"""/papers listing and /papers/{slug} alias."""
from __future__ import annotations

from typing import Any

from fastapi import APIRouter, Query, Request

from aiatlas.api.common import (
    ENTITY_COLS,
    ENTITY_FROM,
    PAGINATION,
    ApiError,
    Pagination,
    cached,
    entity_summary,
    page,
    parse_date,
)
from aiatlas.api.routers.entities import detail_for_type
from aiatlas.db import connection, fetch_all, fetch_val

router = APIRouter(prefix="/api/v1/papers", tags=["papers"])
SORTS = {"published": "e.attributes->>'published_at' desc nulls last", "updated": "e.updated_at desc", "name": "e.canonical_name asc",
         "citations": "(case when e.attributes->>'metric.citations' ~ '^[0-9]+$' then (e.attributes->>'metric.citations')::bigint end) desc nulls last"}


@router.get("")
@cached(300)
async def list_papers(request: Request, p: Pagination = PAGINATION, q: str | None = Query(None, max_length=200), category: str | None = None, org: str | None = None,
                      since: str | None = None, until: str | None = None, sort: str = "published") -> dict[str, Any]:
    if sort not in SORTS:
        raise ApiError(400, f"sort must be one of {', '.join(SORTS)}")
    where = ["e.entity_type = 'paper'", "e.merged_into is null"]
    params: dict[str, Any] = {}
    if q:
        where.append("(e.canonical_name ilike :qlike or e.search @@ plainto_tsquery('english', :q))")
        params["q"], params["qlike"] = q, f"%{q}%"
    if category:
        where.append("(e.attributes->>'primary_category' = :cat or e.attributes->'categories' ? :cat)")
        params["cat"] = category
    if org:
        where.append("(eo.slug = :org or eo.id = :org or exists (select 1 from relations r join entities x on x.id = r.object_id where r.subject_id = e.id and r.valid_to is null and (x.slug = :org or x.id = :org)))")
        params["org"] = org
    if since:
        where.append("e.attributes->>'published_at' >= :since")
        params["since"] = parse_date(since, "since").isoformat()  # type: ignore[union-attr]
    if until:
        where.append("e.attributes->>'published_at' <= :until")
        params["until"] = parse_date(until, "until").isoformat()  # type: ignore[union-attr]
    where_sql = " and ".join(where)
    async with connection() as conn:
        rows = await fetch_all(conn, f"select {ENTITY_COLS} from {ENTITY_FROM} where {where_sql} order by {SORTS[sort]}, e.id limit :lim offset :off", lim=p.limit, off=p.offset, **params)
        total = await fetch_val(conn, f"select count(*) from {ENTITY_FROM} where {where_sql}", **params)
    return page([entity_summary(r) for r in rows], int(total or 0), p)


@router.get("/{slug}")
@cached(300)
async def get_paper(request: Request, slug: str) -> dict[str, Any]:
    return await detail_for_type(slug, ("paper",))