"use strict";

// modules
const fs = require('fs');
const express = require('express');
const multer = require('multer');
const storage = multer.memoryStorage();
const upload = multer({storage: storage});
const logger = require('debug')('cc:decorations');

// HTTP status codes by name
const codes = require('./http-codes');

const apiAuthenticationMiddleware = require('../middleware/auth-middleware');
const routerHandling = require('../middleware/router-handling');

// Mongoose Model using mongoDB
const DecorationModel = require('../models/decoration');
const AwardingsModel = require('../models/awarding');

const decoration = express.Router();


// routes **********************
decoration.route('/')
  .get((req, res, next) => {
    const filter = {};
    if (req.query.fractFilter) {
      filter.fraction = req.query.fractFilter.toUpperCase()
    }
    if (req.query.q) {
      filter.name = {$regex: req.query.q, $options: 'i'}
    }
    DecorationModel.find(filter, {}, {sort: {fraction: 'asc', sortingNumber: 'asc'}}, (err, items) => {
      if (err) {
        err.status = codes.servererror;
        return next(err);
      }
      if (items && items.length > 0) {
        res.locals.items = items;
      } else {
        res.locals.items = [];
      }
      res.locals.processed = true;
      next();
    });
  })

  .post(apiAuthenticationMiddleware, upload.single('image'), (req, res, next) => {
    const decoration = new DecorationModel(req.body);
    // timestamp and default are set automatically by Mongoose Schema Validation
    decoration.save((err) => {
      if (err) {
        err.status = codes.wrongrequest;
        err.message += ' in fields: ' + Object.getOwnPropertyNames(err.errors);
        return next(err);
      }
      res.status(codes.created);
      res.locals.items = decoration;
      fs.appendFile(__dirname + '/../resource/decoration/' + decoration.id + '.png', new Buffer(req.file.buffer),
        (err) => {
          if (err) next(err);
        });
      next();
    })
  })

  .all(
    routerHandling.httpMethodNotAllowed
  );

decoration.route('/:id')
  .get((req, res, next) => {
    DecorationModel.findById(req.params.id, (err, item) => {
      if (err) {
        err.status = codes.servererror;
        return next(err);
      }
      else if (!item) {
        err = new Error("item not found");
        err.status = codes.notfound;
        return next(err);
      }
      res.locals.items = item;
      next();
    });
  })

  .patch(apiAuthenticationMiddleware, upload.single('image'), (req, res, next) => {
    if (!req.body || (req.body._id && req.body._id !== req.params.id)) {
      // little bit different as in PUT. :id does not need to be in data, but if the _id and url id must match
      const err = new Error('id of PATCH resource and send JSON body are not equal ' + req.params.id + " " + req.body._id);
      err.status = codes.notfound;
      next(err);
      return; // prevent node to process this function further after next() has finished.
    }

    // optional task 3: increment version manually as we do not use .save(.)
    req.body.updatedAt = new Date();
    req.body.$inc = {__v: 1};

    if (req.file) {
      const file = __dirname + '/../resource/decoration/' + req.body._id + '.png';
      fs.unlink(file, (err) => {
        if (err) next(err);
        fs.appendFile(file, new Buffer(req.file.buffer), (err) => {
          if (err) next(err);
        });
      });
    }

    // PATCH is easier with mongoose than PUT. You simply update by all data that comes from outside. no need to reset attributes that are missing.
    DecorationModel.findByIdAndUpdate(req.params.id, req.body, {new: true}, (err, item) => {
      if (err) {
        err.status = codes.wrongrequest;
      }
      else if (!item) {
        err = new Error("item not found");
        err.status = codes.notfound;
      }
      else {
        res.locals.items = item;
      }
      next(err);
    })
  })

  .delete(apiAuthenticationMiddleware, (req, res, next) => {
    DecorationModel.findByIdAndRemove(req.params.id, (err, item) => {
      if (err) {
        err.status = codes.wrongrequest;
      }
      else if (!item) {
        err = new Error("item not found");
        err.status = codes.notfound;
      }

      // deleted all awardings linked to this decoration
      AwardingsModel.find({decorationId: req.params.id}).remove().exec();

      // delete graphic
      fs.unlink(__dirname + '/../resource/decoration/' + req.params.id + '.png',
        (err) => {
          if (err) next(err);
        });

      // we don't set res.locals.items  and thus it will send a 204 (no content) at the end. see last handler user.use(..)
      res.locals.processed = true;
      next(err); // this works because err is in normal case undefined and that is the same as no parameter
    });
  })

  .all(
    routerHandling.httpMethodNotAllowed
  );

// this middleware function can be used, if you like or remove it
// it looks for object(s) in res.locals.items and if they exist, they are send to the client as json
decoration.use(routerHandling.emptyResponse);


module.exports = decoration;