// session.rs — Session state for ambient hooks and agent interactions
//
// Tracks per-session state (seen set, state directory) across hook
// invocations. Created from hook JSON input or POC_SESSION_ID env var.

use std::collections::HashSet;
use std::fs;
use std::path::PathBuf;

pub struct Session {
    pub session_id: String,
    pub transcript_path: String,
    pub hook_event: String,
    pub state_dir: PathBuf,
}

impl Session {
    pub fn from_json(input: &str) -> Option<Self> {
        let state_dir = PathBuf::from("/tmp/claude-memory-search");
        fs::create_dir_all(&state_dir).ok();

        let json: serde_json::Value = serde_json::from_str(input).ok()?;
        let session_id = json["session_id"].as_str().unwrap_or("").to_string();
        if session_id.is_empty() { return None; }
        let transcript_path = json["transcript_path"].as_str().unwrap_or("").to_string();
        let hook_event = json["hook_event_name"].as_str().unwrap_or("").to_string();

        Some(Session { session_id, transcript_path, hook_event, state_dir })
    }

    pub fn path(&self, prefix: &str) -> PathBuf {
        self.state_dir.join(format!("{}-{}", prefix, self.session_id))
    }

    /// Load from POC_SESSION_ID environment variable
    pub fn from_env() -> Option<Self> {
        let session_id = std::env::var("POC_SESSION_ID").ok()?;
        if session_id.is_empty() { return None; }
        let state_dir = PathBuf::from("/tmp/claude-memory-search");
        Some(Session {
            session_id,
            transcript_path: String::new(),
            hook_event: String::new(),
            state_dir,
        })
    }

    /// Get the seen set for this session
    pub fn seen(&self) -> HashSet<String> {
        super::hippocampus::memory_search::load_seen(&self.state_dir, &self.session_id)
    }
}