//! # terminal-garden
//!
//! The first face of the bus: a renderer, not a collector.
//! Git is the cleanest signal in the suite — discrete, unambiguous, no privacy
//! questions — so the garden proves the bus before anything reads the shell.
//!
//! Like every renderer, the garden is thin: connect to the socket → read the
//! git aggregates → fold them into per-repo plots → render. It never touches a
//! sensor. The mapping (commits → growth, staleness → wilt) lives in the
//! `terminal-garden` library so it can be unit-tested; this binary is just the
//! subscriber loop.
//!
//! Usage:
//! ```text
//!   terminal-garden [--socket <path>]
//!   terminal-garden --help | --version
//! ```
//! Socket defaults to `$XDG_RUNTIME_DIR/signald.sock`, falling back to
//! `~/.local/state/signald/sock`.

use std::collections::BTreeMap;
use std::path::{Path, PathBuf};

use signal_schema::{Signal, SignalName};
use terminal_garden::{plots_from_signals, render};

/// The `name`s the garden cares about: the git aggregates.
const SUBSCRIBE: &[SignalName] = &[
    SignalName::CommitsWindow,
    SignalName::CommitsToday,
    SignalName::BranchCount,
    SignalName::DaysSinceLastCommit,
];

fn main() {
    let socket = parse_socket();
    if let Err(e) = run(&socket) {
        eprintln!("terminal-garden: could not read signald at {}: {e}", socket.display());
        eprintln!("terminal-garden: is signald running? (signald --socket {})", socket.display());
        std::process::exit(1);
    }
}

/// Connect and render live: the daemon replays the last-value cache on connect,
/// then streams updates. We keep the latest value of each metric (keyed by name
/// and repo tag) and re-render the garden on every frame. `Ok(())` is a clean EOF
/// (the daemon closed the stream). Frames this build cannot decode are skipped,
/// so an older renderer keeps working against a newer daemon.
fn run(socket: &Path) -> std::io::Result<()> {
    let frames = signal_client::Frames::connect(socket)?;

    // Keyed by (metric name, source, repo tag) so per-repo signals coexist,
    // two collectors reporting the same name stay distinct, and updates replace
    // prior values rather than accumulating.
    let mut latest: BTreeMap<(u8, u8, Option<String>), Signal> = BTreeMap::new();
    // Frames this build cannot decode are skipped by the iterator, so a metric
    // appended after this renderer was built does not end the stream.
    for sig in frames {
        let sig = sig?;
        if !SUBSCRIBE.contains(&sig.name) {
            continue;
        }
        let key = (
            sig.name.to_u8(),
            sig.source.to_u8(),
            sig.tag.as_ref().map(|t| t.as_str().to_string()),
        );
        latest.insert(key, sig);

        let signals: Vec<Signal> = latest.values().cloned().collect();
        let plots = plots_from_signals(&signals);
        // Clear + home so the garden redraws in place as signals change.
        print!("\x1b[2J\x1b[H{}", render(&plots));
    }
    Ok(())
}

const USAGE: &str = "\
Usage: terminal-garden [--socket <path>]

  --socket <path>   signald's socket (default $XDG_RUNTIME_DIR/signald.sock,
                    else ~/.local/state/signald/sock)
  -h, --help        print this and exit
  -V, --version     print the version and exit
";

fn parse_socket() -> PathBuf {
    let mut args = std::env::args().skip(1);
    while let Some(arg) = args.next() {
        match arg.as_str() {
            "--help" | "-h" => {
                print!("{USAGE}");
                std::process::exit(0);
            }
            "--version" | "-V" => {
                println!("terminal-garden {}", env!("CARGO_PKG_VERSION"));
                std::process::exit(0);
            }
            _ => {}
        }
        if arg == "--socket" {
            if let Some(path) = args.next() {
                return PathBuf::from(path);
            }
        }
    }
    signal_client::default_socket_path()
}