// What a document's page says about the document above its lines: its status, how many lines wait and
// how many are approved, and which pages the extraction left out. The page keeps the document live, so
// these are built wherever it renders -- on the server for the first paint and in the browser on each
// change -- from messages that keep their placeholders (`@conusai-kit/i18n/format`: the language's plural
// rules, and no catalogue).

import { formatMessage } from "@conusai-kit/i18n/format"
import type { PAGE_CLASSES } from "../contract/constants.js"
import type { DocumentView } from "../contract/procedures.js"
import type { DocumentListLabels } from "./document-list.js"

export interface DocumentHeaderLabels {
  /** "Status", the word before the status. */
  readonly status: string
  readonly statuses: DocumentListLabels["statuses"]
  readonly failures: DocumentListLabels["failures"]
  /** `{count, plural, ...}`, with its placeholder left in. */
  readonly pendingCount: string
  /** `{count, plural, ...}`, with its placeholder left in. */
  readonly approvedCount: string
  /** What a document nobody has read yet says. */
  readonly waiting: string
  readonly skippedTitle: string
  /** `Page {page}: {kind}. ...`, with both placeholders left in. */
  readonly skippedPage: string
  readonly pageClasses: Readonly<Record<(typeof PAGE_CLASSES)[number], string>>
}

export interface DocumentHeader {
  readonly status: string
  readonly counts: string
  readonly waiting?: string
  readonly skipped?: {
    readonly title: string
    readonly pages: readonly { readonly page: number; readonly text: string }[]
  }
}

export function documentHeader(document: DocumentView, labels: DocumentHeaderLabels, locale: string): DocumentHeader {
  const failure = document.failureCode ? ` ${labels.failures[document.failureCode]}` : ""
  return {
    status: `${labels.status}: ${labels.statuses[document.status]}${failure}`,
    counts: `${formatMessage(labels.pendingCount, { count: document.pending }, locale)}. ${formatMessage(labels.approvedCount, { count: document.approved }, locale)}.`,
    ...(document.status === "queued" || document.status === "processing" ? { waiting: labels.waiting } : {}),
    ...(document.skippedPages.length > 0
      ? {
          skipped: {
            title: labels.skippedTitle,
            pages: document.skippedPages.map((skipped) => ({
              page: skipped.page,
              text: formatMessage(
                labels.skippedPage,
                { page: skipped.page, kind: labels.pageClasses[skipped.pageClass] },
                locale,
              ),
            })),
          },
        }
      : {}),
  }
}