Help needed for new ceiling light, please.

Hi, i’m hoping someone can help, if possible….. i’m fitting a new ceiling light (with 3 seperate 25w bulbs) in the bathroom, and don’t know how to connect with the old wiring from above, which has 2 earth wires (previously connected to a “line”? screw point for the old light), 2 black wires (which went to the “loop-in”, then to the bulb), and 1 red (to the neutral, then to the bulb). i think i can identify which of these run back to the switch, but how should the new light be connected through its live, neutral, earth block, please?

At the (1-way) switch end, there are 2 earth wires, 2 red wires joined together, and 1 more single red. Will they connect to the new pull-switch quite easily? The connectors there are com-L, L1 and L2, as well as the earth.

Sorry if this is basic – or if i’ve made no sense – but good advice would really be appreciated. Thanks in advance.