#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <semaphore.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <openssl/evp.h>
#include <openssl/sha.h>
#include <zlib.h>
#include <time.h>

// 线程、信号量全局变量
pthread_t thread1, thread2;
sem_t semaphore;

// 消息队列结构
struct message {
    long mtype;
    char mtext[100];
};

// 函数声明
void file_system_demo();
void thread_control_demo();
void process_communication_demo();
void socket_communication_demo();
void encryption_demo();

int main() {
    int choice;
    while (1) {
        printf("\n请选择要演示的功能模块：\n");
        printf("1. 文件系统操作\n");
        printf("2. 线程控制与信号量\n");
        printf("3. 进程间通信\n");
        printf("4. Socket通信\n");
        printf("5. 加密解密与哈希\n");
        printf("0. 退出\n");
        printf("输入选择：");
        scanf("%d", &choice);

        switch (choice) {
            case 1:
                file_system_demo();
                break;
            case 2:
                thread_control_demo();
                break;
            case 3:
                process_communication_demo();
                break;
            case 4:
                socket_communication_demo();
                break;
            case 5:
                encryption_demo();
                break;
            case 0:
                printf("退出程序。\n");
                exit(0);
            default:
                printf("无效选择，请重试。\n");
        }
    }
    return 0;
}

//文件系统操作
void file_system_demo() {
    const char *filename = "testfile.txt";
    const char *data = "这是一个文件系统操作的测试文件。\n";

    // 创建文件并写入数据
    int fd = open(filename, O_CREAT | O_WRONLY | O_TRUNC, 0644);
    if (fd == -1) {
        perror("创建文件失败");
        return;
    }
    write(fd, data, strlen(data));
    close(fd);
    printf("文件已创建并写入数据。\n");

    // 读取文件数据
    fd = open(filename, O_RDONLY);
    if (fd == -1) {
        perror("打开文件失败");
        return;
    }
    char buffer[256];
    ssize_t bytes_read = read(fd, buffer, sizeof(buffer) - 1);
    if (bytes_read > 0) {
        buffer[bytes_read] = '\0';
        printf("文件内容：%s", buffer);
    }
    close(fd);

    // 删除文件
    if (remove(filename) == 0) {
        printf("文件已删除。\n");
    } else {
        perror("删除文件失败");
    }
}

//线程控制与信号量
void *thread_function(void *arg) {
    sem_wait(&semaphore);
    printf("线程 %d: 信号量已获取。\n", *(int *)arg);
    sleep(2);
    printf("线程 %d: 任务完成，释放信号量。\n", *(int *)arg);
    sem_post(&semaphore);
    return NULL;
}

void thread_control_demo() {
    sem_init(&semaphore, 0, 1);
    int id1 = 1, id2 = 2;

    pthread_create(&thread1, NULL, thread_function, &id1);
    pthread_create(&thread2, NULL, thread_function, &id2);

    pthread_join(thread1, NULL);
    pthread_join(thread2, NULL);

    sem_destroy(&semaphore);
}

//进程间通信 (消息队列)
#define PORT 8080
#define BUFFER_SIZE 256
void process_communication_demo() {
    key_t key = ftok("msgqueue", 65);
    int msgid = msgget(key, 0666 | IPC_CREAT);
    if (msgid == -1) {
        perror("创建消息队列失败");
        return;
    }

    struct message msg;
    msg.mtype = 1;
    strcpy(msg.mtext, "来自进程间通信的消息！");

    if (msgsnd(msgid, &msg, sizeof(msg.mtext), 0) == -1) {
        perror("发送消息失败");
    } else {
        printf("消息已发送：%s\n", msg.mtext);
    }

    if (msgrcv(msgid, &msg, sizeof(msg.mtext), 1, 0) == -1) {
        perror("接收消息失败");
    } else {
        printf("接收到消息：%s\n", msg.mtext);
    }

    msgctl(msgid, IPC_RMID, NULL);
}

//Socket通信
void socket_communication_demo() {
    int server_fd, client_fd;
    struct sockaddr_in server_addr, client_addr;
    socklen_t client_addr_len = sizeof(client_addr);
    char buffer[BUFFER_SIZE];

    // 创建套接字
    server_fd = socket(AF_INET, SOCK_STREAM, 0);
    if (server_fd == -1) {
        perror("创建Socket失败");
        exit(EXIT_FAILURE);
    }

    // 配置服务器地址
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(PORT);
    server_addr.sin_addr.s_addr = INADDR_ANY;

    // 绑定地址
    if (bind(server_fd, (struct sockaddr *)&server_addr, sizeof(server_addr)) == -1) {
        perror("绑定失败");
        close(server_fd);
        exit(EXIT_FAILURE);
    }

    // 开始监听
    if (listen(server_fd, 5) == -1) {
        perror("监听失败");
        close(server_fd);
        exit(EXIT_FAILURE);
    }

    printf("服务器已启动，等待客户端连接...\n");

    // 接受客户端连接
    client_fd = accept(server_fd, (struct sockaddr *)&client_addr, &client_addr_len);
    if (client_fd == -1) {
        perror("接受连接失败");
        close(server_fd);
        exit(EXIT_FAILURE);
    }

    printf("客户端已连接。\n");

    // 接收消息
    ssize_t bytes_received = recv(client_fd, buffer, BUFFER_SIZE - 1, 0);
    if (bytes_received > 0) {
        buffer[bytes_received] = '\0';
        printf("收到客户端消息：%s\n", buffer);

        // 发送回应
        const char *response = "Hello from server!";
        send(client_fd, response, strlen(response), 0);
        printf("回应已发送。\n");
    }

    // 关闭套接字
    close(client_fd);
    close(server_fd);
}

//加密解密与哈希
void encryption_demo() {
    const char *plaintext = "这是需要加密的文本。";
    unsigned char hash[SHA256_DIGEST_LENGTH];
    SHA256((unsigned char *)plaintext, strlen(plaintext), hash);

    printf("SHA-256 哈希值：");
    for (int i = 0; i < SHA256_DIGEST_LENGTH; i++) {
        printf("%02x", hash[i]);
    }
    printf("\n");
}