#!/usr/bin/env python3
# Copyright (c) 2014-2019 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
from io import BytesIO
import json
from struct import pack, unpack

import http.client
import urllib.parse

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.messages import BLOCK_HEADER_SIZE

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.setup_clean_chain = True
        self.num_nodes = 2
        self.extra_args = [["-rest"], []]
        self.supports_cli = False

    def skip_test_if_missing_module(self):
        self.skip_if_no_wallet()

    def test_rest_request(self, uri, http_method='GET', req_type=ReqType.JSON, body='', status=200, ret_type=RetType.JSON):
        rest_uri = '/rest' + uri
        if req_type == ReqType.JSON:
            rest_uri += '.json'
        elif req_type == ReqType.BIN:
            rest_uri += '.bin'
        elif req_type == ReqType.HEX:
            rest_uri += '.hex'

        conn = http.client.HTTPConnection(self.url.hostname, self.url.port)
        self.log.debug('%s %s %s', 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)

    def run_test(self):
        self.url = urllib.parse.urlparse(self.nodes[0].url)
        self.log.info("Mine blocks and send Bitcoin to node 1")

        # Random address so node1's balance doesn't increase
        not_related_address = "2MxqoHEdNQTyYeX1mHcbrrpzgojbosTpCvJ"

        self.nodes[0].generate(1)
        self.sync_all()
        self.nodes[1].generatetoaddress(100, not_related_address)
        self.sync_all()

        assert_equal(self.nodes[0].getbalance(), 50)

        txid = self.nodes[0].sendtoaddress(self.nodes[1].getnewaddress(), 0.1)
        self.sync_all()

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

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

        # Check hex format response
        hex_response = self.test_rest_request("/tx/{}".format(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)

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

        self.nodes[1].generatetoaddress(1, not_related_address)
        self.sync_all()
        bb_hash = self.nodes[0].getbestblockhash()

        assert_equal(self.nodes[1].getbalance(), Decimal("0.1"))

        # Check chainTip response
        json_obj = self.test_rest_request("/getutxos/{}-{}".format(*spending))
        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("/getutxos/{}-{}".format(*spent))

        # 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("/getutxos/{}-{}/{}-{}".format(*(spending + spent)))

        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, 102)  # chain height must be 102

        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.nodes[0].sendtoaddress(self.nodes[1].getnewaddress(), 0.1)
        json_obj = self.test_rest_request("/tx/{}".format(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("/getutxos/{}-{}".format(*spending))
        assert_equal(len(json_obj['utxos']), 0)

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

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

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

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

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

        json_obj = self.test_rest_request("/getutxos/checkmempool/{}-{}".format(*spending))
        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(["{}-{}".format(txid, n_) for n_ in range(20)])
        self.test_rest_request("/getutxos/checkmempool/{}".format(long_uri), http_method='POST', status=400, ret_type=RetType.OBJ)

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

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

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

        # Check result if block does not exists
        assert_equal(self.test_rest_request('/headers/1/0000000000000000000000000000000000000000000000000000000000000000'), [])
        self.test_rest_request('/block/0000000000000000000000000000000000000000000000000000000000000000', 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('/headers/1/{}'.format(bb_hash)), [])
        self.test_rest_request('/block/{}'.format(bb_hash))
        self.nodes[0].reconsiderblock(bb_hash)

        # Check binary format
        response = self.test_rest_request("/block/{}".format(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("/headers/1/{}".format(bb_hash), req_type=ReqType.BIN, ret_type=RetType.OBJ)
        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("/block/{}".format(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("/headers/1/{}".format(bb_hash), req_type=ReqType.HEX, ret_type=RetType.OBJ)
        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("/block/{}".format(bb_hash))
        assert_equal(block_json_obj['hash'], bb_hash)
        assert_equal(self.test_rest_request("/blockhashbyheight/{}".format(block_json_obj['height']))['blockhash'], bb_hash)

        # Check hex/bin format
        resp_hex = self.test_rest_request("/blockhashbyheight/{}".format(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("/blockhashbyheight/{}".format(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("/blockhashbyheight/abc", ret_type=RetType.OBJ, status=400)
        assert_equal(resp.read().decode('utf-8').rstrip(), "Invalid height: abc")
        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("/headers/1/{}".format(bb_hash))
        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.nodes[1].generate(5)
        self.sync_all()
        json_obj = self.test_rest_request("/headers/5/{}".format(bb_hash))
        assert_equal(len(json_obj), 5)  # now we should have 5 header objects

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

        # Make 3 tx and mine them on node 1
        txs = []
        txs.append(self.nodes[0].sendtoaddress(not_related_address, 11))
        txs.append(self.nodes[0].sendtoaddress(not_related_address, 11))
        txs.append(self.nodes[0].sendtoaddress(not_related_address, 11))
        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)

        # Check that there are our submitted transactions in the TX memory pool
        json_obj = self.test_rest_request("/mempool/contents")
        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.nodes[1].generate(1)
        self.sync_all()

        # Check if the 3 tx show up in the new block
        json_obj = self.test_rest_request("/block/{}".format(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))

        # Check the same but without tx details
        json_obj = self.test_rest_request("/block/notxdetails/{}".format(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)

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