#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/ioctl.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/fs.h>
#include <linux/err.h>

#define DEVICE_NAME "temp_monitor"
#define IOCTL_GET_TEMP _IOR('t', 1, int)
#define TEMP_SENSOR_PATH "/sys/class/thermal/thermal_zone0/temp"

static int major_number;
static struct class* temp_monitor_class = NULL;
static struct device* temp_monitor_device = NULL;

static int device_open(struct inode *inode, struct file *file) {
    return 0;
}

static int device_release(struct inode *inode, struct file *file) {
    return 0;
}

static long device_ioctl(struct file *file, unsigned int cmd, unsigned long arg) {
    switch (cmd) {
        case IOCTL_GET_TEMP: {
            int temp = 0;
            struct file *f;
            char *buf;
            loff_t pos = 0;

            // Check if the temperature file exists
            f = filp_open(TEMP_SENSOR_PATH, O_RDONLY, 0);
            if (IS_ERR(f)) {
                printk(KERN_INFO "temp_monitor: Temperature file not found\n");
            } else {
                buf = kmalloc(16, GFP_KERNEL);
                if (!buf) {
                    filp_close(f, NULL);
                    return -ENOMEM;
                }

                // Read the temperature
                kernel_read(f, buf, 16, &pos);
                sscanf(buf, "%d", &temp);
                temp /= 1000; // Convert to degrees Celsius
                filp_close(f, NULL);
                kfree(buf);
            }

            if (copy_to_user((int *)arg, &temp, sizeof(temp))) {
                return -EACCES;
            }
            break;
        }
        default:
            return -EINVAL;
    }
    return 0;
}

static struct file_operations fops = {
    .open = device_open,
    .release = device_release,
    .unlocked_ioctl = device_ioctl,
};

static int __init temp_monitor_init(void) {
    major_number = register_chrdev(0, DEVICE_NAME, &fops);
    if (major_number < 0) {
        printk(KERN_ALERT "temp_monitor: Failed to register a major number\n");
        return major_number;
    }
    temp_monitor_class = class_create(THIS_MODULE->name); // Updated this line
    if (IS_ERR(temp_monitor_class)) {
        unregister_chrdev(major_number, DEVICE_NAME);
        printk(KERN_ALERT "temp_monitor: Failed to register device class\n");
        return PTR_ERR(temp_monitor_class);
    }
    temp_monitor_device = device_create(temp_monitor_class, NULL, MKDEV(major_number, 0), NULL, DEVICE_NAME);
    if (IS_ERR(temp_monitor_device)) {
        class_destroy(temp_monitor_class);
        unregister_chrdev(major_number, DEVICE_NAME);
        printk(KERN_ALERT "temp_monitor: Failed to create the device\n");
        return PTR_ERR(temp_monitor_device);
    }
    printk(KERN_INFO "temp_monitor: Device initialized with major number %d\n", major_number);
    return 0;
}

static void __exit temp_monitor_exit(void) {
    device_destroy(temp_monitor_class, MKDEV(major_number, 0));
    class_unregister(temp_monitor_class);
    class_destroy(temp_monitor_class);
    unregister_chrdev(major_number, DEVICE_NAME);
    printk(KERN_INFO "temp_monitor: Device removed\n");
}

module_init(temp_monitor_init);
module_exit(temp_monitor_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Your Name");
MODULE_DESCRIPTION("A CPU Temperature Monitoring Kernel Module");