# retoor <retoor@molodetz.nl>
import math

from molodetz.database.core import db


def paginate(table_name, before=None, order="desc", cursor_field="created_at", limit=25, **filters):
    if table_name not in db.tables:
        return [], None
    table = db[table_name]
    criteria = dict(filters)
    if "deleted_at" not in criteria:
        criteria["deleted_at"] = None
    if before:
        criteria[cursor_field] = {"<": before} if order == "desc" else {">": before}
    order_by = [f"-{cursor_field}"] if order == "desc" else [cursor_field]
    rows = list(table.find(_limit=limit + 1, order_by=order_by, **criteria))
    next_cursor = None
    if len(rows) > limit:
        rows = rows[:limit]
        next_cursor = rows[-1][cursor_field]
    return rows, next_cursor


def build_pagination(page, total, per_page):
    pages = max(1, math.ceil(total / per_page)) if per_page else 1
    page = min(max(1, page), pages)
    return {
        "page": page,
        "pages": pages,
        "total": total,
        "per_page": per_page,
        "offset": (page - 1) * per_page,
        "has_prev": page > 1,
        "has_next": page < pages,
    }