// LiquidityMining — Phase D of silent-iron-keystone v4.
//
// LP positions earn rewards from a per-pool emission rate. The
// contract tracks share-block accruals tied to LP commitments
// (NOT addresses, preserving privacy). Anti-flash-LP: minimum
// 100-block holding period before any accrual starts.
//
// Privacy: per-position eligibility, no link to long-term identity.
// Claims emit nullifiers + a token-transfer event for the reward.

dark contract LiquidityMining {
  public mapping(bytes => bytes)   eligPool;            // positionId → pool_id
  public mapping(bytes => uint64)  eligRegisteredBlk;   // positionId → register block
  public mapping(bytes => uint64)  eligAccumulated;     // positionId → share-blocks accumulated
  public mapping(bytes => uint64)  eligLastClaimBlock;  // positionId → last claim block
  public mapping(bytes => bool)    claimNullifiers;

  @direct
  entry register(bytes positionId, bytes pool_id) {
    require(eligRegisteredBlk[positionId] == 0,           "MINE_DUPE_REGISTER");
    eligPool[positionId]            = pool_id;
    eligRegisteredBlk[positionId]   = block.number;
    eligAccumulated[positionId]     = 0;
    eligLastClaimBlock[positionId]  = block.number;
  }

  // Anyone can call checkpoint to advance accumulation. Anti-flash-LP:
  // first checkpoint must be >100 blocks after register. After that,
  // checkpoints accrue (current_block - last_claim_block) share-blocks.
  @direct
  entry checkpoint(bytes positionId) {
    require(eligRegisteredBlk[positionId] != 0,                    "MINE_UNREGISTERED");
    require(block.number > eligRegisteredBlk[positionId] + 100,    "MINE_TOO_SOON");
    require(block.number > eligLastClaimBlock[positionId],         "MINE_NO_PROGRESS");
    eligAccumulated[positionId]    = eligAccumulated[positionId] + (block.number - eligLastClaimBlock[positionId]);
    eligLastClaimBlock[positionId] = block.number;
  }

  @direct
  entry claim(bytes positionId, bytes nullifier, uint64 claim_amount) {
    require(eligRegisteredBlk[positionId] != 0,           "MINE_UNREGISTERED");
    require(!claimNullifiers[nullifier],                   "MINE_REPLAY");
    require(claim_amount > 0,                              "MINE_ZERO_CLAIM");
    require(claim_amount <= eligAccumulated[positionId],   "MINE_OVERCLAIM");

    eligAccumulated[positionId] = eligAccumulated[positionId] - claim_amount;
    claimNullifiers[nullifier]  = true;
    syscall(TOKEN_TRANSFER_EMIT_V1, ctx.txHash);
  }
}