/**
 * Listing exports.
 *
 * The backend runs the listing query once and writes the rows straight to a file
 * in S3, so an export is not limited by what the browser can hold. Everything
 * that could be rendered more than one way — which half of a reference, which
 * part of a user, the value or its timestamp — is decided here and sent along.
 *
 * A reference shown by name is written as a link to the element in the app.
 */

export type ExportFormat = 'csv' | 'xlsx'

/** Which part of the stored value wrapper the column reads. */
export type ExportField = 'value' | 'timestamp' | 'author' | 'timestampAt'

/** Which part of a complex value ends up in the cell. */
export type ExportPick =
  // references
  | 'elementName'
  | 'hash'
  | 'both'
  // users
  | 'cnSn'
  | 'uid'
  | 'email'
  // files
  | 'filename'
  // reference projections: the projected attribute on its own
  | 'refValue'
  // dropdowns
  | 'label'
  | 'raw'
  // dates
  | 'date'
  | 'dateTime'
  | 'iso'
  // dates in ExportColumn.dateFormat
  | 'custom'
  // coordinates, stored as [lat, lng]: "lat, lng", or one of them as a number
  | 'latLng'
  | 'lat'
  | 'lng'

/**
 * Whether reference and file cells carry their URL as text:
 * 'none' "Acme, Globex"; 'nameAndUrl' "Acme (https://…), Globex (https://…)";
 * 'url' "https://…, https://…". A cell with a single value is also a real
 * hyperlink.
 */
export type ExportLinks = 'none' | 'nameAndUrl' | 'url'

export interface ExportColumn {
  /** Projected attribute, or an element field such as hash, author, timestamp. */
  key: string
  /** Column header. Defaults to the key. */
  label?: string
  /** Defaults to 'value'. */
  field?: ExportField
  pick?: ExportPick
  /** Overrides the export wide separator for this column only. */
  separator?: string
  /**
   * For a reference (ATE) column: project this attribute out of every
   * referenced element, e.g. `room_code` on a `room_ate` column. Each
   * referenced element is then rendered as "identifier - value", or as the
   * value alone with pick 'refValue'.
   */
  refAttribute?: string
  /**
   * For a file column: put its files into the export, which then downloads as
   * a ZIP of the table plus one folder per such column (up to 2 GB of files).
   * The cells link to the files in the ZIP.
   */
  includeFiles?: boolean
  /** Reference and file columns. Files in the ZIP link to their path in it. */
  links?: ExportLinks
  /** For pick 'custom': day.js style tokens, e.g. 'D.M.YYYY H:mm'. */
  dateFormat?: string
  /** Numbers: add the column's total under the last row. */
  sum?: boolean
  /** XLSX: add a sheet counting the rows per value of this column. */
  summary?: boolean
  /** With summary: split the counts by the column at this index (pivot). */
  splitBy?: number
}

/**
 * Folders of the files in the ZIP: 'attributeElement' `Drawings/Hall 1/a.pdf`,
 * 'elementAttribute' `Hall 1/Drawings/a.pdf`. Defaults to 'attributeElement'.
 */
export type ExportFilesLayout = 'attributeElement' | 'elementAttribute'

export interface ExportRequest {
  /** The listing query, in the same shape the listing itself sends. */
  query: Record<string, unknown>
  format: ExportFormat
  columns: ExportColumn[]
  /** attribute -> stored value -> label, for dropdown columns. */
  valueLabels?: Record<string, Record<string, string>>
  /** Joins multiple values in one cell. Defaults to ', '. */
  separator?: string
  /** IANA name, e.g. 'Europe/Prague'. Dates are formatted in it. */
  timezone?: string
  alsoPublic?: boolean
  filesLayout?: ExportFilesLayout
  /** Words written into the file, in the user's language. */
  labels?: { total?: string; count?: string; empty?: string }
}

export interface ExportStarted {
  /** S3 key of the file being written; also the id of its notifications. */
  key: string
}

export interface ExportFile {
  key: string
  name: string
  size: number
  lastModified: string
  /** Signed link, valid for an hour from the moment it was listed. */
  url: string
}