import { useCallback, useEffect, useState } from "react";
import { api } from "../api/client";
import type { CbzPagesDto, ReaderMode } from "../api/types";
import type { ReaderControls } from "./ReaderShell";

export function CbzReader({
  bookId,
  page,
  mode,
  onPageCommit,
  onControlsChange
}: {
  bookId: number;
  page: number;
  mode: ReaderMode;
  onPageCommit: (page: number, pages: number) => void;
  onControlsChange: (controls: ReaderControls) => void;
}) {
  const [pages, setPages] = useState<CbzPagesDto | null>(null);
  const [error, setError] = useState<string>();
  const [imageError, setImageError] = useState(false);

  useEffect(() => {
    let alive = true;
    setError(undefined);
    api
      .cbzPages(bookId)
      .then((nextPages) => {
        if (!alive) return;
        setPages(nextPages);
        if (page > nextPages.pageCount) onPageCommit(nextPages.pageCount, nextPages.pageCount);
      })
      .catch(() => {
        if (alive) setError("Archive CBZ indisponible.");
      });
    return () => {
      alive = false;
    };
  }, [bookId]);

  const pageCount = pages?.pageCount ?? 1;
  const currentPage = Math.max(1, Math.min(page, pageCount));
  const currentName = pages?.pages.find((item) => item.page === currentPage)?.name;

  const go = useCallback((nextPage: number) => {
    setImageError(false);
    onPageCommit(Math.max(1, Math.min(nextPage, pageCount)), pageCount);
  }, [onPageCommit, pageCount]);

  useEffect(() => {
    onControlsChange({
      canPrevious: !error && !imageError && currentPage > 1,
      canNext: !error && !imageError && currentPage < pageCount,
      positionLabel: pages ? `${currentPage} / ${pageCount}` : "Ouverture archive",
      onPrevious: () => go(currentPage - 1),
      onNext: () => go(currentPage + 1)
    });
  }, [currentPage, error, go, imageError, onControlsChange, pageCount, pages]);

  return (
    <div className={`cbz-reader cbz-reader-${mode}`}>
      {error || imageError ? (
        <div className="reader-fallback">
          <span>{error ?? "Page CBZ indisponible."}</span>
          <button className="ghost-button" onClick={() => go(currentPage)}>
            Reessayer
          </button>
        </div>
      ) : (
        <img src={api.cbzPageUrl(bookId, currentPage)} alt={currentName ?? `Page ${currentPage}`} onError={() => setImageError(true)} />
      )}
    </div>
  );
}