#pragma once

#include <string>
#include <vector>
#include <algorithm>
#include <cctype>
#include <iostream>

namespace bstl {

class String {
public:
    String();
    String(std::string str);
    String(const char* str);
    String(const String& other) = default;
    String& operator=(const String& other) = default;

    // 获取标准字符串
    [[nodiscard]] std::string str() const;
    [[nodiscard]] const char* c_str() const;
    [[nodiscard]] size_t length() const;
    [[nodiscard]] size_t size() const;
    [[nodiscard]] bool empty() const;

    // 获取/修改字符
    [[nodiscard]] char at(size_t pos) const;
    char operator[](size_t pos) const;
    char& operator[](size_t pos);

    // 分割 - 按分隔符分割字符串
    [[nodiscard]] std::vector<String> split(const String& delimiter = " ") const;

    // 连接 - 用分隔符连接多个字符串
    static String join(const std::vector<String>& parts, const String& delimiter = "");

    // 替换 - 替换第一个/所有匹配项
    [[nodiscard]] String replace(const String& oldStr, const String& newStr, int count = -1) const;

    // 大小写转换
    [[nodiscard]] String upper() const;
    [[nodiscard]] String lower() const;
    [[nodiscard]] String capitalize() const;  // 首字母大写
    [[nodiscard]] String title() const;       // 每个单词首字母大写

    // 判断函数
    [[nodiscard]] bool startswith(const String& prefix) const;
    [[nodiscard]] bool endswith(const String& suffix) const;
    [[nodiscard]] bool contains(const String& substring) const;
    [[nodiscard]] bool isdigit() const;
    [[nodiscard]] bool isalpha() const;
    [[nodiscard]] bool isalnum() const;
    [[nodiscard]] bool isspace() const;
    [[nodiscard]] bool isupper() const;
    [[nodiscard]] bool islower() const;

    // 查找和计数
    [[nodiscard]] int find(const String& substring, size_t start = 0) const;
    [[nodiscard]] int rfind(const String& substring) const;  // 从后往前查找
    [[nodiscard]] int count(const String& substring) const;

    // 去除空格和其他字符
    [[nodiscard]] String strip() const;           // 去除前后空格
    [[nodiscard]] String lstrip() const;          // 去除前导空格
    [[nodiscard]] String rstrip() const;          // 去除尾部空格
    [[nodiscard]] String strip(const String& chars) const;  // 去除指定字符

    // 对齐和填充
    [[nodiscard]] String ljust(size_t width, char fillchar = ' ') const;
    [[nodiscard]] String rjust(size_t width, char fillchar = ' ') const;
    [[nodiscard]] String center(size_t width, char fillchar = ' ') const;

    // 字符串转换
    [[nodiscard]] int toInt() const;
    [[nodiscard]] long long toLongLong() const;
    [[nodiscard]] double toDouble() const;

    // 运算符重载
    String operator+(const String& other) const;
    String operator+(const char* str) const;
    String& operator+=(const String& other);
    bool operator==(const String& other) const;
    bool operator!=(const String& other) const;
    bool operator<(const String& other) const;
    bool operator>(const String& other) const;
    bool operator<=(const String& other) const;
    bool operator>=(const String& other) const;

private:
    std::string m_data;
};

// 流运算符重载
std::ostream& operator<<(std::ostream& os, const String& str);
std::istream& operator>>(std::istream& is, String& str);

} // namespace bstl