FileController.h

//
// Created by 下水道的小老鼠 on 2023/6/3.
//

#ifndef UNTITLED_FILECONTROLLER_H
#define UNTITLED_FILECONTROLLER_H

#include "CEmployee.h"
#include <optional>
#include <cstring>
#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
#include <vector>
#include <algorithm>

using namespace std;

class FileController {
public:

    /**
     * 读取文件中的数据
     *
     * @param filename 文件名
     * @return
     */
    static vector<CEmployee> readEmployeesFromFile(const string &filename) {
        vector<CEmployee> employees;
        //打开文件
        ifstream infile(filename);

        if (!infile.is_open()) {
            cout << "Error opening file: " << filename << endl;
            return employees;
        }

        //读取文件中的每一行
        string line;
        while (getline(infile, line)) {
            istringstream iss(line);
            vector<string> tokens;
            string token;

            //每一行以逗号分隔符读取
            while (getline(iss, token, ',')) {
                tokens.push_back(token);
            }

            if (tokens.size() == 5) {
                BDay birthday = BDay(0, 0, 0);
                stringstream ss(tokens[3]);
                ss >> birthday.year;
                ss.ignore();
                ss >> birthday.month;
                ss.ignore();
                ss >> birthday.day;
                //读取的数据放到集合中
                employees.emplace_back(tokens[0].c_str(), tokens[1].c_str(), tokens[2].c_str(), birthday,
                                       stod(tokens[4]));
            } else {
                cout << "Invalid line: " << line << endl;
            }
        }

        infile.close();
        //返回集合
        return employees;
    }

    /**
     * 向文件中写入员工数据
     *
     * @param employees 员工的数据
     * @param filename 要写入的文件名
     */
    static void writeEmployeeToFile(vector<CEmployee> &employees, const string &filename) {
        // ios_base::app 表示在文件尾部添加新数据
        ofstream outfile(filename, ios_base::app);

        if (!outfile.is_open()) {
            cout << "Error opening file: " << filename << endl;
            return;
        }
        for (CEmployee employee: employees) {
            outfile << employee.getName() << "," << employee.getSex() << "," << employee.getKind() << ","
                    << employee.getBirthday().year << "-"
                    << employee.getBirthday().month << "-"
                    << employee.getBirthday().day << ","
                    << employee.getTotalSalary() << endl;
        }

        outfile.close();
    }

    /**
     * 根据名字删除文件中文件中员工信息
     *
     * @param name 员工名字
     * @param filename 文件名
     */
    static void deleteEmployeeFromFile(const string &name, const string &filename) {
        std::ifstream infile(filename);
        //ios_base::trunc 是指如果文件已经存在，则先删除源文件，然后重新创建一个空文件，以便进行下一步的写入操作
        std::ofstream outfile("temp.data", ios_base::trunc);

        if (!infile.is_open() || !outfile.is_open()) {
            std::cout << "Error opening file: " << filename << std::endl;
            return;
        }

        std::string line;
        bool found = false;
        while (std::getline(infile, line)) {
            istringstream iss(line);
            vector<std::string> tokens;
            string token;

            while (getline(iss, token, ',')) {
                tokens.push_back(token);
            }

            // 判断是否为要删除的行
            if (!tokens.empty() && tokens[0] == name) {
                found = true;
                //跳过这次循环，不将此行输出到临时文件中
                continue;
            }

            //将不是要删除的行复制到临时文件
            outfile << line << endl;
        }

        infile.close();
        outfile.close();

        //如果没有要删除的行，则要删除掉临时文件
        if (!found) {
            cout << "Could not find employee: " << name << endl;
            remove("temp.data");
            return;
        }

        //删除之前的文件，并将临时文件改名为原来的文件名
        remove(filename.c_str());
        rename("temp.data", filename.c_str());

        cout << "Deleted employee: " << name << endl;
    }

    /**
     * 根据员工名字修改员工的信息
     *
     * @param name 员工名字
     * @param employee 员工要修改后的信息
     * @param filename 文件名
     */
    static void UpdateEmployeeFromFile(const string &name, CEmployee employee, const string &filename) {
        std::ifstream infile(filename);
        std::ofstream outfile("temp.data", ios_base::trunc);

        if (!infile.is_open() || !outfile.is_open()) {
            std::cout << "Error opening file: " << filename << std::endl;
            return;
        }

        std::string line;
        bool found = false;
        while (std::getline(infile, line)) {
            istringstream iss(line);
            vector<std::string> tokens;
            string token;

            while (getline(iss, token, ',')) {
                tokens.push_back(token);
            }

            // 判断是否为要修改的行
            if (!tokens.empty() && tokens[0] == name) {
                found = true;
                //将要修改的数据输出到临时文件
                outfile << employee.getName() << "," << employee.getSex() << "," << employee.getKind() << ","
                        << employee.getBirthday().year << "-"
                        << employee.getBirthday().month << "-"
                        << employee.getBirthday().day << ","
                        << employee.getTotalSalary() << endl;
                //跳过这次循环，不仔将此行输出到临时文件中
                continue;
            }
            //将不是要修改的行复制到临时文件
            outfile << line << endl;
        }

        infile.close();
        outfile.close();

        //如果没有要删除的行，则要删除掉临时文件
        if (!found) {
            cout << "Could not find employee: " << name << endl;
            remove("temp.data");
            return;
        }

        //删除之前的文件，并将临时文件改名为原来的文件名
        remove(filename.c_str());
        rename("temp.data", filename.c_str());

        cout << "Update employee: " << name << endl;
    }

    /**
     * 根据员工名字查询员工
     *
     * @param name 员工名字
     * @param filename 文件名
     * @return
     */
    static optional<CEmployee> searchByNameFormFile(const string &name, const string &filename) {
        vector<CEmployee> temp = readEmployeesFromFile(filename);
        for(CEmployee tempEmployee : temp){
            if(tempEmployee.getName() == name){
                return tempEmployee;
            }
        }

        //如果没有找到指定员工返回空指针
        cout << "Could not find employee: " << name << endl;
        return nullopt;
    }

    /**
     * 根据员工职位查询员工
     *
     * @param type 职位
     * @param filename 文件名
     * @return
     */
    static vector<CEmployee> searchByTypeFromFile(const string &type, const string &filename) {
        vector<CEmployee> temp = readEmployeesFromFile(filename);
        vector<CEmployee> employees;
        for(CEmployee employee : temp){
            if(employee.getKind() == type){
                employees.push_back(employee);
            }
        }
        return employees;
    }

    /**
     * 输出薪资文件
     *
     * @param name 名字
     * @param filename 文件名
     */
    static void getSalaryByFile(const string &type, const string &filename) {
        //ios_base::trunc 是指如果文件已经存在，则先删除源文件，然后重新创建一个空文件，以便进行下一步的写入操作
        std::ofstream outfile(R"(D:\C or C++\C++\Employees\Employees-management-system\C--simple-homework\salary.data)",
                              ios_base::trunc);

        if (!outfile.is_open()) {
            std::cout << "Error opening file: " << filename << std::endl;
            return;
        }

        std::string line;
        string arr[] = {"CMgr", "CManager", "CWage", "CSales"};
        if (type == "kind") {
            //按“雇员类型”排序输出
            vector<CEmployee> employees;
            for (const auto &i: arr) {
                ifstream infile(filename);
                if (!infile.is_open()) {
                    cout << "Error opening file: " << filename << endl;
                    return;
                }
                while (getline(infile, line)) {
                    istringstream iss(line);
                    vector<std::string> tokens;
                    string token;
                    while (getline(iss, token, ',')) {
                        tokens.push_back(token);
                    }

                    // 判断是否为查找的行 类型：post雇员类型 name名字
                    if (!tokens.empty() && tokens.size() == 5 && tokens[2] == i) {
                        BDay birthday = BDay(0, 0, 0);
                        stringstream ss(tokens[3]);
                        ss >> birthday.year;
                        ss.ignore();
                        ss >> birthday.month;
                        ss.ignore();
                        ss >> birthday.day;
                        employees.emplace_back(tokens[0].c_str(), tokens[1].c_str(), tokens[2].c_str(), birthday,
                                               stod(tokens[4]));
                    }
                }

                outfile << "post is " << i << ":" << endl;
                // 依次将堆顶元素移到最后一个位置，并从容器中删除
                for (CEmployee emp: employees) {
                    outfile << "Name: " << emp.getName()
                            << "; Sex: " << emp.getSex()
                            << "; Salary: " << emp.getTotalSalary() << endl;
                }
                employees.clear();
                infile.close();
            }
        } else if (type == "name") {
            //选择是按“姓名”排序输出
            vector<CEmployee> employees = readEmployeesFromFile(filename);

            // 按名称排序
            sort(employees.begin(), employees.end(), simpleSortByName());
            for (CEmployee emp: employees) {
                outfile << "Name: " << emp.getName()
                        << "; Sex: " << emp.getSex()
                        << "; Kind: " << emp.getKind()
                        << "; Salary: " << emp.getTotalSalary() << endl;
            }
        } else if (type == "salary") {
            //按“薪水”排序输出
            vector<CEmployee> employees = readEmployeesFromFile(filename);
            //增加堆排序算法
            // 将容器转换为最大堆
            make_heap(employees.begin(), employees.end(), heapSortBySalary());

            // 依次将堆顶元素移到最后一个位置，并从容器中删除
            while (!employees.empty()) {
                pop_heap(employees.begin(), employees.end(), heapSortBySalary()); // 执行对堆的操作
                // 获取堆顶元素
                CEmployee emp = employees.back();
                outfile << "name: " << emp.getName() << "; Salary: "
                        << emp.getTotalSalary() << endl;
                // 删除堆顶元素
                employees.pop_back();
            }
        } else {
            return;
        }
        outfile.close();
    }

    // 按工资由高到低排序的比较函数对象
    struct heapSortBySalary {
        bool operator()(const CEmployee &emp1, const CEmployee &emp2) {
            // 返回 emp1 和 emp2 工资的大小关系
            return emp1.getTotalSalary() < emp2.getTotalSalary();
        }
    };

    //按名字排序
    struct simpleSortByName {
        bool operator()(CEmployee &emp1, CEmployee &emp2) {
            return emp1.getName() > emp2.getName();
        }
    };
};

#endif //UNTITLED_FILECONTROLLER_H