#include "disk.h"


// 获取指定路径的磁盘使用率
int get_disk_usage(const char *path, double *usage) {
    struct statvfs stat;

    if (statvfs(path, &stat) != 0) {
        perror("statvfs failed");
        return -1;
    }

    // 计算磁盘使用率
    unsigned long total_blocks = stat.f_blocks;
    unsigned long free_blocks = stat.f_bfree;
    unsigned long used_blocks = total_blocks - free_blocks;

    *usage = (double)used_blocks / total_blocks * 100;
    return 0;
}



// 第三方邮箱告警, 磁盘使用率
int QQ_mail_warning_Disk_Use(const char *recv_mail, const char *local_ip, const char *text, int current_length) {
    
    int command_len = current_length + sizeof(QQMAIL_DISK_USE) + strlen(recv_mail) + strlen(local_ip) + 256;
    char command[command_len];

    // 生成邮件正文
    char mail_text[command_len];
    snprintf(mail_text, command_len, "Host:%s\n%s", local_ip, text);

    // 生成命令字符串
    snprintf(command, command_len, QQMAIL_DISK_USE, recv_mail, mail_text);

    // 打印命令用于调试
    printf("Command: %s %d\n", command, current_length);

    // 执行命令
    int ret = system(command);
    if (ret == -1) {
        perror("system command failed");
        return -1;
    }

    return 0;
}

int disk_usage(conf *conf, char *local_ip, int threshold) {
    FILE *mounts;
    struct mntent *ent;
    char *result;
    size_t result_size = INITIAL_SIZE;
    size_t current_length = 0;

    result = (char *)malloc(result_size);
    if (result == NULL) {
        perror("内存分配失败");
        return 1;
    }
    result[0] = '\0';  // 初始化为空字符串

    // 打开挂载表
    mounts = setmntent("/etc/mtab", "r");
    if (mounts == NULL) {
        perror("打开挂载表失败");
        free(result);
        return 1;
    }

    // 遍历每个挂载的文件系统
    while ((ent = getmntent(mounts)) != NULL) {
        double usage = 0;

        // 检查文件系统是否为设备
        if (strstr(ent->mnt_fsname, "/dev/") != NULL) {
            // 获取挂载点的磁盘使用率
            if (get_disk_usage(ent->mnt_dir, &usage) != 0) {
                fprintf(stderr, "获取 %s 的磁盘使用率失败\n", ent->mnt_dir);
                continue;
            }

            // 如果使用率超过阈值则拼接字符串
            if (usage > threshold) {
                char buffer[BUFFER_INCREMENT];
                int len = snprintf(buffer, BUFFER_INCREMENT, "挂载点:%s 使用率:%.2f%% 阀值:%d%%\n", ent->mnt_dir, usage, threshold);
                
                // 检查缓冲区大小是否足够
                if (current_length + len >= result_size) {
                    result_size += BUFFER_INCREMENT;
                    result = (char *)realloc(result, result_size);
                    if (result == NULL) {
                        perror("内存重新分配失败");
                        endmntent(mounts);
                        return 1;
                    }
                }
                strcat(result, buffer);
                current_length += len;
            }
        }
    }

    // 发送邮件警告
    if (current_length > 0) {
        if (QQ_mail_warning_Disk_Use(conf->RECV_MAIL, local_ip, result, current_length) != 0) {
            fprintf(stderr, "发送邮件失败\n");
        }
    }

    // 清理
    free(result);
    endmntent(mounts);
    return 0;
}