import { Button, ComposedModal, InlineNotification, ModalBody, ModalFooter, ModalHeader, ProgressBar } from "@carbon/react";
import type { ExportProgress } from "../lib/exportFlow";

export interface FlattenProgressModalProps {
  open: boolean;
  progress: ExportProgress | null;
  /** The flatten failed: show it with Retry and "Export searchable instead". */
  error: string | null;
  onCancel: () => void;
  onRetry: () => void;
  onExportSearchable: () => void;
  onClose: () => void;
}

function describe(p: ExportProgress | null): { label: string; value?: number; max: number } {
  if (p?.phase === "flattening" && p.page && p.pages) {
    // The page being rendered counts as in progress, so the bar shows the pages finished before it.
    return { label: `Rendering page ${p.page} of ${p.pages}…`, value: p.page - 1, max: p.pages };
  }
  if (p?.phase === "assembling") return { label: "Building the PDF…", value: 1, max: 1 };
  return { label: "Preparing the invoice…", max: 1 };
}

export default function FlattenProgressModal({ open, progress, error, onCancel, onRetry, onExportSearchable, onClose }: FlattenProgressModalProps) {
  const { label, value, max } = describe(progress);
  return (
    <ComposedModal open={open} size="sm" preventCloseOnClickOutside onClose={() => (error ? onClose() : onCancel())} aria-label="Flattened PDF export">
      <ModalHeader title="Flattened PDF" label="Export" />
      <ModalBody hasForm={false}>
        {error ? (
          <InlineNotification
            kind="error"
            lowContrast
            hideCloseButton
            title="The flattened PDF could not be made"
            subtitle={`${error} Nothing was saved, and the resolution was not lowered.`}
          />
        ) : (
          <ProgressBar label={label} value={value} max={max} helperText="Each page is drawn at 300 DPI; this takes a few seconds per page." />
        )}
      </ModalBody>
      {error ? (
        // Three direct children: Carbon lays a three-button footer out differently from a two-button one.
        <ModalFooter>
          <Button kind="secondary" onClick={onClose}>
            Close
          </Button>
          <Button kind="tertiary" onClick={onExportSearchable}>
            Export searchable instead
          </Button>
          <Button kind="primary" onClick={onRetry}>
            Retry
          </Button>
        </ModalFooter>
      ) : (
        <ModalFooter>
          <Button kind="secondary" onClick={onCancel}>
            Cancel
          </Button>
        </ModalFooter>
      )}
    </ComposedModal>
  );
}