# Copyright BigchainDB GmbH and BigchainDB contributors
# SPDX-License-Identifier: (Apache-2.0 AND CC-BY-4.0)
# Code is Apache-2.0 and docs are CC-BY-4.0

import codecs

import abci.types_pb2 as types
import json
import pytest


from abci.server import ProtocolHandler
from abci.encoding import read_messages
from io import BytesIO


@pytest.mark.bdb
def test_app(b, init_chain_request):
    from bigchaindb import App
    from bigchaindb.tendermint_utils import calculate_hash
    from bigchaindb.common.crypto import generate_key_pair
    from bigchaindb.models import Transaction

    app = App(b)
    p = ProtocolHandler(app)

    data = p.process('info', types.Request(info=types.RequestInfo(version='2')))
    res = next(read_messages(BytesIO(data), types.Response))
    assert res
    assert res.info.last_block_app_hash == b''
    assert res.info.last_block_height == 0
    assert not b.get_latest_block()

    p.process('init_chain', types.Request(init_chain=init_chain_request))
    block0 = b.get_latest_block()
    assert block0
    assert block0['height'] == 0
    assert block0['app_hash'] == ''

    pk = codecs.encode(init_chain_request.validators[0].pub_key.data, 'base64').decode().strip('\n')
    [validator] = b.get_validators(height=1)
    assert validator['public_key']['value'] == pk
    assert validator['voting_power'] == 10

    alice = generate_key_pair()
    bob = generate_key_pair()
    tx = Transaction.create([alice.public_key],
                            [([bob.public_key], 1)])\
                    .sign([alice.private_key])
    etxn = json.dumps(tx.to_dict()).encode('utf8')

    r = types.Request(check_tx=types.RequestCheckTx(tx=etxn))
    data = p.process('check_tx', r)
    res = next(read_messages(BytesIO(data), types.Response))
    assert res
    assert res.check_tx.code == 0

    r = types.Request()
    r.begin_block.hash = b''
    p.process('begin_block', r)

    r = types.Request(deliver_tx=types.RequestDeliverTx(tx=etxn))
    data = p.process('deliver_tx', r)
    res = next(read_messages(BytesIO(data), types.Response))
    assert res
    assert res.deliver_tx.code == 0

    new_block_txn_hash = calculate_hash([tx.id])

    r = types.Request(end_block=types.RequestEndBlock(height=1))
    data = p.process('end_block', r)
    res = next(read_messages(BytesIO(data), types.Response))
    assert res
    assert 'end_block' == res.WhichOneof('value')

    new_block_hash = calculate_hash([block0['app_hash'], new_block_txn_hash])

    data = p.process('commit', None)
    res = next(read_messages(BytesIO(data), types.Response))
    assert res.commit.data == new_block_hash.encode('utf-8')
    assert b.get_transaction(tx.id).id == tx.id

    block0 = b.get_latest_block()
    assert block0
    assert block0['height'] == 1
    assert block0['app_hash'] == new_block_hash

    # empty block should not update height
    r = types.Request()
    r.begin_block.hash = new_block_hash.encode('utf-8')
    p.process('begin_block', r)

    r = types.Request()
    r.end_block.height = 2
    p.process('end_block', r)

    data = p.process('commit', None)
    res = next(read_messages(BytesIO(data), types.Response))
    assert res.commit.data == new_block_hash.encode('utf-8')

    block0 = b.get_latest_block()
    assert block0
    assert block0['height'] == 2

    # when empty block is generated hash of previous block should be returned
    assert block0['app_hash'] == new_block_hash


@pytest.mark.abci
def test_post_transaction_responses(tendermint_ws_url, b):
    from bigchaindb.common.crypto import generate_key_pair
    from bigchaindb.models import Transaction

    alice = generate_key_pair()
    bob = generate_key_pair()
    tx = Transaction.create([alice.public_key],
                            [([alice.public_key], 1)],
                            asset=None)\
                    .sign([alice.private_key])

    code, message = b.write_transaction(tx, 'broadcast_tx_commit')
    assert code == 202

    tx_transfer = Transaction.transfer(tx.to_inputs(),
                                       [([bob.public_key], 1)],
                                       asset_id=tx.id)\
                             .sign([alice.private_key])

    code, message = b.write_transaction(tx_transfer, 'broadcast_tx_commit')
    assert code == 202

    carly = generate_key_pair()
    double_spend = Transaction.transfer(
        tx.to_inputs(),
        [([carly.public_key], 1)],
        asset_id=tx.id,
    ).sign([alice.private_key])
    for mode in ('broadcast_tx_sync', 'broadcast_tx_commit'):
        code, message = b.write_transaction(double_spend, mode)
        assert code == 500
        assert message == 'Transaction validation failed'