"""Unit tests for the backup export contract.

This is the no-database lane, so these cover the parts that need none: the
version/coverage constants, the pure row helpers, and the export dict shape
(via a mocked session). The full FK-remapping round-trip needs real Postgres
and belongs in a `@pytest.mark.integration` module — it is not written yet,
which is why every row helper here is a plain function that can be tested
without a session.
"""
from datetime import datetime, timezone
from types import SimpleNamespace
from unittest.mock import patch

import pytest

from scribe.services import backup


def test_backup_version_is_current():
    """The bump is the point of the test — a payload section added without
    moving the version produces backups that are structurally different and
    indistinguishable by inspection.

    (Named for the number it asserted until v10, which is exactly the drift a
    name-carrying-a-value invites; it now says what it checks.)"""
    assert backup.BACKUP_VERSION == 14


def _exportable_note(**over):
    """A Note-shaped stand-in for the pure row helper. SimpleNamespace, not a
    MagicMock: `_note_rows` calls .isoformat() on the timestamps, and a mock
    would happily return another mock instead of failing."""
    base = dict(
        id=1, user_id=7, title="t", body="b", description=None, tags=["x"],
        parent_id=None, arose_from_id=None,
        project_id=None, milestone_id=None, status=None, priority=None,
        due_date=None, created_at=datetime(2026, 1, 1, tzinfo=timezone.utc),
        updated_at=datetime(2026, 1, 2, tzinfo=timezone.utc),
        note_type="note", task_kind="work", data=None,
        started_at=None, completed_at=None,
        recurrence_rule=None, recurrence_next_spawn_at=None,
        verify_with=None, expires_when=None, verified_at=None,
    )
    base.update(over)
    return SimpleNamespace(**base)


def test_note_rows_carry_the_verification_trio():
    """Operator judgment — somebody checked this fact, and this is when —
    which nothing downstream can recompute (milestone 317)."""
    [row] = backup._note_rows([_exportable_note(
        verify_with="curl the AMO docs",
        expires_when="AMO starts allowing re-signing",
        verified_at=datetime(2026, 8, 28, tzinfo=timezone.utc),
    )])
    assert row["verify_with"] == "curl the AMO docs"
    assert row["expires_when"] == "AMO starts allowing re-signing"
    assert row["verified_at"] == "2026-08-28T00:00:00+00:00"


def test_a_never_checked_note_exports_a_null_stamp_and_restores_as_one():
    """The round trip that matters. NULL `verified_at` means nobody has ever
    looked, and it is what sorts FIRST in the sweep. Restoring it as now() —
    which is what `_dt` would do — silently converts the sweep's top result
    into its bottom one."""
    [row] = backup._note_rows([_exportable_note(verify_with="check the runner shell")])
    assert row["verified_at"] is None
    assert backup._dt_or_none(row["verified_at"]) is None
    # ...and the helper that must NOT be used here, for contrast.
    assert backup._dt(row["verified_at"]) is not None


def test_the_record_type_and_kind_survive_the_export():
    """#3182's headline. Without these two columns a restore reported success
    and handed back a corpus where all 90 snippets and 3 processes were plain
    notes and all 435 issues and the spike were `work` — the entire vocabulary
    milestone 312 and #3128 were about, gone, with nothing to notice it by."""
    [snippet] = backup._note_rows([_exportable_note(note_type="snippet")])
    [issue] = backup._note_rows([_exportable_note(task_kind="issue", status="done")])
    assert snippet["note_type"] == "snippet"
    assert issue["task_kind"] == "issue"


def test_provenance_and_lifecycle_travel():
    started = datetime(2026, 3, 1, tzinfo=timezone.utc)
    [row] = backup._note_rows([_exportable_note(
        arose_from_id=42,
        description="one-liner",
        started_at=started,
        recurrence_rule={"freq": "weekly"},
    )])
    assert row["arose_from_id"] == 42
    assert row["description"] == "one-liner"
    assert row["started_at"] == started.isoformat()
    assert row["recurrence_rule"] == {"freq": "weekly"}
    # Absent lifecycle stamps stay absent — a note that never started must not
    # restore as one that started at restore time.
    assert row["completed_at"] is None


def test_a_milestone_carries_its_plan():
    """A milestone IS the plan (0066); `body` is its design and intent and
    `description` is only the one-line summary. Dropping it restored every
    plan as a title with no reasoning behind it (#3182)."""
    m = SimpleNamespace(
        id=1, user_id=7, project_id=2, title="t", description="d",
        body="## Goal\n\nthe actual plan", status="active", order_index=0,
        created_at=datetime(2026, 1, 1, tzinfo=timezone.utc),
        updated_at=datetime(2026, 1, 2, tzinfo=timezone.utc),
    )
    [row] = backup._milestone_rows([m])
    assert row["body"] == "## Goal\n\nthe actual plan"


def test_a_repo_binding_carries_the_branch_its_ledger_follows():
    """#2873. Without `ref` a restored binding silently falls back to the
    default branch and the shape ledger starts accounting for a different
    tree — a wrong answer that looks like a working one."""
    b = SimpleNamespace(user_id=7, project_id=2, repo_key="Scribe", ref="dev")
    [row] = backup._repo_binding_rows([b])
    assert row["ref"] == "dev"


# The table -> (model, row helper) registry the column guard walks. Kept here
# rather than in the service because it exists only to be introspected: the
# product code already knows these pairings by calling them.
def _column_guard_targets():
    from scribe.models.canonical_system import CanonicalSystem
    from scribe.models.code_shape import CodeShape, CodeShapeEvent, CodeShapeUse
    from scribe.models.design_system import DesignSystem, DesignToken
    from scribe.models.milestone import Milestone
    from scribe.models.note import Note
    from scribe.models.note_draft import NoteDraft
    from scribe.models.note_supersession import NoteSupersession
    from scribe.models.note_usage import NoteUsageEvent
    from scribe.models.rule_usage import RuleUsageEvent
    from scribe.models.note_version import NoteVersion
    from scribe.models.rule_version import RuleVersion
    from scribe.models.project import Project
    from scribe.models.repo_binding import RepoBinding
    from scribe.models.rulebook import Rule, Rulebook, RulebookTopic, RuleRelation
    from scribe.models.setting import Setting
    from scribe.models.system import RecordSystem, System
    from scribe.models.task_log import TaskLog
    from scribe.models.user import User

    return {
        "users": (User, backup._user_rows),
        "projects": (Project, backup._project_rows),
        "milestones": (Milestone, backup._milestone_rows),
        "notes": (Note, backup._note_rows),
        "task_logs": (TaskLog, backup._task_log_rows),
        "note_drafts": (NoteDraft, backup._note_draft_rows),
        "note_versions": (NoteVersion, backup._note_version_rows),
        "settings": (Setting, backup._setting_rows),
        "rulebooks": (Rulebook, backup._rulebook_rows),
        "rulebook_topics": (RulebookTopic, backup._topic_rows),
        "rules": (Rule, backup._rule_rows),
        "rule_versions": (RuleVersion, backup._rule_version_rows),
        "systems": (System, lambda rows: backup._system_rows(rows, {})),
        "canonical_systems": (CanonicalSystem, backup._canonical_system_rows),
        "record_systems": (RecordSystem, backup._record_system_rows),
        "note_supersessions": (NoteSupersession, backup._note_supersession_rows),
        "rule_relations": (RuleRelation, backup._rule_relation_rows),
        "note_usage_events": (NoteUsageEvent, backup._usage_event_rows),
        "rule_usage_events": (RuleUsageEvent, backup._rule_usage_event_rows),
        "design_systems": (DesignSystem, backup._design_system_rows),
        "design_tokens": (DesignToken, backup._design_token_rows),
        "repo_bindings": (RepoBinding, backup._repo_binding_rows),
        "code_shapes": (CodeShape, backup._code_shape_rows),
        "code_shape_events": (CodeShapeEvent, backup._code_shape_event_rows),
        "code_shape_uses": (CodeShapeUse, backup._code_shape_use_rows),
    }


def _stand_in(model):
    """A real instance of `model` with every column set to a value of roughly
    the right type, so the serialiser runs and we can read which KEYS it
    produced. Values are meaningless; only the shape of the output dict is
    under test.

    A real instance rather than a MagicMock because several helpers delegate to
    the model's own `to_dict()`, and a mock would return another mock instead
    of a dict. Typed rather than a bare instance because the helpers call
    `.isoformat()` on the timestamps, which `None` does not have.
    """
    import sqlalchemy as sa

    row = model()
    for column in model.__table__.columns:
        t = column.type
        if isinstance(t, sa.DateTime):
            value = datetime(2026, 1, 1, tzinfo=timezone.utc)
        elif isinstance(t, sa.Date):
            value = datetime(2026, 1, 1).date()
        elif isinstance(t, sa.Boolean):
            value = False
        elif isinstance(t, sa.Integer):
            value = 1
        elif isinstance(t, sa.ARRAY) or isinstance(getattr(t, "impl", None), sa.ARRAY):
            value = []
        elif isinstance(t, (sa.Text, sa.String)):
            value = "x"
        else:
            # JSON/JSONB and anything exotic. None is what these actually hold
            # most of the time, and no serialiser calls a method on one.
            value = None
        setattr(row, column.name, value)
    return row


@pytest.mark.parametrize("table", sorted(_column_guard_targets()))
def test_every_column_is_exported_or_declared_excluded(table):
    """THE COLUMN GUARD (#3182) — _NOT_INCLUDED's shape, one level down.

    The table guard below catches a whole table going missing. It cannot catch
    a COLUMN going missing from a table it already considers covered, which is
    how nine of them vanished from `notes` alone: note_type and task_kind, so
    every snippet and process restored as a plain note and every issue and
    spike as `work`; arose_from_id, so every provenance edge went; the
    recurrence pair, so recurring tasks stopped recurring. Plus milestones.body
    — which IS the plan — and repo_bindings.ref.

    Each arrived the same way: added to the model and the migration, both of
    which fail loudly, and never to the serialiser, which fails silently.

    A new column must now be exported or named in _COLUMN_EXCLUSIONS with a
    reason. Forgetting is no longer expressible.
    """
    model, helper = _column_guard_targets()[table]
    [row] = helper([_stand_in(model)])

    columns = {c.name for c in model.__table__.columns}
    missing = columns - set(row)
    declared = backup._COLUMN_EXCLUSIONS[table]

    assert missing == declared, (
        f"{table}: exported columns and _COLUMN_EXCLUSIONS disagree.\n"
        f"  dropped but not declared: {sorted(missing - declared)}\n"
        f"  declared but exported anyway: {sorted(declared - missing)}"
    )


def test_the_column_guard_covers_every_table_with_a_row_helper():
    """The guard is only as good as its registry — a table added to _BACKED_UP
    with a new helper, and not to the registry, would be unguarded and look
    guarded. Join tables have no model class and carry both their columns by
    construction, so they are the only permitted absences."""
    # REAL table names, as _BACKED_UP holds them — not the shorter keys the
    # payload uses for the same sections. Getting this wrong is what the guard
    # caught on its own first run.
    join_tables = {
        "project_rulebook_subscriptions", "project_rule_suppressions",
        "project_topic_suppressions", "project_rulebook_exclusions",
        "rule_systems",
    }
    covered = set(_column_guard_targets()) | join_tables
    assert set(backup._BACKED_UP) - covered == set()
    # And no stale entries: every declaration must name a real target.
    assert set(backup._COLUMN_EXCLUSIONS) == set(_column_guard_targets())


def test_not_included_lists_the_known_gaps():
    # The deferred tables must be surfaced explicitly, not silently dropped.
    # forge_connections is excluded as CREDENTIALS (api_keys reasoning): a
    # backup that carries forge tokens is a token-exfiltration file (#2778).
    for table in ("groups", "project_shares", "note_shares", "api_keys",
                  "note_embeddings", "retrieval_logs", "forge_connections"):
        assert table in backup._NOT_INCLUDED


def test_every_table_is_either_backed_up_or_explicitly_excluded():
    """THE GUARD (#2293), and the only shape of test that catches an ABSENCE.

    A new table gets a model and a migration — both fail loudly if wrong — and
    then silently never gets a backup section. No error, no warning, and a
    restore that reports success. That is how `systems`, `record_systems`,
    `note_usage_events`, `design_systems`, `design_tokens` and `repo_bindings`
    all went missing, over five migrations, with nothing to notice.

    Extending the export fixes today. THIS fixes the next one: adding a table
    now fails here until someone either backs it up or states in
    `_NOT_INCLUDED` that it shouldn't be. Either is fine; silence is not.
    """
    from scribe.models import Base

    schema = set(Base.metadata.tables)
    accounted = set(backup._BACKED_UP) | set(backup._NOT_INCLUDED)

    unaccounted = schema - accounted
    assert not unaccounted, (
        f"{len(unaccounted)} table(s) are neither backed up nor explicitly "
        f"excluded: {sorted(unaccounted)}. Add each to backup._BACKED_UP (and "
        f"give it an export + restore section) or to backup._NOT_INCLUDED with "
        f"a reason in the comment above it."
    )

    # And the reverse: a name in either list that no longer exists is a lie the
    # guard would otherwise keep telling. This half is what caught "embeddings",
    # "invitations" and "password_resets" — three entries that named nothing.
    phantom = accounted - schema
    assert not phantom, (
        f"backup lists table(s) that are not in the schema: {sorted(phantom)}. "
        f"Renamed or dropped — fix the list rather than leaving it to read as "
        f"coverage."
    )


def test_join_table_row_helpers_are_pure():
    subs = [SimpleNamespace(project_id=1, rulebook_id=2)]
    rsup = [SimpleNamespace(project_id=1, rule_id=9)]
    tsup = [SimpleNamespace(project_id=1, topic_id=7)]
    assert backup._subscription_rows(subs) == [{"project_id": 1, "rulebook_id": 2}]
    assert backup._rule_suppression_rows(rsup) == [{"project_id": 1, "rule_id": 9}]
    assert backup._topic_suppression_rows(tsup) == [{"project_id": 1, "topic_id": 7}]


class _Result:
    def scalars(self):
        return self

    def all(self):
        return []


class _Session:
    async def execute(self, *a, **k):
        return _Result()

    async def get(self, *a, **k):
        return None


class _CM:
    async def __aenter__(self):
        return _Session()

    async def __aexit__(self, *a):
        return False


@pytest.mark.asyncio
async def test_export_full_backup_contains_every_declared_section():
    with patch("scribe.services.backup.async_session", lambda: _CM()):
        out = await backup.export_full_backup()

    assert out["version"] == backup.BACKUP_VERSION
    assert out["scope"] == "full"
    assert "api_keys" in out["_not_included"]
    # The sections v2 silently dropped, the six v5 added, v6's
    # note_supersessions, and v7's code_shapes (all empty here).
    for key in ("rulebooks", "rulebook_topics", "rules",
                "rulebook_subscriptions", "rule_suppressions",
                "topic_suppressions",
                "systems", "record_systems", "design_systems",
                "design_tokens", "note_usage_events", "repo_bindings",
                "note_supersessions", "code_shapes", "code_shape_events",
                "code_shape_uses", "rulebook_exclusions"):
        assert key in out, f"missing export section: {key}"
        assert out[key] == []


def test_supersession_rows_serialise_the_pair():
    """The row builder is a plain function precisely so it can be tested with
    no database — same reason as the other v5/v6 builders."""
    class _Row:
        def __init__(self, a, b):
            self.superseder_id, self.superseded_id = a, b

    assert backup._note_supersession_rows([_Row(9, 4), _Row(9, 5)]) == [
        {"superseder_id": 9, "superseded_id": 4},
        {"superseder_id": 9, "superseded_id": 5},
    ]


def test_rule_rows_carry_the_verification_fields():
    """A rule's check must survive a backup.

    `verify_with`/`expires_when`/`verified_at` (milestone 312) say whether a
    rule is a fact that can go false and when it was last confirmed. A backup
    that drops them restores a rulebook that has forgotten which of its rules
    can rot — the exact blindness the fields were added to end.

    Column additions do not bump BACKUP_VERSION; only new SECTIONS do. Same
    call made for when_to_apply/tier/arose_from_id in 0088 (commit 6ddb8bf).
    """
    checked = datetime(2026, 8, 27, 12, 0, tzinfo=timezone.utc)
    row = SimpleNamespace(
        id=1, topic_id=2, project_id=None, title="t", statement="s",
        why="w", how_to_apply="h", order_index=0,
        when_to_apply="when", tier="conditional",
        verify_with="cat some/file", expires_when="the file grows a shell",
        verified_at=checked, arose_from_id=99,
        created_at=checked, updated_at=checked,
    )
    out = backup._rule_rows([row])[0]

    assert out["verify_with"] == "cat some/file"
    assert out["expires_when"] == "the file grows a shell"
    assert out["verified_at"] == checked.isoformat()
    # Provenance was exported from 0088 onward but silently dropped on the way
    # back IN until milestone 312. Export side asserted here; the restore side
    # remaps it through note_id_map.
    assert out["arose_from_id"] == 99


def test_rule_rows_keep_an_unverified_rule_unverified():
    """NULL verified_at means never checked, and it must round-trip as null.

    _dt substitutes now() so created_at/updated_at are never null. Reusing it
    here would restore a rule nobody ever checked as though it had just been
    checked — dropping it to the BOTTOM of the sweep it should top. That is
    why _dt_or_none exists.
    """
    row = SimpleNamespace(
        id=1, topic_id=2, project_id=None, title="t", statement="s",
        why=None, how_to_apply=None, order_index=0,
        when_to_apply=None, tier="always_on",
        verify_with=None, expires_when=None, verified_at=None,
        arose_from_id=None,
        created_at=datetime(2026, 8, 27, tzinfo=timezone.utc),
        updated_at=datetime(2026, 8, 27, tzinfo=timezone.utc),
    )
    assert backup._rule_rows([row])[0]["verified_at"] is None
    assert backup._dt_or_none(None) is None
    assert backup._dt_or_none("2026-08-27T12:00:00+00:00") == datetime(
        2026, 8, 27, 12, 0, tzinfo=timezone.utc
    )
