const _ = require('underscore');
const helptext = `The \`!help\` command can be used to get a list of commands, or to get specific help text using \`!help <command>\`
Also see the \`!alias\` command for extra simplifications.`

const ex = /^[\w\d]+$/
function help(context) {
  return new Promise((resolve, reject) => {
    if(context.isHelpRequest) {
      context.message.reply(helptext)
        .then(() => {
          console.info(`[${context.id}] ? help`);
          resolve();
        }).catch(err => reject(err));
    } else if(!context.args) {
      let text = 'Listing commands, use \`!help <command>\` for detailed information. Use \`!alias\` to find easy shortcut commands\n```';
      _.each(_.keys(context.commands), key => text += `\n${key}`);
      text += '\n```'
      context.message.reply(text)
        .then(() => {
          console.info(`[${context.id}] List commands -> [${context.pid}]`)
          resolve();
        }).catch(err => reject(err));
    } else {
      let match = ex.exec(context.args);
      if(match && _.has(context.commands, context.args)) {
        console.info(`[${context.id}] Passing help request to <${context.args}>`);
        context.isHelpRequest = true;
        context.commands[context.args](context);
      } else if (match && _.has(context.alias, context.args)) {
        console.info(`[${context.id}] Alias help request to <${context.command}>`);
        context.message.reply(`\`!${context.args}\`: ${context.alias[context.args].desc}`)
          .then(() => {
            console.info(`[${context.id}] Alias -> [${context.pid}]`);
            resolve();
          }).catch(err => reject(err));
      } else {
        context.message.reply(`No such command <${context.args}>`)
          .then(() => {
            console.info(`[${context.id}] No command -> [${context.pid}]`)
            resolve();
          }).catch(err => reject(err));
      }
    }
  });
}

module.exports = commands => {
  commands.help = help;
};