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Merge pull request #117 from KomodoPlatform/fix/candlestick-data-source
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Migrate candlestick charting to Binance
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@CharlVS
CharlVS committed Feb 29, 2024
2 parents 8e34f0a + a96b8b4 commit 47fece1
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Showing 12 changed files with 1,514 additions and 548 deletions.
124 changes: 51 additions & 73 deletions lib/model/cex_provider.dart
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Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,7 @@ import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'package:intl/intl.dart';
import 'package:komodo_dex/blocs/coins_bloc.dart';
import 'package:komodo_dex/packages/binance_candlestick_charts/bloc/binance_repository.dart';
import 'package:shared_preferences/shared_preferences.dart';

import '../app_config/app_config.dart';
Expand Down Expand Up @@ -87,56 +88,38 @@ class CexProvider extends ChangeNotifier {
cexPrices.unlinkProvider(this);
}

final String _chartsUrl = appConfig.candlestickData;
final Uri _tickersListUrl = Uri.parse(appConfig.candlestickTickersList);
final Map<String, ChartData> _charts = {}; // {'BTC-USD': ChartData(),}
final Map<String, ChartData> _charts = {};
bool _updatingChart = false;
List<String> _tickers;
final BinanceRepository _binanceRepository = BinanceRepository();

void _updateRates() => cexPrices.updateRates();

List<String> _getTickers() {
if (_tickers != null) return _tickers;
if (_tickers != null) {
return _tickers;
}

_updateTickersList();
return _tickersFallBack;
}

Future<void> _updateTickersList() async {
http.Response _res;
String _body;
try {
_res = await http.get(_tickersListUrl).timeout(
const Duration(seconds: 60),
onTimeout: () {
Log('cex_provider', 'Fetching tickers timed out');
return;
},
);
_body = _res.body;
_tickers = await _binanceRepository.getLegacyTickers();
notifyListeners();
} catch (e) {
Log('cex_provider', 'Failed to fetch tickers list: $e');
}

List<dynamic> json;
try {
json = jsonDecode(_body);
} catch (e) {
Log('cex_provider', 'Failed to parse tickers json: $e');
}

if (json != null) {
_tickers =
json.map<String>((dynamic ticker) => ticker.toString()).toList();
notifyListeners();
}
}

Future<void> _updateChart(String pair) async {
if (_updatingChart) return;

final List<ChainLink> chain = _findChain(pair);
if (chain == null) throw 'No chart data available';
if (chain == null) {
throw 'No chart data available';
}

Map<String, dynamic> json0;
Map<String, dynamic> json1;
Expand Down Expand Up @@ -178,7 +161,7 @@ class CexProvider extends ChangeNotifier {
json0.forEach((String duration, dynamic list) {
final List<CandleData> _durationData = [];

for (var candle in list) {
for (final Map<String, dynamic> candle in list) {
double open = chain[0].reverse
? 1 / candle['open'].toDouble()
: candle['open'].toDouble();
Expand Down Expand Up @@ -248,7 +231,6 @@ class CexProvider extends ChangeNotifier {
}

data[duration] = _durationData;
notifyListeners();
});

_charts[pair] = ChartData(
Expand All @@ -258,79 +240,69 @@ class CexProvider extends ChangeNotifier {
status: ChartStatus.success,
updated: DateTime.now().millisecondsSinceEpoch,
);

notifyListeners();
}

Future<Map<String, dynamic>> _fetchChartData(ChainLink link) async {
final String pair = '${link.rel}-${link.base}';
http.Response _res;
String _body;
try {
_res = await http
.get(Uri.parse('$_chartsUrl/${pair.toLowerCase()}'))
.timeout(
const Duration(seconds: 60),
onTimeout: () {
Log('cex_provider', 'Fetching $pair data timed out');
throw 'Fetching $pair timed out';
},
);
_body = _res.body;
final String pair = '${link.rel}-${link.base}';
final Map<String, dynamic> result =
await _binanceRepository.getLegacyOhlcCandleData(pair);
return result;
} catch (e) {
Log('cex_provider', 'Failed to fetch data: $e');
rethrow;
}

Map<String, dynamic> json;
try {
json = jsonDecode(_body);
} catch (e) {
Log('cex_provider', 'Failed to parse json: $e');
rethrow;
}

return json;
}

List<ChainLink> _findChain(String pair) {
// remove cex postfixes
pair = getCoinTickerRegex(pair);

final List<String> abbr = pair.split('-');
if (abbr[0] == abbr[1]) return null;
if (abbr[0] == abbr[1]) {
return null;
}
final String base = abbr[1].toLowerCase();
final String rel = abbr[0].toLowerCase();
final List<String> tickers = _getTickers();
List<ChainLink> chain;

if (tickers == null) return null;
if (tickers == null) {
return null;
}

// try to find simple chain, direct or reverse
for (String ticker in tickers) {
for (final String ticker in tickers) {
final List<String> availableAbbr = ticker.split('-');
if (!(availableAbbr.contains(rel) && availableAbbr.contains(base))) {
continue;
}

chain = [
ChainLink(
rel: availableAbbr[0],
base: availableAbbr[1],
reverse: availableAbbr[0] != rel,
)
];
break;
}

if (chain != null) return chain;
if (chain != null) {
return chain;
}

tickers.sort((String a, String b) {
if (a.toLowerCase().contains('btc') && !b.toLowerCase().contains('btc'))
if (a.toLowerCase().contains('btc') && !b.toLowerCase().contains('btc')) {
return -1;
if (b.toLowerCase().contains('btc') && !a.toLowerCase().contains('btc'))
}
if (b.toLowerCase().contains('btc') && !a.toLowerCase().contains('btc')) {
return 1;
}
return 0;
});

OUTER:
for (String firstLinkStr in tickers) {
for (final String firstLinkStr in tickers) {
final List<String> firstLinkCoins = firstLinkStr.split('-');
if (!firstLinkCoins.contains(rel) && !firstLinkCoins.contains(base)) {
continue;
Expand All @@ -344,7 +316,7 @@ class CexProvider extends ChangeNotifier {
firstLink.reverse ? firstLink.rel : firstLink.base;
final String secondBase = firstLinkCoins.contains(rel) ? base : rel;

for (String secondLink in tickers) {
for (final String secondLink in tickers) {
final List<String> secondLinkCoins = secondLink.split('-');
if (!(secondLinkCoins.contains(secondRel) &&
secondLinkCoins.contains(secondBase))) {
Expand All @@ -364,7 +336,9 @@ class CexProvider extends ChangeNotifier {
}
}

if (chain != null) return chain;
if (chain != null) {
return chain;
}

return null;
}
Expand Down Expand Up @@ -649,16 +623,18 @@ class CexPrices {
// Some coins are presented in multiple networks,
// like BAT-ERC20 and BAT-BEP20, but have same
// coingeckoId and same usd price
final List<Coin> coins =
(allCoins.where((coin) => getCoinTicker(coin.abbr) == ticker) ?? [])
.toList();
final List<Coin> coins = (allCoins.where(
(Coin coin) => getCoinTickerRegex(coin.abbr) == ticker,
) ??
[])
.toList();

// check if coin volume is enough
double minVolume = 10000;
double lastPrice = double.tryParse(pricesData['last_price']) ?? 0;
double volume24h = double.tryParse(pricesData['volume24h']) ?? 0;
const double minVolume = 10000;
final double lastPrice = double.tryParse(pricesData['last_price']) ?? 0;
final double volume24h = double.tryParse(pricesData['volume24h']) ?? 0;

for (Coin coin in coins) {
for (final Coin coin in coins) {
final String coinAbbr = coin.abbr;
if (coin.type == CoinType.smartChain) {
// enough_volume for all smartChain tokens is always true :. proceed
Expand Down Expand Up @@ -769,7 +745,9 @@ class CexPrices {
}

void _notifyListeners() {
for (CexProvider provider in _providers) provider.notify();
for (final CexProvider provider in _providers) {
provider.notify();
}
}
}

Expand Down
85 changes: 85 additions & 0 deletions lib/packages/binance_candlestick_charts/bloc/binance_provider.dart
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Original file line number Diff line number Diff line change
@@ -0,0 +1,85 @@
import 'dart:convert';

import 'package:http/http.dart' as http;

import '../models/binance_exchange_info.dart';
import '../models/binance_klines.dart';

/// A provider class for fetching data from the Binance API.
class BinanceProvider {
BinanceProvider({this.apiUrl = 'https://api.binance.com/api/v3'});

/// The base URL for the Binance API. Defaults to 'https://api.binance.com/api/v3'.
final String apiUrl;

/// Fetches candlestick chart data from Binance API.
///
/// Retrieves the candlestick chart data for a specific symbol and interval from the Binance API.
/// Optionally, you can specify the start time, end time, and limit of the data to fetch.
///
/// Parameters:
/// - [symbol]: The trading symbol for which to fetch the candlestick chart data.
/// - [interval]: The time interval for the candlestick chart data (e.g., '1m', '1h', '1d').
/// - [startTime]: The start time (in milliseconds since epoch, Unix time) of the data range to fetch (optional).
/// - [endTime]: The end time (in milliseconds since epoch, Unix time) of the data range to fetch (optional).
/// - [limit]: The maximum number of data points to fetch (optional). Defaults to 500, maximum is 1000.
///
/// Returns:
/// A [Future] that resolves to a [BinanceKlinesResponse] object containing the fetched candlestick chart data.
///
/// Example usage:
/// ```dart
/// final BinanceKlinesResponse klines = await fetchKlines('BTCUSDT', '1h', limit: 100);
/// ```
///
/// Throws:
/// - [Exception] if the API request fails.
Future<BinanceKlinesResponse> fetchKlines(
String symbol,
String interval, {
int startTime,
int endTime,
int limit,
}) async {
final Map<String, dynamic> queryParameters = <String, dynamic>{
'symbol': symbol,
'interval': interval,
if (startTime != null) 'startTime': startTime.toString(),
if (endTime != null) 'endTime': endTime.toString(),
if (limit != null) 'limit': limit.toString(),
};

final Uri uri =
Uri.parse('$apiUrl/klines').replace(queryParameters: queryParameters);

final http.Response response = await http.get(uri);
if (response.statusCode == 200) {
return BinanceKlinesResponse.fromJson(
jsonDecode(response.body) as List<dynamic>,
);
} else {
throw Exception(
'Failed to load klines: ${response.statusCode} ${response.body}',
);
}
}

/// Fetches the exchange information from Binance.
///
/// Returns a [Future] that resolves to a [BinanceExchangeInfoResponse] object.
/// Throws an [Exception] if the request fails.
Future<BinanceExchangeInfoResponse> fetchExchangeInfo() async {
final http.Response response = await http.get(
Uri.parse('$apiUrl/exchangeInfo'),
);

if (response.statusCode == 200) {
return BinanceExchangeInfoResponse.fromJson(
jsonDecode(response.body),
);
} else {
throw Exception(
'Failed to load symbols: ${response.statusCode} ${response.body}');
}
}
}
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