"""SIGN_TX end to end, including an independent check of what was signed."""

import pytest
from ecdsa import SECP256k1, VerifyingKey
from ecdsa.util import sigdecode_string
from ragger.error import ExceptionRAPDU

from application_client.handshake_command_sender import Errors, HandshakeCommandSender
from application_client.handshake_response_unpacker import (
    unpack_get_public_key_response, unpack_sign_input_response,
)
from application_client.handshake_sighash import (
    p2wpkh_script_code, serialize_output, sighash_all,
)
from .review_nav import approve_review
from application_client.handshake_transaction import (
    COVENANT_OPEN, COVENANT_TRANSFER, SIGHASH_ALL,
    begin_payload, input_payload, open_items, output_payload, transfer_items,
)

PATH = "m/44'/5353'/0'/0/0"
COIN = 100_000_000
TXID = b"\x11" * 32
DEST = b"\x22" * 20
CHANGE = b"\x33" * 20


def _pubkey(client: HandshakeCommandSender) -> bytes:
    pubkey, _, _ = unpack_get_public_key_response(client.get_public_key(path=PATH).data)
    return pubkey


def test_sign_tx_accepted(backend, device, navigator, default_screenshot_path, test_name):
    """Approve a two-output spend and verify the signature commits to exactly
    the transaction the device was given."""
    client = HandshakeCommandSender(backend)
    pubkey = _pubkey(client)

    outputs = [
        output_payload(60_000_000, addr_hash=DEST),
        output_payload(39_000_000, addr_hash=CHANGE),
    ]

    client.sign_tx_begin(begin_payload(n_in=1, n_out=2))
    client.sign_tx_add_input(input_payload(PATH, COIN, txid=TXID))
    for out in outputs:
        client.sign_tx_add_output(out)

    with client.sign_tx_review():
        approve_review(device, navigator, default_screenshot_path, test_name)

    rapdu = client.sign_tx_input(0)
    signature, sighash_type, returned_pubkey = unpack_sign_input_response(rapdu.data)
    assert sighash_type == SIGHASH_ALL
    assert returned_pubkey == pubkey

    digest = sighash_all(
        version=0,
        inputs=[(TXID, 0, 0xFFFFFFFF)],
        outputs=[serialize_output(60_000_000, DEST),
                 serialize_output(39_000_000, CHANGE)],
        locktime=0,
        index=0,
        script_code=p2wpkh_script_code(pubkey),
        value=COIN,
    )
    vk = VerifyingKey.from_string(pubkey, curve=SECP256k1)
    assert vk.verify_digest(signature, digest, sigdecode=sigdecode_string)


def test_sign_tx_refused(backend, scenario_navigator):
    client = HandshakeCommandSender(backend)
    client.sign_tx_begin(begin_payload(n_in=1, n_out=1))
    client.sign_tx_add_input(input_payload(PATH, COIN, txid=TXID))
    client.sign_tx_add_output(output_payload(90_000_000, addr_hash=DEST))

    with pytest.raises(ExceptionRAPDU) as e:
        with client.sign_tx_review():
            scenario_navigator.review_reject()
    assert e.value.status == Errors.SW_DENY

    # A refusal must leave no session behind for the host to sign against.
    with pytest.raises(ExceptionRAPDU) as e:
        client.sign_tx_input(0)
    assert e.value.status == Errors.SW_WRONG_STATE


def test_sign_tx_open_covenant(backend, device, navigator, default_screenshot_path, test_name):
    """OPEN carries the plaintext name, which the device verifies against the
    hash the covenant commits to before showing it."""
    client = HandshakeCommandSender(backend)
    client.sign_tx_begin(begin_payload(n_in=1, n_out=1))
    client.sign_tx_add_input(input_payload(PATH, COIN, txid=TXID))
    client.sign_tx_add_output(output_payload(
        0, addr_hash=DEST,
        covenant_kind=COVENANT_OPEN, covenant_items=open_items(b"alice")))

    with client.sign_tx_review():
        approve_review(device, navigator, default_screenshot_path, test_name)
    assert client.sign_tx_input(0).status == 0x9000


def test_sign_tx_transfer_covenant(backend, device, navigator, default_screenshot_path, test_name):
    """TRANSFER's destination is the only thing distinguishing a transfer to
    yourself from one to a thief, and it lives in the covenant rather than in
    the output address."""
    client = HandshakeCommandSender(backend)
    client.sign_tx_begin(begin_payload(n_in=1, n_out=1))
    client.sign_tx_add_input(input_payload(PATH, COIN, txid=TXID))
    client.sign_tx_add_output(output_payload(
        COIN // 2, addr_hash=CHANGE,
        covenant_kind=COVENANT_TRANSFER,
        covenant_items=transfer_items(b"alice", dest_hash=DEST)))

    with client.sign_tx_review():
        approve_review(device, navigator, default_screenshot_path, test_name)
    assert client.sign_tx_input(0).status == 0x9000