智能家居状态服务器-数据库交互与建议生成

#include <stdio.h> #include <stdlib.h> #include <string.h> #include <sqlite3.h> #include <unistd.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h>

#define DATABASE 'database.db' #define PORT 8080

typedef struct { int uid; char device_name[10]; char device_state[10]; char value[10]; char mode[10]; } Status;

int get_status_by_uid(int uid, Status *status) { sqlite3 *db; sqlite3_stmt *stmt; int rc;

rc = sqlite3_open(DATABASE, &db);
if (rc != SQLITE_OK) {
    fprintf(stderr, 'Cannot open database: %s\n', sqlite3_errmsg(db));
    return rc;
}

char query[100];
sprintf(query, 'SELECT * FROM Status WHERE uid = %d ORDER BY sid DESC LIMIT 1', uid);

rc = sqlite3_prepare_v2(db, query, -1, &stmt, NULL);
if (rc != SQLITE_OK) {
    fprintf(stderr, 'Failed to prepare statement: %s\n', sqlite3_errmsg(db));
    return rc;
}

rc = sqlite3_step(stmt);
if (rc != SQLITE_ROW && rc != SQLITE_DONE) {
    fprintf(stderr, 'Failed to execute statement: %s\n', sqlite3_errmsg(db));
    return rc;
}

if (rc == SQLITE_DONE) {
    status->uid = -1;
} else {
    status->uid = sqlite3_column_int(stmt, 1);
    strcpy(status->device_name, sqlite3_column_text(stmt, 2));
    strcpy(status->device_state, sqlite3_column_text(stmt, 3));
    strcpy(status->value, sqlite3_column_text(stmt, 4));
    strcpy(status->mode, sqlite3_column_text(stmt, 5));
}

sqlite3_finalize(stmt);
sqlite3_close(db);

return SQLITE_OK;

}

void process_request(int client_socket) { char buffer[1024]; memset(buffer, 0, sizeof(buffer));

ssize_t bytes_received = recv(client_socket, buffer, sizeof(buffer), 0);
if (bytes_received < 0) {
    perror('Error receiving data from client');
    return;
}

printf('Received request from client: %s\n', buffer);

int uid;
sscanf(buffer, '{"userid": %d}', &uid);

Status status;
int rc = get_status_by_uid(uid, &status);
if (rc != SQLITE_OK) {
    perror('Error getting status from database');
    return;
}

char response[1024];
memset(response, 0, sizeof(response));

if (status.uid == -1) {
    strcpy(response, 'No status found for the given userid');
} else {
    if (strcmp(status.device_name, '空调') == 0 && atoi(status.value) < 24) {
        strcpy(response, '空调温度过低，建议提高温度至26℃');
    } else if (strcmp(status.device_name, '加湿器') == 0 && (atoi(status.value) < 40 || atoi(status.value) > 70)) {
        strcpy(response, '加湿器湿度过高或过低，建议调整加湿器湿度');
    } else {
        strcpy(response, 'No suggestion');
    }
}

ssize_t bytes_sent = send(client_socket, response, strlen(response), 0);
if (bytes_sent < 0) {
    perror('Error sending response to client');
    return;
}

printf('Sent response to client: %s\n', response);

}

int main() { int server_socket, client_socket; struct sockaddr_in server_address, client_address; socklen_t client_address_length = sizeof(client_address);

server_socket = socket(AF_INET, SOCK_STREAM, 0);
if (server_socket < 0) {
    perror('Error creating server socket');
    exit(EXIT_FAILURE);
}

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

if (bind(server_socket, (struct sockaddr *) &server_address, sizeof(server_address)) < 0) {
    perror('Error binding server socket');
    exit(EXIT_FAILURE);
}

if (listen(server_socket, 5) < 0) {
    perror('Error listening for connections');
    exit(EXIT_FAILURE);
}

printf('Server is listening on port %d\n', PORT);

while (1) {
    client_socket = accept(server_socket, (struct sockaddr *) &client_address, &client_address_length);
    if (client_socket < 0) {
        perror('Error accepting client connection');
        exit(EXIT_FAILURE);
    }

    printf('Accepted client connection from %s:%d\n', inet_ntoa(client_address.sin_addr), ntohs(client_address.sin_port));

    pid_t pid = fork();
    if (pid == 0) {
        close(server_socket);
        process_request(client_socket);
        close(client_socket);
        exit(EXIT_SUCCESS);
    } else if (pid < 0) {
        perror('Error forking child process');
        exit(EXIT_FAILURE);
    } else {
        close(client_socket);
    }
}

close(server_socket);

return 0;

}