), **extra},
            headers=superuser_token_headers,
        )
        assert answer.status_code == 200
        return answer

    rows = _lines(export(format="jsonl"))
    assert [row["id"] for row in rows] == ["exp-1", "exp-0"]
    assert {row["param.lr"] for row in rows} == {0.1, 0.01}
    # `epochs` is the same on both runs and stays a column anyway: which runs
    # were asked for is not something a downstream filter should have to know.
    assert rows[0]["param.epochs"] == 10
    assert rows[0]["param.config.model"] == "mlp"
    assert {row["param.config.depth"] for row in rows} == {1, 2}

    narrowed = _lines(export(format="jsonl", params="epochs"))[0]
    assert "param.epochs" in narrowed
    assert "param.lr" not in narrowed

    # A number inside a record is a column of its own, however deep; a string
    # is not one of the run's numbers wherever it sits.
    assert rows[0]["metric.acc"] == 0.25
    assert rows[0]["metric.final_metrics.train_loss"] == 0.5
    assert rows[0]["metric.test_metrics.known.perfect"] == 1.0
    assert "metric.note" not in rows[0]

    named = _lines(export(format="jsonl", metrics="test_metrics.known.perfect"))
    assert list(named[0])[-1] == "metric.test_metrics.known.perfect"
    assert "metric.acc" not in named[0]

    # csv is the default, and the columns are in the order the header names.
    header = export().text.splitlines()[0]
    assert header.startswith("id,flow,status,")
    assert header.endswith(
        "param.config.depth,param.config.model,param.epochs,param.lr,"
        "metric.acc,metric.final_metrics.train_loss,"
        "metric.test_metrics.known.perfect"
    )

    # `final_metrics` alone, short of `.train_loss`, is a record rather than a
    # leaf — the shape a large nested blob is. jsonl keeps it a json value;
    # csv still has nowhere to put it but a quoted string, unchanged.
    nested = _lines(export(format="jsonl", metrics="final_metrics"))
    assert nested[0]["metric.final_metrics"] == {"train_loss": 0.5}

    rows = list(csv.reader(export(metrics="final_metrics").text.splitlines()))
    assert rows[1][-1] == '{"train_loss": 0.5}'


@pytest.fixture
def paged():
    """Three runs of one flow, a minute apart."""
    made = datetime.now(UTC).replace(microsecond=0)
    with Session(db_engine) as session:
        for index in range(3):
            session.add(
                Run(
                    id=f"page-{index}",
                    flow="paged-study",
                    status="ok",
                    created_at=made + timedelta(minutes=index),
                )
            )
        session.commit()
    yield made
    with Session(db_engine) as session:
        for index in range(3):
            run = session.get(Run, f"page-{index}")
            if run is not None:
                session.delete(run)
        session.commit()


def test_runs_page_by_when_they_were_created(client, superuser_token_headers, paged):
    """`before` is the cursor: the last row's own timestamp reads the next page."""

    def listed(**params):
        answer = client.get(
            f"{settings.API_V1_STR}/runs",
            params={"flow": "paged-study", **params},
            headers=superuser_token_headers,
        )
        assert answer.status_code == 200
        return [row["id"] for row in answer.json()]

    assert listed() == ["page-2", "page-1", "page-0"]
    assert listed(before=(paged + timedelta(minutes=2)).isoformat()) == [
        "page-1",
        "page-0",
    ]
    assert listed(since=(paged + timedelta(minutes=1)).isoformat()) == [
        "page-2",
        "page-1",
    ]