import {
  DiscordAPIError,
  MessageFlags,
} from 'discord.js';
import logger from './logger.js';

/**
 * Replies or follows up with an ephemeral error message.
 * @param {import('discord.js').ChatInputCommandInteraction} interaction
 * @param {string} content
 */
export async function replyEphemeralError(interaction, content) {
  try {
    if (interaction.replied || interaction.deferred) {
      await interaction.followUp({ content, flags: MessageFlags.Ephemeral });
    } else {
      await interaction.reply({ content, flags: MessageFlags.Ephemeral });
    }
  } catch (error) {
    logger.error('Failed to send ephemeral error reply', {
      error: error instanceof Error ? error.message : String(error),
      commandName: interaction.commandName,
    });
  }
}

/**
 * Maps known failure modes to user-facing messages.
 * @param {unknown} error
 * @returns {string}
 */
export function describeCommandError(error) {
  if (error instanceof Error) {
    switch (error.message) {
      case 'DUPLICATE_MAPPING':
        return 'A reaction role for that emoji already exists on this message.';
      case 'MESSAGE_NOT_FOUND':
        return 'Message not found in this channel. Make sure the message ID is correct and the message is in the current channel.';
      case 'INVALID_EMOJI':
        return 'Invalid emoji. Use a unicode emoji (🎮) or custom emoji markup such as `<:name:id>` or `<a:name:id>`.';
      case 'CUSTOM_EMOJI_UNAVAILABLE':
        return 'That custom emoji is unavailable to the bot. Use an emoji from a server the bot is in.';
      case 'ROLE_NOT_FOUND':
        return 'That role could not be found in this server.';
      case 'MAPPING_NOT_FOUND':
        return 'No reaction-role mapping was found for that message and emoji.';
      case 'NO_MAPPINGS_FOR_MESSAGE':
        return 'No reaction-role mappings were found for that message.';
      default:
        break;
    }

    if (error.message.startsWith('PERMISSION:')) {
      return error.message.slice('PERMISSION:'.length).trim();
    }
  }

  if (error instanceof DiscordAPIError) {
    logger.error('Discord API error', {
      code: error.code,
      message: error.message,
      status: error.status,
    });

    if (error.code === 50013) {
      return 'Missing bot permissions. I need Manage Roles, Add Reactions, View Channels, and Read Message History.';
    }

    if (error.code === 10008) {
      return 'Message not found. It may have been deleted.';
    }

    if (error.code === 10014) {
      return 'Unknown emoji. The emoji may be invalid or unavailable.';
    }

    return `Discord API error: ${error.message}`;
  }

  logger.error('Unexpected command error', {
    error: error instanceof Error ? error.message : String(error),
    stack: error instanceof Error ? error.stack : undefined,
  });

  return 'An unexpected error occurred. Please try again later.';
}

/**
 * @param {unknown} error
 * @returns {boolean}
 */
export function isDatabaseError(error) {
  return (
    error instanceof Error &&
    (error.message.includes('SQLITE_') ||
      error.message.toLowerCase().includes('database'))
  );
}