From c5875724324c4a98ea9ce47522ce002380469b1a Mon Sep 17 00:00:00 2001
From: jie <depressedjie@outlook.com>
Date: Mon, 14 Oct 2024 18:08:50 +0800
Subject: [PATCH] init

---
 build.sh        |  1 +
 main.cc         |  6 ++++
 sqlConnection.h | 87 ++++++++++++++++++++++++++++++++++++++++++++
 util.h          | 96 +++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 190 insertions(+)
 create mode 100755 build.sh
 create mode 100644 main.cc
 create mode 100644 sqlConnection.h
 create mode 100644 util.h

diff --git a/build.sh b/build.sh
new file mode 100755
index 0000000..88b2619
--- /dev/null
+++ b/build.sh
@@ -0,0 +1 @@
+g++ -o demo main.cc -I/usr/include/mysql -lmysqlclient -std=c++23 -g
diff --git a/main.cc b/main.cc
new file mode 100644
index 0000000..3f7b1b2
--- /dev/null
+++ b/main.cc
@@ -0,0 +1,6 @@
+#include "sqlConnection.h"
+
+int main(int argc, char** const argv){
+    SqlConnection conn{};
+    return 0;
+}
\ No newline at end of file
diff --git a/sqlConnection.h b/sqlConnection.h
new file mode 100644
index 0000000..9f28fee
--- /dev/null
+++ b/sqlConnection.h
@@ -0,0 +1,87 @@
+#include <optional>
+#include <ranges>
+#include <algorithm>
+#include <string_view>
+#include <expected>
+
+#include "mysql.h"
+
+#include "util.h"
+
+using util::_support_string;
+
+class SqlConnection{
+private:
+    MYSQL mysql_client;
+    auto get_error_msg(){
+        return mysql_error(&mysql_client);
+    }
+
+public:
+    char* ip;
+    char* port;
+    char* username;
+    char* password;
+    char* database_name;
+    
+    SqlConnection(){
+        Init();
+    }
+    ~SqlConnection() noexcept{
+        Close();
+    }
+    
+    SqlConnection(const SqlConnection& other) = delete;
+    SqlConnection& operator=(const SqlConnection& other) = delete;
+    
+    SqlConnection(SqlConnection&& other){
+        other.Close();        
+        this->Connect(other.ip, other.port, other.username, other.password, other.database_name);
+    }
+    
+    SqlConnection& operator=(SqlConnection&& other){
+        if(this != &other){
+            auto temp = SqlConnection{};
+            temp.Connect(other.ip, other.port, other.username, other.password, other.database_name);
+            other.Close();
+        }
+        return *this;
+    }
+    
+    void Init() noexcept {
+        mysql_init(&mysql_client); 
+    }
+    
+    std::expected<bool, std::string_view> Connect(std::string_view _ip, std::string_view _port = "3306", std::string_view _username = "root", std::string_view _password = "", std::string_view _database_name = "mysql"){
+        this->ip = util::to_char(_ip);
+        this->port = util::to_char(_port);
+        this->username = util::to_char(_username);
+        this->password = util::to_char(_password);
+        this->database_name = util::to_char(_database_name);
+        if(mysql_real_connect(&mysql_client, ip, username, password, database_name, std::stoi(port), nullptr, 0) == nullptr){
+            auto error_msg = get_error_msg();
+            return std::unexpected(error_msg);
+        }
+        return true;
+    }
+    
+    void Close() noexcept {
+        mysql_close(&mysql_client);
+    }
+    
+    std::optional<std::vector<std::string_view>> Query(std::string_view command){
+        //Not Implemented;
+        return std::nullopt;
+    }
+    
+    bool Execute(std::string_view command){
+        //Not Implemented;
+        return false;
+    }
+    
+    std::vector<std::string_view> GetTables(){
+        //Not Implemented;
+        return std::vector<std::string_view>{};
+    };
+    
+};
diff --git a/util.h b/util.h
new file mode 100644
index 0000000..563b5ef
--- /dev/null
+++ b/util.h
@@ -0,0 +1,96 @@
+#ifndef UTIL_H
+#define UTIL_H
+
+#include <type_traits>
+#include <string>
+#include <string_view>
+#include <vector>
+#include <ranges>
+
+namespace util{
+    namespace ranges = std::ranges;
+    namespace views = std::ranges::views;
+
+    //util template
+    
+    // find the most strong type,
+    template<typename... Types>
+     struct _strong_type{};
+    
+    template<typename T>
+    struct _strong_type<T>{
+        using type = T;
+    };
+    
+    template<typename Ta, typename Tb>
+    struct _strong_type<Ta, Tb>{
+        using type = decltype(true ? std::declval<Ta>() : std::declval<Tb>());
+    };
+    
+    template<typename T, typename... args>
+    struct _strong_type<T, args...>{
+        using type =
+             typename _strong_type<T, typename _strong_type<args...>::type>::type;
+    };
+    
+    template<typename... args>
+    using _strong_type_t = typename _strong_type<args...>::type;
+    
+    //can type T convert to Args...
+    template<typename... Types>
+    struct _is_castable{};
+    
+    template<typename T>
+    struct _is_castable<T>{
+        static constexpr bool value = true;
+        using type = T;
+    };
+    
+    template<typename T, typename U>
+    struct _is_castable<T, U>{
+        using __true = char; 
+        using __false = struct {char _[2];};
+        static consteval __true __test(U);
+        static consteval __false __test(...);
+        static constexpr bool value = sizeof(__test(std::declval<T>())) == sizeof(__true);
+        using type = std::conditional<value, U, void>;
+    };
+    
+    template<typename T, typename... args>
+    struct _is_castable<T, args...>{
+        static constexpr bool value = _is_castable<T, typename _is_castable<args...>::type>::value;
+        using type = std::conditional<value, T, void>;
+    };
+    
+    template<typename... args>
+    using _is_castable_v = _is_castable<args...>::value;
+    
+    //type can convert to const char*, char* std::string, std::string_view;
+    template<typename T>
+    concept _support_string = requires{
+        _is_castable<T, const char*, char*, std::string, std::string_view>::value;
+    };
+    
+    //util function
+    template<_support_string T>
+    std::vector<std::string_view> split_str(T str, T d){
+        auto view = views::split(str, d) | views::transform([](auto word){return std::string_view{word.begin(), word.end()};});
+        return std::vector<std::string_view>{view.begin(), view.end()};
+    };
+    
+    template<_support_string T>
+    char* to_char(T str){
+        if constexpr (std::is_same_v<T, const char*> || std::is_same_v<T, char>){
+            return const_cast<char*>(str);
+        }
+        if constexpr (std::is_same_v<T, std::string>){
+            return const_cast<char*>(str.c_str());
+        }
+        if constexpr (std::is_same_v<T, std::string_view>){
+            return const_cast<char*>(str.data());
+        }
+    }
+    
+};
+    
+#endif
\ No newline at end of file