import logging
from discord.ext import commands
import os
import json

logger = logging.getLogger(__name__)

CONFIG_FILE = 'config.json'
REQUIRED_MESSAGES = ['upper_desc', 'footer', 'pfx_message']

class HelpCog(commands.Cog):
    def __init__(self, bot: commands.Bot):
        self.bot = bot
        self.help_config = self._load_and_validate_config()
        self.cogs_dir = os.path.join(
            os.path.dirname(__file__),
            self.help_config["settings"]["cogs_dir"]
        )

    def _load_and_validate_config(self) -> dict:
        path = os.path.join(os.path.dirname(__file__), CONFIG_FILE)
        
        if not os.path.exists(path):
            raise FileNotFoundError(f"Help cog config not found at {path}")
            
        with open(path, 'r', encoding='utf-8') as f:
            config = json.load(f)

        messages = config.get("messages", {})
        missing_msgs = [key for key in REQUIRED_MESSAGES if key not in messages]
        if missing_msgs:
            raise KeyError(f"Help config 'messages' is missing required keys: {missing_msgs}")

        settings = config.get("settings", {})
        settings.setdefault("cogs_dir", "..")
        settings.setdefault("column_width", 20)
        settings.setdefault("command_pfx", "!")
        
        config["messages"] = messages
        config["settings"] = settings

        logger.info("Help cog config loaded successfully")
        return config

    def _build_help_text(self, prefix: str) -> list[str]:
        settings = self.help_config["settings"]
        column_width = settings["column_width"]
        lines = []

        if not os.path.exists(self.cogs_dir):
            logger.error(f"Cogs directory not found at: {self.cogs_dir}")
            return lines

        for item in sorted(os.listdir(self.cogs_dir)):
            cog_dir = os.path.join(self.cogs_dir, item)
            if not os.path.isdir(cog_dir):
                continue
                
            config_path = os.path.join(cog_dir, CONFIG_FILE)
            if not os.path.exists(config_path):
                continue
                
            try:
                with open(config_path, 'r', encoding='utf-8') as f:
                    cog_config = json.load(f)
            except (json.JSONDecodeError, OSError) as e:
                logger.warning(f"Failed to load config for cog '{item}': {e}")
                continue

            description = cog_config.get('description', '')
            usages = cog_config.get('usages', [])
            hidden = cog_config.get('hidden', False)

            if not usages or hidden:
                continue

            for usage in usages:
                usage_text = usage if usage.startswith(prefix) else f"{prefix}{usage}"
                lines.append(f"{usage_text:<{column_width}} : {description}")

        return lines

    @commands.command(name="help")
    async def help(self, ctx: commands.Context):
        cfg_msgs = self.help_config["messages"]
        cfg_sets = self.help_config["settings"]
        
        prefix = ctx.prefix or cfg_sets['command_pfx']
        lines = self._build_help_text(prefix)

        if not lines:
            await ctx.send("No commands available.")
            return

        help_text = (
            f"{cfg_msgs['upper_desc']}\n"
            f"```\n"
            f"{chr(10).join(lines)}\n"
            f"```\n"
            f"{cfg_msgs['pfx_message']} `{cfg_sets['command_pfx']}`\n"
            f"{cfg_msgs['footer']}"
        )

        await ctx.send(help_text)

async def setup(bot: commands.Bot):
    await bot.add_cog(HelpCog(bot))