/**
 * @author Mike Hamilton <mike@mikehamilton.ca>
 * @copyright Mike Hamilton 2017
 * @license MIT
 *
 * @requires koa@next
 * @requires koa-router
 * @requires pg
 * @requires knex
 * @requires knex-postgis
 */

const Koa = require('koa')
const app = new Koa()

const Router = require('koa-router')
const router = new Router({
  prefix: '/hydrant'
})

// REQUIRE PostGRES module
var pg = require('pg')

// REQUIRE knex + setup
var knex = require('knex')({
  dialect: 'postgres',
  client: 'pg',
  connection: {
    host: 'wbsnowmaking.com',
    user: 'xxx',
    password: 'xxxx',
    database: 'whistlerblackcomb'
  },
  pool: {
    min: 0,
    max: 7
  }
})

// REQUIRE knex-postgis (PostGRES extension)
var st = require('knex-postgis')(knex);

/**
 * @desc Function to return single element
 * @param {number} id
 * @param {string} table
 * @param {string} schema
 * @param {number} srid
 */
async function getSingle(id, table, schema, srid) {
  return await knex
    .withSchema(schema)
    .from(table)
    .where({
      id: id
    })
    .select(
      '*',
      st.y(st.transform('geom', srid)).as('lat_gen'),
      st.x(st.transform('geom', srid)).as('lon_gen')
    )
}

/**
 * @desc Function to return all elements
 * @param {string} table
 * @param {string} schema
 * @param {number} srid
 */
async function getAll(table, schema, srid) {
  return await knex
    .withSchema(schema)
    .select(
      '*',
      st.y(st.transform('geom', srid)).as('lat_gen'),
      st.x(st.transform('geom', srid)).as('lon_gen')
    )
    .from(table)
}

/**
 * @desc Function to delete single element
 * @param {number} id
 * @param {string} table
 * @param {string} schema
 */
async function delSingle(id, table, schema) {
  return await knex
    .withSchema(schema)
    .where({
      id: id
    })
    .del()
    .from(table)
}

router
    // (C)reate
    .put('/', async ctx => {
        ctx.body = JSON.stringify('Create')
    })

    // (R)ead All
    .get('/', async ctx => {
        ctx.body = await getAll('hydrants', 'snowmaking', '4326')
    })

    // (R)ead Single
    .get('/:id', async (ctx, next) => {
      try {
        response = await getSingle(ctx.params.id, 'hydrants', 'snowmaking', '4326')
        if (response == '') {
          return ctx.status = 404
        } else {
          return ctx.body = response
        }
      } catch (err) {
        ctx.status = err.status || 500
        ctx.body = JSON.stringify('Oh dear, something seems to have gone wrong.')
        ctx.app.emit('error', err, ctx)
      }
    })

    // (U)pdate
    .patch('/:id', async ctx => {
        ctx.body = JSON.stringify('Update')
    })

    // (D)elete
    .delete('/:id', async ctx => {
        ctx.body = JSON.stringify('Delete')
    })

app
  .use(router.routes())
  .use(router.allowedMethods())

app.listen(3000)