Aiming at the issue of degraded image quality in photoacoustic tomography (PAT) caused by the inhomogeneous light fluence distribution, complex optical and acoustic properties of biological tissues, and non-ideal properties of ultrasonic detectors, we propose a comprehensive forward imaging model. The model takes into account variables such as the inhomogeneous light fluence, unsteady speed of sound, spatial and electrical impulse responses of ultrasonic transducers, limited-view scanning, and sparse sampling. The inverse problem of the imaging model is solved by alternate optimization, and images representing optical absorption and speed of sound (SoS) distributions are reconstructed simultaneously. The results indicate that the structural similarity of the reconstructed images of the proposed method can be enhanced by about 83%, 56%, and 22%, in comparison with back projection, time-reversal, and short-lag spatial coherence techniques, respectively. Additionally, the peak signal-to-noise ratio can be improved by approximately 80%, 68% and 58%, respectively. This method considerably enhances the image quality of non-ideal imaging scenarios when compared to traditional techniques.