consciousness/src/subconscious/hook.rs

// hook.rs — Claude Code session hook: context injection + agent orchestration
//
// Called on each UserPromptSubmit via the poc-hook binary. Handles
// context loading, chunking, seen-set management, and delegates
// agent orchestration to AgentCycleState.

use std::collections::HashSet;
use std::fs;
use std::io::Write;
use std::path::Path;
use std::process::Command;
use std::time::Instant;

pub use crate::session::HookSession;
pub use super::subconscious::*;

const CHUNK_SIZE: usize = 9000;

/// Run the hook logic on parsed JSON input. Returns output to inject.
pub fn run_hook(input: &str) -> String {
    let Some(session) = HookSession::from_json(input) else { return String::new() };
    hook(&session)
}

fn chunk_context(ctx: &str, max_bytes: usize) -> Vec<String> {
    let mut sections: Vec<String> = Vec::new();
    let mut current = String::new();

    for line in ctx.lines() {
        if line.starts_with("--- ") && line.ends_with(" ---") && !current.is_empty() {
            sections.push(std::mem::take(&mut current));
        }
        if !current.is_empty() {
            current.push('\n');
        }
        current.push_str(line);
    }
    if !current.is_empty() {
        sections.push(current);
    }

    let mut chunks: Vec<String> = Vec::new();
    let mut chunk = String::new();
    for section in sections {
        if !chunk.is_empty() && chunk.len() + section.len() + 1 > max_bytes {
            chunks.push(std::mem::take(&mut chunk));
        }
        if !chunk.is_empty() {
            chunk.push('\n');
        }
        chunk.push_str(&section);
    }
    if !chunk.is_empty() {
        chunks.push(chunk);
    }
    chunks
}

fn save_pending_chunks(dir: &Path, session_id: &str, chunks: &[String]) {
    let chunks_dir = dir.join(format!("chunks-{}", session_id));
    let _ = fs::remove_dir_all(&chunks_dir);
    if chunks.is_empty() { return; }
    fs::create_dir_all(&chunks_dir).ok();
    for (i, chunk) in chunks.iter().enumerate() {
        let path = chunks_dir.join(format!("{:04}", i));
        fs::write(path, chunk).ok();
    }
}

fn pop_pending_chunk(dir: &Path, session_id: &str) -> Option<String> {
    let chunks_dir = dir.join(format!("chunks-{}", session_id));
    if !chunks_dir.exists() { return None; }

    let mut entries: Vec<_> = fs::read_dir(&chunks_dir).ok()?
        .flatten()
        .filter(|e| e.file_type().map(|t| t.is_file()).unwrap_or(false))
        .collect();
    entries.sort_by_key(|e| e.file_name());

    let first = entries.first()?;
    let content = fs::read_to_string(first.path()).ok()?;
    fs::remove_file(first.path()).ok();

    if fs::read_dir(&chunks_dir).ok().map(|mut d| d.next().is_none()).unwrap_or(true) {
        fs::remove_dir(&chunks_dir).ok();
    }

    Some(content)
}

fn generate_cookie() -> String {
    uuid::Uuid::new_v4().as_simple().to_string()[..12].to_string()
}

fn parse_seen_line(line: &str) -> &str {
    line.split_once('\t').map(|(_, key)| key).unwrap_or(line)
}

pub fn load_seen(dir: &Path, session_id: &str) -> HashSet<String> {
    let path = dir.join(format!("seen-{}", session_id));
    if path.exists() {
        fs::read_to_string(&path)
            .unwrap_or_default()
            .lines()
            .filter(|s| !s.is_empty())
            .map(|s| parse_seen_line(s).to_string())
            .collect()
    } else {
        HashSet::new()
    }
}

fn mark_seen(dir: &Path, session_id: &str, key: &str, seen: &mut HashSet<String>) {
    if !seen.insert(key.to_string()) { return; }
    let path = dir.join(format!("seen-{}", session_id));
    if let Ok(mut f) = fs::OpenOptions::new().create(true).append(true).open(path) {
        let ts = chrono::Local::now().format("%Y-%m-%dT%H:%M:%S");
        writeln!(f, "{}\t{}", ts, key).ok();
    }
}

/// Standalone entry point for the Claude Code hook path.
/// Loads saved state, runs cycles, saves state back.
pub fn run_agent_cycles(session: &HookSession) -> AgentCycleOutput {
    let mut state = AgentCycleState::new(&session.session_id);
    state.restore(&SavedAgentState::load(&session.session_id));
    state.trigger(session);
    state.save(&session.session_id);
    state.last_output
}

fn hook(session: &HookSession) -> String {
    let start_time = Instant::now();

    let mut out = String::new();
    let is_compaction = crate::transcript::detect_new_compaction(
        &session.state_dir, &session.session_id, &session.transcript_path,
    );
    let cookie_path = session.path("cookie");
    let is_first = !cookie_path.exists();

    let log_dir = dirs::home_dir().unwrap_or_default().join(".consciousness/logs");
    fs::create_dir_all(&log_dir).ok();
    let log_path = log_dir.join(format!("hook-{}", session.session_id));
    let Ok(mut log_f) = fs::OpenOptions::new().create(true).append(true).open(log_path) else { return Default::default(); };
    let ts = chrono::Local::now().format("%Y-%m-%dT%H:%M:%S");
    let _ = writeln!(log_f, "\n=== {} ({}) {} bytes ===", ts, session.hook_event, out.len());

    let _ = writeln!(log_f, "is_first {is_first} is_compaction {is_compaction}");

    if is_first || is_compaction {
        if is_compaction {
            fs::rename(&session.path("seen"), &session.path("seen-prev")).ok();
        } else {
            fs::remove_file(&session.path("seen")).ok();
            fs::remove_file(&session.path("seen-prev")).ok();
        }
        fs::remove_file(&session.path("returned")).ok();

        if is_first {
            fs::write(&cookie_path, generate_cookie()).ok();
        }

        if let Ok(output) = Command::new("poc-memory").args(["admin", "load-context"]).output() {
            if output.status.success() {
                let ctx = String::from_utf8_lossy(&output.stdout).to_string();
                if !ctx.trim().is_empty() {
                    let mut ctx_seen = session.seen();
                    for line in ctx.lines() {
                        if line.starts_with("--- ") && line.ends_with(" ---") {
                            let inner = &line[4..line.len() - 4];
                            if let Some(paren) = inner.rfind(" (") {
                                let key = inner[..paren].trim();
                                mark_seen(&session.state_dir, &session.session_id, key, &mut ctx_seen);
                            }
                        }
                    }

                    let chunks = chunk_context(&ctx, CHUNK_SIZE);

                    if let Some(first) = chunks.first() {
                        out.push_str(first);
                    }
                    save_pending_chunks(&session.state_dir, &session.session_id, &chunks[1..]);
                }
            }
        }
    }

    if let Some(chunk) = pop_pending_chunk(&session.state_dir, &session.session_id) {
        out.push_str(&chunk);
    } else {
        let cfg = crate::config::get();
        if cfg.surface_hooks.iter().any(|h| h == &session.hook_event) {
            let cycle_output = run_agent_cycles(&session);
            out.push_str(&format_agent_output(&cycle_output));
        }
    }

    let _ = write!(log_f, "{}", out);

    let duration = (Instant::now() - start_time).as_secs_f64();
    let _ = writeln!(log_f, "\nran in {duration:.2}s");

    out
}