import * as _ from 'lodash'
import * as path from 'path'
import * as fs from 'fs'
import * as chalk from 'chalk'
import * as express from 'express'
import * as isPromise from 'is-promise'

export { UserError } from "./errors"

import { expand } from "./expander"
import Server from "./server"
import { CLIError } from "./errors"

export function loadSpec(dir) {

  if (!fs.existsSync(path.join(dir, 'api.json')))
    throw new CLIError(`Could not access ${chalk.yellow('./api.json')} from ${chalk.yellow(dir)}`)

  let spec = JSON.parse(fs.readFileSync(path.join(dir, 'api.json')))
  spec.dir = path.resolve(dir, spec.dir || '.')

  return expand(spec)
}

export function createServer(spec) {
  
  const server = new Server()

  const controllers = require(path.resolve(spec.dir, spec.main ? spec.main : 'controller'))

  _.forEach(spec.endpoints, (endpointSpec, route) => {
    const controllerName = endpointSpec.controller
    server.endpoint(route, controllerName)
  })

  const endpointControllers = _.values(spec.endpoints).map(_.property('controller'))

  async function finalize(app) {

    for (const controllerName of endpointControllers)
      if (!server.hasController(controllerName))
        console.log(chalk.red(`Controller ${chalk.yellow(controllerName)} not found at initial startup.`))

    return server
  }

  _.forEach(_.omit(controllers, 'init'), (callback, name) => {
    server.controller(name, (params) => callback(app, params))
  })

  if (controllers.init) {
    const res = controllers.init(spec)
    if (isPromise(res))
      return res
        .then(finalize)
        .catch(e => console.log(e))
    else
      finalize(res)
  } else {
    return finalize({})
  }
   
}