zesdex/src/app/runtime/shortsend.rs

use crate::dto::chat::message::ChatMessage;

const MAX_WIRE_TOKENS: usize = 2_000_000;
const MIN_MESSAGES_BEFORE_SHAPE: usize = 20;
const ENGAGE_HYSTERESIS: usize = 5;

pub fn should_shape(total_messages: usize, prev_shaped: bool) -> bool {
    if total_messages < MIN_MESSAGES_BEFORE_SHAPE {
        return false;
    }
    let threshold = if prev_shaped {
        MIN_MESSAGES_BEFORE_SHAPE + ENGAGE_HYSTERESIS
    } else {
        MIN_MESSAGES_BEFORE_SHAPE
    };
    total_messages >= threshold
}

pub fn shape_messages(messages: &[ChatMessage], token_count: usize) -> Vec<ChatMessage> {
    if token_count <= MAX_WIRE_TOKENS || messages.len() < 10 {
        return messages.to_vec();
    }
    let keep_recent = messages
        .iter()
        .rev()
        .take(MAX_WIRE_TOKENS / 200)
        .cloned()
        .collect::<Vec<_>>();
    let mut result = Vec::new();
    if let Some(first) = messages.first() {
        result.push(first.clone());
    }
    result.push(ChatMessage::system(
        "[prior conversation compacted]".to_string(),
    ));
    result.extend(keep_recent.into_iter().rev());
    result
}