"""Retry-submission contracts against the creation-only Atlas SCM broker.

The broker deliberately permits only new namespaced branch creation, so a pool
retry that adds commits to an already-published branch could never submit: the
push was refused, the worker unwound, and the run's actual work was discarded
along with it. Submission now targets a fresh attempt- or content-scoped ref, and
a refused submission downgrades the result instead of losing it.
"""

from __future__ import annotations

import sys
from pathlib import Path

import pytest


ROOT = Path(__file__).parents[2]
SCRIPTS = ROOT / "services/hermes/scripts"
SCM_SCRIPTS = ROOT / "services/hermes/scm-common/scripts"
sys.path[:0] = [str(SCRIPTS), str(SCM_SCRIPTS)]

import execution_pool_client as client  # noqa: E402
import execution_pool_protocol as protocol  # noqa: E402
import execution_pool_scm as scm  # noqa: E402
import receive_pack_scan  # noqa: E402
import scm_broker  # noqa: E402
from testing.tests.test_hermes_scm_broker_support import _receive_command  # noqa: E402
from testing.tests.test_hermes_execution_pool_mediator import (  # noqa: E402
    KEY,
    RESULT,
    assignment,
    binding,
    payload,
)


def attempt_assignment(attempt):
    """One signed assignment envelope bound to an exact retry attempt."""
    return protocol.sign_envelope(
        KEY, "assignment", binding(attempt=attempt), payload()
    )


def test_submission_refs_are_creation_only_and_attempt_scoped():
    first = scm.submission_refs("feature/pool", 1, "a" * 40)
    assert first[0] == "feature/pool"
    assert first[1] == "feature/pool-attempt-1"
    assert first[2] == f"feature/pool-{'a' * 12}"
    retry = scm.submission_refs("feature/pool", 3, "b" * 40)
    assert retry[1] == "feature/pool-attempt-3"
    # Every candidate stays inside a reviewed namespace the broker accepts, and
    # none of them is a protected or base ref.
    for candidate in first + retry:
        assert receive_pack_scan.FEATURE_REF_RE.fullmatch(f"refs/heads/{candidate}")
        assert candidate not in {"main", "master"}


def test_submission_refs_drop_oversized_names_and_fail_closed_when_empty():
    long_branch = "feature/" + "a" * 185
    candidates = scm.submission_refs(long_branch, 2, "c" * 40)
    assert candidates == (long_branch,)
    with pytest.raises(protocol.ProtocolError, match="reviewed branch name"):
        scm.submission_refs("main", 1, "d" * 40)


def test_the_broker_accepts_the_attempt_ref_as_a_creation_and_still_refuses_updates():
    zero, head = b"0" * 40, b"1" * 40
    ref = b"refs/heads/feature/pool-attempt-2"
    scm_broker._validate_receive_pack(_receive_command(zero, head, ref), "token")
    update = _receive_command(b"2" * 40, head, ref)
    with pytest.raises(scm_broker.PolicyError, match="feature-branch creation"):
        scm_broker._validate_receive_pack(update, "token")


def submit_harness(tmp_path, monkeypatch, remote_refs, *, attempt=1):
    """A Boundary whose broker advertises exactly ``remote_refs``."""
    monkeypatch.setattr(scm, "WORKSPACE_ROOT", tmp_path / "workspace")
    monkeypatch.setattr(scm, "SCM_ROOT", tmp_path / "state")
    monkeypatch.setattr(scm, "ORDINAL", 0)
    exact = attempt_assignment(attempt)
    destination = scm.workspace_path(exact)
    destination.mkdir(parents=True)
    protocol.atomic_json(scm._state_path(exact), {"baseline_sha": "a" * 40})
    head = "b" * 40
    monkeypatch.setattr(scm, "_workspace_identity", lambda *_a: head)
    calls: list[tuple[str, ...]] = []

    def run(*arguments, **_kwargs):
        calls.append(arguments)
        if arguments[0] == "ls-remote":
            return "\n".join(
                f"{sha}\trefs/heads/{ref}" for ref, sha in remote_refs.items()
            )
        if arguments[0] == "rev-list":
            return "2"
        return ""

    monkeypatch.setattr(scm, "_run", run)
    boundary = scm.Boundary(KEY)
    monkeypatch.setattr(boundary, "_draft", lambda *args: f"https://scm/pulls/{args[1]}")
    return boundary, exact, calls, head


def test_a_retry_publishes_an_attempt_ref_instead_of_updating_the_existing_one(
    tmp_path, monkeypatch
):
    boundary, exact, calls, _head = submit_harness(
        tmp_path, monkeypatch, {"wt/t_deadbeef": "c" * 40}, attempt=2
    )
    result = boundary.submit(exact, {"title": "retry", "body": "evidence"})
    pushes = [item for item in calls if item[0] == "push"]
    assert pushes == [("push", "hermes-broker", "HEAD:refs/heads/wt/t_deadbeef-attempt-2")]
    assert result["branch"] == "wt/t_deadbeef-attempt-2"
    assert result["pull_request"] == "https://scm/pulls/wt/t_deadbeef-attempt-2"


def test_an_already_published_head_is_adopted_without_a_second_push(
    tmp_path, monkeypatch
):
    boundary, exact, calls, head = submit_harness(
        tmp_path, monkeypatch, {"wt/t_deadbeef-attempt-2": "b" * 40}, attempt=2
    )
    assert head == "b" * 40
    result = boundary.submit(exact, {"title": "replay", "body": "evidence"})
    assert [item for item in calls if item[0] == "push"] == []
    assert result["branch"] == "wt/t_deadbeef-attempt-2"
    assert result["pull_request"].endswith("wt/t_deadbeef-attempt-2")


def test_a_run_with_no_new_commits_still_reports_work_a_prior_attempt_published(
    tmp_path, monkeypatch
):
    boundary, exact, calls, _head = submit_harness(
        tmp_path, monkeypatch, {"wt/t_deadbeef": "b" * 40}
    )

    real_run = scm._run

    def run(*arguments, **kwargs):
        if arguments[0] == "rev-list":
            return "0"
        return real_run(*arguments, **kwargs)

    monkeypatch.setattr(scm, "_run", run)
    result = boundary.submit(exact, {"title": "nothing new", "body": "evidence"})
    assert [item for item in calls if item[0] == "push"] == []
    assert result["pull_request"].endswith("wt/t_deadbeef")


def test_a_run_that_produced_nothing_at_all_submits_nothing(tmp_path, monkeypatch):
    boundary, exact, calls, _head = submit_harness(tmp_path, monkeypatch, {})

    real_run = scm._run

    def run(*arguments, **kwargs):
        if arguments[0] == "rev-list":
            return "0"
        return real_run(*arguments, **kwargs)

    monkeypatch.setattr(scm, "_run", run)
    result = boundary.submit(exact, {})
    assert [item for item in calls if item[0] == "push"] == []
    assert result["pull_request"] == "" and result["branch"] == "wt/t_deadbeef"


def test_submission_fails_closed_when_every_candidate_ref_is_taken(
    tmp_path, monkeypatch
):
    taken = {
        "wt/t_deadbeef": "c" * 40,
        "wt/t_deadbeef-attempt-1": "d" * 40,
        f"wt/t_deadbeef-{'b' * 12}": "e" * 40,
    }
    boundary, exact, calls, _head = submit_harness(tmp_path, monkeypatch, taken)
    with pytest.raises(protocol.ProtocolError, match="every reviewed branch name"):
        boundary.submit(exact, {"title": "blocked", "body": "evidence"})
    assert [item for item in calls if item[0] == "push"] == []


def test_remote_head_parsing_ignores_anything_that_is_not_a_branch(
    tmp_path, monkeypatch
):
    monkeypatch.setattr(
        scm, "_run",
        lambda *_a, **_k: "aaa\trefs/tags/v1\nbbb\trefs/heads/feature/x\ngarbage\n",
    )
    assert scm._remote_heads(tmp_path, ("feature/x",)) == {"feature/x": "bbb"}


class FailingSCM:
    def __init__(self, error):
        self.error = error
        self.calls = 0

    def submit(self, _assignment, _request):
        self.calls += 1
        raise self.error


def test_a_refused_submission_downgrades_the_result_instead_of_discarding_it():
    failing = FailingSCM(protocol.ProtocolError("every reviewed branch name is taken"))
    boundary = client.ClientBoundary(KEY, failing)
    boundary.current = assignment()
    boundary._post = lambda _path, _envelope: protocol.sign_envelope(
        KEY, "ack", binding(), {"accepted": True, "duplicate": False}
    )
    finished = boundary.finish(
        {
            "binding": binding(),
            "payload": {"structured": dict(RESULT), "returncode": 0},
            "title": "safe", "body": "evidence",
        }
    )
    assert failing.calls == 1
    structured = finished["structured"]
    # The run is recorded rather than unwound, and it says exactly why.
    assert structured["status"] == "blocked"
    assert structured["changed_files"] == ["safe.py"]
    assert len(structured["blockers"]) == 1
    assert "commits remain on this ordinal's workspace" in structured["blockers"][0]
    assert "every reviewed branch name is taken" in structured["blockers"][0]
    assert finished["ack"]["accepted"] is True


def test_a_successful_submission_records_both_the_draft_and_the_exact_branch():
    class Recording:
        def submit(self, _assignment, _request):
            return {
                "workspace": "/workspace/runs/metis/t_deadbeef/42",
                "branch": "wt/t_deadbeef-attempt-2",
                "pull_request": "https://scm/pulls/9",
            }

    boundary = client.ClientBoundary(KEY, Recording())
    boundary.current = assignment()
    boundary._post = lambda _path, _envelope: protocol.sign_envelope(
        KEY, "ack", binding(), {"accepted": True, "duplicate": False}
    )
    finished = boundary.finish(
        {
            "binding": binding(),
            "payload": {"structured": dict(RESULT), "returncode": 0},
            "title": "safe", "body": "evidence",
        }
    )
    assert finished["structured"]["status"] == "completed"
    assert finished["structured"]["artifacts"] == [
        "https://scm/pulls/9", "branch:wt/t_deadbeef-attempt-2",
    ]