import { useEffect, useState } from "react";
import { Tabs as TabsPrimitive } from "radix-ui";
import { cn } from "@/lib/utils";
import { isAudiobookLibraryType } from "@/pages/libraryPageSearchParams";

type LibraryTab = "recommended" | "library" | "collections";

interface LibraryHeaderProps {
  libraryName: string;
  /** Library type ("movies", "series", "audiobooks", ...); drives tab labels. */
  libraryType?: string;
  /**
   * When true, the header renders transparently to sit over a hero backdrop,
   * and switches to a glass surface once the user scrolls past a threshold.
   */
  overlay?: boolean;
  availableTabs?: readonly LibraryTab[];
}

const DEFAULT_TABS: readonly LibraryTab[] = ["recommended", "library", "collections"];

const TAB_LABELS: Record<LibraryTab, string> = {
  recommended: "Recommended",
  library: "Library",
  collections: "Collections",
};

// Audiobook libraries open on a resume-first deck rather than a discovery
// feed, so "Recommended" would mislabel what the tab actually shows.
const AUDIOBOOK_TAB_LABELS: Record<LibraryTab, string> = {
  ...TAB_LABELS,
  recommended: "Home",
};

/** Scroll distance (in px) at which an overlay header switches to glass. */
const GLASS_THRESHOLD_PX = 160;

export default function LibraryHeader({
  libraryName,
  libraryType = "",
  overlay = false,
  availableTabs = DEFAULT_TABS,
}: LibraryHeaderProps) {
  const tabLabels = isAudiobookLibraryType(libraryType) ? AUDIOBOOK_TAB_LABELS : TAB_LABELS;
  const [pastThreshold, setPastThreshold] = useState(false);

  useEffect(() => {
    if (!overlay) return;
    const update = () => {
      setPastThreshold(window.scrollY > GLASS_THRESHOLD_PX);
    };
    update();
    window.addEventListener("scroll", update, { passive: true });
    return () => window.removeEventListener("scroll", update);
  }, [overlay]);

  const scrolled = overlay && pastThreshold;

  return (
    <header
      className={cn("library-marquee-header", overlay && "is-overlay")}
      data-scrolled={overlay ? (scrolled ? "true" : "false") : undefined}
    >
      {/* Eyebrow is hidden on mobile — the top nav already identifies the
          current page, and at narrow widths it would either crowd out the
          tab pills or truncate to "LIBRAR…". */}
      <div className="hidden min-w-0 items-center gap-4 sm:flex">
        <p className="hero-eyebrow truncate">
          <span>Library</span>
          <span className="hero-eyebrow-divider">/</span>
          <span className="hero-eyebrow-strong">{libraryName}</span>
        </p>
      </div>
      <TabsPrimitive.List className="marquee-tab-bar" aria-label="Library view">
        {availableTabs.map((tab) => (
          <TabsPrimitive.Trigger key={tab} value={tab} className="marquee-tab-trigger">
            {tabLabels[tab]}
          </TabsPrimitive.Trigger>
        ))}
      </TabsPrimitive.List>
    </header>
  );
}