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

class Story {
  /**
   * Construct a story object. You should use the API instead of calling this.
   * 
   * @param {string} id
   * @param {string} name
   * @param {string} author
   * @param {"Info"|"News"|"Document"|"Background"|"Story"} category Story's category
   * @param {string} createdDate
   * @param {string} updatedDate
   * @param {string} fictionalDate
   * @param {{kind:string, name:string}[]} tags 
   * @param {Chapter[]} chapters
   */
  constructor(id, name, author, category, createdDate, updatedDate, fictionalDate, tags, chapters) {
    this.id = id
    this.name = name
    this.author = author
    this.category = category
    this.createdDate = new Date(createdDate)
    this.updatedDate = new Date(updatedDate)
    this.fictionalDate = new Date(fictionalDate)
    this.tags = tags.map(dt => new Tag(dt.kind, dt.name))
    this.chapters = chapters != null ? chapters.map(c => new Chapter(c.id, c.title, c.author, c.source, c.createdDate, c.fictionalDate, c.editedDate)) : null
  }
}

class StoryCategory {
  constructor(name, description) {
    this.name = name
    this.description = description
  }
}

const data = {
  categories: null
}

/**
 * storyApi contains the API queries
 */
const storyApi = {
  /**
   * Call `stories(filter)` query
   * 
   * @param {{author:string, category:string, tags:Tag[]|Tag, unlisted: boolean, open: boolean, earliestFictionalDate:Date|string, latestFictionalDate:Date|string, limit:number}} filter 
   * @returns {Promise<Story[]>}
   */
  list(filter = {}) {
    if (filter.earliestFictionalDate != null && typeof(filter.earliestFictionalDate) !== "string") {
      filter.earliestFictionalDate = filter.earliestFictionalDate.toISOString()
    }
    if (filter.latestFictionalDate != null && typeof(filter.latestFictionalDate) !== "string") {
      filter.latestFictionalDate = filter.latestFictionalDate.toISOString()
    }

    return query(`
      query ListStories($filter: StoriesFilter) {
        stories(filter: $filter) {
          id
          name
          author
          category
          tags {
            kind
            name
          }
          createdDate
          fictionalDate
          updatedDate    
        }
      }
    `, {filter}).then(({stories}) => {
       return stories.map(d => new Story(d.id, d.name, d.author, d.category, d.createdDate, d.updatedDate, d.fictionalDate, d.tags))
    })
  },

  /**
   * @param {string} id 
   * @returns {Promise<Story>}
   */
  find(id) {
    return query(`
      query FindStory($id: String!) {
        story(id: $id) {
          id
          name
          author
          category
          tags {
            kind
            name
          }
          createdDate
          fictionalDate
          updatedDate
          chapters {
            id
            title
            author
            source
            createdDate
            fictionalDate
            editedDate
          }
        }
      }
    `, {id}).then(({story}) => {
      return new Story(
        story.id, story.name, story.author, story.category, 
        story.createdDate, story.updatedDate, story.fictionalDate, 
        story.tags, story.chapters
      )
    })
  },

  /**
   * Call `__type(name: "StoryCategory")` query and extracts the catogires from it
   * 
   * @returns {Promise<StoryCategory[]>}
   */
  categories() {
    if (data.categories !== null) {
      return data.categories
    }

    return query(`
      query ListStoryCategories {
        categoryType: __type(name: "StoryCategory") {
          enumValues {
            name
            description
          }
        }
      }
    `, {}).then(({categoryType}) => {
      data.categories = categoryType.enumValues.map(d => new StoryCategory(d.name, d.description))
      return data.categories
    })
  },
}

module.exports = {storyApi, Story}