From 92d7b5552f4030bd2db981b80db1423c5a9ebba2 Mon Sep 17 00:00:00 2001
From: Patrick Wuttke <mewin@mewin.de>
Date: Wed, 11 Sep 2024 08:57:43 +0200
Subject: [PATCH] WIP: CURL/request implementation.

---
 source/mijin/net/curl_wrappers.hpp | 134 +++++++++++++++++++++++++++++
 source/mijin/net/request.cpp       |  60 +++++++++++++
 source/mijin/net/request.hpp       |  15 ++++
 3 files changed, 209 insertions(+)
 create mode 100644 source/mijin/net/curl_wrappers.hpp
 create mode 100644 source/mijin/net/request.cpp
 create mode 100644 source/mijin/net/request.hpp

diff --git a/source/mijin/net/curl_wrappers.hpp b/source/mijin/net/curl_wrappers.hpp
new file mode 100644
index 0000000..a600da9
--- /dev/null
+++ b/source/mijin/net/curl_wrappers.hpp
@@ -0,0 +1,134 @@
+
+#pragma once
+
+#if !defined(MIJIN_NET_CURL_WRAPPERS_HPP_INCLUDED)
+#define MIJIN_NET_CURL_WRAPPERS_HPP_INCLUDED 1
+
+#include <curl/curl.h>
+
+#include "./url.hpp"
+#include "../debug/assert.hpp"
+#include "../internal/common.hpp"
+#include "../types/result.hpp"
+
+namespace curl
+{
+#if !MIJIN_WITH_EXCEPTIONS
+struct [[nodiscard]] Error
+{
+    CURLcode code = CURLE_OK;
+
+    [[nodiscard]]
+    bool isSuccess() const MIJIN_NOEXCEPT { return code == CURLE_OK; }
+};
+
+#define MIJIN_CURL_VERIFY_RESULT(curlResult) \
+do                                           \
+{                                            \
+    if ((curlResult) != CURLE_OK)            \
+    {                                        \
+        return Error{curlResult};            \
+    }                                        \
+} while (0)
+#define MIJIN_CURL_RETURN_SUCCESS() return Error()
+#else
+using Error = void;
+
+[[nodiscard]]
+std::string curlCodeMessage(CURLcode code)
+{
+    switch (code)
+    {
+        default:
+            return "Unknown CURL error.";
+    }
+}
+
+class CurlException : public std::runtime_error
+{
+private:
+    CURLcode code_;
+public:
+    explicit CurlException(CURLcode code) MIJIN_NOEXCEPT: std::runtime_error(curlCodeMessage(code)), code_(code)
+    {}
+
+    [[nodiscard]]
+    constexpr CURLcode getCode() const MIJIN_NOEXCEPT
+    { return code_; }
+};
+
+#define MIJIN_CURL_VERIFY_RESULT(curlResult) \
+do                                           \
+{                                            \
+    if ((curlResult) != CURLE_OK)            \
+    {                                        \
+        throw CurlException((curlResult));   \
+    }                                        \
+} while (0)
+#define MIJIN_CURL_RETURN_SUCCESS() return
+#endif
+
+class CurlEasy
+{
+private:
+    CURL* handle_ = nullptr;
+public:
+    CurlEasy() MIJIN_NOEXCEPT = default;
+    CurlEasy(const CurlEasy&) = delete;
+    CurlEasy(CurlEasy&& other) MIJIN_NOEXCEPT : handle_(std::exchange(other.handle_, nullptr)) {}
+    ~CurlEasy() MIJIN_NOEXCEPT
+    {
+        reset();
+    }
+
+    CurlEasy& operator=(const CurlEasy&) = delete;
+    CurlEasy& operator=(CurlEasy&& other) MIJIN_NOEXCEPT
+    {
+        if (this == &other)
+        {
+            return *this;
+        }
+        reset();
+        handle_ = std::exchange(other.handle_, nullptr);
+        return *this;
+    }
+
+    MIJIN_ERROR_BOOL init() MIJIN_THROWS
+    {
+        reset();
+        handle_ = curl_easy_init();
+        if (handle_ != nullptr)
+        {
+            MIJIN_THROW_OR_RETURN_STD(false, "Error initializing CURL easy.");
+        }
+        MIJIN_RETURN_SUCCESS(true);
+    }
+    void reset() MIJIN_NOEXCEPT
+    {
+        if (handle_)
+        {
+            curl_easy_cleanup(handle_);
+            handle_ = nullptr;
+        }
+    }
+
+    Error setURL(const char* url) MIJIN_THROWS
+    {
+        const CURLcode result = curl_easy_setopt(handle_, CURLOPT_URL, url);
+        MIJIN_CURL_VERIFY_RESULT(result);
+        MIJIN_CURL_RETURN_SUCCESS();
+    }
+
+    Error setURL(const std::string& url) MIJIN_NOEXCEPT
+    {
+        return setURL(url.c_str());
+    }
+
+    Error setURL(const mijin::URL& url) MIJIN_NOEXCEPT
+    {
+        return setURL(url.getBase().c_str());
+    }
+};
+} // namespace curl
+
+#endif // !defined(MIJIN_NET_CURL_WRAPPERS_HPP_INCLUDED)
diff --git a/source/mijin/net/request.cpp b/source/mijin/net/request.cpp
new file mode 100644
index 0000000..84f6168
--- /dev/null
+++ b/source/mijin/net/request.cpp
@@ -0,0 +1,60 @@
+
+#include "./request.hpp"
+
+#include <mutex>
+
+#include "./curl_wrappers.hpp"
+
+namespace mijin
+{
+namespace
+{
+bool gCurlInited = false;
+std::mutex gCurlInitMutex;
+
+class CURLGuard
+{
+public:
+    ~CURLGuard() MIJIN_NOEXCEPT
+    {
+        if (gCurlInited)
+        {
+            curl_global_cleanup();
+        }
+    }
+} gCURLGuard [[maybe_unused]];
+
+bool initCURL() MIJIN_NOEXCEPT
+{
+    if (gCurlInited)
+    {
+        return true;
+    }
+    const std::unique_lock initLock(gCurlInitMutex);
+    if (gCurlInited)
+    {
+        return true;
+    }
+    gCurlInited = (curl_global_init(0) == CURLE_OK);
+    return gCurlInited;
+}
+}
+
+Task<StreamResult<HTTPResponse>> c_request(const URL& url, HTTPRequest request) MIJIN_NOEXCEPT
+{
+    (void) url;
+    (void) request;
+    if (!initCURL())
+    {
+        co_return StreamError::UNKNOWN_ERROR;
+    }
+    curl::CurlEasy easy;
+    if (!easy.init())
+    {
+        co_return StreamError::UNKNOWN_ERROR;
+    }
+    easy.setURL(url);
+
+    co_return StreamError::UNKNOWN_ERROR;
+}
+} // namespace mijin
diff --git a/source/mijin/net/request.hpp b/source/mijin/net/request.hpp
new file mode 100644
index 0000000..fd76b4a
--- /dev/null
+++ b/source/mijin/net/request.hpp
@@ -0,0 +1,15 @@
+
+#pragma once
+
+#if !defined(MIJIN_NET_REQUST_HPP_INCLUDED)
+#define MIJIN_NET_REQUST_HPP_INCLUDED 1
+
+#include "./http.hpp"
+#include "../internal/common.hpp"
+
+namespace mijin
+{
+Task<StreamResult<HTTPResponse>> c_request(const URL& url, HTTPRequest request = {}) MIJIN_NOEXCEPT;
+} // namespace mijin
+
+#endif // !defined(MIJIN_NET_REQUST_HPP_INCLUDED)