import { CheckCircle2, AlertTriangle, Minus } from "lucide-react";

/**
 * One 999 ACK segment status row. The 999 spec labels each transaction
 * set with a 3-char code:
 *
 *   "A" = Accepted
 *   "E" = Accepted, but errors are noted (one or more segments had
 *         errors; the transaction set as a whole was accepted)
 *   "R" = Rejected
 *   "P" = Partially accepted (mixed — some segments accepted, some
 *         not; a degraded success the operator must investigate)
 *
 * The wire shape's `rawJson` (set by the parser, see backend
 * `cyclone.parsers.parsers_999`) carries an array of segment rows.
 * Until that array is parsed into a stable UI shape, we render the
 * rolled-up counts on the ack row (`acceptedCount` / `rejectedCount`)
 * and a placeholder explaining how to read it.
 */
interface SegmentRow {
  /** Loop / segment reference like "ST*999*0001" or "AK2*HC*0001". */
  reference?: string;
  /** "A" | "E" | "R" | "P". */
  status: "A" | "E" | "R" | "P";
  /** Free-form note from the parser (e.g. "SVC*HC:9450 missing"). */
  note?: string;
}

interface Props {
  segments: SegmentRow[];
}

/**
 * Pill for one segment status. Color mirrors the badge palette used on
 * the Acks page (`Acks.tsx`) so a status reads the same in both
 * surfaces.
 */
function StatusPill({ status }: { status: SegmentRow["status"] }) {
  const cfg = {
    A: {
      fg: "hsl(152 64% 30%)",
      bg: "hsl(152 50% 88%)",
      border: "hsl(152 64% 38% / 0.30)",
      label: "Accepted",
      Icon: CheckCircle2,
    },
    E: {
      fg: "hsl(36 92% 30%)",
      bg: "hsl(36 82% 88%)",
      border: "hsl(36 92% 50% / 0.30)",
      label: "Accepted w/ errors",
      Icon: AlertTriangle,
    },
    R: {
      fg: "hsl(358 70% 36%)",
      bg: "hsl(358 70% 92%)",
      border: "hsl(358 70% 50% / 0.30)",
      label: "Rejected",
      Icon: AlertTriangle,
    },
    P: {
      fg: "hsl(36 92% 30%)",
      bg: "hsl(36 82% 88%)",
      border: "hsl(36 92% 50% / 0.30)",
      label: "Partially accepted",
      Icon: Minus,
    },
  }[status];

  const Icon = cfg.Icon;
  return (
    <span
      className="inline-flex items-center gap-1.5 rounded-sm border px-2 py-0.5 mono text-[10.5px] font-semibold uppercase tracking-[0.14em]"
      style={{ color: cfg.fg, backgroundColor: cfg.bg, borderColor: cfg.border }}
    >
      <Icon className="h-3 w-3" strokeWidth={1.75} aria-hidden />
      {cfg.label}
    </span>
  );
}

/**
 * Per-segment status list inside the AckDrawer body (SP21 Phase 5
 * Task 5.2). Renders one row per parsed 999 segment, each with the
 * segment reference (when present), the parsed status code, and the
 * parser's note (when present). An empty list renders a small
 * explanatory note so the drawer doesn't look broken on old acks
 * without the per-segment slice.
 */
export function SegmentStatusList({ segments }: Props) {
  return (
    <section
      className="flex flex-col gap-3 px-6 py-4"
      data-testid="ack-segment-list"
    >
      <div className="flex items-baseline justify-between gap-3">
        <span className="text-[10.5px] font-semibold uppercase tracking-[0.18em] text-muted-foreground">
          Segment status
        </span>
        <span
          className="mono text-[10.5px] text-muted-foreground"
          data-testid="ack-segment-count"
        >
          {segments.length} segment{segments.length === 1 ? "" : "s"}
        </span>
      </div>
      {segments.length === 0 ? (
        <p
          className="text-[12.5px] text-muted-foreground"
          data-testid="ack-segment-empty"
        >
          No per-segment breakdown for this ack — the rolled-up accepted
          / rejected counts above are the only signal.
        </p>
      ) : (
        <ul className="flex flex-col divide-y divide-border/40 border-y border-border/30">
          {segments.map((seg, idx) => (
            <li
              key={`${seg.reference ?? idx}`}
              className="flex items-start gap-3 py-2.5"
              data-testid="ack-segment-row"
            >
              <span
                className="mono text-[12px] tabular-nums text-muted-foreground shrink-0"
                style={{ minWidth: 32 }}
              >
                {idx + 1}
              </span>
              <div className="flex-1 min-w-0">
                <div className="flex items-center gap-2 flex-wrap">
                  <StatusPill status={seg.status} />
                  {seg.reference ? (
                    <span className="mono text-[12px] truncate">
                      {seg.reference}
                    </span>
                  ) : null}
                </div>
                {seg.note ? (
                  <p className="text-[12.5px] text-muted-foreground mt-1 leading-snug">
                    {seg.note}
                  </p>
                ) : null}
              </div>
            </li>
          ))}
        </ul>
      )}
    </section>
  );
}