"use client";

// Overlay wrapper for the nav-driven section panels of the /trade-in/v2
// "МЕРА Оценка" design. Faithful port of the design overlay container
// (МЕРА Оценка.dc.html lines 443-453 + 615-616): a glass/blur absolute layer
// with HUD corner brackets, a header (section number + title + "← К ОЦЕНКЕ"
// button) and a scrollable body that swaps the active view.

import { useEffect, useRef } from "react";

import { tokens } from "./tokens";
import { overlayNums, overlayTitles } from "./fixtures";
import HistoryView from "./HistoryView";
import SourcesView from "./SourcesView";
import AnalyticsView from "./AnalyticsView";
import { CacheView } from "./CacheView";
import type { CacheData, HistoryData, SourcesData } from "./mappers";
import type { Analytics } from "./types";

interface SectionOverlayProps {
  active: number;
  onClose: () => void;
  onNavigate: (i: number) => void;
  // Mapped overlay data, fed by page.tsx (mapHistory / mapSources / mapAnalytics
  // / mapCache). Optional so unwired/storybook usage falls back to each view's
  // fixture default.
  history?: HistoryData;
  sources?: SourcesData;
  analytics?: Analytics;
  cache?: CacheData;
}

export default function SectionOverlay({
  active,
  onClose,
  onNavigate,
  history,
  sources,
  analytics,
  cache,
}: SectionOverlayProps) {
  // Modal dialog plumbing. `dialogRef` is the dialog root, `lastFocused` keeps
  // the element that had focus before the overlay opened so we can restore it on
  // close, and `onCloseRef` holds the latest onClose so the mount-only effect
  // (deps []) never re-runs / re-traps focus on parent re-renders even though
  // page.tsx passes a fresh arrow each render.
  const dialogRef = useRef<HTMLDivElement>(null);
  const lastFocused = useRef<Element | null>(null);
  const onCloseRef = useRef(onClose);
  onCloseRef.current = onClose;

  useEffect(() => {
    const dialog = dialogRef.current;
    // Remember the trigger, then move focus into the dialog.
    lastFocused.current = document.activeElement;
    dialog?.focus();

    function getFocusable(): HTMLElement[] {
      if (!dialog) return [];
      const nodes = dialog.querySelectorAll<HTMLElement>(
        'button, [href], input, select, [tabindex]:not([tabindex="-1"])',
      );
      return Array.from(nodes).filter((el) => !el.hasAttribute("disabled"));
    }

    function onKeyDown(e: KeyboardEvent) {
      if (e.key === "Escape") {
        e.preventDefault();
        onCloseRef.current();
        return;
      }
      if (e.key !== "Tab" || !dialog) return;

      const focusable = getFocusable();
      if (focusable.length === 0) {
        // Nothing tabbable inside — keep focus pinned on the dialog itself.
        e.preventDefault();
        dialog.focus();
        return;
      }

      const first = focusable[0];
      const last = focusable[focusable.length - 1];
      const activeEl = document.activeElement;
      const inside = dialog.contains(activeEl);

      if (e.shiftKey) {
        if (activeEl === first || activeEl === dialog || !inside) {
          e.preventDefault();
          last.focus();
        }
      } else if (activeEl === last || !inside) {
        e.preventDefault();
        first.focus();
      }
    }

    document.addEventListener("keydown", onKeyDown);
    return () => {
      document.removeEventListener("keydown", onKeyDown);
      // Return focus to whatever opened the overlay.
      (lastFocused.current as HTMLElement | null)?.focus?.();
    };
    // Mount-only: refs (dialogRef/onCloseRef) are stable, so no extra deps.
  }, []);

  return (
    <div
      ref={dialogRef}
      role="dialog"
      aria-modal="true"
      aria-labelledby="v2-overlay-title"
      tabIndex={-1}
      style={{
        position: "absolute",
        left: 28,
        right: 28,
        top: 80,
        bottom: 30,
        zIndex: 30,
        display: "flex",
        flexDirection: "column",
        background:
          "linear-gradient(180deg,rgba(244,248,252,.985),rgba(235,242,250,.985))",
        backdropFilter: "blur(12px)",
        border: `1px solid ${tokens.line3}`,
        borderRadius: 8,
        boxShadow: "0 22px 60px rgba(40,80,130,.18)",
        overflow: "hidden",
        fontFamily: tokens.font.sans,
      }}
    >
      <style>{`
        .tiv2-so-back { color: ${tokens.ink}; transition: all .15s; }
        .tiv2-so-back:hover { border-color: ${tokens.accent}; color: ${tokens.accent}; }
      `}</style>

      {/* HUD corner brackets */}
      <div
        style={{
          position: "absolute",
          left: 12,
          top: 12,
          width: 15,
          height: 15,
          borderLeft: `1.5px solid ${tokens.accent}`,
          borderTop: `1.5px solid ${tokens.accent}`,
          pointerEvents: "none",
        }}
      />
      <div
        style={{
          position: "absolute",
          right: 12,
          bottom: 12,
          width: 15,
          height: 15,
          borderRight: `1.5px solid ${tokens.accent}`,
          borderBottom: `1.5px solid ${tokens.accent}`,
          pointerEvents: "none",
        }}
      />

      {/* overlay header */}
      <div
        style={{
          flex: "0 0 auto",
          display: "flex",
          alignItems: "center",
          justifyContent: "space-between",
          padding: "16px 24px",
          borderBottom: "1px solid #cdd9e6",
        }}
      >
        <div style={{ display: "flex", alignItems: "baseline", gap: 11 }}>
          <span
            style={{
              fontFamily: tokens.font.mono,
              fontSize: 15,
              color: tokens.accent,
            }}
          >
            {overlayNums[active]}
          </span>
          <span
            id="v2-overlay-title"
            style={{
              fontSize: 14,
              fontWeight: 600,
              letterSpacing: 2.5,
              color: tokens.ink2,
            }}
          >
            {overlayTitles[active]}
          </span>
        </div>
        <button
          type="button"
          onClick={onClose}
          className="tiv2-so-back"
          style={{
            display: "flex",
            alignItems: "center",
            gap: 8,
            cursor: "pointer",
            border: `1px solid ${tokens.line}`,
            borderRadius: 6,
            padding: "6px 12px",
            background: tokens.surface.w60,
            // reset UA button defaults while keeping the original box look;
            // base colour lives in .tiv2-so-back so :hover can win
            fontFamily: "inherit",
          }}
        >
          <span style={{ fontSize: 13 }}>←</span>
          <span
            style={{ fontSize: 10, letterSpacing: 1.5, color: tokens.muted }}
          >
            К ОЦЕНКЕ
          </span>
        </button>
      </div>

      {/* overlay body */}
      <div
        style={{
          flex: 1,
          minHeight: 0,
          overflowY: "auto",
          padding: "22px 24px 26px",
        }}
      >
        {active === 1 && <HistoryView data={history} />}
        {active === 2 && <SourcesView data={sources} />}
        {active === 3 && (
          <AnalyticsView data={analytics} onNavigate={onNavigate} />
        )}
        {active === 4 && <CacheView data={cache} />}
      </div>
    </div>
  );
}