// Claude Desktop — Programm-Steuerung
// D-Bus: Linux-Apps via dbus-send/qdbus
// Xvfb: Virtuelles Display fuer Computer-Use (Scaffold)
// Playwright: Tool-Hinweise (eigentliche Steuerung laeuft ueber MCP-Server)

use serde::{Deserialize, Serialize};
use std::process::Command;

// ============ D-Bus ============

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct DbusCallResult {
    pub success: bool,
    pub stdout: String,
    pub stderr: String,
    pub exit_code: i32,
}

#[tauri::command]
pub async fn dbus_call(
    service: String,
    path: String,
    method: String,
    args: Option<Vec<String>>,
    session: Option<bool>,
) -> Result<DbusCallResult, String> {
    let bus = if session.unwrap_or(true) { "--session" } else { "--system" };

    let mut cmd = Command::new("dbus-send");
    cmd.arg("--print-reply")
        .arg(bus)
        .arg(format!("--dest={}", service))
        .arg(&path)
        .arg(&method);

    if let Some(args) = args {
        for a in args {
            cmd.arg(a);
        }
    }

    let output = cmd.output().map_err(|e| format!("dbus-send Fehler: {}", e))?;

    Ok(DbusCallResult {
        success: output.status.success(),
        stdout: String::from_utf8_lossy(&output.stdout).to_string(),
        stderr: String::from_utf8_lossy(&output.stderr).to_string(),
        exit_code: output.status.code().unwrap_or(-1),
    })
}

#[tauri::command]
pub async fn dbus_list_services(session: Option<bool>) -> Result<Vec<String>, String> {
    let bus = if session.unwrap_or(true) { "--session" } else { "--system" };

    let output = Command::new("dbus-send")
        .arg("--print-reply")
        .arg(bus)
        .arg("--dest=org.freedesktop.DBus")
        .arg("/org/freedesktop/DBus")
        .arg("org.freedesktop.DBus.ListNames")
        .output()
        .map_err(|e| format!("dbus-send ListNames: {}", e))?;

    if !output.status.success() {
        return Err(String::from_utf8_lossy(&output.stderr).to_string());
    }

    let text = String::from_utf8_lossy(&output.stdout);
    let mut services: Vec<String> = text
        .lines()
        .filter_map(|l| {
            let t = l.trim();
            if t.starts_with("string \"") && t.ends_with('"') {
                Some(t[8..t.len() - 1].to_string())
            } else {
                None
            }
        })
        .filter(|s| !s.starts_with(':'))
        .collect();
    services.sort();
    services.dedup();
    Ok(services)
}

// ============ Xvfb (Virtuelles Display) ============

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct XvfbStatus {
    pub running: bool,
    pub display_num: u16,
    pub pid: Option<u32>,
    pub resolution: String,
}

static XVFB_STATE: std::sync::OnceLock<std::sync::Mutex<XvfbStatus>> = std::sync::OnceLock::new();

fn xvfb_state() -> &'static std::sync::Mutex<XvfbStatus> {
    XVFB_STATE.get_or_init(|| {
        std::sync::Mutex::new(XvfbStatus {
            running: false,
            display_num: 1,
            pid: None,
            resolution: "1920x1080x24".into(),
        })
    })
}

#[tauri::command]
pub async fn xvfb_start(display_num: Option<u16>, resolution: Option<String>) -> Result<XvfbStatus, String> {
    let display = display_num.unwrap_or(1);
    let res = resolution.unwrap_or_else(|| "1920x1080x24".into());

    // Pruefen ob Xvfb verfuegbar
    let check = Command::new("which").arg("Xvfb").output();
    if check.map(|o| !o.status.success()).unwrap_or(true) {
        return Err("Xvfb nicht installiert. Auf NixOS: nixpkgs.xorg.xvfb".into());
    }

    let child = Command::new("Xvfb")
        .arg(format!(":{}", display))
        .arg("-screen")
        .arg("0")
        .arg(&res)
        .spawn()
        .map_err(|e| format!("Xvfb-Start fehlgeschlagen: {}", e))?;

    let status = XvfbStatus {
        running: true,
        display_num: display,
        pid: Some(child.id()),
        resolution: res,
    };

    *xvfb_state().lock().unwrap() = status.clone();
    Ok(status)
}

#[tauri::command]
pub async fn xvfb_stop() -> Result<XvfbStatus, String> {
    let mut state = xvfb_state().lock().unwrap();
    if let Some(pid) = state.pid {
        let _ = Command::new("kill").arg(pid.to_string()).output();
    }
    state.running = false;
    state.pid = None;
    Ok(state.clone())
}

#[tauri::command]
pub async fn xvfb_status() -> Result<XvfbStatus, String> {
    Ok(xvfb_state().lock().unwrap().clone())
}

#[tauri::command]
pub async fn xvfb_screenshot(display_num: Option<u16>) -> Result<String, String> {
    // Screenshot vom virtuellen Display — probiert mehrere Tools durch
    let display = display_num.unwrap_or(1);
    let display_env = format!(":{}", display);
    let tmp = std::env::temp_dir().join(format!("claude-xvfb-{}.png", uuid::Uuid::new_v4()));

    // Versuchte Kommandos in Reihenfolge
    let attempts: Vec<(&str, Vec<String>)> = vec![
        ("scrot", vec!["-q".into(), "80".into(), tmp.to_string_lossy().into_owned()]),
        ("import", vec!["-window".into(), "root".into(), tmp.to_string_lossy().into_owned()]),
        ("ffmpeg", vec![
            "-f".into(), "x11grab".into(),
            "-i".into(), display_env.clone(),
            "-frames:v".into(), "1".into(),
            "-y".into(),
            tmp.to_string_lossy().into_owned(),
        ]),
    ];

    let mut last_err = String::new();
    for (cmd, args) in &attempts {
        // Tool vorhanden?
        if Command::new("which").arg(cmd).output().map(|o| !o.status.success()).unwrap_or(true) {
            last_err = format!("'{}' nicht installiert", cmd);
            continue;
        }

        let result = Command::new(cmd)
            .env("DISPLAY", &display_env)
            .args(args)
            .output();

        match result {
            Ok(o) if o.status.success() && tmp.exists() => {
                let bytes = std::fs::read(&tmp).map_err(|e| e.to_string())?;
                let _ = std::fs::remove_file(&tmp);
                use base64::Engine;
                return Ok(base64::engine::general_purpose::STANDARD.encode(&bytes));
            }
            Ok(o) => {
                last_err = format!("{} Exit {}: {}", cmd, o.status, String::from_utf8_lossy(&o.stderr));
            }
            Err(e) => {
                last_err = format!("{} Fehler: {}", cmd, e);
            }
        }
    }

    Err(format!(
        "Screenshot fehlgeschlagen. Installiere eines: scrot / imagemagick / ffmpeg.\nLetzter Fehler: {}",
        last_err
    ))
}

// ============ Playwright-Infos ============

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PlaywrightInfo {
    pub available: bool,
    pub hint: String,
}

#[tauri::command]
pub async fn playwright_info() -> Result<PlaywrightInfo, String> {
    // Playwright laeuft bei Eddy ueber MCP — hier nur Info fuer das UI
    Ok(PlaywrightInfo {
        available: true,
        hint: "Playwright-Steuerung laeuft ueber den MCP-Server. Nutze die Tools \
               mcp__plugin_playwright_playwright__browser_navigate, \
               _click, _snapshot etc. im Chat. Für Dolibarr-Automation \
               empfohlen: Session-Login via MCP-Playwright speichern."
            .into(),
    })
}