"""harness/tables.py — a topic-backed TABLE for the grid (CG-2).

The grid's first table (customers) is built from `modules.customer_data.pool()`: one row per
customer, the whole book shipped as component args, filtered client-side. That works at 1,550
rows and does not work at line grain — `sales_lines` is 201,558 rows / ~89 MB.

This module builds the SECOND table: rows come from `semantic.store_rows`, so the fetch is
WINDOWED and the filtering is SQL. Its whole job is to hand the grid a payload in the same
host-neutral shape the React component already speaks, plus the one thing a windowed table must
carry that a whole-book table never needed:

    counts = {matched, total, shown, windowed}

`matched` and `total` come from their own queries over the FULL scope; `shown` is the size of
this window. The component renders "showing SHOWN of MATCHED (filtered from TOTAL)" from those
numbers and NEVER from `rows.length` — which is the difference between an honest window and a
silent `[:N]` wearing a total ([[no-unverifiable-aggregates]]).

The field CONTRACT is derived from the topic, not hand-written: labels and types come from the
model's dims and metrics, so a new metric cannot arrive as an untyped, unlabelled column and the
grid can never disagree with the semantic layer about what a column means.
"""
from harness import semantic as _sem

#: Topic-backed tables the grid can open. `key` is the storage key its saved views live under —
#: separate from the customer table's, so the two tables' views can never collide.
TOPIC_TABLES = {
    "sales_lines": {
        "label": "Sales lines",
        "storage_key": "sales_lines_table_workspace",
        # the columns worth defaulting to visible, in order; everything else stays available
        "default_visible": ["date", "order_partner", "product", "category", "state", "agent",
                            "team", "revenue", "units", "margin"],
        # a line-grain table is unusable sorted by nothing in particular
        "default_sorts": [{"colId": "date", "dir": "desc"}],
    },
}

#: how many rows one window carries. Small enough that the payload stays a few hundred KB at
#: ~440 B/row, large enough to scroll. The honest counts make the window visible rather than
#: silent, so this is a performance knob and not a correctness one.
PAGE_ROWS = 200


def _labels(topic):
    """colId -> human label, taken from the MODEL (dim labels, metric labels)."""
    t = _sem.topics()[topic]
    out = {}
    for key, d in ((t.get("store") or {}).get("dims") or {}).items():
        out[key] = d.get("label") or key.replace("_", " ").title()
        out[f"{key}_id"] = f"{out[key]} id"
    out["date"] = "Date"
    for k, m in _sem.metrics().items():
        if m.get("topic") == topic:
            out[k] = m.get("label") or k
    return out


def table_fields(topic):
    """The grid field contract for a topic, derived from the semantic model.

    Every column is `source='odoo'` — read-only. A line is a fact from the ERP; unlike the
    customer table there is no overlay stratum here (notes/tags hang off a CUSTOMER, not off an
    individual order line), so the two-strata split simply does not arise.
    """
    cfg = TOPIC_TABLES[topic]
    cols = _sem.store_columns(topic, grain="row")
    labels = _labels(topic)
    order = [k for k in cfg["default_visible"] if k in cols]
    order += [k for k in cols if k not in order]
    return [{
        "key": k,
        "label": labels.get(k, k.replace("_", " ").title()),
        "type": cols[k]["type"],
        "source": "odoo",
        "default": k in cfg["default_visible"],
    } for k in order]


def table_payload(topic, config=None, offset=0, limit=None, team_id=None,
                  date_from=None, date_to=None):
    """Fetch ONE window of a topic-backed table plus its scope-wide counts and totals.

    `config` is a grid ViewConfig (filters / filterConj / sorts / search) — the same shape the
    customer table persists, so a saved view means the same thing on either table.

    Returns the component payload: {fields, rows, counts, aggregates, storageKey}.
    """
    if topic not in TOPIC_TABLES:
        raise _sem.ModelError(f"no topic-backed table registered for {topic!r}")
    cfg = TOPIC_TABLES[topic]
    config = config or {}
    limit = PAGE_ROWS if limit is None else limit

    got = _sem.store_rows(
        topic,
        filter_tree=config.get("filters") or [],
        filter_conj=config.get("filterConj") or "and",
        search=config.get("search") or None,
        sorts=config.get("sorts") or cfg["default_sorts"],
        member_ids=config.get("memberPids") or None,
        limit=limit, offset=offset,
        team_id=team_id, date_from=date_from, date_to=date_to,
    )

    rows = []
    for i, r in enumerate(got["rows"]):
        # `pid` is the grid's row identity contract (selection, detail, overlay all key on it).
        # At line grain that identity is the order LINE id, which store_rows returns as _rid.
        row = {k: v for k, v in r.items() if k != "_rid"}
        row["pid"] = r["_rid"]
        rows.append(row)

    return {
        "fields": table_fields(topic),
        "rows": rows,
        # THE honest window. `matched`/`total` are scope-wide queries; `shown` is this window.
        # A caller must never recompute `matched` from len(rows).
        "counts": {
            "shown": len(rows),
            "matched": got["row_count"],
            "total": got["total_count"],
            "windowed": True,
        },
        "aggregates": got["aggregates"],      # over the whole FILTERED scope, not the window
        "storageKey": cfg["storage_key"],
        "label": cfg["label"],
        "window": got["window"],
    }