use anyhow::{Context, Result};
use owo_colors::OwoColorize;
use std::path::PathBuf;

const DESKTOP_NAME: &str = "umutray.desktop";

fn home() -> Result<PathBuf> {
    dirs::home_dir().context("Cannot determine home directory")
}

fn autostart_path() -> Result<PathBuf> {
    Ok(home()?.join(".config/autostart").join(DESKTOP_NAME))
}

fn desktop_path() -> Result<PathBuf> {
    Ok(home()?.join(".local/share/applications").join(DESKTOP_NAME))
}

fn render_desktop(exe: &std::path::Path, autostart: bool) -> String {
    let mut s = format!(
        "[Desktop Entry]\n\
         Name=umutray\n\
         Comment=Wine launcher manager for Windows game launchers\n\
         Exec={exe}\n\
         Icon=applications-games\n\
         Type=Application\n\
         Categories=Game;\n\
         Keywords=wine;proton;gaming;launcher;\n\
         StartupNotify=false\n",
        exe = exe.display(),
    );
    if autostart {
        s.push_str("X-GNOME-Autostart-enabled=true\n");
        s.push_str("Hidden=false\n");
    } else {
        // App-menu entry launches the GUI
        s = s.replace(
            &format!("Exec={}", exe.display()),
            &format!("Exec={} gui", exe.display()),
        );
        s.push_str("StartupNotify=true\n");
    }
    s
}

/// Install only the .desktop file so umutray appears in the app menu.
/// Called automatically on first `umutray gui` run.
pub fn install_desktop() -> Result<()> {
    let exe = std::env::current_exe().context("Cannot determine path to own executable")?;
    let desktop = desktop_path()?;
    if let Some(p) = desktop.parent() {
        std::fs::create_dir_all(p).with_context(|| format!("Failed to create {p:?}"))?;
    }
    std::fs::write(&desktop, render_desktop(&exe, false))
        .with_context(|| format!("Failed to write desktop file {desktop:?}"))?;
    println!("{} App menu entry written: {}", "✓".green().bold(), desktop.display());
    Ok(())
}

/// Remove the .desktop file.
pub fn uninstall_desktop() -> Result<()> {
    let desktop = desktop_path()?;
    if desktop.exists() {
        std::fs::remove_file(&desktop)
            .with_context(|| format!("Failed to remove {desktop:?}"))?;
        println!("Removed {}", desktop.display());
    } else {
        println!("No desktop file at {}", desktop.display());
    }
    Ok(())
}

/// Write an XDG autostart entry and the app-menu .desktop file.
pub fn install() -> Result<()> {
    let exe = std::env::current_exe().context("Cannot determine path to own executable")?;

    // XDG autostart
    let autostart = autostart_path()?;
    if let Some(p) = autostart.parent() {
        std::fs::create_dir_all(p).with_context(|| format!("Failed to create {p:?}"))?;
    }
    std::fs::write(&autostart, render_desktop(&exe, true))
        .with_context(|| format!("Failed to write autostart file {autostart:?}"))?;
    println!("Wrote autostart: {}", autostart.display());

    // App-menu entry
    install_desktop()?;

    println!();
    println!("{} Autostart installed.", "✓".green().bold());
    println!("  umutray will start with your next graphical session.");
    println!("  To start now: {}", exe.display());
    Ok(())
}

/// Remove the XDG autostart entry and the app-menu .desktop file.
pub fn uninstall() -> Result<()> {
    let autostart = autostart_path()?;
    if autostart.exists() {
        std::fs::remove_file(&autostart)
            .with_context(|| format!("Failed to remove {autostart:?}"))?;
        println!("Removed {}", autostart.display());
    } else {
        println!("No autostart file at {}", autostart.display());
    }

    uninstall_desktop()?;

    println!("{} Autostart removed.", "✓".green().bold());
    Ok(())
}

/// Show whether the XDG autostart entry is present.
pub fn status() -> Result<()> {
    let autostart = autostart_path()?;
    if autostart.exists() {
        println!("{} Autostart enabled: {}", "✓".green().bold(), autostart.display());
    } else {
        println!("{} Autostart not installed ({})", "✗".red().bold(), autostart.display());
    }
    Ok(())
}