const {query} = require("../client")

class Chapter {
  /**
   * @param {string} id 
   * @param {string} title 
   * @param {string} author 
   * @param {string} source 
   * @param {string | Date} createdDate 
   * @param {string | Date} fictionalDate 
   * @param {string | Date} editedDate 
   */
  constructor(id, title, author, source, createdDate, fictionalDate, editedDate) {
    this.id = id
    this.title = title
    this.author = author
    this.source = source
    this.createdDate = new Date(createdDate)
    this.fictionalDate = new Date(fictionalDate)
    this.editedDate = new Date(editedDate)
  }

  /**
   * Query the chapter's editable fields and update this object. This promise returns a boolean
   * whether there has been a change.
   * 
   * @returns {Promise<boolean>} `true` if the story was edited in the meantime
   */
  update() {
    return query(`
      query UpdateChapter($id: String!) {
        update: chapter(id: $id) {
          title
          source
          fictionalDate
          editedDate  
        }
      }
    `, {id: this.id}).then(({update}) => {
      const editedDate = new Date(udpate.editedDate)
      const wasEdited = editedDate.getTime() != this.editedDate.getTime()

      this.title = update.title
      this.source = update.source
      this.fictionalDate = new Date(update.fictionalDate)
      this.editedDate = editedDate

      return wasEdited
    })
  }
}

module.exports = {Chapter}