// memory-search CLI — thin wrapper around poc_memory::memory_search
//
// --hook: run hook logic (for debugging; poc-hook calls the library directly)
// surface/reflect: run agent, parse output, render memories to stdout
// no args: show seen set for current session

use clap::{Parser, Subcommand};
use std::fs;
use std::io::{self, Read};
use std::process::Command;

fn stash_path() -> std::path::PathBuf {
    poc_memory::store::memory_dir().join("sessions/last-input.json")
}

#[derive(Parser)]
#[command(name = "memory-search")]
struct Args {
    /// Run hook logic (reads JSON from stdin or stash file)
    #[arg(long)]
    hook: bool,

    /// Session ID (overrides stash file; for multiple concurrent sessions)
    #[arg(long)]
    session: Option<String>,

    #[command(subcommand)]
    command: Option<Cmd>,
}

#[derive(Subcommand)]
enum Cmd {
    /// Run surface agent, parse output, render memories
    Surface,
    /// Run reflect agent, dump output
    Reflect,
}

fn resolve_session(session_arg: &Option<String>) -> Option<poc_memory::memory_search::HookSession> {
    use poc_memory::memory_search::HookSession;

    if let Some(id) = session_arg {
        return HookSession::from_id(id.clone());
    }
    let input = fs::read_to_string(stash_path()).ok()?;
    HookSession::from_json(&input)
}

fn show_seen(session_arg: &Option<String>) {
    let Some(session) = resolve_session(session_arg) else {
        eprintln!("No session state available (use --session ID)");
        return;
    };

    println!("Session: {}", session.session_id);

    if let Ok(cookie) = fs::read_to_string(&session.path("cookie")) {
        println!("Cookie:  {}", cookie.trim());
    }

    match fs::read_to_string(&session.path("compaction")) {
        Ok(s) => {
            let offset: u64 = s.trim().parse().unwrap_or(0);
            let ts = poc_memory::transcript::compaction_timestamp(&session.transcript_path, offset);
            match ts {
                Some(t) => println!("Last compaction: offset {} ({})", offset, t),
                None => println!("Last compaction: offset {}", offset),
            }
        }
        Err(_) => println!("Last compaction: none detected"),
    }

    let pending = fs::read_dir(&session.path("chunks")).ok()
        .map(|d| d.flatten().count()).unwrap_or(0);
    if pending > 0 {
        println!("Pending chunks: {}", pending);
    }

    for (label, suffix) in [("Current seen set", ""), ("Previous seen set (pre-compaction)", "-prev")] {
        let path = session.state_dir.join(format!("seen{}-{}", suffix, session.session_id));
        let content = fs::read_to_string(&path).unwrap_or_default();
        let lines: Vec<&str> = content.lines().filter(|s| !s.is_empty()).collect();
        if lines.is_empty() { continue; }

        println!("\n{} ({}):", label, lines.len());
        for line in &lines { println!("  {}", line); }
    }
}

fn run_agent_and_parse(agent: &str, session_arg: &Option<String>) {
    let session_id = session_arg.clone()
        .or_else(|| std::env::var("CLAUDE_SESSION_ID").ok())
        .or_else(|| {
            fs::read_to_string(stash_path()).ok()
                .and_then(|s| poc_memory::memory_search::HookSession::from_json(&s))
                .map(|s| s.session_id)
        })
        .unwrap_or_default();

    if session_id.is_empty() {
        eprintln!("No session ID available (use --session ID, set CLAUDE_SESSION_ID, or run --hook first)");
        std::process::exit(1);
    }

    eprintln!("Running {} agent (session {})...", agent, &session_id[..8.min(session_id.len())]);

    let output = Command::new("poc-memory")
        .args(["agent", "run", agent, "--count", "1", "--local"])
        .env("POC_SESSION_ID", &session_id)
        .output();

    let output = match output {
        Ok(o) => o,
        Err(e) => {
            eprintln!("Failed to run agent: {}", e);
            std::process::exit(1);
        }
    };

    let result = String::from_utf8_lossy(&output.stdout);
    let stderr = String::from_utf8_lossy(&output.stderr);
    if !stderr.is_empty() {
        eprintln!("{}", stderr);
    }

    // Extract the final response — after the last "=== RESPONSE ===" marker
    let response = result.rsplit_once("=== RESPONSE ===")
        .map(|(_, rest)| rest.trim())
        .unwrap_or(result.trim());

    if agent == "reflect" {
        // Reflect: find REFLECTION marker and dump what follows
        if let Some(pos) = response.find("REFLECTION") {
            let after = &response[pos + "REFLECTION".len()..];
            let text = after.trim();
            if !text.is_empty() {
                println!("{}", text);
            }
        } else if response.contains("NO OUTPUT") {
            println!("(no reflection)");
        } else {
            eprintln!("Unexpected output format");
            println!("{}", response);
        }
        return;
    }

    // Surface: parse NEW RELEVANT MEMORIES, render them
    let tail_lines: Vec<&str> = response.lines().rev()
        .filter(|l| !l.trim().is_empty()).take(8).collect();
    let has_new = tail_lines.iter().any(|l| l.starts_with("NEW RELEVANT MEMORIES:"));
    let has_none = tail_lines.iter().any(|l| l.starts_with("NO NEW RELEVANT MEMORIES"));

    if has_new {
        let after_marker = response.rsplit_once("NEW RELEVANT MEMORIES:")
            .map(|(_, rest)| rest).unwrap_or("");
        let keys: Vec<String> = after_marker.lines()
            .map(|l| l.trim().trim_start_matches("- ").trim().to_string())
            .filter(|l| !l.is_empty() && !l.starts_with("```")).collect();

        if keys.is_empty() {
            println!("(no memories found)");
            return;
        }

        let Ok(store) = poc_memory::store::Store::load() else {
            eprintln!("Failed to load store");
            return;
        };

        for key in &keys {
            if let Some(content) = poc_memory::cli::node::render_node(&store, key) {
                if !content.trim().is_empty() {
                    println!("--- {} (surfaced) ---", key);
                    print!("{}", content);
                    println!();
                }
            } else {
                eprintln!("  key not found: {}", key);
            }
        }
    } else if has_none {
        println!("(no new relevant memories)");
    } else {
        eprintln!("Unexpected output format");
        print!("{}", response);
    }
}

fn main() {
    let args = Args::parse();

    if let Some(cmd) = args.command {
        match cmd {
            Cmd::Surface => run_agent_and_parse("surface", &args.session),
            Cmd::Reflect => run_agent_and_parse("reflect", &args.session),
        }
        return;
    }

    if args.hook {
        // Read from stdin if piped, otherwise from stash
        let input = {
            let mut buf = String::new();
            io::stdin().read_to_string(&mut buf).ok();
            if buf.trim().is_empty() {
                fs::read_to_string(stash_path()).unwrap_or_default()
            } else {
                let _ = fs::create_dir_all(stash_path().parent().unwrap());
                let _ = fs::write(stash_path(), &buf);
                buf
            }
        };

        let output = poc_memory::memory_search::run_hook(&input);
        print!("{}", output);
    } else {
        show_seen(&args.session)
    }
}