pragma cashscript ^0.13.0;

////////////////////////////////////////////////////////////////////////////////
// PoolContract — single pool instance per payout epoch (M=3, K=2)
//
// Holds user deposits. Each deploy is one height-gated payout epoch.
// Next month: redeploy with a new splitBlockheight, then K-of-M migrate.
//
////////////////////////////////////////////////////////////////////////////////

contract PoolContract(
    pubkey node0,
    pubkey node1,
    pubkey node2,
    bytes20 treasuryPkh,
    bytes share0,
    bytes share1,
    bytes share2,
    int minConsolidation,
    int splitBlockheight
) {
    //////////////////////////////////////////////////////////////////////////////
    // Operation: consolidate (permissionless)
    // inputs:
    //   0..N  PoolContract             [BCH]  (one or more pool UTXOs)
    //   ?     feePayer                 [BCH]  (optional)
    // outputs:
    //   0..1  PoolContract             [BCH]  (self-replicating, each >= minConsolidation)
    //////////////////////////////////////////////////////////////////////////////
    function consolidate() {
        require(tx.outputs.length <= 2, "consolidate: too many outputs");
        require(tx.outputs.length >= 1, "consolidate: need at least 1 output");

        int inSum = 0;
        for (int i = 0; i < tx.inputs.length; i = i + 1) {
            inSum = inSum + tx.inputs[i].value;
        }

        // Compare against the P2SH locking bytecode on this input (not redeem script).
        bytes contractLock = tx.inputs[this.activeInputIndex].lockingBytecode;

        int outSum = 0;
        for (int j = 0; j < tx.outputs.length; j = j + 1) {
            require(
                tx.outputs[j].lockingBytecode == contractLock,
                "consolidate: must self-replicate"
            );
            require(tx.outputs[j].tokenCategory == 0x, "consolidate: pure BCH only");
            require(
                tx.outputs[j].value >= minConsolidation,
                "consolidate: output below minConsolidation"
            );
            outSum = outSum + tx.outputs[j].value;
        }

        require(outSum <= inSum, "consolidate: value not conserved");
    }

    //////////////////////////////////////////////////////////////////////////////
    // Operation: split (permissionless, blockheight-gated)
    // inputs:
    //   0   PoolContract               [BCH]  (consolidated pool UTXO — active input)
    //   1?  feePayer                   [BCH]  (optional companion fee input)
    // outputs:
    //   0   treasury                   [BCH]  (20% + rounding remainder)
    //   1   ShareContract node0        [BCH]  (equal share of 80%)
    //   2   ShareContract node1        [BCH]
    //   3   ShareContract node2        [BCH]
    //////////////////////////////////////////////////////////////////////////////
    function split() {
        require(tx.outputs.length == 4, "split: expected 4 outputs");
        require(tx.time >= splitBlockheight, "split: blockheight gate not met");

        // Fee companion allowed; pool value taken from this active input only.
        require(tx.inputs.length <= 2, "split: at most 2 inputs");

        int poolValue = tx.inputs[this.activeInputIndex].value;
        int treasuryBase = poolValue * 20 / 100;
        int remaining = poolValue - treasuryBase;
        int share = remaining / 3;
        int remainder = remaining - share * 3;
        int treasuryValue = treasuryBase + remainder;

        // Output 0: treasury
        require(
            tx.outputs[0].lockingBytecode == new LockingBytecodeP2PKH(treasuryPkh),
            "split: output 0 must be treasury"
        );
        require(tx.outputs[0].tokenCategory == 0x, "split: treasury must be pure BCH");
        require(tx.outputs[0].value == treasuryValue, "split: bad treasury value");

        // Outputs 1..3: equal shares locked in ShareContracts
        require(tx.outputs[1].lockingBytecode == share0, "split: output 1 must be share0");
        require(tx.outputs[1].tokenCategory == 0x, "split: share0 must be pure BCH");
        require(tx.outputs[1].value == share, "split: bad share0 value");

        require(tx.outputs[2].lockingBytecode == share1, "split: output 2 must be share1");
        require(tx.outputs[2].tokenCategory == 0x, "split: share1 must be pure BCH");
        require(tx.outputs[2].value == share, "split: bad share1 value");

        require(tx.outputs[3].lockingBytecode == share2, "split: output 3 must be share2");
        require(tx.outputs[3].tokenCategory == 0x, "split: share2 must be pure BCH");
        require(tx.outputs[3].value == share, "split: bad share2 value");

        // Exact poolValue apportionment (fee paid by companion input if present)
        require(
            treasuryValue + share + share + share == poolValue,
            "split: apportionment mismatch"
        );
    }

    //////////////////////////////////////////////////////////////////////////////
    // Operation: migrate (K-of-M)
    // inputs:
    //   0..N  PoolContract             [BCH]
    //   ?     feePayer                 [BCH]  (optional)
    // outputs:
    //   0..1  next-epoch destination   [BCH]  (authorized by signatures)
    //////////////////////////////////////////////////////////////////////////////
    function migrate(sig s0, sig s1, sig s2) {
        require(tx.outputs.length <= 2, "migrate: too many outputs");
        require(tx.outputs.length >= 1, "migrate: need at least 1 output");

        int validCount = 0;
        if (checkSig(s0, node0)) {
            validCount = validCount + 1;
        }
        if (checkSig(s1, node1)) {
            validCount = validCount + 1;
        }
        if (checkSig(s2, node2)) {
            validCount = validCount + 1;
        }
        require(validCount >= 2, "migrate: need at least 2-of-3 signatures");

        int inSum = 0;
        for (int i = 0; i < tx.inputs.length; i = i + 1) {
            inSum = inSum + tx.inputs[i].value;
        }

        int outSum = 0;
        for (int j = 0; j < tx.outputs.length; j = j + 1) {
            require(tx.outputs[j].tokenCategory == 0x, "migrate: pure BCH only");
            require(tx.outputs[j].value > 0, "migrate: zero output");
            outSum = outSum + tx.outputs[j].value;
        }

        require(outSum <= inSum, "migrate: value not conserved");
    }
}