import os
import asyncio
import tempfile
from binascii import unhexlify

from lbry.wallet.util import ArithUint256
from lbry.testcase import AsyncioTestCase
from lbry.wallet.ledger import Headers as _Headers


class Headers(_Headers):
    checkpoints = {}


def block_bytes(blocks):
    return blocks * Headers.header_size


class TestHeaders(AsyncioTestCase):

    async def test_deserialize(self):
        self.maxDiff = None
        h = Headers(':memory:')
        await h.open()
        await h.connect(0, HEADERS)
        self.assertEqual(await h.get(0), {
            'bits': 520159231,
            'block_height': 0,
            'claim_trie_root': b'0000000000000000000000000000000000000000000000000000000000000001',
            'merkle_root': b'b8211c82c3d15bcd78bba57005b86fed515149a53a425eb592c07af99fe559cc',
            'nonce': 1287,
            'prev_block_hash': b'0000000000000000000000000000000000000000000000000000000000000000',
            'timestamp': 1446058291,
            'version': 1
        })
        self.assertEqual(await h.get(10), {
            'bits': 509349720,
            'block_height': 10,
            'merkle_root': b'f4d8fded6a181d4a8a2817a0eb423cc0f414af29490004a620e66c35c498a554',
            'claim_trie_root': b'0000000000000000000000000000000000000000000000000000000000000001',
            'nonce': 75838,
            'prev_block_hash': b'fdab1b38bcf236bc85b6bcd52fe8ec19bcb0b6c7352e913de05fa5a4e5ae8d55',
            'timestamp': 1466646593,
            'version': 536870912
        })

    async def test_connect_from_genesis(self):
        headers = Headers(':memory:')
        await headers.open()
        self.assertEqual(headers.height, -1)
        await headers.connect(0, HEADERS)
        self.assertEqual(headers.height, 19)

    async def test_connect_from_middle(self):
        headers_temporary_file = tempfile.mktemp()
        self.addCleanup(os.remove, headers_temporary_file)
        with open(headers_temporary_file, 'w+b') as headers_file:
            headers_file.write(HEADERS[:block_bytes(10)])
        h = Headers(headers_temporary_file)
        await h.open()
        self.assertEqual(h.height, 9)
        await h.connect(len(h), HEADERS[block_bytes(10):block_bytes(20)])
        self.assertEqual(h.height, 19)

    def test_target_calculation(self):
        # see: https://github.com/lbryio/lbrycrd/blob/master/src/test/lbry_tests.cpp
        # 1 test block 1 difficulty, should be a max retarget
        self.assertEqual(
            0x1f00e146,
            Headers(':memory').get_next_block_target(
                max_target=ArithUint256(Headers.max_target),
                previous={'timestamp': 1386475638},
                current={'timestamp': 1386475638, 'bits': 0x1f00ffff}
            ).compact
        )
        # test max retarget (difficulty increase)
        self.assertEqual(
            0x1f008ccc,
            Headers(':memory').get_next_block_target(
                max_target=ArithUint256(Headers.max_target),
                previous={'timestamp': 1386475638},
                current={'timestamp': 1386475638, 'bits': 0x1f00a000}
            ).compact
        )
        # test min retarget (difficulty decrease)
        self.assertEqual(
            0x1f00f000,
            Headers(':memory').get_next_block_target(
                max_target=ArithUint256(Headers.max_target),
                previous={'timestamp': 1386475638},
                current={'timestamp': 1386475638 + 60*20, 'bits': 0x1f00a000}
            ).compact
        )
        # test to see if pow limit is not exceeded
        self.assertEqual(
            0x1f00ffff,
            Headers(':memory').get_next_block_target(
                max_target=ArithUint256(Headers.max_target),
                previous={'timestamp': 1386475638},
                current={'timestamp': 1386475638 + 600, 'bits': 0x1f00ffff}
            ).compact
        )

    def test_get_proof_of_work_hash(self):
        # see: https://github.com/lbryio/lbrycrd/blob/master/src/test/lbry_tests.cpp
        self.assertEqual(
            Headers.header_hash_to_pow_hash(Headers.hash_header(b"test string")),
            b"485f3920d48a0448034b0852d1489cfa475341176838c7d36896765221be35ce"
        )
        self.assertEqual(
            Headers.header_hash_to_pow_hash(Headers.hash_header(b"a"*70)),
            b"eb44af2f41e7c6522fb8be4773661be5baa430b8b2c3a670247e9ab060608b75"
        )
        self.assertEqual(
            Headers.header_hash_to_pow_hash(Headers.hash_header(b"d"*140)),
            b"74044747b7c1ff867eb09a84d026b02d8dc539fb6adcec3536f3dfa9266495d9"
        )

    async def test_bounds(self):
        headers = Headers(':memory:')
        await headers.open()
        await headers.connect(0, HEADERS)
        self.assertEqual(19, headers.height)
        with self.assertRaises(IndexError):
            _ = await headers.get(3001)
        with self.assertRaises(IndexError):
            _ = await headers.get(-1)
        self.assertIsNotNone(await headers.get(19))
        self.assertIsNotNone(await headers.get(0))

    async def test_repair(self):
        headers = Headers(':memory:')
        await headers.open()
        await headers.connect(0, HEADERS[:block_bytes(11)])
        self.assertEqual(10, headers.height)
        await headers.repair()
        self.assertEqual(10, headers.height)
        # corrupt the middle of it
        headers.io.seek(block_bytes(8))
        headers.io.write(b"wtf")
        await headers.repair()
        self.assertEqual(7, headers.height)
        self.assertEqual(8, len(headers))
        # corrupt by appending
        headers.io.seek(block_bytes(len(headers)))
        headers.io.write(b"appending")
        await headers.repair()
        self.assertEqual(7, headers.height)
        await headers.connect(len(headers), HEADERS[block_bytes(8):])
        self.assertEqual(19, headers.height)
        # verify from middle
        await headers.repair(start_height=10)
        self.assertEqual(19, headers.height)

    async def test_do_not_estimate_unconfirmed(self):
        headers = Headers(':memory:')
        await headers.open()
        self.assertIsNone(headers.estimated_timestamp(-1))
        self.assertIsNone(headers.estimated_timestamp(0))
        self.assertIsNotNone(headers.estimated_timestamp(1))

    async def test_dont_estimate_whats_there(self):
        headers = Headers(':memory:')
        await headers.open()
        estimated = headers.estimated_timestamp(10)
        await headers.connect(0, HEADERS)
        real_time = (await headers.get(10))['timestamp']
        after_downloading_header_estimated = headers.estimated_timestamp(10)
        self.assertNotEqual(estimated, after_downloading_header_estimated)
        self.assertEqual(after_downloading_header_estimated, real_time)

    async def test_misalignment_triggers_repair_on_open(self):
        headers_temporary_file = tempfile.mktemp()
        self.addCleanup(os.remove, headers_temporary_file)
        with open(headers_temporary_file, 'w+b') as headers_file:
            headers_file.write(HEADERS)
        headers = Headers(headers_temporary_file)
        with self.assertLogs(level='WARN') as cm:
            await headers.open()
            await headers.close()
            self.assertEqual(cm.output, [])
            with open(headers_temporary_file, 'w+b') as headers_file:
                headers_file.seek(0)
                headers_file.truncate()
                headers_file.write(HEADERS[:block_bytes(10)])
                headers_file.write(b'ops')
                headers_file.write(HEADERS[block_bytes(10):])
            await headers.open()
            self.assertEqual(
                cm.output, [
                    'WARNING:lbry.wallet.header:Reader file size doesnt match header size. '
                    'Repairing, might take a while.',
                    'WARNING:lbry.wallet.header:Header file corrupted at height 9, truncating '
                    'it.'
                ]
            )

    async def test_concurrency(self):
        BLOCKS = 19
        headers_temporary_file = tempfile.mktemp()
        headers = Headers(headers_temporary_file)
        await headers.open()
        self.addCleanup(os.remove, headers_temporary_file)
        async def writer():
            for block_index in range(BLOCKS):
                await headers.connect(block_index, HEADERS[block_bytes(block_index):block_bytes(block_index + 1)])
        async def reader():
            for block_index in range(BLOCKS):
                while len(headers) <= block_index:
                    await asyncio.sleep(0.000001)
                assert (await headers.get(block_index))['block_height'] == block_index
        reader_task = asyncio.create_task(reader())
        await writer()
        await reader_task
        await headers.close()


HEADERS = unhexlify(
    b'010000000000000000000000000000000000000000000000000000000000000000000000cc59e59ff97ac092b55e4'
    b'23aa5495151ed6fb80570a5bb78cd5bd1c3821c21b801000000000000000000000000000000000000000000000000'
    b'0000000000000033193156ffff001f070500000000002063f4346a4db34fdfce29a70f5e8d11f065f6b91602b7036'
    b'c7f22f3a03b28899cba888e2f9c037f831046f8ad09f6d378f79c728d003b177a64d29621f481da5d010000000000'
    b'00000000000000000000000000000000000000000000000000003c406b5746e1001f5b4f000000000020246cb8584'
    b'3ac936d55388f2ff288b011add5b1b20cca9cfd19a403ca2c9ecbde09d8734d81b5f2eb1b653caf17491544ddfbc7'
    b'2f2f4c0c3f22a3362db5ba9d4701000000000000000000000000000000000000000000000000000000000000003d4'
    b'06b57ffff001f4ff20000000000200044e1258b865d262587c28ff98853bc52bb31266230c1c648cc9004047a5428'
    b'e285dbf24334585b9a924536a717160ee185a86d1eeb7b19684538685eca761a01000000000000000000000000000'
    b'000000000000000000000000000000000003d406b5746e1001fce9c010000000020bbf8980e3f7604896821203bf6'
    b'2f97f311124da1fbb95bf523fcfdb356ad19c9d83cf1408debbd631950b7a95b0c940772119cd8a615a3d44601568'
    b'713fec80c01000000000000000000000000000000000000000000000000000000000000003e406b573dc6001fec7b'
    b'0000000000201a650b9b7b9d132e257ff6b336ba7cd96b1796357c4fc8dd7d0bd1ff1de057d547638e54178dbdddf'
    b'2e81a3b7566860e5264df6066755f9760a893f5caecc5790100000000000000000000000000000000000000000000'
    b'0000000000000000003e406b5773ae001fcf770000000000206d694b93a2bb5ac23a13ed6749a789ca751cf73d598'
    b'2c459e0cd9d5d303da74cec91627e0dba856b933983425d7f72958e8f974682632a0fa2acee9cfd81940101000000'
    b'000000000000000000000000000000000000000000000000000000003e406b578399001f225c010000000020b5780'
    b'8c188b7315583cf120fe89de923583bc7a8ebff03189145b86bf859b21ba3c4a19948a1263722c45c5601fd10a7ae'
    b'a7cf73bfa45e060508f109155e80ab010000000000000000000000000000000000000000000000000000000000000'
    b'03f406b571787001f0816070000000020a6a5b330e816242d54c8586ba9b6d63c19d921171ef3d4525b8ffc635742'
    b'e83a0fc2da46cf0de0057c1b9fc93d997105ff6cf2c8c43269b446c1dbf5ac18be8c0100000000000000000000000'
    b'00000000000000000000000000000000000000040406b570ae1761edd8f030000000020b8447f415279dffe8a09af'
    b'e6f6d5e335a2f6911fce8e1d1866723d5e5e8a53067356a733f87e592ea133328792dd9d676ed83771c8ff0f51992'
    b'8ce752f159ba6010000000000000000000000000000000000000000000000000000000000000040406b57139d681e'
    b'd40d000000000020558daee5a4a55fe03d912e35c7b6b0bc19ece82fd5bcb685bc36f2bc381babfd54a598c4356ce'
    b'620a604004929af14f4c03c42eba017288a4a1d186aedfdd8f4010000000000000000000000000000000000000000'
    b'000000000000000000000041406b57580f5c1e3e280100000000200381bfc0b2f10c9a3c0fc2dc8ad06388aff8ea5'
    b'a9f7dba6a945073b021796197364b79f33ff3f3a7ccb676fc0a37b7d831bd5942a05eac314658c6a7e4c4b1a40100'
    b'00000000000000000000000000000000000000000000000000000000000041406b574303511ec0ae0100000000202'
    b'aae02063ae0f1025e6acecd5e8e2305956ecaefd185bb47a64ea2ae953233891df3d4c1fc547ab3bbca027c8bbba7'
    b'44c051add8615d289b567f97c64929dcf201000000000000000000000000000000000000000000000000000000000'
    b'0000042406b578c4a471e04ee00000000002016603ef45d5a7c02bfbb30f422016746872ff37f8b0b5824a0f70caa'
    b'668eea5415aad300e70f7d8755d93645d1fd21eda9c40c5d0ed797acd0e07ace34585aaf010000000000000000000'
    b'000000000000000000000000000000000000000000042406b577bbc3e1ea163000000000020cad8863b312914f2fd'
    b'2aad6e9420b64859039effd67ac4681a7cf60e42b09b7e7bafa1e8d5131f477785d8338294da0f998844a85b39d24'
    b'26e839b370e014e3b010000000000000000000000000000000000000000000000000000000000000042406b573935'
    b'371e20e900000000002053d5e608ce5a12eda5931f86ee81198fdd231fea64cf096e9aeae321cf2efbe241e888d5a'
    b'af495e4c2a9f11b932db979d7483aeb446f479179b0c0b8d24bfa0e01000000000000000000000000000000000000'
    b'0000000000000000000000000045406b573c95301e34af0a0000000020df0e494c02ff79e3929bc1f2491077ec4f6'
    b'a607d7a1a5e1be96536642c98f86e533febd715f8a234028fd52046708551c6b6ac415480a6568aaa35cb94dc7203'
    b'01000000000000000000000000000000000000000000000000000000000000004f406b57c4c02a1ec54d230000000'
    b'020341f7d8e7d242e5e46343c40840c44f07e7e7306eb2355521b51502e8070e569485ba7eec4efdff0fc755af6e7'
    b'3e38b381a88b0925a68193a25da19d0f616e9f0100000000000000000000000000000000000000000000000000000'
    b'00000000050406b575be8251e1f61010000000020cd399f8078166ca5f0bdd1080ab1bb22d3c271b9729b6000b44f'
    b'4592cc9fab08c00ebab1e7cd88677e3b77c1598c7ac58660567f49f3a30ec46a48a1ae7652fe01000000000000000'
    b'0000000000000000000000000000000000000000000000052406b57d55b211e6f53090000000020c6c14ed4a53bbb'
    b'4f181acf2bbfd8b74d13826732f2114140ca99ca371f7dd87c51d18a05a1a6ffa37c041877fa33c2229a45a0ab66b'
    b'5530f914200a8d6639a6f010000000000000000000000000000000000000000000000000000000000000055406b57'
    b'0d5b1d1eff1c0900'
)