"use client";
import { useEffect, useRef, useState } from "react";
import {
  Settings as SettingsIcon, X, Palette, Trash2, Wrench, Film, FolderTree, Captions,
} from "lucide-react";
import { useSettingsPanel } from "./SettingsPanelProvider";
import { DefaultSortSelect } from "./DefaultSortSelect";
import { AccentColorPickers } from "./AccentColorPickers";
import { DisplayGroup, TrashGroup, MaintenanceGroup, BackupGroup } from "./SettingsToggles";
import { VideoLibrarySettings } from "./VideoLibrarySettings";
import { WhisperJavSettings } from "./WhisperJavSettings";
import { SubtitleLibraryPaths } from "./SubtitleLibraryPaths";
import { useClickOutside } from "@/lib/hooks/useClickOutside";
import { cn } from "@/lib/utils";
import type { SortKey } from "@/lib/sort";
import type { LibraryStats } from "@/lib/db/queries";

interface PanelData {
  defaultSort: SortKey;
  stats: LibraryStats;
  libraryRoot: string;
  dbPath: string;
}

function fmtBytes(n: number): string {
  if (n < 1024) return `${n} B`;
  if (n < 1024 * 1024) return `${(n / 1024).toFixed(1)} KB`;
  if (n < 1024 * 1024 * 1024) return `${(n / 1024 / 1024).toFixed(1)} MB`;
  return `${(n / 1024 / 1024 / 1024).toFixed(2)} GB`;
}

function fmtDate(ms: number | null): string {
  if (!ms) return "—";
  const d = new Date(ms);
  return d.toISOString().slice(0, 10);
}

export function SettingsPanel({ data }: { data: PanelData }) {
  const { open, close } = useSettingsPanel();
  const panelRef = useRef<HTMLDivElement>(null);
  useClickOutside(panelRef, close, open);

  useEffect(() => {
    if (!open) return;
    const onKey = (e: KeyboardEvent) => { if (e.key === "Escape") close(); };
    window.addEventListener("keydown", onKey);
    document.body.style.overflow = "hidden";
    return () => {
      window.removeEventListener("keydown", onKey);
      document.body.style.overflow = "";
    };
  }, [open, close]);

  if (!open) return null;

  return (
    <div
      className="fixed inset-0 z-50 backdrop-blur-sm grid place-items-center p-4 sm:p-8"
      style={{ background: "color-mix(in oklch, var(--color-bg-0) 65%, transparent)" }}
    >
      <div
        ref={panelRef}
        className="w-full max-w-[1400px] h-[min(900px,calc(100vh-4rem))] flex flex-col rounded-2xl border border-[var(--color-glass-border-strong)] backdrop-blur-2xl overflow-hidden shadow-2xl"
        style={{ background: "color-mix(in oklch, var(--color-bg-0) 96%, transparent)" }}
      >
        <header className="flex items-center justify-between px-6 py-4 border-b border-[var(--color-glass-border)] shrink-0">
          <div className="flex items-center gap-2">
            <SettingsIcon className="w-5 h-5 text-[var(--color-cyan)]" />
            <h2 className="text-xl font-semibold tracking-tight">Settings</h2>
          </div>
          <button
            onClick={close}
            aria-label="Close settings"
            className="w-8 h-8 grid place-items-center rounded-lg text-[var(--color-fg-dim)] hover:text-[var(--color-fg)] hover:bg-[var(--color-glass)]"
          >
            <X className="w-4 h-4" />
          </button>
        </header>

        <SidebarLayout data={data} />
      </div>
    </div>
  );
}

/* =====================================================================
   Section content blocks. Five top-level sections:
     Appearance · Library · Video · Tools · Info
   ===================================================================== */

function AppearanceSection({ data }: { data: PanelData }) {
  return (
    <Card title="Appearance">
      <SubGroup label="Colors">
        <AccentColorPickers />
      </SubGroup>
      <Divider />
      <SubGroup label="Display">
        <DisplayGroup />
      </SubGroup>
      <Divider />
      <SubGroup label="Defaults">
        <DefaultSortSelect initial={data.defaultSort} />
      </SubGroup>
    </Card>
  );
}

function LibrarySection() {
  return (
    <Card title="Library · file handling">
      <TrashGroup />
    </Card>
  );
}

function VideoSection() {
  return <Card title="Video"><VideoLibrarySettings /></Card>;
}

function SubtitlesSection() {
  return (
    <Card title="Subtitles">
      <SubtitleLibraryPaths />
      <Divider />
      <WhisperJavSettings />
    </Card>
  );
}

function ToolsSection() {
  return (
    <Card title="Tools">
      <SubGroup label="Maintenance">
        <MaintenanceGroup />
      </SubGroup>
      <Divider />
      <SubGroup label="Backup">
        <BackupGroup />
      </SubGroup>
    </Card>
  );
}

function InfoSection({ data }: { data: PanelData }) {
  const s = data.stats;
  const watchedPct = s.images > 0 ? Math.round((s.watched / s.images) * 100) : 0;
  return (
    <Card title="Info">
      <div className="grid grid-cols-1 md:grid-cols-2 gap-section">
        <StatGroup label="Covers">
          <Row label="Top-level" value={s.images.toLocaleString()} mono />
          <Row label="Attached (back / stills)" value={s.attached.toLocaleString()} mono />
          {s.trashed > 0 && (
            <Row label="In trash" value={s.trashed.toLocaleString()} mono />
          )}
        </StatGroup>

        <StatGroup label="Entities">
          <Row label="Actresses" value={s.actresses.toLocaleString()} mono />
          <Row label="Studios" value={s.studios.toLocaleString()} mono />
          <Row label="Series" value={s.series.toLocaleString()} mono />
          {s.labels > 0 && <Row label="Labels" value={s.labels.toLocaleString()} mono />}
          <Row label="Genres" value={s.genres.toLocaleString()} mono />
        </StatGroup>

        <StatGroup label="Tagging">
          <Row label="Tags" value={s.tags.toLocaleString()} mono />
          <Row label="Tag categories" value={s.tagCategories.toLocaleString()} mono />
          <Row label="Collections" value={s.collections.toLocaleString()} mono />
        </StatGroup>

        <StatGroup label="State">
          <Row label="Watched" value={`${s.watched.toLocaleString()} (${watchedPct}%)`} mono />
          <Row label="VIP" value={s.vip.toLocaleString()} mono />
          <Row label="Favorite" value={s.favorite.toLocaleString()} mono />
          <Row label="Owned" value={s.owned.toLocaleString()} mono />
          <Row label="Rated" value={s.rated.toLocaleString()} mono />
        </StatGroup>
      </div>
      <Divider />
      <SubGroup label="Disk">
        <dl className="space-y-1.5 text-sm">
          <Row label="Total cover bytes" value={fmtBytes(s.totalBytes)} mono />
          <Row
            label="Imports"
            value={
              s.earliestImportedAt && s.latestImportedAt
                ? `${fmtDate(s.earliestImportedAt)} → ${fmtDate(s.latestImportedAt)}`
                : "—"
            }
            mono
          />
        </dl>
      </SubGroup>
      <Divider />
      <SubGroup label="Paths">
        <dl className="space-y-1.5 text-sm">
          <Row label="Library folder" value={data.libraryRoot} mono />
          <Row label="Database" value={data.dbPath} mono />
        </dl>
      </SubGroup>
    </Card>
  );
}

/* =====================================================================
   Sidebar layout — single layout, no toggle.
   ===================================================================== */

const SIDEBAR_NAV = [
  { id: "appearance", label: "Appearance", Icon: Palette },
  { id: "library",    label: "Library",    Icon: Trash2 },
  { id: "video",      label: "Video",      Icon: Film },
  { id: "subtitles",  label: "Subtitles",  Icon: Captions },
  { id: "tools",      label: "Tools",      Icon: Wrench },
  { id: "info",       label: "Info",       Icon: FolderTree },
] as const;

type SidebarSection = typeof SIDEBAR_NAV[number]["id"];

function SidebarLayout({ data }: { data: PanelData }) {
  const [active, setActive] = useState<SidebarSection>("appearance");

  const content: Record<SidebarSection, React.ReactNode> = {
    appearance: <AppearanceSection data={data} />,
    library:    <LibrarySection />,
    video:      <VideoSection />,
    subtitles:  <SubtitlesSection />,
    tools:      <ToolsSection />,
    info:       <InfoSection data={data} />,
  };

  return (
    <div className="flex-1 grid grid-cols-[220px_1fr] min-h-0">
      <nav className="border-r border-[var(--color-glass-border)] p-3 overflow-y-auto"
        style={{ background: "color-mix(in oklch, var(--color-bg-0) 50%, transparent)" }}>
        {SIDEBAR_NAV.map(({ id, label, Icon }) => {
          const isActive = id === active;
          return (
            <button
              key={id}
              type="button"
              onClick={() => setActive(id)}
              className={cn(
                "w-full flex items-center gap-2.5 px-3 py-2 rounded-lg text-sm text-left transition-colors mb-0.5",
                isActive
                  ? "bg-[var(--color-cyan)]/15 text-[var(--color-cyan)]"
                  : "text-[var(--color-fg-dim)] hover:text-[var(--color-fg)] hover:bg-[var(--color-glass)]",
              )}
            >
              <Icon className="w-4 h-4 shrink-0" />
              <span className="truncate">{label}</span>
            </button>
          );
        })}
      </nav>
      <div className="overflow-y-auto p-card">
        {content[active]}
      </div>
    </div>
  );
}

/* =====================================================================
   Tiny primitives.
   ===================================================================== */

function Card({ title, children }: { title: string; children: React.ReactNode }) {
  return (
    <section className="glass rounded-2xl p-card">
      <h3 className="text-sm uppercase tracking-wider font-mono text-[var(--color-fg-muted)] mb-label">
        {title}
      </h3>
      {children}
    </section>
  );
}

/** Sub-group label inside a Card — small cyan caps header. */
function SubGroup({ label, children }: { label: string; children: React.ReactNode }) {
  return (
    <div>
      <div className="text-[10px] uppercase tracking-wider font-mono text-[var(--color-cyan)] mb-label">{label}</div>
      {children}
    </div>
  );
}

/** Horizontal rule between sub-groups inside a Card. */
function Divider() {
  return <hr className="my-section border-0 border-t border-[var(--color-glass-border)]" />;
}

function StatGroup({ label, children }: { label: string; children: React.ReactNode }) {
  return (
    <div>
      <div className="text-[10px] uppercase tracking-wider font-mono text-[var(--color-cyan)] mb-label">{label}</div>
      <dl className="space-y-1.5 text-sm border-t border-[var(--color-glass-border)] pt-1.5">
        {children}
      </dl>
    </div>
  );
}

function Row({ label, value, mono }: { label: string; value: string; mono?: boolean }) {
  return (
    <div className="flex items-start justify-between gap-4">
      <dt className="text-[var(--color-fg-dim)]">{label}</dt>
      <dd className={`text-right break-all ${mono ? "font-mono text-xs text-[var(--color-fg)]" : ""}`}>{value}</dd>
    </div>
  );
}