#ifndef __CORE_STR_H__
#define __CORE_STR_H__ 

#include "core_type.h"
#include "core_impl.h"
#include "log.h"

typedef struct cstring {
    char* data;
    usize len;
    usize cap;
} cstring_t;

/**
 * 创建一个新的空字符串
 */
static inline cstring_t cstring_new(void) {
    return (cstring_t) { .data = null, .len = 0, .cap = 0 };
}

/**
 * 使用指定容量创建字符串
 */
static inline cstring_t cstring_with_capacity(usize capacity) {
    char* data = null;
    if (capacity > 0) {
        data = (char*)smcc_malloc(capacity);
        Assert(data != null);
    }
    return (cstring_t) { .data = data, .len = 0, .cap = capacity };
}

/**
 * 从 C 字符串创建 Rust 风格字符串
 */
static inline cstring_t cstring_from_cstr(const char* s) {
    if (s == null) {
        return cstring_new();
    }
    
    usize len = 0;
    const char* p = s;
    while (*p++) len++;
    
    char* data = (char*)smcc_malloc(len + 1);
    Assert(data != null);
    smcc_memcpy(data, s, len);
    data[len] = '\0';
    
    return (cstring_t) { .data = data, .len = len, .cap = len };
}

/**
 * 释放字符串资源
 */
static inline void cstring_free(cstring_t* str) {
    if (str && str->data) {
        smcc_free(str->data);
        str->data = null;
        str->len = 0;
        str->cap = 0;
    }
}

/**
 * 向字符串追加内容
 */
static inline void cstring_push_str(cstring_t* str, const char* data, usize len) {
    if (str == null || data == null || len == 0) {
        return;
    }
    
    // 如果需要扩容
    if (str->len + len + 1 > str->cap) {
        // FIXME c string 兼容性问题 bad practice a lot of `+ 1`
        usize new_cap = str->cap == 0 ? len + 1 : str->cap;
        while (new_cap < str->len + len + 1) {
            new_cap *= 2;
            if (new_cap == 0) { // 处理溢出情况
                new_cap = str->len + len + 1;
                break;
            }
        }
        
        char* new_data = str->data ? 
            (char*)smcc_realloc(str->data, new_cap) : 
            (char*)smcc_malloc(new_cap);
        Assert(new_data != null);
        
        str->data = new_data;
        str->cap = new_cap;
    }
    
    smcc_memcpy(str->data + str->len, data, len);
    str->len += len;
    str->data[str->len] = '\0'; // 保证 C 字符串兼容性
}

/**
 * 向字符串追加单个字符
 */
static inline void cstring_push(cstring_t* str, char ch) {
    cstring_push_str(str, &ch, 1);
}

/**
 * 获取字符串长度
 */
static inline usize cstring_len(const cstring_t* str) {
    return str ? str->len : 0;
}

/**
 * 检查字符串是否为空
 */
static inline cbool cstring_is_empty(const cstring_t* str) {
    return str == null || str->len == 0;
}

/**
 * 清空字符串内容但保留分配的内存
 */
static inline void cstring_clear(cstring_t* str) {
    if (str) {
        str->len = 0;
        if (str->data) {
            str->data[0] = '\0';
        }
    }
}

/**
 * 获取 C 风格字符串
 */
static inline const char* cstring_as_cstr(const cstring_t* str) {
    if (str == null || str->data == null) {
        return "";
    }
    return str->data;
}

#endif /* __CORE_STR_H__ */