import qs from 'qs'
import { Params, Id, Query, NullableId, ServiceInterface } from '@feathersjs/feathers'
import { BadRequest, Unavailable, convert } from '@feathersjs/errors'
import { _, stripSlashes } from '@feathersjs/commons'

function toError(error: Error & { code: string }) {
  if (error.code === 'ECONNREFUSED') {
    throw new Unavailable(error.message, _.pick(error, 'address', 'port', 'config'))
  }

  throw convert(error)
}

export interface RestClientParams extends Params {
  connection?: any
}

interface RestClientSettings {
  name: string
  base: string
  connection: any
  options: any
}

export abstract class Base<
  T = any,
  D = Partial<T>,
  P extends Params = RestClientParams
> implements ServiceInterface<T, D, P> {
  name: string
  base: string
  connection: any
  options: any

  constructor(settings: RestClientSettings) {
    this.name = stripSlashes(settings.name)
    this.options = settings.options
    this.connection = settings.connection
    this.base = `${settings.base}/${this.name}`
  }

  makeUrl(query: Query, id?: string | number | null, route?: { [key: string]: string }) {
    let url = this.base

    if (route) {
      Object.keys(route).forEach((key) => {
        url = url.replace(`:${key}`, route[key])
      })
    }

    query = query || {}

    if (typeof id !== 'undefined' && id !== null) {
      url += `/${encodeURIComponent(id)}`
    }

    return url + this.getQuery(query)
  }

  getQuery(query: Query) {
    if (Object.keys(query).length !== 0) {
      const queryString = qs.stringify(query)

      return `?${queryString}`
    }

    return ''
  }

  abstract request(options: any, params: P): any

  methods(this: any, ...names: string[]) {
    names.forEach((method) => {
      const _method = `_${method}`
      this[_method] = function (data: any, params: Params = {}) {
        return this.request(
          {
            body: data,
            url: this.makeUrl(params.query, null, params.route),
            method: 'POST',
            headers: Object.assign(
              {
                'Content-Type': 'application/json',
                'X-Service-Method': method
              },
              params.headers
            )
          },
          params
        ).catch(toError)
      }
      this[method] = function (data: any, params: Params = {}) {
        return this[_method](data, params)
      }
    })

    return this
  }

  _find(params?: P) {
    return this.request(
      {
        url: this.makeUrl(params.query, null, params.route),
        method: 'GET',
        headers: Object.assign({}, params.headers)
      },
      params
    ).catch(toError)
  }

  find(params?: P) {
    return this._find(params)
  }

  _get(id: Id, params?: P) {
    if (id === undefined || id === '') {
      return Promise.reject(new BadRequest('id for .get is required'))
    }

    return this.request(
      {
        url: this.makeUrl(params.query, id, params.route),
        method: 'GET',
        headers: Object.assign({}, params.headers)
      },
      params
    ).catch(toError)
  }

  get(id: Id, params?: P) {
    return this._get(id, params)
  }

  _create(data: D, params?: P) {
    return this.request(
      {
        url: this.makeUrl(params.query, null, params.route),
        body: data,
        method: 'POST',
        headers: Object.assign({ 'Content-Type': 'application/json' }, params.headers)
      },
      params
    ).catch(toError)
  }

  create(data: D, params?: P) {
    return this._create(data, params)
  }

  _update(id: NullableId, data: D, params?: P) {
    if (id === undefined || id === '') {
      return Promise.reject(new BadRequest('id for .update is required'))
    }

    return this.request(
      {
        url: this.makeUrl(params.query, id, params.route),
        body: data,
        method: 'PUT',
        headers: Object.assign({ 'Content-Type': 'application/json' }, params.headers)
      },
      params
    ).catch(toError)
  }

  update(id: NullableId, data: D, params?: P) {
    return this._update(id, data, params)
  }

  _patch(id: NullableId, data: D, params?: P) {
    if (id === undefined || id === '') {
      return Promise.reject(new BadRequest('id for .patch is required'))
    }

    return this.request(
      {
        url: this.makeUrl(params.query, id, params.route),
        body: data,
        method: 'PATCH',
        headers: Object.assign({ 'Content-Type': 'application/json' }, params.headers)
      },
      params
    ).catch(toError)
  }

  patch(id: NullableId, data: D, params?: P) {
    return this._patch(id, data, params)
  }

  _remove(id: NullableId, params?: P) {
    if (id === undefined || id === '') {
      return Promise.reject(new BadRequest('id for .remove is required'))
    }

    return this.request(
      {
        url: this.makeUrl(params.query, id, params.route),
        method: 'DELETE',
        headers: Object.assign({}, params.headers)
      },
      params
    ).catch(toError)
  }

  remove(id: NullableId, params?: P) {
    return this._remove(id, params)
  }
}