/**
 * Markdown builder for `strategy_periodic_report` (weekly / monthly rolling windows).
 */

/** One row for the performance ranking table. */
export interface StrategyRankRow {
  strategyId: string;
  strategyName: string;
  totalReturn: number | null;
  sharpe: number | null;
  maxDrawdown: number | null;
}

/** Inputs collected by the tool before formatting. */
export interface PeriodicReportPayload {
  period: "weekly" | "monthly";
  windowStartIso: string;
  windowEndIso: string;
  scanCountsByType: Map<string, number>;
  priceAlertCount: number;
  rankRows: StrategyRankRow[];
}

/**
 * Format a periodic performance report as Markdown for the agent.
 *
 * @param payload - Aggregated stats and ranking rows for the reporting window.
 * @returns Markdown string (zh headings, decimal returns as percent like daily scan).
 */
export function formatPeriodicReportMarkdown(payload: PeriodicReportPayload): string {
  const periodLabel = payload.period === "weekly" ? "周报" : "月报";
  const start = payload.windowStartIso.slice(0, 10);
  const end = payload.windowEndIso.slice(0, 10);
  const lines: string[] = [];

  lines.push(`## 策略绩效${periodLabel} — ${start} ~ ${end}`);
  lines.push("");

  lines.push("### 绩效排名");
  lines.push("");
  lines.push("| 排名 | 策略 | 总收益 | 夏普 | 最大回撤 |");
  lines.push("|------|------|--------|------|----------|");

  const sorted = [...payload.rankRows].sort((a, b) => {
    const ar = a.totalReturn ?? Number.NEGATIVE_INFINITY;
    const br = b.totalReturn ?? Number.NEGATIVE_INFINITY;
    return br - ar;
  });

  sorted.forEach((row, i) => {
    const ret = row.totalReturn == null ? "—" : `${(row.totalReturn * 100).toFixed(2)}%`;
    const sharpe = row.sharpe == null ? "—" : row.sharpe.toFixed(2);
    const dd = row.maxDrawdown == null ? "—" : `${(row.maxDrawdown * 100).toFixed(2)}%`;
    lines.push(`| ${i + 1} | ${row.strategyName} | ${ret} | ${sharpe} | ${dd} |`);
  });

  lines.push("");
  lines.push("### 活动统计");
  const keys = [...payload.scanCountsByType.keys()].sort();
  if (keys.length === 0) {
    lines.push("- （窗口内无扫描记录）");
  } else {
    for (const k of keys) {
      lines.push(`- ${k}: ${payload.scanCountsByType.get(k)} 次`);
    }
  }
  lines.push(`- 价格告警: ${payload.priceAlertCount} 条`);
  lines.push("");

  return lines.join("\n");
}