"""The traceability CSV: the old exportCsv, row for row, from the packet read model.

Every cell goes through `csv_cell`, the formula guard: a value that starts with =, +, -, @, a tab or a CR gets a
leading apostrophe, so a spreadsheet shows it as text and never runs it. Lines end in CRLF. UTF-8, no BOM.
"""

from __future__ import annotations

from collections.abc import Iterable, Mapping, Sequence
from datetime import date, datetime
from typing import Any
from zoneinfo import ZoneInfo, ZoneInfoNotFoundError

from ..domain import packets as packets_dom
from ..domain.pipeline import qty_text

FORMULA_START = ("=", "+", "-", "@", "\t", "\r")
TITLE = "PESCO weld & heat traceability record"
BOM_HEAD = (
    "BOM item",
    "Qty",
    "Issued",
    "Location",
    "Part ID",
    "Description",
    "Length",
    "Material",
    "Heat no.",
    "MTR on file",
    "Open short qty",
    "Short reason",
    "Short received",
)
WELD_HEAD = (
    "Weld",
    "Work order",
    "Piece",
    "Joins items",
    "Heats joined",
    "Type",
    "Size",
    "Process",
    "WPS",
    "Stamp",
    "Logged",
)
CHECK_HEAD = ("Checklist item", "Done", "Stamp", "When")


def csv_cell(value: Any) -> str:
    """One CSV cell with the formula guard and RFC 4180 quoting."""
    text = "" if value is None else str(value)
    if text.startswith(FORMULA_START):
        text = "'" + text
    if any(c in text for c in ('"', ",", "\n", "\r")):
        text = '"' + text.replace('"', '""') + '"'
    return text


def to_csv(rows: Iterable[Sequence[Any]]) -> str:
    return "\r\n".join(",".join(csv_cell(v) for v in r) for r in rows)


def _zone(tz: str | None) -> ZoneInfo:
    try:
        return ZoneInfo(tz or "America/Denver")
    except (ZoneInfoNotFoundError, ValueError):
        return ZoneInfo("America/Denver")


def _when(value: Any, tz: str | None) -> datetime | date | None:
    if value is None or value == "":
        return None
    if isinstance(value, datetime):
        return value.astimezone(_zone(tz)) if value.tzinfo else value
    if isinstance(value, date):
        return value
    try:
        d = datetime.fromisoformat(str(value).replace("Z", "+00:00"))
    except ValueError:
        return None
    return d.astimezone(_zone(tz)) if d.tzinfo else d


def fmt_dt(value: Any, tz: str | None) -> str:
    """M/D/YYYY h:mm AM in the site time zone; empty for no value."""
    d = _when(value, tz)
    if d is None:
        return ""
    if not isinstance(d, datetime):
        return f"{d.month}/{d.day}/{d.year}"
    hour = d.hour % 12 or 12
    return f"{d.month}/{d.day}/{d.year} {hour}:{d.minute:02d} {'AM' if d.hour < 12 else 'PM'}"


def fmt_d(value: Any, tz: str | None) -> str:
    """M/D/YYYY in the site time zone; empty for no value."""
    d = _when(value, tz)
    if d is None:
        return ""
    return f"{d.month}/{d.day}/{d.year}"


def _num(value: Any) -> str:
    return "" if value is None else qty_text(value)


def _done(entry: Any) -> bool:
    return entry is True or (isinstance(entry, Mapping) and entry.get("done") is True)


def _entry(entry: Any) -> Mapping[str, Any]:
    return entry if isinstance(entry, Mapping) else {}


def _shorts(conn: Any, packet_id: int) -> dict[int, dict[str, Any]]:
    """The newest short per BOM line, open or closed, with its receipts (a closed short still has its record)."""
    out: dict[int, dict[str, Any]] = {}
    for s in packets_dom.rows(conn, "SELECT * FROM bom_shorts WHERE packet_id = %s ORDER BY id", (packet_id,)):
        out[int(s["bom_line_id"])] = {**s, "receipts": []}
    ids = {int(s["id"]): line for line, s in out.items()}
    if ids:
        for r in packets_dom.rows(
            conn, "SELECT * FROM short_receipts WHERE short_id = ANY(%s) ORDER BY id", (list(ids),)
        ):
            out[ids[int(r["short_id"])]]["receipts"].append(r)
    return out


def _stage(read: Mapping[str, Any]) -> Mapping[str, Any]:
    """The open stage, else the last closed one, else nothing."""
    if read.get("stage"):
        return read["stage"]
    stages = read.get("stages") or []
    return stages[-1] if stages else {}


def _inspection(conn: Any, read: Mapping[str, Any]) -> Mapping[str, Any] | None:
    """The open inspection, else the newest closed one (its snapshot carries every field)."""
    if read.get("qc"):
        return read["qc"]
    r = packets_dom.one(
        conn,
        "SELECT result, inspector, at, snapshot FROM qc_history WHERE packet_id = %s ORDER BY id DESC LIMIT 1",
        (read["id"],),
    )
    if r is None:
        return None
    snap = r["snapshot"] if isinstance(r["snapshot"], Mapping) else {}
    return {
        **snap,
        "result": r["result"] or snap.get("result"),
        "inspector": r["inspector"] or snap.get("inspector"),
        "result_at": snap.get("result_at") or r["at"],
    }


def rows_for(conn: Any, read: Mapping[str, Any], tz: str | None) -> list[list[Any]]:
    """Every CSV row for one packet read model."""
    unit = read.get("unit") or {}
    project = (unit.get("project") or {}).get("number") or ""
    lot = unit.get("lot") or unit.get("number") or ""
    stage = _stage(read)
    welder = stage.get("welder") or {}
    station = stage.get("station") or {}
    out: list[list[Any]] = [
        [TITLE],
        ["Project", project, "Lot", lot, "Operation", read.get("op")],
        [
            "Drawing",
            read.get("drawing"),
            "Rev",
            read.get("rev"),
            "Title",
            read.get("title"),
            "Customer",
            read.get("customer"),
        ],
        [
            "WPS",
            read.get("wps"),
            "Station",
            station.get("name"),
            "Welder",
            welder.get("display_name"),
            "Stamp",
            welder.get("stamp"),
        ],
        ["Filler", stage.get("filler"), "Filler lot", stage.get("filler_lot"), "Preheat", stage.get("preheat")],
        [],
        list(BOM_HEAD),
    ]
    bom = read.get("bom") or []
    shorts = _shorts(conn, int(read["id"]))
    for b in bom:
        s = shorts.get(int(b["id"])) if b.get("id") is not None else None
        open_short = b.get("short")
        heat = b.get("heat") or ("N/A" if b.get("na") else "")
        received = "; ".join(
            f"{_num(r['qty'])} pc {r['heat'] or ''} {fmt_d(r['at'], tz)}" for r in (s or {}).get("receipts", [])
        )
        out.append(
            [
                b.get("item"),
                _num(b.get("qty")),
                _num(b.get("issued")),
                b.get("loc") or "",
                b.get("part_id"),
                b.get("description"),
                b.get("length"),
                b.get("material"),
                heat,
                "Yes" if b.get("mtr_asset_id") else "No",
                _num(open_short.get("qty_open")) if open_short else "",
                (s.get("reason") or "") if s else "",
                received,
            ]
        )
    out += [[], list(WELD_HEAD)]
    heat_of = {str(b.get("item")): b.get("heat") for b in bom}
    for w in read.get("welds") or []:
        items = [str(i) for i in (w.get("items") or [])]
        out.append(
            [
                f"W{w.get('weld_no')}",
                w.get("wo_base"),
                w.get("piece"),
                " + ".join(items),
                " + ".join((heat_of.get(i) or "-") for i in items),
                w.get("type"),
                w.get("size"),
                w.get("process"),
                read.get("wps"),
                w.get("stamp"),
                fmt_dt(w.get("at"), tz),
            ]
        )
    out += [[], list(CHECK_HEAD)]
    checklist = stage.get("checklist") or {}
    for item in read.get("checklist_items") or []:
        c = checklist.get(item["key"])
        e = _entry(c)
        out.append([item["text"], "Yes" if _done(c) else "No", e.get("stamp") or "", fmt_dt(e.get("at"), tz)])
    insp = _inspection(conn, read)
    if insp is not None:
        out += [
            [],
            [
                "Q.C. inspection",
                insp.get("result") or "open",
                "Inspector",
                insp.get("inspector"),
                "Stamp",
                insp.get("stamp"),
                "Date",
                fmt_dt(insp.get("result_at"), tz),
            ],
            [
                "NDE",
                insp.get("nde_method"),
                insp.get("nde_result"),
                insp.get("nde_report"),
                "Hardness",
                insp.get("hardness"),
            ],
        ]
        checks = _entry(insp.get("checks"))
        for item in read.get("qc_items") or []:
            c = checks.get(item["key"])
            e = _entry(c)
            out.append(
                [
                    "Q.C.: " + str(item["text"]),
                    "Yes" if _done(c) else "No",
                    e.get("stamp") or "",
                    fmt_dt(e.get("at"), tz),
                ]
            )
        exam = _entry(insp.get("weld_exam"))
        for w in read.get("welds") or []:
            v = _entry(exam.get(str(w.get("weld_no"))))
            out.append([f"VT W{w.get('weld_no')}", v.get("result") or "", v.get("note") or ""])
    return out


def build(conn: Any, settings: Any, packet_id: int) -> tuple[str, dict[str, Any]]:
    """The CSV text and the read model it came from. 404 not_found for an unknown packet."""
    read = packets_dom.read_packet(conn, packet_id, None)
    return to_csv(rows_for(conn, read, getattr(settings, "site_tz", None))), read