Virtual Pagination

/**
 * Pagination
 *
 * Handle page results and meta data from a list of items
 *
 *
 * @use ```
 * pagination = new Pagination()
 * pagination.setLimit(10)
 * pagination.setItems(items)
 * pagination.getResults(1)
 * pagination.getMeta()
 * ```
 */
export class Pagination {
  /**
   * @type {any[]}
   */
  items = []

  /**
   * @type {number}
   */
  limit

  /**
   * @type {{totalItems: number, totalPage: number, limit: number, page: number}}
   */
  meta

  constructor({ limit = 10, items = [] } = {}) {
    this.items = items
    this.limit = limit
    this.meta = {
      totalPage: 1,
      page: 1,
      totalItems: items.length,
      limit,
    }
  }

  setItems(value) {
    this.items = value
    const totalItems = this.items.length
    this.setMeta({ totalItems })
  }

  getItems() {
    return this.items
  }

  setLimit(value) {
    this.limit = value
  }

  getLimit() {
    return this.limit
  }

  getMeta() {
    return { ...this.meta }
  }

  setMeta({ page = 1 }) {
    const totalPage = this.computeMaxPage()
    this.meta = {
      totalPage,
      page,
      totalItems: this.items.length,
      limit: this.limit,
    }
  }

  getResults(page) {
    this.setMeta({ page: page > 0 ? page : 1 })
    const index = this.limit * (page - 1)
    return [...this.items].splice(index, this.limit)
  }

  computeMaxPage() {
    const divided = this.items.length / this.limit
    const isNaN = divided !== divided
    return isNaN || !divided ? 1 : Math.ceil(divided)
  }
}