deepstrike-core 0.2.28

use serde::{Deserialize, Serialize};

use super::config::ContextConfig;
use super::partitions::ContextPartitions;
use super::pressure::PressureMonitor;
use super::token_engine::ContextTokenEngine;

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ContractCheckResult {
    pub criterion_id: String,
    pub passed: bool,
    pub evidence: Option<String>,
}

/// Structured state passed between sprints.
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct HandoffArtifact {
    pub goal: String,
    pub sprint: u32,
    pub progress_summary: String,
    pub open_tasks: Vec<String>,
    pub context_snapshot: serde_json::Value,
    #[serde(default)]
    pub contract_status: Vec<ContractCheckResult>,
    #[serde(default)]
    pub drift_rate_24h: f64,
    #[serde(default)]
    pub blocked_on: Vec<String>,
}

pub struct RenewalPolicy {
    pub renewal_threshold: f64,
    pub carryover_ratio: f64,
}

impl RenewalPolicy {
    pub fn from_config(config: &ContextConfig) -> Self {
        Self {
            renewal_threshold: config.renewal_threshold,
            carryover_ratio: config.carryover_ratio,
        }
    }

    pub fn should_renew(
        &self,
        monitor: &PressureMonitor,
        partitions: &ContextPartitions,
        engine: &ContextTokenEngine,
    ) -> bool {
        monitor.pressure(partitions, engine, None) > self.renewal_threshold
    }

    /// Perform renewal: carry system + knowledge + task_state into new sprint.
    /// History is reset; only the last `carryover_tokens` worth of turns are kept.
    /// Signals are cleared (they are per-turn ephemeral).
    pub fn renew(
        &self,
        partitions: &ContextPartitions,
        goal: &str,
        sprint: u32,
        max_tokens: u32,
    ) -> (ContextPartitions, HandoffArtifact) {
        let config = ContextConfig {
            carryover_ratio: self.carryover_ratio,
            renewal_threshold: self.renewal_threshold,
            ..Default::default()
        };
        let mut renewed = ContextPartitions::new(&config);

        // Identity and Knowledge slots carry over unchanged.
        for msg in &partitions.system.messages {
            renewed.system.push(msg.clone(), msg.token_count.unwrap_or(0));
        }
        for msg in &partitions.knowledge.messages {
            renewed.knowledge.push(msg.clone(), msg.token_count.unwrap_or(0));
        }

        // State: carry task_state (goal/plan/progress), clear scratchpad.
        renewed.task_state = partitions.task_state.clone();
        renewed.task_state.scratchpad.clear();
        // Signals are ephemeral — not carried over.

        // History: carry recent turns up to carryover budget.
        let carryover_budget = config.carryover_tokens(max_tokens);
        let mut remaining = carryover_budget;
        let mut carried: Vec<_> = partitions.history.messages.iter().rev()
            .take_while(|msg| {
                let t = msg.token_count.unwrap_or(0);
                if t <= remaining { remaining = remaining.saturating_sub(t); true } else { false }
            })
            .cloned()
            .collect();
        carried.reverse();
        for msg in carried {
            let t = msg.token_count.unwrap_or(0);
            renewed.history.push(msg, t);
        }

        let artifact = HandoffArtifact {
            goal: goal.to_string(),
            sprint,
            progress_summary: partitions.task_state.progress.clone(),
            open_tasks: partitions.task_state.open_steps(),
            context_snapshot: serde_json::json!({
                "history_len": partitions.history.messages.len(),
                "knowledge_len": partitions.knowledge.messages.len(),
            }),
            contract_status: Vec::new(),
            drift_rate_24h: 0.0,
            blocked_on: partitions.task_state.blocked_on.clone(),
        };

        (renewed, artifact)
    }
}

impl Default for RenewalPolicy {
    fn default() -> Self { Self::from_config(&ContextConfig::default()) }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::context::config::ContextConfig;
    use crate::context::partitions::ContextPartitions;
    use crate::context::task_state::TaskState;
    use crate::types::message::Message;

    fn make_policy(carryover_ratio: f64) -> RenewalPolicy {
        RenewalPolicy::from_config(&ContextConfig { carryover_ratio, ..Default::default() })
    }

    #[test]
    fn renewal_preserves_system_and_knowledge() {
        let cfg = ContextConfig::default();
        let mut ctx = ContextPartitions::new(&cfg);
        ctx.system.push(Message::system("rules"), 10);
        ctx.knowledge.push(Message::system("skill: debug"), 20);
        let (renewed, _) = make_policy(0.05).renew(&ctx, "goal", 0, 1_000);
        assert_eq!(renewed.system.len(), 1);
        assert_eq!(renewed.knowledge.len(), 1);
    }

    #[test]
    fn renewal_clears_signals() {
        let cfg = ContextConfig::default();
        let mut ctx = ContextPartitions::new(&cfg);
        ctx.signals.push("[ROLLBACK] failed".to_string());
        let (renewed, _) = make_policy(0.05).renew(&ctx, "goal", 0, 1_000);
        assert!(renewed.signals.is_empty());
    }

    #[test]
    fn carryover_respects_token_budget() {
        let cfg = ContextConfig::default();
        let mut ctx = ContextPartitions::new(&cfg);
        for i in 0..10 {
            ctx.history.push(Message::user(format!("msg {i}")), 100);
        }
        let (renewed, _) = make_policy(0.05).renew(&ctx, "goal", 0, 1_000);
        assert!(renewed.history.token_count <= 100);
    }

    #[test]
    fn renewal_clears_task_scratchpad_keeps_goal() {
        let cfg = ContextConfig::default();
        let mut ctx = ContextPartitions::new(&cfg);
        ctx.task_state = TaskState {
            goal: "build".to_string(),
            scratchpad: "temp data".to_string(),
            ..Default::default()
        };
        let (renewed, artifact) = make_policy(0.05).renew(&ctx, "build", 0, 1_000);
        assert_eq!(renewed.task_state.goal, "build");
        assert!(renewed.task_state.scratchpad.is_empty());
        assert_eq!(artifact.goal, "build");
    }
}