import { MarketState } from "../types.js";
import { isTimestampPassed } from "../math.js";

/**
 * SettlementChecker - Monitors market expiry and triggers settlement
 *
 * Responsibilities:
 * - Checks if market has expired (timestamp passed)
 * - Detects when settlement is needed
 * - Triggers settlement callback when ready
 */
export class SettlementChecker {
  private checkInterval: number;
  private verbose: boolean;
  private timer: NodeJS.Timeout | null = null;
  private isRunning = false;

  constructor(checkInterval: number = 10000, verbose: boolean = false) {
    this.checkInterval = checkInterval;
    this.verbose = verbose;
  }

  /**
   * Start settlement checking
   *
   * @param market - Current market state
   * @param onSettlementNeeded - Callback when settlement is needed
   * @param onBothSettled - Callback when both pools are settled (stop signal)
   */
  start(
    market: MarketState,
    onSettlementNeeded: () => Promise<void>,
    onBothSettled?: () => void
  ): void {
    if (this.isRunning) {
      throw new Error("SettlementChecker is already running");
    }

    this.isRunning = true;

    const checkSettlement = async () => {
      if (!this.isRunning) return;

      // Check if market has expired
      if (!isTimestampPassed(market.endTimestamp)) {
        return; // Market not yet expired
      }

      try {
        // Settle both pools if either is unsettled
        if (!market.highPool.isSettled || !market.lowPool.isSettled) {
          this.log("Market expired, settlement needed");
          await onSettlementNeeded();
        }

        // Check if both pools are now settled
        if (market.highPool.isSettled && market.lowPool.isSettled) {
          this.log("Both pools settled");
          if (onBothSettled) {
            onBothSettled();
          }
          this.stop();
        }
      } catch (err) {
        this.log(`Settlement check error: ${(err as Error).message}`);
        throw err;
      }
    };

    this.timer = setInterval(checkSettlement, this.checkInterval);
  }

  /**
   * Stop settlement checking
   */
  stop(): void {
    this.isRunning = false;

    if (this.timer) {
      clearInterval(this.timer);
      this.timer = null;
    }
  }

  private log(message: string): void {
    if (this.verbose) {
      console.log(`[SettlementChecker] ${message}`);
    }
  }
}