//! `codecraft` – CodeCraft in the terminal.
//!
//! A local coding agent: tools and files stay on this machine; models come
//! from a CodeCraft server (sign in) and/or your own providers (standalone).

mod agent;
mod app;
mod conf;
mod editor;
mod i18n;
mod models;
mod server;
mod session;
mod stats;
mod theme;
mod tools;

use agent::{Agent, Env, Reply, UiEvent, builtin_modes, modes_from_server};
use anyhow::{Result, bail};
use app::Cmd;
use clap::{Parser, Subcommand};
use codecraft_core::config::PermissionConfig;
use conf::Config;
use serde_json::Value;
use session::LocalSession;
use std::io::{IsTerminal, Write};
use std::sync::Arc;
use tokio::sync::mpsc;
use tokio_util::sync::CancellationToken;

#[derive(Parser)]
#[command(name = "codecraft", version = codecraft_core::version::VERSION, about = "CodeCraft in the terminal – a local coding agent")]
struct Cli {
    /// Start with this prompt
    prompt: Option<String>,
    /// Continue the last session in this folder
    #[arg(short, long)]
    r#continue: bool,
    /// Resume a session by id
    #[arg(long)]
    resume: Option<String>,
    /// Model ("provider/model" or "server:provider/model")
    #[arg(short, long)]
    model: Option<String>,
    /// Mode: build, plan, craft …
    #[arg(long)]
    mode: Option<String>,
    #[command(subcommand)]
    cmd: Option<Sub>,
}

#[derive(Subcommand)]
enum Sub {
    /// Sign in to a CodeCraft server (creates an API token for this machine)
    Login { url: Option<String>, username: Option<String> },
    /// Forget the server login
    Logout,
    /// Guided setup: server login and own model providers
    Setup,
    /// Run one prompt without the full-screen UI (for scripts)
    Run {
        prompt: String,
        #[arg(short, long)]
        model: Option<String>,
        #[arg(long, default_value = "build")]
        mode: String,
        /// Permission mode: default, auto, accept_edits, bypass
        #[arg(long, default_value = "auto")]
        permissions: String,
    },
    /// Update codecraft from your server
    Update,
    /// List local sessions
    Sessions,
}

/// Configuration, models and modes (server and/or local).
pub async fn build_env() -> Result<Env> {
    let cfg = Config::load()?;
    let server = cfg.server.as_ref().map(server::Server::new);
    let mut server_cfg = None;
    let mut offline = None;
    if let Some(s) = &server {
        match tokio::time::timeout(std::time::Duration::from_secs(10), s.get("/cli/config")).await {
            Ok(Ok(v)) => server_cfg = Some(v),
            Ok(Err(e)) => offline = Some(format!("{e:#}")),
            Err(_) => offline = Some("server timeout".into()),
        }
    }
    let catalog = models::Catalog::load(&cfg, server_cfg.as_ref()).await;
    let sc = server_cfg.clone().unwrap_or(Value::Null);
    let modes = if server_cfg.is_some() { modes_from_server(&sc) } else { builtin_modes() };
    let permissions: PermissionConfig = serde_json::from_value(sc["permissions"].clone()).unwrap_or_default();
    let remote_tools = sc["mcp_tools"]
        .as_array()
        .into_iter()
        .flatten()
        .map(|t| tools::ToolSpec {
            name: t["name"].as_str().unwrap_or("").into(),
            description: t["description"].as_str().unwrap_or("").into(),
            schema: t["input_schema"].clone(),
            read_only: false,
            is_edit: false,
            remote: true,
        })
        .collect();
    let server_skills = sc["skills"].as_array().into_iter().flatten().map(|s| (s["name"].as_str().unwrap_or("").to_string(), s["description"].as_str().unwrap_or("").to_string())).collect();
    // Language and theme: local override, else the server's, else the system's.
    let prefs = &sc["prefs"];
    let lang = cfg.lang.clone().or_else(|| prefs["lang"].as_str().map(String::from)).unwrap_or_else(i18n::system_lang);
    i18n::set_lang(&lang);
    let base = cfg.theme.clone().or_else(|| prefs["theme"].as_str().map(String::from)).unwrap_or_else(|| "gruvbox".into());
    let mode = cfg.theme_mode.clone().or_else(|| prefs["theme_mode"].as_str().map(String::from)).unwrap_or_else(|| "auto".into());
    theme::set(theme::Theme::load(&base, &mode));
    let env = Env {
        base_prompt: sc["base_prompt"].as_str().unwrap_or(codecraft_core::prompts::BASE_PROMPT).to_string(),
        auto_prompt: sc["auto_mode_prompt"].as_str().unwrap_or(codecraft_core::prompts::AUTO_MODE_PROMPT).to_string(),
        memory: sc["memory"].as_str().unwrap_or("").to_string(),
        cfg,
        server,
        server_cfg,
        catalog,
        modes,
        permissions,
        remote_tools,
        server_skills,
    };
    if let Some(e) = offline {
        eprintln!("warning: CodeCraft server not reachable ({e}) – using local providers only");
    }
    Ok(env)
}

fn prompt_line(label: &str, secret: bool) -> Result<String> {
    eprint!("{label}: ");
    std::io::stderr().flush()?;
    if !secret || !std::io::stdin().is_terminal() {
        let mut s = String::new();
        std::io::stdin().read_line(&mut s)?;
        return Ok(s.trim().to_string());
    }
    use crossterm::event::{Event, KeyCode, KeyEventKind, read};
    crossterm::terminal::enable_raw_mode()?;
    let mut s = String::new();
    let res = loop {
        match read() {
            Ok(Event::Key(k)) if k.kind != KeyEventKind::Release => match k.code {
                KeyCode::Enter => break Ok(()),
                KeyCode::Backspace => {
                    s.pop();
                }
                KeyCode::Esc => break Err(anyhow::anyhow!("cancelled")),
                KeyCode::Char('c') if k.modifiers.contains(crossterm::event::KeyModifiers::CONTROL) => break Err(anyhow::anyhow!("cancelled")),
                KeyCode::Char(c) => s.push(c),
                _ => {}
            },
            Ok(_) => {}
            Err(e) => break Err(e.into()),
        }
    };
    crossterm::terminal::disable_raw_mode()?;
    eprintln!();
    res.map(|_| s)
}

fn version_newer(server: &str, ours: &str) -> bool {
    codecraft_core::version::newer(server, ours)
}

fn target() -> String {
    format!("{}-{}", std::env::consts::OS, std::env::consts::ARCH)
}

async fn self_update() -> Result<()> {
    let cfg = Config::load()?;
    let Some(login) = &cfg.server else { bail!("not signed in – updates come from your CodeCraft server (codecraft login)") };
    let http = server::http();
    let info: Value = http.get(format!("{}/api/info", login.url)).send().await?.json().await?;
    let latest = info["version"].as_str().unwrap_or("0");
    if !version_newer(latest, codecraft_core::version::VERSION) {
        println!("codecraft {} is up to date.", codecraft_core::version::VERSION);
        return Ok(());
    }
    let url = format!("{}/cli/download/{}", login.url, target());
    println!("Downloading codecraft {latest} for {} …", target());
    let resp = http.get(&url).send().await?;
    if !resp.status().is_success() {
        bail!("no build for {} on the server ({})", target(), resp.status());
    }
    let bytes = resp.bytes().await?;
    let exe = std::env::current_exe()?;
    let tmp = exe.with_extension("new");
    std::fs::write(&tmp, &bytes)?;
    #[cfg(unix)]
    {
        use std::os::unix::fs::PermissionsExt;
        std::fs::set_permissions(&tmp, std::fs::Permissions::from_mode(0o755))?;
    }
    std::fs::rename(&tmp, &exe)?;
    println!("Updated to {latest}.");
    Ok(())
}

/// Process commands for the agent (one turn at a time).
fn spawn_agent(env: Arc<Env>, session: LocalSession, ui: mpsc::UnboundedSender<UiEvent>) -> mpsc::UnboundedSender<Cmd> {
    let (tx, mut rx) = mpsc::unbounded_channel::<Cmd>();
    tokio::spawn(async move {
        let mut agent = Agent::new(env, session, ui.clone());
        while let Some(cmd) = rx.recv().await {
            match cmd {
                Cmd::Prompt { text, images, effort, cancel } => agent.prompt(text, images, effort, cancel).await,
                Cmd::SetModel(m) => {
                    agent.session.model = m;
                    let _ = agent.session.save();
                }
                Cmd::SetMode(m) => {
                    agent.session.mode = m;
                    let _ = agent.session.save();
                }
                Cmd::SetPermission(p) => {
                    agent.session.permission_mode = p;
                    let _ = agent.session.save();
                }
                Cmd::Load(s) => agent = Agent::new(agent.env.clone(), *s, ui.clone()),
                Cmd::New => {
                    let s = LocalSession::new(&agent.session.cwd, &agent.session.model, &agent.session.mode, &agent.session.permission_mode);
                    agent = Agent::new(agent.env.clone(), s, ui.clone());
                }
                Cmd::Compact(cancel) => {
                    let _ = ui.send(UiEvent::Busy(true));
                    let model = agent.env.catalog.find(&agent.session.model).cloned();
                    match model {
                        Some(m) => {
                            if let Err(e) = agent.compact(&m, &cancel).await {
                                let _ = ui.send(UiEvent::Error(format!("{e:#}")));
                            }
                        }
                        None => {
                            let _ = ui.send(UiEvent::Error(i18n::t("no_model").into()));
                        }
                    }
                    let _ = ui.send(UiEvent::Busy(false));
                }
                Cmd::SetEnv(e) => agent.env = e,
            }
        }
    });
    tx
}

fn default_model(env: &Env, cfg: &Config, wanted: Option<String>) -> String {
    wanted
        .or_else(|| cfg.default_model.clone())
        .filter(|m| env.catalog.find(m).is_some())
        .or_else(|| env.server_cfg.as_ref().and_then(|s| s["default_model"].as_str()).map(|m| format!("{}{m}", models::SERVER_PREFIX)).filter(|m| env.catalog.find(m).is_some()))
        .or_else(|| env.catalog.models.first().map(|m| m.spec.clone()))
        .unwrap_or_default()
}

/// One prompt without the UI: answer on stdout, tools on stderr.
async fn run_once(prompt: String, model: Option<String>, mode: String, permissions: String) -> Result<()> {
    let env = Arc::new(build_env().await?);
    let cwd = std::env::current_dir()?.display().to_string();
    let model = default_model(&env, &env.cfg.clone(), model);
    if model.is_empty() {
        bail!("no model configured – run `codecraft setup`");
    }
    let session = LocalSession::new(&cwd, &model, &mode, &permissions);
    let (ui_tx, mut ui_rx) = mpsc::unbounded_channel();
    let mut agent = Agent::new(env, session, ui_tx);
    let cancel = CancellationToken::new();
    let task = tokio::spawn(async move { agent.prompt(prompt, vec![], None, cancel).await });
    let interactive = std::io::stdin().is_terminal();
    while let Some(ev) = ui_rx.recv().await {
        match ev {
            UiEvent::Text(t) => {
                print!("{t}");
                std::io::stdout().flush()?;
            }
            UiEvent::ToolStart { name, input, .. } => eprintln!("\n> {name} {}", input["description"].as_str().or(input["command"].as_str()).or(input["path"].as_str()).unwrap_or("")),
            UiEvent::Error(e) => eprintln!("error: {e}"),
            UiEvent::Permission { tool, title, reply, .. } => {
                let answer = if interactive { prompt_line(&format!("allow {tool} {title}? [y/a/N]"), false)? } else { String::new() };
                let _ = reply.send(match answer.as_str() {
                    "y" | "j" => Reply::Once,
                    "a" => Reply::Always,
                    _ => Reply::Reject(Some(if interactive { "rejected".into() } else { "not allowed in non-interactive mode – use --permissions bypass or accept_edits".into() })),
                });
            }
            UiEvent::Question { reply, .. } => {
                let _ = reply.send(None);
            }
            UiEvent::Busy(false) => break,
            _ => {}
        }
    }
    let _ = task.await;
    println!();
    Ok(())
}

#[tokio::main]
async fn main() -> Result<()> {
    let cli = Cli::parse();
    match cli.cmd {
        Some(Sub::Login { url, username }) => {
            let url = match url {
                Some(u) => u,
                None => prompt_line("CodeCraft server URL", false)?,
            };
            let user = match username {
                Some(u) => u,
                None => prompt_line("Username", false)?,
            };
            let pass = prompt_line("Password", true)?;
            let login = server::login(&url, &user, &pass).await?;
            let mut cfg = Config::load()?;
            println!("Signed in to {} as {}.", login.url, login.username);
            cfg.server = Some(login);
            cfg.save()?;
            return Ok(());
        }
        Some(Sub::Logout) => {
            let mut cfg = Config::load()?;
            cfg.server = None;
            cfg.save()?;
            println!("Signed out (revoke the token under Settings → Account → API tokens if needed).");
            return Ok(());
        }
        Some(Sub::Update) => return self_update().await,
        Some(Sub::Run { prompt, model, mode, permissions }) => return run_once(prompt, model, mode, permissions).await,
        Some(Sub::Sessions) => {
            for s in session::list(None).into_iter().take(50) {
                let when = chrono::DateTime::from_timestamp_millis(s.updated_at).map(|d| d.with_timezone(&chrono::Local).format("%Y-%m-%d %H:%M").to_string()).unwrap_or_default();
                println!("{}  {when}  {:<40}  {}", s.id, s.title.chars().take(40).collect::<String>(), s.cwd);
            }
            return Ok(());
        }
        Some(Sub::Setup) | None => {}
    }
    let setup = matches!(cli.cmd, Some(Sub::Setup)) || Config::load()?.is_empty();
    let env = Arc::new(build_env().await?);
    let cwd = std::env::current_dir()?.display().to_string();
    let cfg = env.cfg.clone();
    let session = if let Some(id) = cli.resume {
        LocalSession::load(&id)?
    } else if cli.r#continue {
        session::list(Some(&cwd)).into_iter().next().unwrap_or_else(|| LocalSession::new(&cwd, "", "build", "auto"))
    } else {
        LocalSession::new(&cwd, "", "build", "auto")
    };
    let mut session = session;
    if session.model.is_empty() || env.catalog.find(&session.model).is_none() {
        session.model = default_model(&env, &cfg, cli.model.clone());
    } else if let Some(m) = cli.model {
        session.model = m;
    }
    if let Some(m) = cli.mode {
        session.mode = m;
    }
    if session.messages.is_empty() {
        session.permission_mode = cfg.permission_mode.clone().unwrap_or_else(|| "auto".into());
    }
    // Notice when the server has a newer CLI.
    let mut status = String::new();
    if let Some(v) = env.server_cfg.as_ref().and_then(|s| s["version"].as_str()) {
        if version_newer(v, codecraft_core::version::VERSION) {
            status = format!("update available: {v} – run `codecraft update`");
        }
    }
    let (ui_tx, ui_rx) = mpsc::unbounded_channel();
    let cmd = spawn_agent(env.clone(), session.clone(), ui_tx);
    let mut app = app::App::new(env, session, cmd);
    app.set_status(status);
    app::run(app, ui_rx, cli.prompt, setup).await
}