// The sheet of the simulation. What Java opens as a window of its own — a
// computer's desktop, a switch's or home router's table, the data exchange —
// opens here as the dashboard's sheet does (its AppSheet), not as a window in
// the window: over the surface, below the toolbar (the mode buttons stay in
// reach), with a head — icon, title, who else has it open, ×. One at a time:
// it covers the surface, so another is opened once it is closed.
//
// Beyond the dashboard's sheet: „Durchsichtig“ lets the network show through
// the sheet (the cables light up while one types a ping), the sheet still
// takes the pointer. The choice is the person's, kept in this browser.

import { useCallback, useState, type ReactNode } from "react";
import { useTranslate } from "../i18n/i18n.js";
import { WindowWatchers } from "../remote/PresenceMarks.js";
import type { PresenceUser } from "../remote/presence.js";

/** What every sheet of the simulation gets from the editor: where it begins, whether it is see-through, how it closes, who else has it open. */
export interface SheetFrame {
  /** Its top edge in the editor's area: below the toolbar. */
  readonly top: number;
  readonly seeThrough: boolean;
  readonly onSeeThrough: (on: boolean) => void;
  readonly onClose: () => void;
  /** Who else in the project has it open (plan §7.4). */
  readonly watchers?: readonly PresenceUser[] | undefined;
}

export interface SimulationSheetProps {
  readonly frame: SheetFrame;
  readonly title: string;
  readonly icon?: string;
  /** Marks for what it shows (`data-desktop`, `data-viewer`, `data-capture`). */
  readonly attributes: Readonly<Record<`data-${string}`, string>>;
  readonly className?: string;
  readonly children: ReactNode;
}

export function SimulationSheet({
  frame,
  title,
  icon,
  attributes,
  className,
  children,
}: SimulationSheetProps) {
  const t = useTranslate();
  return (
    <section
      className={`simulation-sheet${className === undefined ? "" : ` ${className}`}`}
      role="dialog"
      aria-label={title}
      data-see-through={frame.seeThrough ? "true" : undefined}
      style={{ top: frame.top }}
      {...attributes}
    >
      <header className="simulation-sheet__head">
        {icon === undefined ? null : <img src={icon} alt="" />}
        <h2 title={title}>{title}</h2>
        <WindowWatchers watchers={frame.watchers} />
        <button
          type="button"
          className="simulation-sheet__see-through"
          aria-pressed={frame.seeThrough}
          aria-label={t("sheet.seeThrough")}
          title={t("sheet.seeThrough")}
          onClick={() => frame.onSeeThrough(!frame.seeThrough)}
        >
          <SeeThroughIcon />
        </button>
        <button
          type="button"
          className="simulation-sheet__close"
          aria-label={t("sheet.close")}
          title={t("sheet.close")}
          onClick={frame.onClose}
        >
          ×
        </button>
      </header>
      <div className="simulation-sheet__body">{children}</div>
    </section>
  );
}

/** Two overlapping squares, the front one half filled: something showing through. */
function SeeThroughIcon() {
  return (
    <svg width="20" height="20" viewBox="0 0 20 20" aria-hidden="true">
      <rect
        x="2.5"
        y="2.5"
        width="10"
        height="10"
        rx="1.5"
        fill="none"
        stroke="currentColor"
        strokeWidth="1.5"
      />
      <rect
        x="7.5"
        y="7.5"
        width="10"
        height="10"
        rx="1.5"
        fill="currentColor"
        fillOpacity="0.35"
        stroke="currentColor"
        strokeWidth="1.5"
      />
    </svg>
  );
}

const SEE_THROUGH_KEY = "filius.sheetSeeThrough";

/** „Durchsichtig“, remembered in this browser; storage that is not there (a private window, blocked) only forgets it. */
export function useSeeThrough(): [boolean, (on: boolean) => void] {
  const [on, setOn] = useState(() => {
    try {
      return window.localStorage.getItem(SEE_THROUGH_KEY) === "true";
    } catch {
      return false;
    }
  });
  const change = useCallback((next: boolean) => {
    setOn(next);
    try {
      window.localStorage.setItem(SEE_THROUGH_KEY, String(next));
    } catch {
      // Not kept; it still holds for this page.
    }
  }, []);
  return [on, change];
}