[RFC PATCH 4/9] gwarnt: p2p: Add P2P OKX

[Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>]

Add an interface to collect P2P ads from OKX.

Signed-off-by: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>
---
 Makefile               |   3 +-
 src/gwarnt/p2p/okx.cpp | 101 +++++++++++++++++++++++++++++++++++++++++
 src/gwarnt/p2p/okx.hpp |  35 ++++++++++++++
 3 files changed, 138 insertions(+), 1 deletion(-)
 create mode 100644 src/gwarnt/p2p/okx.cpp
 create mode 100644 src/gwarnt/p2p/okx.hpp

diff --git a/Makefile b/Makefile
index 732d1b7..6aa0b32 100644
--- a/Makefile
+++ b/Makefile
@@ -15,7 +15,8 @@ CXX_SOURCES	:= \
 	src/gwarnt/helpers.cpp \
 	src/gwarnt/net.cpp \
 	src/gwarnt/p2p_ad.cpp \
-	src/gwarnt/p2p/binance.cpp
+	src/gwarnt/p2p/binance.cpp \
+	src/gwarnt/p2p/okx.cpp
 
 C_OBJECTS	:= $(C_SOURCES:.c=.o)
 CXX_OBJECTS	:= $(CXX_SOURCES:.cpp=.o)
diff --git a/src/gwarnt/p2p/okx.cpp b/src/gwarnt/p2p/okx.cpp
new file mode 100644
index 0000000..f37ace4
--- /dev/null
+++ b/src/gwarnt/p2p/okx.cpp
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <gwarnt/p2p/okx.hpp>
+#include <gwarnt/helpers.hpp>
+#include <gwarnt/json.hpp>
+#include <exception>
+
+using json = nlohmann::json;
+
+namespace gwarnt {
+namespace p2p {
+
+okx::okx(void)
+{
+	net_.add_header("Content-Type", "application/json");
+}
+
+okx::~okx(void) = default;
+
+void okx::set_fiat(const std::string &fiat)
+{
+	fiat_ = fiat;
+}
+
+void okx::set_crypto(const std::string &crypto)
+{
+	crypto_ = crypto;
+}
+
+void okx::set_trade_type(const std::string &trade_type)
+{
+	trade_type_ = trade_type;
+}
+
+std::vector<gwarnt::p2p_ad> okx::get_data(void)
+{
+	return get_data(fiat_, crypto_, trade_type_);
+}
+
+std::vector<gwarnt::p2p_ad> okx::get_data(const std::string &fiat,
+					  const std::string &crypto,
+					  const std::string &trade_type)
+{
+	std::vector<gwarnt::p2p_ad> ads;
+	std::string type;
+	std::string url;
+	std::string p;
+	json *jent;
+	json j;
+
+	type = trade_type;
+	strtoupper(type);
+	if (type != "BUY" && type != "SELL")
+		throw std::runtime_error("Invalid trade type: " + trade_type);
+
+	p = "side=" + trade_type + "&fiatCurrency=" + fiat + "&cryptoCurrency=" + crypto;
+	url = "https://www.okx.com/v3/c2c/tradingOrders/getMarketplaceAdsPrelogin?&paymentMethod=all&userType=all&hideOverseasVerificationAds=false&sortType=price_asc&limit=1000&currentPage=1&numberPerPage=1000&"
+		+ p;
+
+	net_.set_method("GET");
+	net_.set_url(url);
+	net_.set_curl_opt(CURLOPT_ACCEPT_ENCODING, "gzip");
+	net_.exec();
+
+	const std::string &res = net_.get_resp();
+	j = json::parse(res);
+
+	if (type == "SELL")
+		jent = &j["data"]["sell"];
+	else
+		jent = &j["data"]["buy"];
+
+	for (const auto &q : *jent) {
+		try {
+			gwarnt::p2p_ad p;
+
+			p.ad_id_ = q["id"];
+			p.merchant_name_ = q["nickName"];
+			p.trade_type_ = type;
+			p.fiat_ = fiat;
+			p.crypto_ = crypto;
+			p.price_ = strtod(q["price"].get<std::string>().c_str(), nullptr);
+			p.min_amount_ = strtod(q["quoteMinAmountPerOrder"].get<std::string>().c_str(), nullptr);
+			p.max_amount_ = strtod(q["quoteMaxAmountPerOrder"].get<std::string>().c_str(), nullptr);
+			p.tradable_amount_ = strtod(q["availableAmount"].get<std::string>().c_str(), nullptr);
+			p.exchange_ = "okx";
+
+			for (auto &r : q["paymentMethods"])
+				p.methods_.push_back(r);
+
+			ads.push_back(p);
+		} catch (const std::exception &e) {
+			printf("gwarnt::p2p::okx::get_data: %s\n", e.what());
+		}
+	}
+
+	return ads;
+}
+
+} /* namespace gwarnt */
+} /* namespace p2p */
diff --git a/src/gwarnt/p2p/okx.hpp b/src/gwarnt/p2p/okx.hpp
new file mode 100644
index 0000000..3422ac5
--- /dev/null
+++ b/src/gwarnt/p2p/okx.hpp
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#ifndef GWARNT__P2P__OKX_HPP
+#define GWARNT__P2P__OKX_HPP
+
+#include <gwarnt/net.hpp>
+#include <gwarnt/p2p_ad.hpp>
+
+namespace gwarnt {
+namespace p2p {
+
+class okx {
+public:
+	okx(void);
+	~okx(void);
+
+	void set_fiat(const std::string &fiat);
+	void set_crypto(const std::string &crypto);
+	void set_trade_type(const std::string &trade_type);
+	std::vector<gwarnt::p2p_ad> get_data(void);
+	std::vector<gwarnt::p2p_ad> get_data(const std::string &fiat,
+					     const std::string &crypto,
+					     const std::string &trade_type);
+
+private:
+	gwarnt::net	net_;
+	std::string	fiat_;
+	std::string	crypto_;
+	std::string	trade_type_;
+};
+
+} /* namespace p2p */
+} /* namespace gwarnt */
+
+#endif /* GWARNT__P2P__OKX_HPP */
-- 
Alviro Iskandar Setiawan