zc2 0.0.25

//! Guided onboarding wizard — a full-screen, Claude-Code-style setup flow.
//!
//! Launched by `zc login` / `zc init` and by a plain `zc` when no API key is
//! set. Steps: choose environment → browser device-code sign-in (show a code,
//! open the dashboard, poll for approval) → join the mesh. No key pasting.
//!
//! The device-code HTTP/parse logic is factored into small pure-ish functions
//! so it is unit-testable without a terminal.

use std::io;
use std::time::{Duration, Instant};

use crossterm::{
    event::{self, Event, KeyCode, KeyEventKind, KeyModifiers},
    execute,
    terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
};
use ratatui::{
    backend::CrosstermBackend,
    layout::{Alignment, Constraint, Direction, Layout},
    style::{Color, Modifier, Style},
    text::{Line, Span},
    widgets::{Block, Borders, Paragraph},
    Frame, Terminal,
};

use crate::credentials;
use crate::init::{decide, Decision};

/// The dashboards a user can target, in menu order.
pub const ENVS: &[(&str, &str)] = &[
    ("Production", credentials::PROD_API_URL),
    ("Staging", credentials::STAGING_API_URL),
];

/// Parsed `/api/auth/cli/start` response.
pub struct DeviceStart {
    pub device_code: String,
    pub user_code: String,
    pub verification_uri: String,
    pub interval: u64,
    pub expires_in: u64,
}

/// Parse a `/api/auth/cli/start` body. Pure — unit-tested without the network.
pub fn parse_device_start(body: &str) -> Option<DeviceStart> {
    let v: serde_json::Value = serde_json::from_str(body).ok()?;
    Some(DeviceStart {
        device_code: v["device_code"].as_str()?.to_string(),
        user_code: v["user_code"].as_str()?.to_string(),
        verification_uri: v["verification_uri"].as_str()?.to_string(),
        interval: v["interval"].as_u64().unwrap_or(5).clamp(1, 30),
        expires_in: v["expires_in"].as_u64().unwrap_or(600),
    })
}

/// Begin a device-code sign-in against a dashboard.
pub fn device_start(api_url: &str) -> Result<DeviceStart, String> {
    let url = format!("{}/api/auth/cli/start", api_url.trim_end_matches('/'));
    let resp = ureq::post(&url)
        .config()
        .http_status_as_error(false)
        .timeout_global(Some(Duration::from_secs(15)))
        .build()
        .send("")
        .map_err(|e| format!("could not reach {api_url}: {e}"))?;
    let status = resp.status().as_u16();
    if status == 404 {
        return Err(format!("browser sign-in isn't available on {api_url}"));
    }
    if status != 200 {
        return Err(format!(
            "sign-in could not start ({api_url}: HTTP {status})"
        ));
    }
    let body = resp
        .into_body()
        .read_to_string()
        .map_err(|e| e.to_string())?;
    parse_device_start(&body).ok_or_else(|| "malformed start response".into())
}

/// Poll once for approval. Wraps the shared `init::decide` logic.
pub fn device_poll(api_url: &str, device_code: &str) -> Decision {
    let url = format!("{}/api/auth/cli/poll", api_url.trim_end_matches('/'));
    let payload = serde_json::json!({ "device_code": device_code }).to_string();
    match ureq::post(&url)
        .config()
        .http_status_as_error(false)
        .timeout_global(Some(Duration::from_secs(15)))
        .build()
        .header("Content-Type", "application/json")
        .send(payload.as_str())
    {
        Ok(r) => {
            let s = r.status().as_u16();
            let b = r.into_body().read_to_string().unwrap_or_default();
            decide(s, &b)
        }
        // Transient network error — treat as still-pending so we keep polling.
        Err(_) => Decision::Pending,
    }
}

/// Which screen the wizard is on.
enum Step {
    ChooseEnv,
    Await {
        user_code: String,
        device_code: String,
        verification_uri: String,
        deadline: Instant,
        next_poll: Instant,
    },
    Connected {
        summary: String,
    },
    Failed(String),
}

struct Wizard {
    step: Step,
    env_idx: usize,
    notice: Option<String>,
    pending: Option<Pending>,
    quit: bool,
    connected: bool,
}

impl Wizard {
    fn new() -> Self {
        Self {
            step: Step::ChooseEnv,
            env_idx: 0,
            notice: None,
            pending: None,
            quit: false,
            connected: false,
        }
    }
    fn api_url(&self) -> &'static str {
        ENVS[self.env_idx].1
    }
}

/// Run the wizard. Returns `true` when the user finished connected (so callers
/// can drop straight into the shell). Falls back to text guidance off a TTY.
pub fn run() -> bool {
    use std::io::IsTerminal;
    if !io::stdout().is_terminal() {
        crate::init::print_connect_guidance();
        return false;
    }
    match run_inner() {
        Ok(connected) => connected,
        Err(e) => {
            eprintln!("onboarding error: {e}");
            false
        }
    }
}

fn run_inner() -> io::Result<bool> {
    let default_panic = std::panic::take_hook();
    std::panic::set_hook(Box::new(move |info| {
        let _ = disable_raw_mode();
        let _ = execute!(io::stdout(), LeaveAlternateScreen);
        default_panic(info);
    }));

    enable_raw_mode()?;
    let mut stdout = io::stdout();
    execute!(stdout, EnterAlternateScreen)?;
    let mut terminal = Terminal::new(CrosstermBackend::new(stdout))?;

    let mut w = Wizard::new();
    while !w.quit {
        terminal.draw(|f| draw(f, &w))?;

        // Run any queued blocking action (start / connect) between frames.
        if let Some(action) = w.pending.take() {
            action.run(&mut w);
            continue;
        }

        // While awaiting approval, poll on the server's interval.
        if let Step::Await {
            device_code,
            deadline,
            next_poll,
            ..
        } = &w.step
        {
            let now = Instant::now();
            if now >= *deadline {
                w.step = Step::Failed("the code expired — press Enter to try again".into());
                continue;
            }
            if now >= *next_poll {
                let url = w.api_url();
                let dc = device_code.clone();
                match device_poll(url, &dc) {
                    Decision::Pending => {
                        if let Step::Await { next_poll, .. } = &mut w.step {
                            *next_poll = Instant::now() + Duration::from_secs(5);
                        }
                    }
                    Decision::Approved(token) => {
                        let _ = credentials::save(&token, Some(url));
                        std::env::set_var("ZAKURO_API_KEY", &token);
                        std::env::set_var("ZAKURO_API_URL", url);
                        w.notice = Some("Approved — connecting to the mesh…".into());
                        w.pending = Some(Pending::Connect);
                    }
                    Decision::Failed(msg) => {
                        w.step = Step::Failed(msg);
                    }
                }
                continue;
            }
        }

        if !event::poll(Duration::from_millis(120))? {
            continue;
        }
        if let Event::Key(k) = event::read()? {
            if k.kind == KeyEventKind::Press {
                handle_key(&mut w, k.code, k.modifiers);
            }
        }
    }

    disable_raw_mode()?;
    execute!(terminal.backend_mut(), LeaveAlternateScreen)?;
    terminal.show_cursor()?;
    if w.connected {
        if let Step::Connected { summary } = &w.step {
            println!("  ✓ Signed in · {summary}");
        }
    }
    Ok(w.connected)
}

enum Pending {
    Start,
    Connect,
}

impl Pending {
    fn run(self, w: &mut Wizard) {
        match self {
            Pending::Start => match device_start(w.api_url()) {
                Ok(ds) => {
                    let _ = crate::init::open_browser(&ds.verification_uri);
                    w.notice = Some("Opened the dashboard — approve the code there.".into());
                    w.step = Step::Await {
                        user_code: ds.user_code,
                        device_code: ds.device_code,
                        verification_uri: ds.verification_uri,
                        deadline: Instant::now() + Duration::from_secs(ds.expires_in),
                        next_poll: Instant::now() + Duration::from_secs(ds.interval),
                    };
                }
                Err(e) => w.step = Step::Failed(e),
            },
            Pending::Connect => {
                match crate::vpn::connect(crate::vpn::connector::Preference::Auto) {
                    Ok(info) => {
                        w.connected = true;
                        w.step = Step::Connected {
                            summary: format!(
                                "mesh up — {} · {} peer(s)",
                                info.address,
                                info.peers.len()
                            ),
                        };
                        w.notice = None;
                    }
                    Err(e) => {
                        w.step = Step::Failed(format!("{e}"));
                        w.notice = None;
                    }
                }
            }
        }
    }
}

fn handle_key(w: &mut Wizard, code: KeyCode, mods: KeyModifiers) {
    if code == KeyCode::Esc || (code == KeyCode::Char('c') && mods.contains(KeyModifiers::CONTROL))
    {
        w.quit = true;
        return;
    }
    match &w.step {
        Step::ChooseEnv => match code {
            KeyCode::Up | KeyCode::Char('k') => {
                w.env_idx = (w.env_idx + ENVS.len() - 1) % ENVS.len()
            }
            KeyCode::Down | KeyCode::Char('j') => w.env_idx = (w.env_idx + 1) % ENVS.len(),
            KeyCode::Char('q') => w.quit = true,
            KeyCode::Enter => {
                w.notice = Some("Starting browser sign-in…".into());
                w.pending = Some(Pending::Start);
            }
            _ => {}
        },
        Step::Await {
            verification_uri, ..
        } => {
            if code == KeyCode::Char('o') {
                let _ = crate::init::open_browser(verification_uri);
            }
        }
        Step::Connected { .. } => w.quit = true,
        Step::Failed(_) => match code {
            KeyCode::Enter | KeyCode::Char('r') => {
                w.step = Step::ChooseEnv;
                w.notice = None;
            }
            _ => w.quit = true,
        },
    }
}

fn draw(f: &mut Frame, w: &Wizard) {
    let area = f.size();
    let accent = Style::default()
        .fg(Color::Cyan)
        .add_modifier(Modifier::BOLD);
    let dim = Style::default().fg(Color::DarkGray);
    let ok = Style::default().fg(Color::Green);
    let err = Style::default().fg(Color::Red);

    let chunks = Layout::default()
        .direction(Direction::Vertical)
        .margin(1)
        .constraints([
            Constraint::Length(3),
            Constraint::Min(6),
            Constraint::Length(2),
            Constraint::Length(1),
        ])
        .split(area);

    let step_no = match w.step {
        Step::ChooseEnv => "Step 1/2",
        Step::Await { .. } => "Step 2/2",
        Step::Connected { .. } => "Done",
        Step::Failed(_) => "Problem",
    };
    f.render_widget(
        Paragraph::new(Line::from(vec![
            Span::styled(" Connect to Zakuro ", accent),
            Span::styled(format!("· {step_no}"), dim),
        ]))
        .block(Block::default().borders(Borders::ALL).border_style(accent)),
        chunks[0],
    );

    let body: Vec<Line> = match &w.step {
        Step::ChooseEnv => {
            let mut lines = vec![Line::from("Choose your environment:"), Line::from("")];
            for (i, (name, url)) in ENVS.iter().enumerate() {
                let sel = i == w.env_idx;
                lines.push(Line::from(vec![
                    Span::styled(if sel { "  ›  " } else { "     " }, accent),
                    Span::styled(
                        format!("{name}  "),
                        if sel { accent } else { Style::default() },
                    ),
                    Span::styled(format!("({url})"), dim),
                ]));
            }
            lines
        }
        Step::Await {
            user_code,
            verification_uri,
            ..
        } => vec![
            Line::from(vec![
                Span::raw("Environment: "),
                Span::styled(ENVS[w.env_idx].0, accent),
            ]),
            Line::from(""),
            Line::from("In the browser tab that opened, enter this code and approve:"),
            Line::from(""),
            Line::from(Span::styled(format!("        {user_code}"), accent)),
            Line::from(""),
            Line::from(vec![
                Span::styled("  ", dim),
                Span::styled(verification_uri.clone(), dim),
            ]),
            Line::from(""),
            Line::from(Span::styled("  Waiting for approval…", dim)),
        ],
        Step::Connected { summary } => vec![
            Line::from(vec![Span::styled("  ✓ ", ok), Span::raw(summary.clone())]),
            Line::from(""),
            Line::from("You're on the mesh. Press any key to open the zc terminal."),
        ],
        Step::Failed(msg) => vec![
            Line::from(vec![Span::styled("  ✗ ", err), Span::raw(msg.clone())]),
            Line::from(""),
            Line::from("Press Enter to start over, or Esc to quit."),
        ],
    };
    f.render_widget(
        Paragraph::new(body).block(Block::default().borders(Borders::ALL)),
        chunks[1],
    );

    let notice = w.notice.clone().unwrap_or_default();
    f.render_widget(
        Paragraph::new(Line::from(Span::styled(notice, dim))),
        chunks[2],
    );

    let hint = match w.step {
        Step::ChooseEnv => "↑/↓ select · ⏎ sign in · q quit",
        Step::Await { .. } => "o re-open browser · Esc cancel",
        Step::Connected { .. } => "press any key to continue",
        Step::Failed(_) => "⏎ start over · Esc quit",
    };
    f.render_widget(
        Paragraph::new(Line::from(Span::styled(hint, dim))).alignment(Alignment::Center),
        chunks[3],
    );
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn parses_a_full_start_response() {
        let body = r#"{"device_code":"abc","user_code":"WXYZ-1234","verification_uri":"https://x/activate","interval":5,"expires_in":600}"#;
        let ds = parse_device_start(body).expect("parse");
        assert_eq!(ds.user_code, "WXYZ-1234");
        assert_eq!(ds.device_code, "abc");
        assert_eq!(ds.interval, 5);
    }

    #[test]
    fn start_defaults_interval_and_expiry() {
        let body = r#"{"device_code":"d","user_code":"c","verification_uri":"u"}"#;
        let ds = parse_device_start(body).expect("parse");
        assert_eq!(ds.interval, 5);
        assert_eq!(ds.expires_in, 600);
    }

    #[test]
    fn start_none_on_missing_fields() {
        assert!(parse_device_start(r#"{"user_code":"c"}"#).is_none());
        assert!(parse_device_start("garbage").is_none());
    }

    #[test]
    fn envs_are_prod_then_staging() {
        assert_eq!(ENVS[0].1, credentials::PROD_API_URL);
        assert_eq!(ENVS[1].1, credentials::STAGING_API_URL);
    }
}