Recursive Error Recovery Pipeline via Fallback Decoders

enum PipelineError {
    InvalidFormat(String),
    NetworkFailure(String),
}
 
fn primary_decoder(input: &str) -> Result<String, PipelineError> {
    if input.starts_with("RAW:") {
        Ok(input[4..].to_string())
    } else {
        Err(PipelineError::InvalidFormat("Missing RAW prefix".to_string()))
    }
}
 
fn secondary_decoder(input: &str) -> Result<String, PipelineError> {
    if input.starts_with("HEX:") {
        Ok(format!("Decoded Hex: {}", &input[4..]))
    } else {
        Err(PipelineError::InvalidFormat("Missing HEX prefix".to_string()))
    }
}
 
fn run_pipeline(input: &str, depth: usize) -> Result<String, PipelineError> {
    if depth == 0 {
        return Err(PipelineError::NetworkFailure("Max recovery depth reached".to_string()));
    }
    
    primary_decoder(input).or_else(|err| match err {
        PipelineError::InvalidFormat(_) => {
            secondary_decoder(input).or_else(|_| run_pipeline("RAW:fallback", depth - 1))
        }
        other => Err(other),
    })
}