import { calculateOutcome } from "./calculate.js";

/**
 * Verify that SDK outcome calculation matches expected on-chain verification
 *
 * This helper is primarily used in tests to ensure SDK and on-chain logic remain aligned.
 * It compares the SDK's calculateOutcome result against the expected outcome that the
 * on-chain program would verify.
 *
 * On-chain reference: programs/pit/src/instructions/mark_extreme.rs:205-241
 *
 * @param priceInCents - Price in cents
 * @param strikes - Strike prices in cents
 * @param expectedHighOutcome - Expected High pool outcome (or null to skip)
 * @param expectedLowOutcome - Expected Low pool outcome (or null to skip)
 * @returns True if SDK matches expected outcomes
 *
 * @example
 * ```typescript
 * // Verify High Pool outcome=1 requires price >= strikes[0]
 * const strikes = [14000, 15000, 16000];
 * assert(verifyOutcomeAlignment(14000, strikes, 1, null)); // price >= 140
 * assert(!verifyOutcomeAlignment(13999, strikes, 1, null)); // price < 140
 *
 * // Verify Low Pool outcome=1 requires price < strikes[0]
 * const lowStrikes = [16000, 15000, 14000]; // descending
 * assert(verifyOutcomeAlignment(15999, lowStrikes, null, 1)); // price < 160
 * assert(!verifyOutcomeAlignment(16000, lowStrikes, null, 1)); // price >= 160
 * ```
 */
export function verifyOutcomeAlignment(
  priceInCents: number,
  strikes: [number, number, number],
  expectedHighOutcome: number | null = null,
  expectedLowOutcome: number | null = null
): boolean {
  const result = calculateOutcome(priceInCents, strikes);

  if (expectedHighOutcome !== null && result.highOutcome !== expectedHighOutcome) {
    return false;
  }

  if (expectedLowOutcome !== null && result.lowOutcome !== expectedLowOutcome) {
    return false;
  }

  return true;
}

/**
 * Get the required strike price for a given outcome and pool type
 *
 * This matches the on-chain verification logic in mark_extreme.rs where
 * the program checks if the price satisfies the claimed outcome.
 *
 * @param poolType - "high" or "low"
 * @param outcome - Outcome number (0-3)
 * @param strikes - Strike prices in cents
 * @returns Required strike price for verification
 *
 * @example
 * ```typescript
 * const highStrikes = [14000, 15000, 16000];
 * getRequiredStrike("high", 1, highStrikes); // Returns 14000 (must be >= s0)
 * getRequiredStrike("high", 2, highStrikes); // Returns 15000 (must be >= s1)
 *
 * const lowStrikes = [16000, 15000, 14000];
 * getRequiredStrike("low", 1, lowStrikes); // Returns 16000 (must be < s0)
 * getRequiredStrike("low", 3, lowStrikes); // Returns 14000 (must be < s2)
 * ```
 */
export function getRequiredStrike(
  poolType: "high" | "low",
  outcome: number,
  strikes: [number, number, number]
): number | null {
  if (outcome === 0) {
    return null; // Outcome 0 has no strike requirement
  }

  // Both High and Low use outcome-1 as strike index
  // High: outcome 1 → strikes[0], outcome 2 → strikes[1], outcome 3 → strikes[2]
  // Low: outcome 1 → strikes[0], outcome 2 → strikes[1], outcome 3 → strikes[2]
  const strikeIndex = outcome - 1;
  return strikes[strikeIndex];
}