import { fmt } from "@/lib/format";
import type {
  LineReconciliationResponse,
  LineReconciliationRow,
} from "@/types";

/**
 * Per-line reconciliation tab for the ClaimDrawer (SP7 §6.2).
 *
 * Two-column layout: left = "Billed (837 SV1)", right = "Adjudicated
 * (835 SVC)". Each row is a service line, matched when both sides
 * are present; unmatched 835 lines appear at the bottom with an
 * oxblood accent rail. Per-line CAS adjustments are listed under each
 * row.
 */
export function LineReconciliationTab({
  data,
}: {
  data: LineReconciliationResponse;
}) {
  const { summary, lines } = data;
  const allMatched = summary.matchedLines === summary.totalLines;
  const leftRows = lines.filter((l) => l.status !== "unmatched_835_only");
  const rightRows = lines;

  return (
    <section className="flex flex-col gap-4 px-6 py-4">
      <header
        className="flex items-baseline justify-between flex-wrap gap-3"
        data-testid="line-reconciliation-summary"
      >
        <div className="flex gap-5 font-mono tabular-nums text-sm">
          <span data-testid="billed-total" className="flex flex-col gap-0.5">
            <span className="text-muted-foreground eyebrow">
              Billed
            </span>
            <span className="text-foreground font-semibold">
              {fmt.usdPrecise(Number(summary.billedTotal))}
            </span>
          </span>
          <span data-testid="paid-total" className="flex flex-col gap-0.5">
            <span className="text-muted-foreground eyebrow">
              Paid
            </span>
            <span className="text-foreground font-semibold">
              {fmt.usdPrecise(Number(summary.paidTotal))}
            </span>
          </span>
          <span data-testid="adjustments-total" className="flex flex-col gap-0.5">
            <span className="text-muted-foreground eyebrow">
              Adjustments
            </span>
            <span className="text-foreground font-semibold">
              {fmt.usdPrecise(Number(summary.adjustmentTotal))}
            </span>
          </span>
        </div>
        <span
          className="font-mono text-xs uppercase tracking-[0.14em]"
          style={{
            color: allMatched ? "var(--tt-amber)" : "var(--tt-oxblood)",
          }}
          data-testid="match-summary"
        >
          {allMatched
            ? `matched ${summary.matchedLines} of ${summary.totalLines} lines`
            : `matched ${summary.matchedLines} of ${summary.totalLines} lines (${summary.totalLines - summary.matchedLines} unmatched)`}
        </span>
      </header>

      <div className="grid grid-cols-2 gap-4">
        <div data-testid="left-column">
          <h3 className="eyebrow text-muted-foreground mb-2">
            Billed (837 SV1)
          </h3>
          {leftRows.map((row) => (
            <LineCard key={rowKey(row, "left")} row={row} side="left" />
          ))}
        </div>
        <div data-testid="right-column">
          <h3 className="eyebrow text-muted-foreground mb-2">
            Adjudicated (835 SVC)
          </h3>
          {rightRows.map((row) => (
            <LineCard key={rowKey(row, "right")} row={row} side="right" />
          ))}
        </div>
      </div>
    </section>
  );
}

function rowKey(row: LineReconciliationRow, side: "left" | "right"): string {
  const ln =
    row.claimServiceLine?.lineNumber ??
    row.serviceLinePayment?.lineNumber ??
    -1;
  return `${side}-${row.status}-${ln}`;
}

function LineCard({
  row,
  side,
}: {
  row: LineReconciliationRow;
  side: "left" | "right";
}) {
  const cl = row.claimServiceLine;
  const svc = row.serviceLinePayment;
  const isUnmatched835 = row.status === "unmatched_835_only";
  const accentColor = isUnmatched835 ? "var(--tt-oxblood)" : "var(--tt-ink-blue)";
  const procCode = cl?.procedureCode ?? svc?.procedureCode ?? "—";
  const lineNumber = cl?.lineNumber ?? svc?.lineNumber ?? null;

  return (
    <div
      className="flex flex-col gap-1 py-2 px-3 mb-2 rounded-r-md transition-colors hover:bg-muted/40"
      style={{
        borderLeft: `3px solid ${accentColor}`,
        background: "rgba(255,255,255,0.02)",
      }}
      data-line-status={row.status}
    >
      <div className="flex items-baseline justify-between">
        <div className="font-mono text-sm">
          <span className="font-semibold text-foreground">{procCode}</span>
          {lineNumber !== null ? (
            <span className="text-muted-foreground ml-2">
              #{lineNumber}
            </span>
          ) : null}
          {isUnmatched835 ? (
            <span
              className="ml-2 text-xs italic"
              style={{ color: "var(--tt-oxblood)" }}
            >
              no 837 line matched
            </span>
          ) : null}
          {row.status === "unmatched_837_only" ? (
            <span
              className="ml-2 text-xs italic"
              style={{ color: "var(--tt-oxblood)" }}
            >
              no 835 line adjudicated this line
            </span>
          ) : null}
        </div>
        <div className="font-mono tabular-nums text-xs text-foreground font-semibold">
          {side === "left" && cl ? <span>{fmt.usdPrecise(Number(cl.charge))}</span> : null}
          {side === "right" && svc ? <span>{fmt.usdPrecise(Number(svc.payment))}</span> : null}
        </div>
      </div>
      {row.adjustments.length > 0 ? (
        <ul className="text-xs font-mono text-muted-foreground mt-1 space-y-0.5">
          {row.adjustments.map((a, i) => (
            <li key={i}>
              <span className="text-foreground/80">{a.groupCode}-{a.reasonCode}</span>
              <span className="ml-2 tabular-nums">{fmt.usdPrecise(Number(a.amount))}</span>
            </li>
          ))}
        </ul>
      ) : null}
    </div>
  );
}