const fs = require('fs');
const _  = require('underscore');
const cache = require('../backbone/cache.js');
const alias = require('./alias.json');

let commands = {};
fs.readdirSync('./game/commands').forEach(file => {
  require(`./commands/${file}`)(commands);
});

function a(context) {
  try {
    let cmd = context.alias[context.command].command;
    if(context.alias[context.command].arg) {
      let args = alias[context.command].arg + context.args;
      context.args = args;
    }
    context.command = cmd;
  } catch {
    console.info(`[${context.id}] Not an alias <${context.command}>`);
  }
}

const ex = /^!(?:([\w\d]+)|(?:([\w\d]+?)\s(.+)))$/
function c (context) {
  return new Promise((resolve, reject) => {
    let match = ex.exec(context.message.content);
    if (match) {
      context.command = match[2] ? match[2] : match[1];
      context.args = match[3];
      context.alias = alias;
      a(context);
      context.commands = commands;
      context.pid = context.message.author.id;
      cache.state(context.id)
        .then(data => {
          context.state = data;
          resolve(context);
        }).catch(err => reject(err));
    } else { resolve(false); }
  });
}

function p(message) {
  return new Promise((resolve, reject) => {
    let context = { message: message, id: message.guild.id };
    c(context)
      .then(context => resolve(context))
      .catch(err => reject(err));
  });
}

function x(context) {
  return new Promise((resolve, reject) => {
    if(context) {
      if(_.has(commands, context.command)) {
        console.info(`[${context.id}] Execute command <${context.command}>`);
        commands[context.command](context)
          .then(() => {
            if(context.stateChanged){
              cache.commit(context.id);
            } else {
              console.info(`[${context.id}] No change to commit (Context.stateChanged == false)`);
            }
            resolve();
          })
          .catch(err => reject(err));
      } else {
        console.warn(`[${context.id}] Unknown command <${context.command}>`);
      }
    }
  });
}

module.exports = {
  parse: p,
  execute: x
}