#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <time.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <signal.h>
#include <sys/wait.h>

#define PORT 9999
#define TIMEOUT 3

pid_t play_pid = 0;

// 启动播放
void start_playback()
{
    if (play_pid == 0)
    {
        play_pid = fork();
        if (play_pid == 0)
        {
            execl("./audio_play", "./audio_play", NULL);
            perror("execl failed");
            exit(1);
        }
        printf("播放进程已启动，PID=%d\n", play_pid);
    }
}

// 停止播放
void stop_playback()
{
    if (play_pid > 0)
    {
        printf("停止播放，终止 PID=%d\n", play_pid);
        kill(play_pid, SIGTERM);
        waitpid(play_pid, NULL, 0);
        play_pid = 0;
    }
}

int main()
{
    int listen_fd, conn_fd;
    struct sockaddr_in addr;
    char buffer[128];
    time_t last_time = 0;
    int playing = 0;
    fd_set read_fds;
    struct timeval tv;

    listen_fd = socket(AF_INET, SOCK_STREAM, 0);
    if (listen_fd < 0)
    {
        perror("socket error");
        return 1;
    }

    int opt = 1;
    setsockopt(listen_fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));

    memset(&addr, 0, sizeof(addr));
    addr.sin_family = AF_INET;
    addr.sin_port = htons(PORT);
    addr.sin_addr.s_addr = htonl(INADDR_ANY);

    if (bind(listen_fd, (struct sockaddr *)&addr, sizeof(addr)) < 0)
    {
        perror("bind error");
        close(listen_fd);
        return 1;
    }

    if (listen(listen_fd, 5) < 0)
    {
        perror("listen error");
        close(listen_fd);
        return 1;
    }

    printf("语音守护 TCP 服务器已启动，监听端口 %d...\n", PORT);

    while (1)
    {
        printf("等待客户端连接...\n");
        conn_fd = accept(listen_fd, NULL, NULL);
        if (conn_fd < 0)
        {
            perror("accept error");
            continue;
        }
        printf("客户端已连接\n");

        last_time = 0;
        playing = 0;

        // 设置非阻塞模式
        fcntl(conn_fd, F_SETFL, O_NONBLOCK);

        while (1)
        {
            FD_ZERO(&read_fds);
            FD_SET(conn_fd, &read_fds);
            tv.tv_sec = 1;
            tv.tv_usec = 0;

            int ret = select(conn_fd + 1, &read_fds, NULL, NULL, &tv);
            if (ret > 0 && FD_ISSET(conn_fd, &read_fds))
            {
                ssize_t len = read(conn_fd, buffer, sizeof(buffer) - 1);
                if (len > 0)
                {
                    buffer[len] = '\0';
                    if (strstr(buffer, "RUNNING"))
                    {
                        last_time = time(NULL);
                        if (!playing)
                        {
                            printf("收到心跳，启动播报...\n");
                            start_playback();
                            playing = 1;
                        }
                    }
                }
                else if (len == 0)
                {
                    printf("客户端关闭连接\n");
                    break;
                }
            }
            else if (ret == 0)
            {
                // 超时
                if (playing && (time(NULL) - last_time > TIMEOUT))
                {
                    printf("超时未收到心跳，停止播报...\n");
                    stop_playback();
                    playing = 0;
                }
            }
            else
            {
                perror("select error");
                break;
            }
        }

        close(conn_fd);
        // 断开连接时停止播放
        if (playing)
        {
            printf("连接断开，停止播放\n");
            stop_playback();
            playing = 0;
        }
    }

    close(listen_fd);
    return 0;
}