"use client";
/* Stock — on hand against par, worst first, with the three things you do about it underneath. */
import Link from "next/link";
import { useMemo, useState } from "react";
import { useDerived, useSnap } from "@/lib/client";
import { bcBound, label, locMap, locTrail, onhand, touched, reorderAt, variantName } from "@/lib/compute";
import { INK, IconRight, MBody, MEmpty, MNav, MRow, MRule, MSection, MTop, inputStyle } from "@/components/m";

export default function MStock() {
  const { s } = useSnap();
  const { L, byId, variants } = useDerived();
  const [q, setQ] = useState("");
  const locs = useMemo(() => locMap(s), [s]);

  const rows = useMemo(() => {
    const needle = q.trim().toLowerCase();
    return variants
      .filter((v) => touched(s, L, v.key))
      .map((v) => {
        const oh = onhand(s, L, v.key), par = reorderAt(s, v.key);
        // The bound supplier code, not bcFor()'s generated stand-in: this line is read against a
        // label on a garment, and a number printed on nothing is worse than saying there isn't one.
        return { ...v, oh, par, low: oh <= par, code: bcBound(s, v.item, v.si), where: locTrail(locs, s.placed[v.key], 0), name: `${variantName(byId[v.itemId], v.size)}` };
      })
      .filter((r) => !needle || `${r.name} ${r.code} ${r.where}`.toLowerCase().includes(needle))
      // Short lines first, then furthest below par — the shelf you have to do something about.
      .sort((a, b) => Number(b.low) - Number(a.low) || (a.oh - a.par) - (b.oh - b.par) || a.name.localeCompare(b.name));
  }, [s, L, variants, byId, q, locs]);

  const low = rows.filter((r) => r.low).length;
  const link: React.CSSProperties = { display: "flex", alignItems: "center", gap: 12, minHeight: 64, padding: "0 20px", border: "2px solid " + INK, color: INK, textDecoration: "none", fontFamily: "var(--font-heading)", fontWeight: 800, fontSize: 14, letterSpacing: "0.08em", textTransform: "uppercase" };

  return (
    <>
      <MTop title="Stock" right={low ? `${low} below par` : `${rows.length} line${rows.length === 1 ? "" : "s"}`} />
      <MRule />
      <MBody>
        <div style={{ padding: 16, borderBottom: "2px solid " + INK }}>
          <input value={q} onChange={(e) => setQ(e.target.value)} placeholder="Garment, code or shelf" aria-label="Filter stock" style={inputStyle} />
        </div>
        <MSection label="Line" right="On hand / par" />
        {rows.length === 0
          ? <MEmpty title="Nothing in stock yet" sub="This list is what has moved. Add a garment to the catalogue and scan some in, and it appears here." />
          : rows.slice(0, 200).map((r) => (
              <MRow key={r.key} mark={r.low ? "accent" : "ink"} attention={r.low}
                title={r.name}
                sub={[r.code || "No barcode bound", `par ${r.par}`, r.where].filter(Boolean).join(" · ")}
                right={
                  <span style={{ fontFamily: "var(--font-heading)", fontWeight: 800, fontSize: 21, fontVariantNumeric: "tabular-nums", color: r.low ? "var(--color-accent-700)" : INK }}>
                    {r.oh}<span style={{ color: "var(--color-neutral-700)", fontSize: 17 }}>/{r.par}</span>
                  </span>
                } />
            ))}

        <div style={{ padding: 16, display: "grid", gap: 12 }}>
          <Link href="/m/reorder" style={link}><span style={{ flex: 1 }}>{low ? `Reorder ${low} line${low === 1 ? "" : "s"}` : "Reorder draft"}</span><IconRight /></Link>
          <Link href="/m/variance" style={link}><span style={{ flex: 1 }}>Variance over time</span><IconRight /></Link>
          <Link href="/m/label" style={link}><span style={{ flex: 1 }}>Reprint a label</span><IconRight /></Link>
          {/* Stock only lists variants with history, so a garment added five minutes ago isn’t here
              yet. The catalogue is where it actually lives. */}
          <Link href="/m/catalogue" style={link}><span style={{ flex: 1 }}>Catalogue</span><IconRight /></Link>
        </div>
      </MBody>
      <MNav />
    </>
  );
}