"""Core plugin: ping, help, version."""

from derp import __version__
from derp.plugin import command


@command("ping", help="Check if the bot is alive")
async def cmd_ping(bot, message):
    """Respond with pong."""
    await bot.reply(message, "pong")


@command("help", help="List commands or show command help")
async def cmd_help(bot, message):
    """Show available commands or help for a specific command.

    Usage: !help [command]
    """
    parts = message.text.split(None, 2)
    if len(parts) > 1:
        # Help for a specific command
        cmd_name = parts[1].lower().lstrip(bot.prefix)
        handler = bot.registry.commands.get(cmd_name)
        if handler:
            help_text = handler.help or "No help available."
            await bot.reply(message, f"{bot.prefix}{cmd_name} -- {help_text}")
        else:
            await bot.reply(message, f"Unknown command: {cmd_name}")
        return

    # List all commands
    names = sorted(bot.registry.commands.keys())
    await bot.reply(message, f"Commands: {', '.join(bot.prefix + n for n in names)}")


@command("version", help="Show bot version")
async def cmd_version(bot, message):
    """Report the running version."""
    await bot.reply(message, f"derp {__version__}")