import type { HeadlessPaneColumn, HeadlessPaneDefinition, HeadlessPaneRow } from "../../../types/plugin";
import { fetchTape } from "./client";
import { newestFirst, quoteSpread, tapePrice, tapePriceDigits, tapeStatistics } from "./model";

type Format = NonNullable<HeadlessPaneColumn["format"]>;
const fixedPrice = (digits: number): Format => (value) => tapePrice(typeof value === "number" ? value : null, digits);
const bps: Format = (value) => typeof value === "number" && Number.isFinite(value) ? value.toFixed(2) : "--";

/** Every row key in order, with the pane's rounding where the report would otherwise print raw floats. */
function formattedColumns(rows: readonly HeadlessPaneRow[], formats: Record<string, Format>): HeadlessPaneColumn[] {
  return [...new Set(rows.flatMap((row) => Object.keys(row)))]
    .map((key) => ({ key, header: key, ...(formats[key] ? { format: formats[key] } : {}) }));
}

export const timeSalesHeadless: HeadlessPaneDefinition<"bundle"> = {
  shape: "bundle", argument: { kind: "ticker", placeholder: "ticker", description: "US equity ticker." },
  options: [{ key: "limit", type: "integer", minimum: 1, maximum: 1000, defaultValue: 100, description: "Maximum recent prints in the report." }],
  discovery: { aliases: ["TAS", "QR"], dataRequirements: ["Gloom Cloud SIP trade and quote feed"],
    limitations: ["Bounded observed window, not a complete session", "SIP is delayed fifteen minutes without realtime entitlement", "Quote sizes are round lots", "No Level 2 or inferred aggressor side"] },
  describe: (args) => `Time and sales ${args.argument ?? ""}`,
  async load(args, ctx) {
    const symbol = args.symbols[0] ?? (typeof args.argument === "string" ? args.argument : "");
    const instrument = await ctx.resolveInstrument?.(symbol);
    const data = await fetchTape(symbol, instrument?.exchange ?? "", ctx.signal, ctx.apiClient);
    const statistics = tapeStatistics(data);
    const window = [{ from: statistics.from, asOf: statistics.asOf, prints: statistics.count, shares: statistics.volume,
      vwap: statistics.vwap, low: statistics.low, high: statistics.high, pricePercentile: statistics.pricePercentile }];
    const quotes = newestFirst(data.quotes).slice(0, Number(args.options.limit ?? 100)).map((row) => ({ ...row, ...quoteSpread(row), conditions: row.conditions.join(" ") }));
    // One decimal count per column, as the pane shows it, so sub-penny prints align.
    const price = fixedPrice(tapePriceDigits(data.trades.map((row) => row.price)));
    const trades = newestFirst(data.trades).slice(0, Number(args.options.limit ?? 100)).map((row) => ({ ...row, conditions: row.conditions.join(" ") }));
    return { sections: [
      { title: "Observed window", columns: formattedColumns(window, { vwap: price, low: price, high: price }), rows: window },
      { title: "Regular session", columns: formattedColumns([data.session], { high: price, low: price }), rows: [data.session] },
      { title: "Trades", columns: formattedColumns(trades, { price }), rows: trades },
      { title: "NBBO", columns: formattedColumns(quotes, { bps }), rows: quotes },
    ], errors: data.gaps, metadata: { source: data.source, feed: data.feed, delaySeconds: data.delaySeconds,
      asOf: data.asOf, observedFrom: data.observedFrom, generatedAt: data.generatedAt, status: data.status,
      complete: data.status === "available", capacity: data.capacity, dropped: data.dropped, corrections: data.corrections, cancels: data.cancels, connected: data.connected } };
  },
};