IsValidDate checks if a date is formatted correctly and occurs after the first published APOD.

NewClient creates a new APOD client.

NewImageCache simplifies the creation of an APOD image cache.

NewImageWrapper creates a new ImageWrapper from binary data.

Retry is a helper function that reruns a function until it succeeds, at most 5 times.

ErrorDateInvalid is returned when given date is not in the correct format.

ErrorDateNotFound is returned when given date is not found on the NASA API.

APOD is a client for the NASA APOD API It maintains a cache for APOD responses and an image cache for images.

ImageWrapper is a wrapper around an image.Image that caches the image's binary representation and format.

Response is a single JSON response from the APOD API.