Add wallet key derivation and PSBT building

BIP84 derivation of per-user P2WPKH addresses and the pool address from the encrypted master xprv (app/wallet/hd.py, keystore.py), the PLM mainnet chain params (plm_network.py), and PSBT construction for bets/ payouts/withdrawals with change-output and fee-estimation logic (psbt_builder.py). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-07-21 10:25:29 +02:00
parent d2db762d96
commit f1261584ff
9 changed files with 522 additions and 0 deletions
@@ -0,0 +1,21 @@
+from embit.bip32 import HDKey
+
+from app.wallet.plm_network import PLM_MAINNET
+
+
+def test_p2wpkh_address_uses_plm_hrp():
+    from embit import script
+
+    root = HDKey.from_seed(b"\x01" * 32, version=PLM_MAINNET["xprv"])
+    child = root.derive("m/84h/746h/0h/0/0")
+    address = script.p2wpkh(child.to_public()).address(network=PLM_MAINNET)
+    assert address.startswith("plm1q")
+
+
+def test_derivation_is_deterministic():
+    root = HDKey.from_seed(b"\x02" * 32, version=PLM_MAINNET["xprv"])
+    a = root.derive("m/84h/746h/0h/0/5").sec()
+    b = root.derive("m/84h/746h/0h/0/5").sec()
+    c = root.derive("m/84h/746h/0h/0/6").sec()
+    assert a == b
+    assert a != c
@@ -0,0 +1,100 @@
+import pytest
+from embit import script
+from embit.bip32 import HDKey
+from embit.transaction import Transaction
+
+from app.wallet.plm_network import PLM_MAINNET
+from app.wallet.psbt_builder import InsufficientFundsError, Utxo, build_payout_transaction, estimate_vsize
+
+
+def _key(seed_byte: int) -> HDKey:
+    root = HDKey.from_seed(bytes([seed_byte]) * 32, version=PLM_MAINNET["xprv"])
+    return root.derive("m/84h/746h/0h/0/0")
+
+
+def test_payout_deducts_fee_only_from_winner_share():
+    pool_key = _key(10)
+    pool_script = script.p2wpkh(pool_key.to_public())
+    pool_address = pool_script.address(network=PLM_MAINNET)
+    winner_address = script.p2wpkh(_key(11).to_public()).address(network=PLM_MAINNET)
+    fee_address = script.p2wpkh(_key(12).to_public()).address(network=PLM_MAINNET)
+
+    pool_amount = 10_000_000_000  # 100 PLM pot
+    winner_share = pool_amount * 70 // 100
+    commission = pool_amount - winner_share
+
+    utxos = [Utxo("aa" * 32, 0, pool_amount)]
+    built = build_payout_transaction(
+        signing_key=pool_key,
+        from_script=pool_script,
+        utxos=utxos,
+        winner_address=winner_address,
+        winner_share_sats=winner_share,
+        fee_address=fee_address,
+        commission_sats=commission,
+        change_address=pool_address,
+        fee_rate_sat_vb=1,
+    )
+
+    fee = estimate_vsize(1, 3)
+    assert built.fee_sats == fee
+    assert built.winner_sats == winner_share - fee
+    assert built.commission_sats == commission  # untouched by the fee
+    assert built.change_sats == pool_amount - (winner_share + commission)
+
+    parsed = Transaction.parse(bytes.fromhex(built.raw_hex))
+    assert len(parsed.vout) == 2  # no change needed: winner_share + commission == pool_amount exactly
+    amounts = sorted(o.value for o in parsed.vout)
+    assert amounts == sorted([built.winner_sats, built.commission_sats])
+
+
+def test_payout_adds_change_output_when_pool_utxos_exceed_target():
+    pool_key = _key(20)
+    pool_script = script.p2wpkh(pool_key.to_public())
+    pool_address = pool_script.address(network=PLM_MAINNET)
+    winner_address = script.p2wpkh(_key(21).to_public()).address(network=PLM_MAINNET)
+    fee_address = script.p2wpkh(_key(22).to_public()).address(network=PLM_MAINNET)
+
+    winner_share = 700_000_000
+    commission = 300_000_000
+    utxos = [Utxo("bb" * 32, 0, 2_000_000_000)]  # more than winner_share+commission
+    built = build_payout_transaction(
+        signing_key=pool_key,
+        from_script=pool_script,
+        utxos=utxos,
+        winner_address=winner_address,
+        winner_share_sats=winner_share,
+        fee_address=fee_address,
+        commission_sats=commission,
+        change_address=pool_address,
+        fee_rate_sat_vb=1,
+    )
+    assert built.change_sats == 2_000_000_000 - (winner_share + commission)
+
+    parsed = Transaction.parse(bytes.fromhex(built.raw_hex))
+    assert len(parsed.vout) == 3
+
+
+def test_payout_raises_when_winner_share_too_small():
+    pool_key = _key(30)
+    pool_script = script.p2wpkh(pool_key.to_public())
+    pool_address = pool_script.address(network=PLM_MAINNET)
+    winner_address = script.p2wpkh(_key(31).to_public()).address(network=PLM_MAINNET)
+    fee_address = script.p2wpkh(_key(32).to_public()).address(network=PLM_MAINNET)
+
+    winner_share = 100  # smaller than the ~172 sat fee at 1 sat/vB for 1-in-3-out
+    commission = 50
+    assert winner_share < estimate_vsize(1, 3)
+    utxos = [Utxo("cc" * 32, 0, winner_share + commission)]
+    with pytest.raises(InsufficientFundsError):
+        build_payout_transaction(
+            signing_key=pool_key,
+            from_script=pool_script,
+            utxos=utxos,
+            winner_address=winner_address,
+            winner_share_sats=winner_share,
+            fee_address=fee_address,
+            commission_sats=commission,
+            change_address=pool_address,
+            fee_rate_sat_vb=1,
+        )
@@ -0,0 +1,113 @@
+import pytest
+from embit import script
+from embit.bip32 import HDKey
+
+from app.wallet.plm_network import PLM_MAINNET
+from app.wallet.psbt_builder import (
+    InsufficientFundsError,
+    Utxo,
+    build_signed_transaction,
+    estimate_vsize,
+    select_utxos,
+)
+
+
+def _key(seed_byte: int) -> HDKey:
+    root = HDKey.from_seed(bytes([seed_byte]) * 32, version=PLM_MAINNET["xprv"])
+    return root.derive("m/84h/746h/0h/0/0")
+
+
+def test_estimate_vsize_grows_with_inputs_and_outputs():
+    assert estimate_vsize(1, 2) < estimate_vsize(2, 2)
+    assert estimate_vsize(1, 1) < estimate_vsize(1, 2)
+
+
+def test_select_utxos_picks_largest_first():
+    utxos = [Utxo("a" * 64, 0, 5_000_000), Utxo("b" * 64, 0, 20_000_000), Utxo("c" * 64, 0, 1_000_000)]
+    selected, total = select_utxos(utxos, target_sats=10_000_000)
+    assert selected == [utxos[1]]  # the 20M UTXO alone covers 10M
+    assert total == 20_000_000
+
+
+def test_select_utxos_raises_when_insufficient():
+    utxos = [Utxo("a" * 64, 0, 1_000_000)]
+    with pytest.raises(InsufficientFundsError):
+        select_utxos(utxos, target_sats=10_000_000)
+
+
+def test_build_signed_transaction_deducts_fee_from_amount_not_change():
+    signer = _key(1)
+    from_script = script.p2wpkh(signer.to_public())
+    my_address = from_script.address(network=PLM_MAINNET)
+    to_address = script.p2wpkh(_key(2).to_public()).address(network=PLM_MAINNET)
+
+    utxos = [Utxo("11" * 32, 0, 150_000_000)]
+    built = build_signed_transaction(
+        signing_key=signer,
+        from_script=from_script,
+        utxos=utxos,
+        to_address=to_address,
+        amount_sats=10_000_000,
+        change_address=my_address,
+        fee_rate_sat_vb=1,
+    )
+
+    fee = estimate_vsize(1, 2)
+    assert built.fee_sats == fee
+    assert built.recipient_sats == 10_000_000 - fee
+    # change reflects the full amount_sats deducted from the sender, fee comes out
+    # of what the recipient gets, not out of the sender's remaining balance
+    assert built.change_sats == 150_000_000 - 10_000_000
+    assert built.spent_utxos == utxos
+    assert len(built.txid) == 64
+
+    from embit.transaction import Transaction
+
+    parsed = Transaction.parse(bytes.fromhex(built.raw_hex))
+    assert len(parsed.vin[0].witness.items) == 2
+    assert len(parsed.vout) == 2
+
+
+def test_build_signed_transaction_omits_change_output_when_exact_amount():
+    signer = _key(3)
+    from_script = script.p2wpkh(signer.to_public())
+    my_address = from_script.address(network=PLM_MAINNET)
+    to_address = script.p2wpkh(_key(4).to_public()).address(network=PLM_MAINNET)
+
+    utxos = [Utxo("22" * 32, 0, 10_000_000)]  # exactly amount_sats, zero change
+    built = build_signed_transaction(
+        signing_key=signer,
+        from_script=from_script,
+        utxos=utxos,
+        to_address=to_address,
+        amount_sats=10_000_000,
+        change_address=my_address,
+        fee_rate_sat_vb=1,
+    )
+    assert built.change_sats == 0
+
+    from embit.transaction import Transaction
+
+    parsed = Transaction.parse(bytes.fromhex(built.raw_hex))
+    assert len(parsed.vout) == 1
+
+
+def test_build_signed_transaction_raises_when_amount_smaller_than_fee():
+    signer = _key(5)
+    from_script = script.p2wpkh(signer.to_public())
+    my_address = from_script.address(network=PLM_MAINNET)
+    to_address = script.p2wpkh(_key(6).to_public()).address(network=PLM_MAINNET)
+
+    small_amount = 100  # smaller than the ~141 sat fee at 1 sat/vB for 1-in-2-out
+    assert small_amount < estimate_vsize(1, 2)
+    utxos = [Utxo("33" * 32, 0, small_amount)]
+    with pytest.raises(InsufficientFundsError):
+        build_signed_transaction(
+            signing_key=signer,
+            from_script=from_script,
+            utxos=utxos,
+            to_address=to_address,
+            amount_sats=small_amount,
+            change_address=my_address,
+            fee_rate_sat_vb=1,
+        )