// src/middlewares/flatten-response.js
function flattenArray(obj) {
  return obj.map(e => flatten(e));
}

function flattenData(obj) {
  return flatten(obj.data);
}

function flattenAttrs(obj) {
  let attrs = {}
  for (var key in obj.attributes) {
    attrs[key] = flatten(obj.attributes[key]);
  }
  return {
    id: obj.id, 
    ...attrs
  };
}

function flatten(obj) {
  if(Array.isArray(obj))
  {
    return flattenArray(obj);
  }
  if(obj.data) {
    return flattenData(obj);
  }
  if(obj.attributes) {
    return flattenAttrs(obj);
  }
  return obj;
}

module.exports = () => {
  return async (ctx, next) => {
    await next();
    if (ctx.url.startsWith('/api')) {
      console.log(`API request (${ctx.url}) detected, transforming response json...`);
      ctx.response.body = {
        data: flatten(ctx.response.body.data),
        meta: ctx.response.body.meta
      };
    }
  };
};