use bamboo_domain::Session;
pub(crate) fn validate_image_fallback_for_session(
session: &Session,
image_fallback: Option<&crate::ImageFallbackConfig>,
) -> Result<(), String> {
use crate::ImageFallbackMode;
if matches!(
image_fallback,
Some(crate::ImageFallbackConfig {
mode: ImageFallbackMode::Error,
..
})
) {
let images_seen = session
.messages
.iter()
.filter_map(|message| message.content_parts.as_ref())
.flat_map(|parts| parts.iter())
.filter(|part| matches!(part, bamboo_agent_core::MessagePart::ImageUrl { .. }))
.count();
if images_seen > 0 {
return Err(format!(
"This server does not currently support image inputs (found {images_seen} image part(s)). \
Configure hooks.image_fallback.mode='placeholder' or 'ocr' to degrade gracefully."
));
}
}
Ok(())
}