#!/usr/bin/env python3
# Copyright (c) 2014-2021 The Bitcoin Core developers
# Distributed under the MIT software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.
"""Test the REST API."""

from decimal import Decimal
from enum import Enum
import http.client
from io import BytesIO
import json
from struct import pack, unpack
import typing
import urllib.parse


from test_framework.messages import (
    BLOCK_HEADER_SIZE,
    COIN,
)
from test_framework.test_framework import BitcoinTestFramework
from test_framework.util import (
    assert_equal,
    assert_greater_than,
    assert_greater_than_or_equal,
)
from test_framework.wallet import (
    MiniWallet,
    getnewdestination,
)


INVALID_PARAM = "abc"
UNKNOWN_PARAM = "0000000000000000000000000000000000000000000000000000000000000000"


class ReqType(Enum):
    JSON = 1
    BIN = 2
    HEX = 3

class RetType(Enum):
    OBJ = 1
    BYTES = 2
    JSON = 3

def filter_output_indices_by_value(vouts, value):
    for vout in vouts:
        if vout['value'] == value:
            yield vout['n']

class RESTTest (BitcoinTestFramework):
    def set_test_params(self):
        self.num_nodes = 2
        self.extra_args = [["-rest", "-blockfilterindex=1"], []]
        # whitelist peers to speed up tx relay / mempool sync
        for args in self.extra_args:
            args.append("-whitelist=noban@127.0.0.1")
        self.supports_cli = False

    def test_rest_request(
            self,
            uri: str,
            http_method: str = 'GET',
            req_type: ReqType = ReqType.JSON,
            body: str = '',
            status: int = 200,
            ret_type: RetType = RetType.JSON,
            query_params: typing.Dict[str, typing.Any] = None,
            ) -> typing.Union[http.client.HTTPResponse, bytes, str, None]:
        rest_uri = '/rest' + uri
        if req_type in ReqType:
            rest_uri += f'.{req_type.name.lower()}'
        if query_params:
            rest_uri += f'?{urllib.parse.urlencode(query_params)}'

        conn = http.client.HTTPConnection(self.url.hostname, self.url.port)
        self.log.debug(f'{http_method} {rest_uri} {body}')
        if http_method == 'GET':
            conn.request('GET', rest_uri)
        elif http_method == 'POST':
            conn.request('POST', rest_uri, body)
        resp = conn.getresponse()

        assert_equal(resp.status, status)

        if ret_type == RetType.OBJ:
            return resp
        elif ret_type == RetType.BYTES:
            return resp.read()
        elif ret_type == RetType.JSON:
            return json.loads(resp.read().decode('utf-8'), parse_float=Decimal)

        return None

    def run_test(self):
        self.url = urllib.parse.urlparse(self.nodes[0].url)
        self.wallet = MiniWallet(self.nodes[0])
        self.wallet.rescan_utxos()

        self.log.info("Broadcast test transaction and sync nodes")
        txid, _ = self.wallet.send_to(from_node=self.nodes[0], scriptPubKey=getnewdestination()[1], amount=int(0.1 * COIN))
        self.sync_all()

        self.log.info("Test the /tx URI")

        json_obj = self.test_rest_request(f"/tx/{txid}")
        assert_equal(json_obj['txid'], txid)

        # Check hex format response
        hex_response = self.test_rest_request(f"/tx/{txid}", req_type=ReqType.HEX, ret_type=RetType.OBJ)
        assert_greater_than_or_equal(int(hex_response.getheader('content-length')),
                                     json_obj['size']*2)

        spent = (json_obj['vin'][0]['txid'], json_obj['vin'][0]['vout'])  # get the vin to later check for utxo (should be spent by then)
        # get n of 0.1 outpoint
        n, = filter_output_indices_by_value(json_obj['vout'], Decimal('0.1'))
        spending = (txid, n)

        # Test /tx with an invalid and an unknown txid
        resp = self.test_rest_request(uri=f"/tx/{INVALID_PARAM}", ret_type=RetType.OBJ, status=400)
        assert_equal(resp.read().decode('utf-8').rstrip(), f"Invalid hash: {INVALID_PARAM}")
        resp = self.test_rest_request(uri=f"/tx/{UNKNOWN_PARAM}", ret_type=RetType.OBJ, status=404)
        assert_equal(resp.read().decode('utf-8').rstrip(), f"{UNKNOWN_PARAM} not found")

        self.log.info("Query an unspent TXO using the /getutxos URI")

        self.generate(self.wallet, 1)
        bb_hash = self.nodes[0].getbestblockhash()

        # Check chainTip response
        json_obj = self.test_rest_request(f"/getutxos/{spending[0]}-{spending[1]}")
        assert_equal(json_obj['chaintipHash'], bb_hash)

        # Make sure there is one utxo
        assert_equal(len(json_obj['utxos']), 1)
        assert_equal(json_obj['utxos'][0]['value'], Decimal('0.1'))

        self.log.info("Query a spent TXO using the /getutxos URI")

        json_obj = self.test_rest_request(f"/getutxos/{spent[0]}-{spent[1]}")

        # Check chainTip response
        assert_equal(json_obj['chaintipHash'], bb_hash)

        # Make sure there is no utxo in the response because this outpoint has been spent
        assert_equal(len(json_obj['utxos']), 0)

        # Check bitmap
        assert_equal(json_obj['bitmap'], "0")

        self.log.info("Query two TXOs using the /getutxos URI")

        json_obj = self.test_rest_request(f"/getutxos/{spending[0]}-{spending[1]}/{spent[0]}-{spent[1]}")

        assert_equal(len(json_obj['utxos']), 1)
        assert_equal(json_obj['bitmap'], "10")

        self.log.info("Query the TXOs using the /getutxos URI with a binary response")

        bin_request = b'\x01\x02'
        for txid, n in [spending, spent]:
            bin_request += bytes.fromhex(txid)
            bin_request += pack("i", n)

        bin_response = self.test_rest_request("/getutxos", http_method='POST', req_type=ReqType.BIN, body=bin_request, ret_type=RetType.BYTES)
        output = BytesIO(bin_response)
        chain_height, = unpack("<i", output.read(4))
        response_hash = output.read(32)[::-1].hex()

        assert_equal(bb_hash, response_hash)  # check if getutxo's chaintip during calculation was fine
        assert_equal(chain_height, 201)  # chain height must be 201 (pre-mined chain [200] + generated block [1])

        self.log.info("Test the /getutxos URI with and without /checkmempool")
        # Create a transaction, check that it's found with /checkmempool, but
        # not found without. Then confirm the transaction and check that it's
        # found with or without /checkmempool.

        # do a tx and don't sync
        txid, _ = self.wallet.send_to(from_node=self.nodes[0], scriptPubKey=getnewdestination()[1], amount=int(0.1 * COIN))
        json_obj = self.test_rest_request(f"/tx/{txid}")
        # get the spent output to later check for utxo (should be spent by then)
        spent = (json_obj['vin'][0]['txid'], json_obj['vin'][0]['vout'])
        # get n of 0.1 outpoint
        n, = filter_output_indices_by_value(json_obj['vout'], Decimal('0.1'))
        spending = (txid, n)

        json_obj = self.test_rest_request(f"/getutxos/{spending[0]}-{spending[1]}")
        assert_equal(len(json_obj['utxos']), 0)

        json_obj = self.test_rest_request(f"/getutxos/checkmempool/{spending[0]}-{spending[1]}")
        assert_equal(len(json_obj['utxos']), 1)

        json_obj = self.test_rest_request(f"/getutxos/{spent[0]}-{spent[1]}")
        assert_equal(len(json_obj['utxos']), 1)

        json_obj = self.test_rest_request(f"/getutxos/checkmempool/{spent[0]}-{spent[1]}")
        assert_equal(len(json_obj['utxos']), 0)

        self.generate(self.nodes[0], 1)

        json_obj = self.test_rest_request(f"/getutxos/{spending[0]}-{spending[1]}")
        assert_equal(len(json_obj['utxos']), 1)

        json_obj = self.test_rest_request(f"/getutxos/checkmempool/{spending[0]}-{spending[1]}")
        assert_equal(len(json_obj['utxos']), 1)

        # Do some invalid requests
        self.test_rest_request("/getutxos", http_method='POST', req_type=ReqType.JSON, body='{"checkmempool', status=400, ret_type=RetType.OBJ)
        self.test_rest_request("/getutxos", http_method='POST', req_type=ReqType.BIN, body='{"checkmempool', status=400, ret_type=RetType.OBJ)
        self.test_rest_request("/getutxos/checkmempool", http_method='POST', req_type=ReqType.JSON, status=400, ret_type=RetType.OBJ)

        # Test limits
        long_uri = '/'.join([f"{txid}-{n_}" for n_ in range(20)])
        self.test_rest_request(f"/getutxos/checkmempool/{long_uri}", http_method='POST', status=400, ret_type=RetType.OBJ)

        long_uri = '/'.join([f'{txid}-{n_}' for n_ in range(15)])
        self.test_rest_request(f"/getutxos/checkmempool/{long_uri}", http_method='POST', status=200)

        self.generate(self.nodes[0], 1)  # generate block to not affect upcoming tests

        self.log.info("Test the /block, /blockhashbyheight, /headers, and /blockfilterheaders URIs")
        bb_hash = self.nodes[0].getbestblockhash()

        # Check result if block does not exists
        assert_equal(self.test_rest_request(f"/headers/{UNKNOWN_PARAM}", query_params={"count": 1}), [])
        self.test_rest_request(f"/block/{UNKNOWN_PARAM}", status=404, ret_type=RetType.OBJ)

        # Check result if block is not in the active chain
        self.nodes[0].invalidateblock(bb_hash)
        assert_equal(self.test_rest_request(f'/headers/{bb_hash}', query_params={'count': 1}), [])
        self.test_rest_request(f'/block/{bb_hash}')
        self.nodes[0].reconsiderblock(bb_hash)

        # Check binary format
        response = self.test_rest_request(f"/block/{bb_hash}", req_type=ReqType.BIN, ret_type=RetType.OBJ)
        assert_greater_than(int(response.getheader('content-length')), BLOCK_HEADER_SIZE)
        response_bytes = response.read()

        # Compare with block header
        response_header = self.test_rest_request(f"/headers/{bb_hash}", req_type=ReqType.BIN, ret_type=RetType.OBJ, query_params={"count": 1})
        assert_equal(int(response_header.getheader('content-length')), BLOCK_HEADER_SIZE)
        response_header_bytes = response_header.read()
        assert_equal(response_bytes[:BLOCK_HEADER_SIZE], response_header_bytes)

        # Check block hex format
        response_hex = self.test_rest_request(f"/block/{bb_hash}", req_type=ReqType.HEX, ret_type=RetType.OBJ)
        assert_greater_than(int(response_hex.getheader('content-length')), BLOCK_HEADER_SIZE*2)
        response_hex_bytes = response_hex.read().strip(b'\n')
        assert_equal(response_bytes.hex().encode(), response_hex_bytes)

        # Compare with hex block header
        response_header_hex = self.test_rest_request(f"/headers/{bb_hash}", req_type=ReqType.HEX, ret_type=RetType.OBJ, query_params={"count": 1})
        assert_greater_than(int(response_header_hex.getheader('content-length')), BLOCK_HEADER_SIZE*2)
        response_header_hex_bytes = response_header_hex.read(BLOCK_HEADER_SIZE*2)
        assert_equal(response_bytes[:BLOCK_HEADER_SIZE].hex().encode(), response_header_hex_bytes)

        # Check json format
        block_json_obj = self.test_rest_request(f"/block/{bb_hash}")
        assert_equal(block_json_obj['hash'], bb_hash)
        assert_equal(self.test_rest_request(f"/blockhashbyheight/{block_json_obj['height']}")['blockhash'], bb_hash)

        # Check hex/bin format
        resp_hex = self.test_rest_request(f"/blockhashbyheight/{block_json_obj['height']}", req_type=ReqType.HEX, ret_type=RetType.OBJ)
        assert_equal(resp_hex.read().decode('utf-8').rstrip(), bb_hash)
        resp_bytes = self.test_rest_request(f"/blockhashbyheight/{block_json_obj['height']}", req_type=ReqType.BIN, ret_type=RetType.BYTES)
        blockhash = resp_bytes[::-1].hex()
        assert_equal(blockhash, bb_hash)

        # Check invalid blockhashbyheight requests
        resp = self.test_rest_request(f"/blockhashbyheight/{INVALID_PARAM}", ret_type=RetType.OBJ, status=400)
        assert_equal(resp.read().decode('utf-8').rstrip(), f"Invalid height: {INVALID_PARAM}")
        resp = self.test_rest_request("/blockhashbyheight/1000000", ret_type=RetType.OBJ, status=404)
        assert_equal(resp.read().decode('utf-8').rstrip(), "Block height out of range")
        resp = self.test_rest_request("/blockhashbyheight/-1", ret_type=RetType.OBJ, status=400)
        assert_equal(resp.read().decode('utf-8').rstrip(), "Invalid height: -1")
        self.test_rest_request("/blockhashbyheight/", ret_type=RetType.OBJ, status=400)

        # Compare with json block header
        json_obj = self.test_rest_request(f"/headers/{bb_hash}", query_params={"count": 1})
        assert_equal(len(json_obj), 1)  # ensure that there is one header in the json response
        assert_equal(json_obj[0]['hash'], bb_hash)  # request/response hash should be the same

        # Compare with normal RPC block response
        rpc_block_json = self.nodes[0].getblock(bb_hash)
        for key in ['hash', 'confirmations', 'height', 'version', 'merkleroot', 'time', 'nonce', 'bits', 'difficulty', 'chainwork', 'previousblockhash']:
            assert_equal(json_obj[0][key], rpc_block_json[key])

        # See if we can get 5 headers in one response
        self.generate(self.nodes[1], 5)
        json_obj = self.test_rest_request(f"/headers/{bb_hash}", query_params={"count": 5})
        assert_equal(len(json_obj), 5)  # now we should have 5 header objects
        json_obj = self.test_rest_request(f"/blockfilterheaders/basic/{bb_hash}", query_params={"count": 5})
        first_filter_header = json_obj[0]
        assert_equal(len(json_obj), 5)  # now we should have 5 filter header objects
        json_obj = self.test_rest_request(f"/blockfilter/basic/{bb_hash}")

        # Compare with normal RPC blockfilter response
        rpc_blockfilter = self.nodes[0].getblockfilter(bb_hash)
        assert_equal(first_filter_header, rpc_blockfilter['header'])
        assert_equal(json_obj['filter'], rpc_blockfilter['filter'])

        # Test blockfilterheaders with an invalid hash and filtertype
        resp = self.test_rest_request(f"/blockfilterheaders/{INVALID_PARAM}/{bb_hash}", ret_type=RetType.OBJ, status=400)
        assert_equal(resp.read().decode('utf-8').rstrip(), f"Unknown filtertype {INVALID_PARAM}")
        resp = self.test_rest_request(f"/blockfilterheaders/basic/{INVALID_PARAM}", ret_type=RetType.OBJ, status=400)
        assert_equal(resp.read().decode('utf-8').rstrip(), f"Invalid hash: {INVALID_PARAM}")

        # Test number parsing
        for num in ['5a', '-5', '0', '2001', '99999999999999999999999999999999999']:
            assert_equal(
                bytes(f'Header count is invalid or out of acceptable range (1-2000): {num}\r\n', 'ascii'),
                self.test_rest_request(f"/headers/{bb_hash}", ret_type=RetType.BYTES, status=400, query_params={"count": num}),
            )

        self.log.info("Test tx inclusion in the /mempool and /block URIs")

        # Make 3 chained txs and mine them on node 1
        txs = []
        input_txid = txid
        for _ in range(3):
            utxo_to_spend = self.wallet.get_utxo(txid=input_txid)
            txs.append(self.wallet.send_self_transfer(from_node=self.nodes[0], utxo_to_spend=utxo_to_spend)['txid'])
            input_txid = txs[-1]
        self.sync_all()

        # Check that there are exactly 3 transactions in the TX memory pool before generating the block
        json_obj = self.test_rest_request("/mempool/info")
        assert_equal(json_obj['size'], 3)
        # the size of the memory pool should be greater than 3x ~100 bytes
        assert_greater_than(json_obj['bytes'], 300)

        mempool_info = self.nodes[0].getmempoolinfo()
        assert_equal(json_obj, mempool_info)

        # Check that there are our submitted transactions in the TX memory pool
        json_obj = self.test_rest_request("/mempool/contents")
        raw_mempool_verbose = self.nodes[0].getrawmempool(verbose=True)

        assert_equal(json_obj, raw_mempool_verbose)

        for i, tx in enumerate(txs):
            assert tx in json_obj
            assert_equal(json_obj[tx]['spentby'], txs[i + 1:i + 2])
            assert_equal(json_obj[tx]['depends'], txs[i - 1:i])

        # Now mine the transactions
        newblockhash = self.generate(self.nodes[1], 1)

        # Check if the 3 tx show up in the new block
        json_obj = self.test_rest_request(f"/block/{newblockhash[0]}")
        non_coinbase_txs = {tx['txid'] for tx in json_obj['tx']
                            if 'coinbase' not in tx['vin'][0]}
        assert_equal(non_coinbase_txs, set(txs))

        # Verify that the non-coinbase tx has "prevout" key set
        for tx_obj in json_obj["tx"]:
            for vin in tx_obj["vin"]:
                if "coinbase" not in vin:
                    assert "prevout" in vin
                    assert_equal(vin["prevout"]["generated"], False)
                else:
                    assert "prevout" not in vin

        # Check the same but without tx details
        json_obj = self.test_rest_request(f"/block/notxdetails/{newblockhash[0]}")
        for tx in txs:
            assert tx in json_obj['tx']

        self.log.info("Test the /chaininfo URI")

        bb_hash = self.nodes[0].getbestblockhash()

        json_obj = self.test_rest_request("/chaininfo")
        assert_equal(json_obj['bestblockhash'], bb_hash)

        # Compare with normal RPC getblockchaininfo response
        blockchain_info = self.nodes[0].getblockchaininfo()
        assert_equal(blockchain_info, json_obj)

        # Test compatibility of deprecated and newer endpoints
        self.log.info("Test compatibility of deprecated and newer endpoints")
        assert_equal(self.test_rest_request(f"/headers/{bb_hash}", query_params={"count": 1}), self.test_rest_request(f"/headers/1/{bb_hash}"))
        assert_equal(self.test_rest_request(f"/blockfilterheaders/basic/{bb_hash}", query_params={"count": 1}), self.test_rest_request(f"/blockfilterheaders/basic/5/{bb_hash}"))


if __name__ == '__main__':
    RESTTest().main()