What does it mean for perch to make chrysanthemum yellow and wine full of bottles, and it's cool in the late evening and mourn when the tide is on?

This is a poem from Bai Juyi, a poet in the Tang Dynasty, who wrote "Seeing the guests off on the river and visiting the south of the Yangtze River". It means: the bass is beautiful, the chrysanthemums are yellow, and the wine fills the glass, which makes people feel a little cold in the evening. Boating in the rivers and lakes is at a time of high tide and endless joy. This poem depicts the beautiful scenery of the south of the Yangtze River and the author's feeling of roaming on the river, and expresses the author's love and praise for the natural beauty of the south of the Yangtze River and his yearning for a free and unrestrained life.