The A1278 designation is much too broad as it covers models from 2009 to 2012 each with their own unique issues. We need the exact model which you can get by entering the serial number here:
https://checkcoverage.apple.com/
Is the laptop using the original Apple hard drive? If so, then most likely the drive has failed, however, the MBPro 13" (mid 2012) model is known to have an extremely high failure rate of the hard drive SATA Cable. I suggest trying to run the Apple Diagnostics to see if any hardware issues are found. Unfortunately the diagnostics do not detect many types of drive failures. If no issues are detected, then I can provide instructions for creating a bootable Linux USB stick which can be used to check the health of the drive if you are interested. If the drive checks out as healthy, then you can try the steps in this Apple article (no sense performing these steps if the drive is worn out or failing):
If your Mac starts up to a question mark - Apple Support
Also knowing the exact model of the laptop will help us to provide suggestions on an SSD if you are going to replace the hard drive. Earlier Mac models have more compatibility issues with many SSDs while later models may support a slightly wider range of SSD models.
