import { PublicKey, TransactionInstruction } from "@solana/web3.js";
import type { PitProgram } from "../program.js";
import { getMarketAddress, getRegistryAddress } from "../accounts/pda.js";

/**
 * Parameters for creating a settle_market instruction
 */
export interface SettleMarketParams {
  /** Week number of the market */
  weekNumber: number;
  /** Settler's public key (signer) - can be anyone */
  settler: PublicKey;
}

/**
 * Create a settle_market instruction to finalize both pools after market expiry
 *
 * This instruction is permissionless - anyone can call it after the market's end_timestamp.
 * It settles BOTH High and Low pools in a single instruction, locking in the winning_outcome
 * that was tracked via mark_extreme calls during the market period.
 *
 * Requirements:
 * - Both pools must be initialized
 * - Neither pool can already be settled
 * - Current timestamp must be > market.end_timestamp
 *
 * @param program - Anchor Program instance
 * @param params - Settle market parameters
 * @returns Promise resolving to TransactionInstruction
 *
 * @example
 * ```typescript
 * import { createProgram, createSettleMarketInstruction } from "@pit-protocol/sdk";
 *
 * const program = createProgram(provider);
 * const ix = await createSettleMarketInstruction(program, {
 *   weekNumber: 1,
 *   settler: wallet.publicKey,
 * });
 *
 * const tx = new Transaction().add(ix);
 * await sendAndConfirmTransaction(connection, tx, [wallet]);
 * ```
 */
export async function createSettleMarketInstruction(
  program: PitProgram,
  params: SettleMarketParams
): Promise<TransactionInstruction> {
  const { weekNumber, settler } = params;

  const marketState = getMarketAddress(weekNumber);
  const registry = getRegistryAddress();

  return await program.methods
    .settleMarket()
    .accountsPartial({
      marketState,
      registry,
      settler,
    })
    .instruction();
}