// schemas.js

var express = require('express'),
  Parse = require('parse/node').Parse,
  SchemaController = require('../Controllers/SchemaController');

import PromiseRouter   from '../PromiseRouter';
import * as middleware from "../middlewares";

function classNameMismatchResponse(bodyClass, pathClass) {
  throw new Parse.Error(
    Parse.Error.INVALID_CLASS_NAME,
    `Class name mismatch between ${bodyClass} and ${pathClass}.`
  );
}

function getAllSchemas(req) {
  return req.config.database.loadSchema()
  .then(schemaController => schemaController.getAllClasses())
  .then(schemas => ({ response: { results: schemas } }));
}

function getOneSchema(req) {
  const className = req.params.className;
  return req.config.database.loadSchema()
  .then(schemaController => schemaController.getOneSchema(className))
  .then(schema => ({ response: schema }))
  .catch(error => {
    if (error === undefined) {
      throw new Parse.Error(Parse.Error.INVALID_CLASS_NAME, `Class ${className} does not exist.`);
    } else {
      throw new Parse.Error(Parse.Error.INTERNAL_SERVER_ERROR, 'Database adapter error.');
    }
  });
}

function createSchema(req) {
  if (req.params.className && req.body.className) {
    if (req.params.className != req.body.className) {
      return classNameMismatchResponse(req.body.className, req.params.className);
    }
  }

  const className = req.params.className || req.body.className;
  if (!className) {
    throw new Parse.Error(135, `POST ${req.path} needs a class name.`);
  }

  return req.config.database.loadSchema()
    .then(schema => schema.addClassIfNotExists(className, req.body.fields, req.body.classLevelPermissions))
    .then(schema => ({ response: schema }));
}

function modifySchema(req) {
  if (req.body.className && req.body.className != req.params.className) {
    return classNameMismatchResponse(req.body.className, req.params.className);
  }

  let submittedFields = req.body.fields || {};
  let className = req.params.className;

  return req.config.database.loadSchema()
  .then(schema => schema.updateClass(className, submittedFields, req.body.classLevelPermissions, req.config.database))
  .then(result => ({response: result}));
}

const deleteSchema = req => {
  if (!SchemaController.classNameIsValid(req.params.className)) {
    throw new Parse.Error(Parse.Error.INVALID_CLASS_NAME, SchemaController.invalidClassNameMessage(req.params.className));
  }
  return req.config.database.deleteSchema(req.params.className)
  .then(() => ({ response: {} }));
}

export class SchemasRouter extends PromiseRouter {
  mountRoutes() {
    this.route('GET', '/schemas', middleware.promiseEnforceMasterKeyAccess, getAllSchemas);
    this.route('GET', '/schemas/:className', middleware.promiseEnforceMasterKeyAccess, getOneSchema);
    this.route('POST', '/schemas', middleware.promiseEnforceMasterKeyAccess, createSchema);
    this.route('POST', '/schemas/:className', middleware.promiseEnforceMasterKeyAccess, createSchema);
    this.route('PUT', '/schemas/:className', middleware.promiseEnforceMasterKeyAccess, modifySchema);
    this.route('DELETE', '/schemas/:className', middleware.promiseEnforceMasterKeyAccess, deleteSchema);
  }
}