#include <exception>
#define DEBUG

#ifdef DEBUG
#include <iostream>
#endif

#include <optional>
#include <ranges>
#include <algorithm>
#include <string_view>
#include <expected>
#include <format>
#include <map>

#include "mysql.h"

#include "util.h"

template<typename T>
void log(T msg){
#ifdef DEBUG
    std::cout<<msg<<std::endl;
#endif
}

using util::_support_string;

[[maybe_unused]]
struct RowItem{
    std::vector<std::string_view> row;
};

//Not Implemented;
[[maybe_unused]]
class Result{
    std::vector<std::string_view> fields;
    std::map<std::string_view, std::vector<std::string_view>> datas;
    
public:
    //get size;
    size_t size() const{
        size_t size = 0;
        for(auto&& [key, value] : datas){
            if(datas.size() > size) size = datas.size();
        }
        return size;
    }
    //return fields
    const std::vector<std::string_view>& get_fields() const {
        return fields;
    }
    
};

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){
            return std::unexpected(get_error_msg());
        }
        return true;
    }
    
    void Close() noexcept {
        mysql_close(&mysql_client);
    }
    
    std::vector<std::string_view> get_fields(std::string_view table_name){
        std::vector<std::string_view> really_result;
        std::string command;
        std::format_to(std::back_inserter(command), "SHOW COLUMNS FROM {};", table_name);
        auto _ = mysql_query(&mysql_client, command.c_str());
        if(auto mysql_result = mysql_store_result(&mysql_client); mysql_result != nullptr){
            auto field_length = mysql_num_fields(mysql_result);
            while(auto row = mysql_fetch_row(mysql_result)){
                really_result.emplace_back(row[0]);
            }
            mysql_free_result(mysql_result);
        }
        return really_result;
    }
    
    std::expected<std::vector<std::vector<std::string_view>>, std::string_view> Query(std::string_view command){
        std::vector<std::vector<std::string_view>> really_result;
        mysql_query(&mysql_client, command.data());
        if(auto mysql_result = mysql_store_result(&mysql_client); mysql_result != nullptr){
            auto row_length = mysql_fetch_lengths(mysql_result);
            auto field_length = mysql_num_fields(mysql_result);	
            std::vector<std::string_view> temp;
            while(auto row = mysql_fetch_row(mysql_result)){
                temp.clear();
                for(int i=0; i<field_length; i++){
                    if(row[i] != nullptr){
                        temp.emplace_back(row[i]);
                    }else{
                        temp.emplace_back("");
                    }
                    
                }
                really_result.emplace_back(temp);
            }
            
            mysql_free_result(mysql_result);
            return really_result;
        }
        
        return std::unexpected(get_error_msg());
    }
    
    std::expected<bool, std::string_view> Execute(std::string_view command){
        auto res = mysql_query(&mysql_client, command.data());
        if(!res)
            return std::unexpected(get_error_msg());
        return res;
    }
    
    std::vector<std::string_view> get_tables(){
        std::vector<std::string_view> really_result;
        mysql_query(&mysql_client, "SHOW TABLES;");
        if(auto mysql_result = mysql_store_result(&mysql_client); mysql_result != nullptr){
            auto row_length = mysql_fetch_lengths(mysql_result);
            while(auto row = mysql_fetch_row(mysql_result)){
                really_result.emplace_back(row[0]);
            }
            mysql_free_result(mysql_result);
        }

        return really_result;
    };
    
};