A 44-year-old patient complains of chest pain on the right, shortness of breath, and cough with expectoration of a large amount of purulent sputum. Objectively, the following is observed: heart rate 116/min, body temperature 39.8°C, cyanosis of the skin, the right half of the chest lagging behind in the act of breathing, dull percussion sound, and weakened breathing on the right. Chest X-ray reveals homogeneous darkening of the right half of the chest. What is the most likely diagnosis in this case?