#!/usr/bin/env python3
"""
Simple script to launch an application or focus it if already running in niri
Usage: niri-launch-or-focus <command> [--class CLASS] [--title TITLE] [args...]

Examples:
  niri-launch-or-focus firefox
  niri-launch-or-focus code --class Code --title "My Project"
  niri-launch-or-focus kitty --class kitty
"""

import argparse
import json
import subprocess
import sys


def find_window(class_name=None, title=None, app_name=None):
    """Find window by app_id (class), title, or app name."""
    try:
        result = subprocess.run(
            ["niri", "msg", "--json", "windows"],
            capture_output=True,
            text=True,
            check=False,
        )
        windows_json = result.stdout.strip()
        
        if not windows_json or windows_json == "[]":
            return None
        
        windows = json.loads(windows_json)
        
        for window in windows:
            app_id = window.get("app_id", "").lower()
            
            if class_name:
                if app_id == class_name.lower():
                    return window.get("id")
            elif title:
                if window.get("title") == title:
                    return window.get("id")
            elif app_name:
                if app_id == app_name.lower():
                    return window.get("id")
        
        return None
    except (json.JSONDecodeError, subprocess.SubprocessError, KeyError):
        return None


def focus_window(window_id):
    """Focus a window by ID."""
    subprocess.run(
        ["niri", "msg", "action", "focus-window", "--id", str(window_id)],
        stdout=subprocess.DEVNULL,
        stderr=subprocess.DEVNULL,
    )


def launch_command(command, args):
    """Launch a command in the background."""
    subprocess.Popen(
        [command] + args,
        stdout=subprocess.DEVNULL,
        stderr=subprocess.DEVNULL,
        start_new_session=True,
    )


def main():
    parser = argparse.ArgumentParser(
        description="Launch an application or focus it if already running in niri"
    )
    parser.add_argument("command", help="Command to run")
    parser.add_argument("--class", dest="class_name", help="Window class (app_id)")
    parser.add_argument("--title", help="Window title")
    parser.add_argument("args", nargs=argparse.REMAINDER, help="Additional arguments for command")
    
    args = parser.parse_args()
    
    # Extract app name from command (basename)
    app_name = args.command.split("/")[-1]
    
    # Try to find existing window
    window_id = find_window(
        class_name=args.class_name,
        title=args.title,
        app_name=app_name if not args.class_name and not args.title else None,
    )
    
    # Build command arguments
    cmd_args = []
    if args.class_name:
        cmd_args.append(f"--class={args.class_name}")
    if args.title:
        cmd_args.append(f"--title={args.title}")
    cmd_args.extend(args.args)
    
    # Focus if found, otherwise launch
    if window_id:
        focus_window(window_id)
    else:
        launch_command(args.command, cmd_args)


if __name__ == "__main__":
    main()