/**
 *   Wechaty Chatbot SDK - https://github.com/wechaty/wechaty
 *
 *   @copyright 2016 Huan LI (李卓桓) <https://github.com/huan>, and
 *                   Wechaty Contributors <https://github.com/wechaty>.
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 *
 */
import Url from 'url'

import {
  UrlLinkPayload,
}                   from 'wechaty-puppet'

import {
  log,
}               from '../config'

import {
  openGraph,
}               from '../helper-functions/impure/open-graph'

class UrlLink {

  /**
   *
   * Create from URL
   *
   */
  public static async create (url: string): Promise<UrlLink> {
    log.verbose('UrlLink', 'create(%s)', url)

    const meta = await openGraph(url)

    let description: string | undefined
    let imageUrl: string | undefined
    let title: string

    if (meta.image) {
      if (typeof meta.image === 'string') {
        imageUrl = meta.image
      } else if (Array.isArray(meta.image)) {
        imageUrl = meta.image[0]
      } else {
        if (Array.isArray(meta.image.url)) {
          imageUrl = meta.image.url[0]
        } else if (meta.image.url) {
          imageUrl = meta.image.url
        }
      }
    }

    if (Array.isArray(meta.title)) {
      title = meta.title[0]!
    } else {
      title = meta.title
    }

    if (Array.isArray(meta.description)) {
      description = meta.description[0]
    } else if (meta.description) {
      description = meta.description
    } else {
      description = title
    }

    if (!imageUrl || !description) {
      throw new Error(`imageUrl(${imageUrl}) or description(${description}) not found!`)
    }

    if (!imageUrl.startsWith('http')) {
      const resolvedUrl = new Url.URL(imageUrl, url)
      imageUrl = resolvedUrl.toString()
    }

    const payload: UrlLinkPayload = {
      description,
      thumbnailUrl: imageUrl,
      title,
      url,
    }

    return new UrlLink(payload)
  }

  /*
   * @hideconstructor
   */
  constructor (
    public readonly payload: UrlLinkPayload,
  ) {
    log.verbose('UrlLink', 'constructor()')
  }

  public toString (): string {
    return `UrlLink<${this.payload.url}>`
  }

  public url (): string {
    return this.payload.url
  }

  public title (): string {
    return this.payload.title
  }

  public thumbnailUrl (): undefined | string {
    return this.payload.thumbnailUrl
  }

  public description (): undefined | string {
    return this.payload.description
  }

}

function wechatifyUrlLink (_: any): typeof UrlLink {

  return UrlLink

}

export {
  UrlLink,
  wechatifyUrlLink,
}