//! dingger: agent state watching for tmux panes.

mod hooks;
mod integrations;
mod manifest_update;
mod names;
mod notify;
mod platform;
mod restore;
mod snapshot;
mod terminals;
mod tmux;
mod watcher;

use clap::{Parser, Subcommand};
use tracing_subscriber::EnvFilter;

#[derive(Parser)]
#[command(name = "dingger", about = "Agent state watching for tmux panes")]
struct Cli {
    #[command(subcommand)]
    command: Command,
}

#[derive(Subcommand)]
enum TerminalAction {
    /// The client gained focus: learn its terminal (tmux's client-focus-in).
    Focused {
        #[arg(long)]
        client: String,
    },
    /// Raise the client's terminal.
    Raise {
        #[arg(long)]
        client: String,
    },
}

#[derive(Subcommand)]
enum Command {
    /// Watch all tmux panes and notify on agent state transitions.
    Watch {
        /// Poll interval in seconds.
        #[arg(long, default_value_t = 1)]
        interval_secs: u64,
        /// Disable notification sounds.
        #[arg(long)]
        no_sounds: bool,
        /// Disable macOS notifications (sounds still play unless --no-sounds).
        #[arg(long)]
        no_notifications: bool,
    },
    /// Print the current agent state of every tmux pane.
    Status,
    /// Refresh detection manifests from herdr's published catalog.
    Manifests {
        #[command(subcommand)]
        command: ManifestCommand,
    },
    /// Show an agent pane and mark it attended. Without --pane, jumps to the
    /// agent that has waited longest (FIFO), skipping the window the client
    /// already shows. Used by the tmux status-line click and the menu bar.
    Focus {
        /// tmux client to switch (default: the most recently active one).
        #[arg(long)]
        client: Option<String>,
        /// Pane to show (default: the head of the ready queue).
        #[arg(long)]
        pane: Option<String>,
    },
    /// Wake the watcher so focus changes show up immediately (tmux hooks).
    Poke,
    /// Restore tmux sessions saved before tmux last stopped (a crash,
    /// shutdown, or kill-server): windows, panes, layouts, directories.
    /// Only adds what is missing; a bare session of the same name (what a
    /// terminal creates on startup) is replaced, its clients moved over.
    Restore {
        /// Show what would happen without changing anything.
        #[arg(long)]
        dry_run: bool,
        /// List the restore candidate and saved snapshots.
        #[arg(long)]
        list: bool,
        /// Restore from this snapshot file instead of the candidate.
        #[arg(long)]
        from: Option<String>,
        /// Restore only these sessions.
        #[arg(long = "session")]
        sessions: Vec<String>,
        /// Write the report to restore.log and notify a summary.
        #[arg(long)]
        report: bool,
        /// Stop offering the saved layout (it can still be restored).
        #[arg(long)]
        dismiss: bool,
    },
    /// Install integrations: an agent's hook extension (state and session
    /// reports), or `zsh` (command lines for restore to retype).
    Install {
        /// `pi`, `claude`, or `zsh`.
        agent: String,
    },
    /// The terminal window of a tmux client (tmux runs these; see
    /// `terminals`).
    #[command(hide = true)]
    Terminal {
        #[command(subcommand)]
        action: TerminalAction,
    },
    /// An agent's hook, run by the agent (`dingger install` sets it up).
    #[command(hide = true)]
    Hook {
        /// `claude`.
        agent: String,
    },
}

#[derive(Subcommand)]
enum ManifestCommand {
    /// Download newer manifests from herdr's published catalog into the
    /// local remote store; bundled manifests are the offline fallback.
    /// Restart `dingger watch` to pick them up.
    Update,
}

fn main() {
    platform::default_sigpipe();
    let cli = Cli::parse();
    // The daemon logs its work; commands print their own output and only
    // log problems.
    let default_level = if matches!(cli.command, Command::Watch { .. }) { "info" } else { "warn" };
    tracing_subscriber::fmt()
        .with_env_filter(EnvFilter::try_from_default_env().unwrap_or_else(|_| default_level.into()))
        .init();

    match cli.command {
        Command::Watch {
            interval_secs,
            no_sounds,
            no_notifications,
        } => {
            if let Err(err) = hooks::spawn_listener() {
                eprintln!("dingger: {err}");
                std::process::exit(1);
            }
            let mut watcher = watcher::Watcher::new(interval_secs, !no_sounds, !no_notifications);
            if let Err(err) = watcher.run() {
                eprintln!("dingger: {err}");
                std::process::exit(1);
            }
        }
        Command::Status => {
            if let Err(err) = status() {
                eprintln!("dingger: {err}");
                std::process::exit(1);
            }
        }
        Command::Manifests { command } => match command {
            ManifestCommand::Update => {
                if let Err(err) = manifest_update::update() {
                    eprintln!("dingger: {err}");
                    std::process::exit(1);
                }
            }
        },
        Command::Focus { client, pane } => {
            if let Err(err) = focus(client, pane) {
                eprintln!("dingger: {err}");
                std::process::exit(1);
            }
        }
        Command::Poke => {
            // Best effort: a stopped watcher just means nothing to wake.
            let _ = hooks::poke();
        }
        Command::Restore { dry_run, list, from, sessions, report, dismiss } => {
            let result = if list {
                restore::list()
            } else if dismiss {
                restore::dismiss()
            } else {
                restore::run(from.as_deref(), &sessions, dry_run, report)
            };
            if let Err(err) = result {
                eprintln!("dingger: {err}");
                std::process::exit(1);
            }
        }
        Command::Install { agent } => {
            if let Err(err) = integrations::install(&agent) {
                eprintln!("dingger: {err}");
                std::process::exit(1);
            }
        }
        Command::Terminal { action } => {
            let result = match &action {
                TerminalAction::Focused { client } => terminals::learn(client),
                TerminalAction::Raise { client } => terminals::raise(client),
            };
            if let Err(err) = result {
                eprintln!("dingger: {err}");
                std::process::exit(1);
            }
        }
        // Never fails the agent: exits 0, prints nothing.
        Command::Hook { agent } => integrations::run_hook(&agent),
    }
}

/// Show a pane in a client and mark it attended (`@dingger_ack`, consumed
/// by the watcher on its next tick), then raise that client's terminal
/// window. The single code path behind every click: the tmux status line,
/// the menu bar rows, the panel, search, and the shortcuts.
///
/// The client: the named one (a status-line click names the clicking
/// client); otherwise one already on a session holding the pane's window
/// (several terminal windows can show one session), else any; the focused
/// one first, then the most recently used (see `terminals::choose`).
fn focus(client: Option<String>, pane: Option<String>) -> Result<(), String> {
    let clients = terminals::clients()?;
    if clients.is_empty() {
        return Err("no tmux client attached".to_string());
    }
    let named = client.and_then(|name| clients.iter().find(|c| c.name == name));

    let pane_id = match pane {
        Some(pane) => pane,
        None => {
            // The queue head, skipping the window the user looks at.
            let looking = named.or_else(|| terminals::choose(&clients, &[]).map(|(c, _)| c));
            let current_window = looking.and_then(|c| tmux::client_format(&c.name, "#{window_id}"));
            let queue = tmux::show_global("@dingger_queue").unwrap_or_default();
            let next = queue.split(',').filter(|id| !id.is_empty()).find(|id| {
                tmux::pane_format(id, "#{window_id}").as_deref() != current_window.as_deref()
            });
            match next {
                Some(id) => id.to_string(),
                None => return Ok(()), // nothing waiting elsewhere
            }
        }
    };

    let showing = tmux::sessions_with_pane(&pane_id);
    let (client, keeps_session) = match named {
        Some(client) => (client, showing.contains(&client.session_id)),
        None => terminals::choose(&clients, &showing).ok_or("no tmux client attached")?,
    };
    tmux::set_pane_option(&pane_id, "@dingger_ack", "1")?;
    tmux::show_pane(&client.name, &pane_id, keeps_session.then_some(client.session_id.as_str()))?;
    let _ = hooks::poke();
    raise(client);
    Ok(())
}

/// Bring a client's terminal forward: its exact window, tab, and split if
/// dingger learned which it is (raised by the tmux server, see
/// `terminals`); otherwise the terminal app.
fn raise(client: &terminals::Client) {
    if terminals::pairing(&client.tty).is_some() {
        if let Ok(exe) = std::env::current_exe() {
            let command = format!(
                "{} terminal raise --client {} >/dev/null 2>&1",
                snapshot::shell_quote(&exe.to_string_lossy()),
                snapshot::shell_quote(&client.name)
            );
            if tmux::run(&["run-shell", "-b", &command]).is_ok() {
                return;
            }
        }
    }
    if let Some(app) = terminals::terminal_app(client.pid) {
        terminals::open_app(&app);
    }
}

/// Every agent pane in herdr's priority order (blocked, done, working,
/// idle), oldest-waiting first within a status.
fn status() -> Result<(), String> {
    let mut panes: Vec<_> = tmux::list_panes()?
        .into_iter()
        .filter(|pane| pane.agent.is_some())
        .collect();
    if panes.is_empty() {
        println!("no agent panes");
        return Ok(());
    }
    panes.sort_by_key(|pane| {
        let status = watcher::Status::from_label(&pane.written_state);
        (watcher::list_order(status, pane.written_since.parse().ok()), pane.display_target.clone())
    });
    let place = |pane: &tmux::Pane| pane.display_target.replacen(':', " · ", 1);
    let width = panes.iter().map(|pane| place(pane).chars().count()).max().unwrap_or(5).max(5);
    println!("{:<8} {:<width$}  {:<7} NAME", "STATUS", "WHERE", "AGENT");
    for pane in &panes {
        let state = if pane.written_state.is_empty() { "-" } else { &pane.written_state };
        let agent = pane.agent.map(detect_core::agent_label).unwrap_or("-");
        println!("{state:<8} {:<width$}  {agent:<7} {}", place(pane), pane.written_name);
    }
    Ok(())
}