"""The shop: the supervisor board, the stations a person may work at, the stall board, and the borrowed heat map.

Everything here reads PostgreSQL only. The cards are the `list_cards` shape plus the shop fields (welder stamp, the
live stage clock, target hours, open change orders as labels, the return note), so a card reads the same on every
screen.
"""

from __future__ import annotations

from collections.abc import Iterable, Mapping
from typing import Any

from .. import policy
from ..api.errors import ApiError
from . import packets, search

LEAD, SUPERVISOR = 2, 3
LEVEL_NAMES = {1: "worker", 2: "lead", 3: "supervisor"}
BOARD_LIMIT = 5000

# The columns of the supervisor board, by packet status. Packets at a station are on the station grid.
COLUMNS = {"ready": "ready", "review": "review", "qc": "qc", "warehouse": "warehouse", "complete": "complete"}
BOARD_STATUSES = ("ready", "assigned", "in_progress", "review", "qc", "warehouse", "complete")

MSG_NO_LEAD = "You do not lead a department."
MSG_NOT_YOURS = "You do not lead that department."
MSG_NO_STATION = "That station is not one of yours."


# ---------------------------------------------------------------- the borrowed heat map


def _has_heat_map(conn: Any, packet_id: int) -> bool:
    return bool(
        conn.execute(
            "SELECT EXISTS (SELECT 1 FROM heat_table_placements WHERE packet_id = %s)"
            " OR EXISTS (SELECT 1 FROM heat_tags WHERE packet_id = %s AND removed_at IS NULL)",
            (packet_id, packet_id),
        ).fetchone()[0]
    )


SIBLING_SQL = """
SELECT p.id
FROM packets p
WHERE p.unit_id = %(unit)s AND p.id <> %(id)s AND p.removed_at IS NULL
  AND upper(regexp_replace(coalesce(p.drawing, ''), '\\s', '', 'g')) = %(dwg)s
  AND (EXISTS (SELECT 1 FROM heat_table_placements h WHERE h.packet_id = p.id)
       OR EXISTS (SELECT 1 FROM heat_tags t WHERE t.packet_id = p.id AND t.removed_at IS NULL))
ORDER BY (coalesce(p.rev, '') = %(rev)s) DESC, p.created_at, p.id
LIMIT 1
"""


def dwg_key(drawing: Any) -> str:
    """The drawing number compared between packets: white space removed, upper case (the old dwgKey)."""
    return "".join(str(drawing or "").split()).upper()


def heat_src(conn: Any, row: Mapping[str, Any], ch: packets.Children) -> dict[str, Any] | None:
    """The heat map this packet borrows from a sibling, or None (the old heatSrc).

    A packet borrows when it has no heat map of its own (no heat table, no heat tag), pulls no raw material of its
    own (every BOM line is N/A or a sub-assembly, or the BOM is empty) and has a drawing. The sibling is a live
    packet in the same unit with the same drawing and a heat map; the same rev first, then the oldest. Read-only.
    """
    if ch.heat_table or ch.heat_tags:
        return None
    if any(not b["na"] and not packets.is_sub(b) for b in ch.bom):
        return None
    dwg = dwg_key(row["drawing"])
    if not dwg:
        return None
    found = conn.execute(
        SIBLING_SQL, {"unit": row["unit_id"], "id": row["id"], "dwg": dwg, "rev": str(row["rev"] or "")}
    ).fetchone()
    if found is None:
        return None
    sib = packets.load_row(conn, int(found[0]))
    if sib is None:
        return None
    sch = packets.load_children(conn, sib, full=True)
    people = packets.People(conn, [h["by"] for h in sch.heat_table] + [pg["void_by"] for pg in sch.pages])
    st = sch.open_stage
    return {
        "packet_id": sib["id"],
        "op": sib["op"],
        "status": sib["status"],
        "drawing": sib["drawing"],
        "rev": sib["rev"],
        "pages": [packets._page(pg, sch, people) for pg in sch.pages if pg["type"] == "drawing"],
        "heat_table": [
            {k: h[k] for k in ("page", "x", "y", "s", "carried_from", "at")} | {"by": people.ref(h["by"])}
            for h in sch.heat_table
        ],
        "heat_tags": [packets._heat_tag(t, st) for t in sch.heat_tags],
        "bom": [{"item": b["item"], "heat": b["heat"], "na": b["na"]} for b in sch.bom],
    }


# ---------------------------------------------------------------- shop cards


EXTRAS_SQL = """
SELECT p.id, p.return_note, p.welder_stamp, s.clock_elapsed_ms, s.clock_running_since, s.clock_started_at,
       (SELECT coalesce(sum(w.target_hrs), 0) FROM packet_work_orders w WHERE w.packet_id = p.id) AS target_hrs
FROM packets p
LEFT JOIN packet_stages s ON s.packet_id = p.id AND s.closed_at IS NULL
WHERE p.id = ANY(%s)
"""


KPI_SQL = """
SELECT p.id, p.status::text AS status, s.clock_elapsed_ms, s.clock_running_since, s.clock_started_at,
       (SELECT coalesce(sum(w.target_hrs), 0) FROM packet_work_orders w WHERE w.packet_id = p.id) AS target_hrs
FROM packets p
LEFT JOIN packet_stages s ON s.packet_id = p.id AND s.closed_at IS NULL
WHERE p.id = ANY(%s)
"""


def add_shop_fields(conn: Any, cards: list[dict[str, Any]]) -> list[dict[str, Any]]:
    """Add the shop fields to list_cards cards, in place: welder_stamp, clock {elapsed_ms, running}, target_hrs,
    open_cos [{co_no, label, review}] and return_note."""
    if not cards:
        return cards
    ids = [int(c["id"]) for c in cards]
    now = conn.execute("SELECT now()").fetchone()[0]
    extras = {int(r["id"]): r for r in packets.rows(conn, EXTRAS_SQL, (ids,))}
    cos: dict[int, list[dict[str, Any]]] = {}
    for r in packets.rows(
        conn,
        "SELECT packet_id, co_no, review::text AS review FROM v_open_cos WHERE packet_id = ANY(%s) ORDER BY co_no",
        (ids,),
    ):
        cos.setdefault(int(r["packet_id"]), []).append(
            {"co_no": r["co_no"], "label": packets.co_label(r["co_no"]), "review": r["review"]}
        )
    for c in cards:
        x = extras.get(int(c["id"])) or {}
        if x.get("clock_elapsed_ms") is not None:
            clock = packets.clock_of({**x, "closed_at": None}, now)
            c["clock"] = {"elapsed_ms": clock["elapsed_ms"], "running": clock["running"]}
        else:
            c["clock"] = {"elapsed_ms": 0, "running": False}
        c["welder_stamp"] = x.get("welder_stamp")
        c["target_hrs"] = float(x.get("target_hrs") or 0)
        c["return_note"] = x.get("return_note")
        c["open_cos"] = cos.get(int(c["id"]), [])
    return cards


def _cards(conn: Any, pp: policy.Principal, ids: Iterable[int], **filters: Any) -> list[dict[str, Any]]:
    want = list(ids)
    if not want:
        return []
    cards = packets.list_cards(conn, pp, {**filters, "ids": want, "limit": BOARD_LIMIT})
    cards.sort(key=lambda c: (c["updated_at"], c["id"]))
    return add_shop_fields(conn, cards)


# ---------------------------------------------------------------- scope


def shop_departments(conn: Any) -> list[dict[str, Any]]:
    return packets.rows(
        conn, "SELECT code, name, weld FROM departments WHERE kind = 'shop' AND active ORDER BY sort, code"
    )


def board_scope(conn: Any, pp: policy.Principal) -> list[dict[str, Any]]:
    """The shop departments the principal leads or supervises (admin: every active shop department), each with
    its level name."""
    out: list[dict[str, Any]] = []
    for d in shop_departments(conn):
        level = pp.level(d["code"])
        if level >= LEAD:
            out.append({**d, "level": LEVEL_NAMES[min(level, SUPERVISOR)]})
        elif pp.admin:
            out.append({**d, "level": "admin"})
    return out


# ---------------------------------------------------------------- the supervisor board


SCOPE_SQL = """
SELECT p.id FROM packets p JOIN units u ON u.id = p.unit_id
WHERE p.removed_at IS NULL AND p.dept_code = ANY(%(depts)s) AND p.status::text = ANY(%(statuses)s) {extra}
ORDER BY p.updated_at, p.id
LIMIT %(limit)s
"""

COS_SQL = """
SELECT c.packet_id, c.co_no, c.review::text AS review, c.hold, c.pending_depts, co.reason, co.ecn, co.issued_at,
       p.dept_code, p.op, p.title, pr.number || u.lot AS unit_number
FROM v_open_cos c
JOIN change_orders co ON co.id = c.co_id
JOIN packets p ON p.id = c.packet_id
JOIN units u ON u.id = p.unit_id
JOIN projects pr ON pr.id = u.project_id
WHERE p.removed_at IS NULL AND (p.dept_code = ANY(%(depts)s) OR c.pending_depts && %(depts)s::text[]) {extra}
ORDER BY co.issued_at NULLS LAST, c.packet_id, c.co_no
LIMIT %(limit)s
"""


def _filter_sql(project_id: int | None, unit_id: int | None) -> tuple[str, dict[str, Any]]:
    terms: list[str] = []
    params: dict[str, Any] = {}
    if project_id is not None:
        terms.append("u.project_id = %(project_id)s")
        params["project_id"] = int(project_id)
    if unit_id is not None:
        terms.append("p.unit_id = %(unit_id)s")
        params["unit_id"] = int(unit_id)
    return "".join(f" AND {t}" for t in terms), params


def board(
    conn: Any,
    pp: policy.Principal,
    *,
    dept: str | None = None,
    project_id: int | None = None,
    unit_id: int | None = None,
    filters: Mapping[str, Any] | None = None,
) -> dict[str, Any]:
    """GET /api/shop/board. 403 forbidden when the principal leads no department, or names one outside the scope.

    `filters` are the find bar's (search.parse_filters): they narrow the cards of every column and the station
    grid. The KPIs follow the department, project and unit only."""
    scope = board_scope(conn, pp)
    if not scope:
        raise ApiError(403, "forbidden", MSG_NO_LEAD)
    if dept and dept.lower() != "all":
        scope = [d for d in scope if d["code"] == dept]
        if not scope:
            raise ApiError(403, "forbidden", MSG_NOT_YOURS)
    codes = [d["code"] for d in scope]
    extra, fparams = _filter_sql(project_id, unit_id)
    ids = [
        int(r[0])
        for r in conn.execute(
            SCOPE_SQL.format(extra=extra),
            {"depts": codes, "statuses": list(BOARD_STATUSES), "limit": BOARD_LIMIT, **fparams},
        )
    ]
    narrow = search.narrowing(filters or {})
    cards = _cards(conn, pp, ids, **search.board_filters(filters or {}))

    columns: dict[str, list[dict[str, Any]]] = {k: [] for k in COLUMNS.values()}
    at_station: list[dict[str, Any]] = []
    for c in cards:
        if c["status"] in policy.ACTIVE:
            at_station.append(c)
        elif c["status"] in COLUMNS:
            columns[COLUMNS[c["status"]]].append(c)

    stations = packets.rows(
        conn,
        "SELECT id, name, dept_code FROM stations WHERE active AND dept_code = ANY(%s) ORDER BY dept_code, sort, name",
        (codes,),
    )
    by_station: dict[Any, list[dict[str, Any]]] = {}
    for c in at_station:
        sid = (c.get("station") or {}).get("id")
        by_station.setdefault(sid, []).append(c)
    depts = []
    for d in scope:
        depts.append(
            {
                "code": d["code"],
                "name": d["name"],
                "weld": bool(d["weld"]),
                "level": d["level"],
                "stations": [
                    {"id": s["id"], "name": s["name"], "packets": by_station.get(s["id"], [])}
                    for s in stations
                    if s["dept_code"] == d["code"]
                ],
            }
        )

    cos = []
    for r in packets.rows(conn, COS_SQL.format(extra=extra), {"depts": codes, "limit": BOARD_LIMIT, **fparams}):
        pending = list(r["pending_depts"] or [])
        cos.append(
            {
                "packet_id": r["packet_id"],
                "unit_number": r["unit_number"],
                "op": r["op"],
                "title": r["title"],
                "dept_code": r["dept_code"],
                "co_no": r["co_no"],
                "label": packets.co_label(r["co_no"]),
                "review": r["review"],
                "hold": bool(r["hold"]),
                "pending_depts": pending,
                "mine": r["review"] == "approved" and any(can_verify(pp, d) for d in pending),
                "reason": r["reason"],
                "ecn": r["ecn"],
                "issued_at": r["issued_at"],
            }
        )

    if narrow:
        kpis = _board_kpis(conn, ids)
    else:
        kpis = {
            "ready": len(columns["ready"]),
            "at_stations": len(at_station),
            "review": len(columns["review"]),
            "elapsed_ms": sum(int(c["clock"]["elapsed_ms"]) for c in at_station),
            "target_hrs": round(sum(float(c["target_hrs"]) for c in at_station), 3),
        }
    return {
        "depts": depts,
        "kpis": kpis,
        "cos": cos,
        "columns": columns,
        "facets": search.facets(conn, ids=ids),
    }


def _board_kpis(conn: Any, ids: list[int]) -> dict[str, Any]:
    """The supervisor KPIs over the board's whole scope, when the find bar narrows the cards."""
    counts = {"ready": 0, "review": 0, "at_stations": 0}
    elapsed = 0
    target = 0.0
    if ids:
        now = conn.execute("SELECT now()").fetchone()[0]
        for r in packets.rows(conn, KPI_SQL, (ids,)):
            st = r["status"]
            if st in ("ready", "review"):
                counts[st] += 1
            elif st in policy.ACTIVE:
                counts["at_stations"] += 1
                if r.get("clock_elapsed_ms") is not None:
                    elapsed += int(packets.clock_of({**r, "closed_at": None}, now)["elapsed_ms"])
                target += float(r.get("target_hrs") or 0)
    return {**counts, "elapsed_ms": elapsed, "target_hrs": round(target, 3)}


def can_verify(pp: policy.Principal, dept: str) -> bool:
    """A supervisor of the department (admin too: the verify itself asks for the IT reason)."""
    if pp.admin:
        return True
    if dept in ("WH", "QC"):
        return dept in pp.support_sup
    return pp.level(dept) >= SUPERVISOR


# ---------------------------------------------------------------- stations and the stall board


def stations_for(conn: Any, pp: policy.Principal) -> list[dict[str, Any]]:
    """The stations the principal may pick on the Stall screen: every station of each shop department they belong
    to at any level, honouring a worker's station limits. Admin: every active station."""
    out: list[dict[str, Any]] = []
    rows = packets.rows(
        conn,
        "SELECT s.id, s.name, s.dept_code, d.name AS dept_name FROM stations s"
        " JOIN departments d ON d.code = s.dept_code WHERE s.active AND d.active AND d.kind = 'shop'"
        " ORDER BY d.sort, d.code, s.sort, s.name",
    )
    for r in rows:
        level = pp.level(r["dept_code"])
        if not pp.admin:
            if level == 0:
                continue
            if level < LEAD and pp.station_limits and int(r["id"]) not in pp.station_limits:
                continue
        out.append({"dept_code": r["dept_code"], "dept_name": r["dept_name"], "id": r["id"], "name": r["name"]})
    return out


def stall(conn: Any, pp: policy.Principal, station_id: int, filters: Mapping[str, Any] | None = None) -> dict[str, Any]:
    """GET /api/shop/stall: the packets at one station. 403 when the station is not in the principal's list.
    `filters` (the find bar's) narrow the station's cards; Mine is the station's own work."""
    mine_list = {int(s["id"]): s for s in stations_for(conn, pp)}
    st = mine_list.get(int(station_id))
    if st is None:
        raise ApiError(403, "forbidden", MSG_NO_STATION)
    found = packets.rows(
        conn,
        "SELECT id, status::text AS status FROM packets WHERE station_id = %s AND removed_at IS NULL"
        " AND status IN ('assigned', 'in_progress', 'review') ORDER BY updated_at, id LIMIT %s",
        (int(station_id), BOARD_LIMIT),
    )
    ids = [int(r["id"]) for r in found]
    cards = _cards(conn, pp, ids, **search.board_filters(filters or {}))
    return {
        "station": {"id": st["id"], "name": st["name"], "dept_code": st["dept_code"], "dept_name": st["dept_name"]},
        "mine": [c for c in cards if c["status"] in policy.ACTIVE],
        "submitted": [c for c in cards if c["status"] == "review"],
        "facets": search.facets(conn, ids=ids),
    }


# ---------------------------------------------------------------- the assign sheet's people


PEOPLE_SQL = """
SELECT u.id, u.display_name, u.welder_stamp, max(CASE r.role::text WHEN 'shop_supervisor' THEN 3
       WHEN 'shop_lead' THEN 2 ELSE 1 END) AS level
FROM users u JOIN user_roles r ON r.user_id = u.id
WHERE u.active AND r.dept_code = %s AND r.role::text IN ('shop_worker', 'shop_lead', 'shop_supervisor')
GROUP BY u.id, u.display_name, u.welder_stamp
ORDER BY lower(u.display_name), u.id
"""


def people(conn: Any, dept: str) -> list[dict[str, Any]]:
    """The active users with a shop role in a department, for the welder picker."""
    found = packets.rows(conn, PEOPLE_SQL, (dept,))
    limits: dict[str, list[int]] = {}
    if found:
        for uid, sid in conn.execute(
            "SELECT user_id, station_id FROM user_station_limits WHERE user_id = ANY(%s) ORDER BY station_id",
            ([r["id"] for r in found],),
        ):
            limits.setdefault(str(uid), []).append(int(sid))
    return [
        {
            "id": str(r["id"]),
            "display_name": r["display_name"],
            "stamp": r["welder_stamp"],
            "level": LEVEL_NAMES[int(r["level"])],
            "station_limits": limits.get(str(r["id"]), []),
        }
        for r in found
    ]


def welder_check(conn: Any, dept: str, welder_id: str, station_id: int) -> None:
    """ASSIGN: the welder has a shop role in the department, and a worker with station limits is limited to a set
    that holds the station. 422 invalid_welder or station_limit."""
    level_row = conn.execute(
        "SELECT max(CASE r.role::text WHEN 'shop_supervisor' THEN 3 WHEN 'shop_lead' THEN 2 ELSE 1 END)"
        " FROM users u JOIN user_roles r ON r.user_id = u.id WHERE u.id = %s AND u.active AND r.dept_code = %s"
        " AND r.role::text IN ('shop_worker', 'shop_lead', 'shop_supervisor')",
        (welder_id, dept),
    ).fetchone()
    level = int(level_row[0]) if level_row and level_row[0] is not None else 0
    if level == 0:
        raise ApiError(422, "invalid_welder", "Pick a welder in this department.")
    if level >= LEAD:
        return
    limits = packets.rows(
        conn,
        "SELECT s.id, s.name FROM user_station_limits l JOIN stations s ON s.id = l.station_id"
        " WHERE l.user_id = %s ORDER BY s.dept_code, s.sort, s.name",
        (welder_id,),
    )
    if limits and int(station_id) not in {int(x["id"]) for x in limits}:
        name = conn.execute("SELECT display_name FROM users WHERE id = %s", (welder_id,)).fetchone()[0]
        names = ", ".join(str(x["name"]) for x in limits)
        raise ApiError(422, "station_limit", f"{name} is limited to {names}.")