import express from 'express';
import _ from 'lodash';

import TemplateValidate from './validate/template';
import ConditionTemplateModel from '../models/condition_template';
import MeasurementTemplateModel from '../models/measurement_template';
import res400 from './validate/res400';
import IdValidate from './validate/id';



const router = express.Router();

router.get('/template/:collection(measurements|conditions)', (req, res, next) => {
  if (!req.auth(res, ['read', 'write', 'maintain', 'dev', 'admin'], 'basic')) return;

  req.params.collection = req.params.collection.replace(/s$/g, '');  // remove trailing s
  model(req).find({}).lean().exec((err, data) => {
     if (err) next (err);
     res.json(_.compact(data.map(e => TemplateValidate.output(e))));  // validate all and filter null values from validation errors
  });
});

router.get('/template/:collection(measurement|condition)/' + IdValidate.parameter(), (req, res, next) => {
  if (!req.auth(res, ['read', 'write', 'maintain', 'dev', 'admin'], 'basic')) return;

  model(req).findById(req.params.id).lean().exec((err, data) => {
    if (err) next (err);
    if (data) {
      res.json(TemplateValidate.output(data));
    }
    else {
      res.status(404).json({status: 'Not found'});
    }
  });
});

router.put('/template/:collection(measurement|condition)/' + IdValidate.parameter(), async (req, res, next) => {
  if (!req.auth(res, ['maintain', 'admin'], 'basic')) return;

  const {error, value: template} = TemplateValidate.input(req.body, 'change');
  if (error) return res400(error, res);

  const templateData = await model(req).findById(req.params.id).lean().exec().catch(err => {next(err);}) as any;
  if (templateData instanceof Error) return;
  if (!templateData) {
    res.status(404).json({status: 'Not found'});
  }

  if (!_.isEqual(_.pick(templateData, _.keys(template)), template)) {  // data was changed
    template.version = templateData.version + 1;  // increase version
    await new (model(req))(_.assign({}, _.omit(templateData, ['_id', '__v']), template)).save((err, data) => {  // save new template, fill with old properties
      if (err) next (err);
      res.json(TemplateValidate.output(data.toObject()));
    });
  }
  else {
    res.json(TemplateValidate.output(templateData));
  }
});

router.post('/template/:collection(measurement|condition)/new', async (req, res, next) => {
  if (!req.auth(res, ['maintain', 'admin'], 'basic')) return;

  const {error, value: template} = TemplateValidate.input(req.body, 'new');
  if (error) return res400(error, res);

  template.version = 1;  // set template version
  await new (model(req))(template).save((err, data) => {
    if (err) next (err);
    res.json(TemplateValidate.output(data.toObject()));
  });
});


module.exports = router;

function model (req) {  // return right template model
  return req.params.collection === 'condition' ? ConditionTemplateModel : MeasurementTemplateModel;
}