"""API read-path indexes: attribute-driven listings (release_date, family, openness), importance-ordered change feeds,
current benchmark leaderboards, page-view trending, review queue by kind.

Revision ID: 0002
"""
from __future__ import annotations

from alembic import op

revision = "0002"
down_revision = "0001"
branch_labels = None
depends_on = None

SQL = r"""
create index if not exists entities_type_release_idx on entities (entity_type, (attributes->>'release_date') desc nulls last) where merged_into is null;
create index if not exists entities_type_family_idx on entities (entity_type, (attributes->>'family')) where merged_into is null;
create index if not exists entities_type_openness_idx on entities (entity_type, (attributes->>'openness')) where merged_into is null;
create index if not exists entities_type_updated_idx on entities (entity_type, updated_at desc) where merged_into is null;
create index if not exists entities_type_first_seen_idx on entities (entity_type, first_seen_at desc) where merged_into is null;
create index if not exists entities_slug_id_idx on entities (id) include (slug);
create index if not exists change_events_importance_idx on change_events (importance desc, observed_at desc);
create index if not exists change_events_type_observed_idx on change_events (observed_at desc) where event_type <> 'DOCUMENT_CHANGED';
create index if not exists benchmark_results_current_idx on benchmark_results (benchmark_id, higher_is_better, score) where valid_to is null;
create index if not exists benchmark_results_model_current_idx on benchmark_results (model_id) where valid_to is null;
create index if not exists prices_current_model_idx on prices (model_id, provider_id) where valid_to is null;
create index if not exists prices_valid_range_idx on prices (valid_from, valid_to);
create index if not exists page_views_day_idx on page_views (day desc, views desc);
create index if not exists review_queue_kind_idx on review_queue (kind, status, created_at desc);
create index if not exists documents_source_idx on documents (source_id, last_fetched_at desc);
create index if not exists claims_entity_valid_idx on claims (entity_id, valid_from, valid_to);
create index if not exists relations_predicate_idx on relations (predicate, subject_id, object_id) where valid_to is null;
"""


def upgrade() -> None:
    for statement in _split(SQL):
        op.execute(statement)


def downgrade() -> None:
    raise RuntimeError("AI Atlas migrations are forward-only: historical data is never disposable")


def _split(sql: str) -> list[str]:
    out: list[str] = []
    buf: list[str] = []
    in_dollar = False
    for line in sql.splitlines():
        stripped = line.strip()
        if stripped.count("$$") % 2 == 1:
            in_dollar = not in_dollar
        buf.append(line)
        if not in_dollar and stripped.endswith(";"):
            body = [ln for ln in buf if not ln.strip().startswith("--") or in_dollar]
            stmt = "\n".join(body).strip()
            if stmt:
                out.append(stmt)
            buf = []
    tail = "\n".join(ln for ln in buf if not ln.strip().startswith("--")).strip()
    if tail:
        out.append(tail)
    return out