تعریف و معنای "[shoot] {oneself} in the foot"

What is the origin of the idiom "shoot oneself in the foot" and when to use it?

The idiom "shoot oneself in the foot" has its origins in military history, where soldiers were sometimes prone to accidentally shooting themselves in the foot while handling a firearm. The phrase now means to do something that ends up harming one's own interests or goals. This phrase is often used to describe situations where someone makes a mistake or takes an action that has negative consequences for themselves.