import { useEffect, useState } from "react";
import { LOCALE_OPTIONS, useI18n, type Locale } from "./i18n";
import { persistTheme, readTheme, THEME_PREFS, type ThemePref } from "./theme";

export const APP_NAME = "LazyBoy";
export const APP_VERSION = "0.1.0";

export type SettingsSectionId = "general" | "updates";

const SECTIONS: readonly { id: SettingsSectionId; icon: "gear" | "download" }[] = [
  { id: "general", icon: "gear" },
  { id: "updates", icon: "download" },
];

export type SettingsComputer = {
  pending: "start" | "restart" | "update" | null;
  working: boolean;
  upToDate: boolean;
  onUpdate: () => void;
  onRestart: () => void;
};

function detectOs(): string {
  const ua = navigator.userAgent;
  if (/Mac/i.test(ua)) return "darwin";
  if (/Win/i.test(ua)) return "win32";
  if (/Linux/i.test(ua)) return "linux";
  return navigator.platform || "unknown";
}

function GearIcon() {
  return (
    <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.8" strokeLinecap="round" strokeLinejoin="round" aria-hidden="true">
      <circle cx="12" cy="12" r="3" />
      <path d="M19.4 15a1.65 1.65 0 0 0 .33 1.82l.06.06a2 2 0 0 1-2.83 2.83l-.06-.06a1.65 1.65 0 0 0-1.82-.33 1.65 1.65 0 0 0-1 1.51V21a2 2 0 0 1-4 0v-.09A1.65 1.65 0 0 0 9 19.4a1.65 1.65 0 0 0-1.82.33l-.06.06a2 2 0 0 1-2.83-2.83l.06-.06A1.65 1.65 0 0 0 4.68 15a1.65 1.65 0 0 0-1.51-1H3a2 2 0 0 1 0-4h.09A1.65 1.65 0 0 0 4.6 9a1.65 1.65 0 0 0-.33-1.82l-.06-.06a2 2 0 0 1 2.83-2.83l.06.06A1.65 1.65 0 0 0 9 4.68a1.65 1.65 0 0 0 1-1.51V3a2 2 0 0 1 4 0v.09a1.65 1.65 0 0 0 1 1.51 1.65 1.65 0 0 0 1.82-.33l.06-.06a2 2 0 0 1 2.83 2.83l-.06.06A1.65 1.65 0 0 0 19.4 9a1.65 1.65 0 0 0 1.51 1H21a2 2 0 0 1 0 4h-.09a1.65 1.65 0 0 0-1.51 1z" />
    </svg>
  );
}

function DownloadIcon() {
  return (
    <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.8" strokeLinecap="round" strokeLinejoin="round" aria-hidden="true">
      <path d="M8 17h8" />
      <path d="M12 7v9" />
      <path d="M16 12l-4 4-4-4" />
      <path d="M20 16.58A5 5 0 0 0 18 7h-1.26A8 8 0 1 0 4 15.25" />
    </svg>
  );
}

function CloseIcon() {
  return (
    <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" aria-hidden="true">
      <path d="M18 6L6 18M6 6l12 12" />
    </svg>
  );
}

function SettingsGroup({ title, children }: { title: string; children: React.ReactNode }) {
  return (
    <section className="lb-settings-group">
      <h3>{title}</h3>
      {children}
    </section>
  );
}

function OverlayShell({
  label,
  className,
  onClose,
  children,
}: {
  label: string;
  className: string;
  onClose: () => void;
  children: React.ReactNode;
}) {
  return (
    <div className="modal-backdrop lb-overlay" onClick={onClose}>
      <div
        className={className}
        role="dialog"
        aria-modal="true"
        aria-label={label}
        onClick={(event) => event.stopPropagation()}
      >
        {children}
      </div>
    </div>
  );
}

function GeneralPanel() {
  const { locale, setLocale, t } = useI18n();
  const [theme, setTheme] = useState<ThemePref>(readTheme);

  return (
    <div className="lb-settings-stack">
      <SettingsGroup title={t.localWorkspace}>
        <div className="lb-account-card">
          <span className="lb-account-card__avatar" aria-hidden="true">GB</span>
          <span className="lb-account-card__body">
            <strong>{t.localWorkspace}</strong>
            <span>{t.workspaceDetail}</span>
          </span>
        </div>
      </SettingsGroup>
      <SettingsGroup title={t.appearance}>
        <label className="lb-settings-row">
          <span className="lb-settings-copy">{t.theme}</span>
          <select
            className="lb-settings-select"
            aria-label={t.theme}
            value={theme}
            onChange={(event) => {
              const next = event.target.value as ThemePref;
              if (!THEME_PREFS.includes(next)) return;
              persistTheme(next);
              setTheme(next);
            }}
          >
            <option value="system">{t.themeSystem}</option>
            <option value="light">{t.themeLight}</option>
            <option value="dark">{t.themeDark}</option>
          </select>
        </label>
        <label className="lb-settings-row">
          <span className="lb-settings-copy">{t.language}</span>
          <select
            className="lb-settings-select"
            aria-label={t.language}
            value={locale}
            onChange={(event) => setLocale(event.target.value as Locale)}
          >
            {LOCALE_OPTIONS.map((option) => (
              <option key={option.id} value={option.id}>{option.native}</option>
            ))}
          </select>
        </label>
      </SettingsGroup>
    </div>
  );
}

function ComputerRow({
  label,
  description,
  extra,
  control,
}: {
  label: string;
  description: string;
  extra: string | null;
  control: React.ReactNode;
}) {
  return (
    <div className="lb-settings-row">
      <span className="lb-settings-copy">
        <strong>{label}</strong>
        <small>{description}</small>
        {extra ? <small>{extra}</small> : null}
      </span>
      <span className="lb-settings-control">{control}</span>
    </div>
  );
}

function UpdatesPanel({ computer }: { computer?: SettingsComputer }) {
  const { t } = useI18n();
  const pending = computer?.pending ?? null;
  const disabled = Boolean(pending);
  const busyCopy = computer?.working ? t.computerBusyCopy : null;
  return (
    <div className="lb-settings-stack">
      <SettingsGroup title={t.updates}>
        <div className="lb-settings-row">
          <span className="lb-settings-copy">
            <strong>{APP_NAME} {APP_VERSION}</strong>
            <small>{t.localBuild}</small>
          </span>
        </div>
      </SettingsGroup>
      {computer ? (
        <SettingsGroup title={t.appComputer}>
          {computer.upToDate ? (
            <div className="lb-settings-banner" role="status">
              <strong>{t.computerUpToDate}</strong>
              <span>{t.computerUpdateCopy}</span>
              {busyCopy ? <span>{busyCopy}</span> : null}
              <button type="button" className="outline" disabled={disabled} onClick={computer.onUpdate}>
                {pending === "update" ? t.computerUpdating : t.update}
              </button>
            </div>
          ) : (
            <ComputerRow
              label={t.updateComputer}
              description={t.computerUpdateCopy}
              extra={busyCopy}
              control={
                <button type="button" className="outline" disabled={disabled} onClick={computer.onUpdate}>
                  {pending === "update" ? t.computerUpdating : t.update}
                </button>
              }
            />
          )}
          <ComputerRow
            label={t.restartComputer}
            description={t.restartComputerCopy}
            extra={busyCopy}
            control={
              <button type="button" className="danger" disabled={disabled} onClick={computer.onRestart}>
                {pending === "restart" ? t.computerRestarting : t.restart}
              </button>
            }
          />
        </SettingsGroup>
      ) : null}
    </div>
  );
}

export function SettingsDialog({ onClose, computer }: { onClose: () => void; computer?: SettingsComputer }) {
  const { t } = useI18n();
  const [section, setSection] = useState<SettingsSectionId>("general");
  const headingId = `lb-settings-heading-${section}`;
  const panelId = `lb-settings-panel-${section}`;
  const sectionLabel = section === "general" ? t.general : t.updates;

  return (
    <OverlayShell label={t.settingsLabel} className="lb-settings-dialog" onClose={onClose}>
      <div className="lb-settings-layout">
        <nav aria-label={t.settings} className="lb-settings-nav">
          {SECTIONS.map((item) => {
            const selected = item.id === section;
            return (
              <button
                key={item.id}
                type="button"
                className="lb-settings-nav__item"
                data-active={selected || undefined}
                aria-current={selected ? "page" : undefined}
                aria-controls={selected ? panelId : undefined}
                onClick={() => setSection(item.id)}
              >
                {item.icon === "gear" ? <GearIcon /> : <DownloadIcon />}
                <span>{item.id === "general" ? t.general : t.updates}</span>
              </button>
            );
          })}
        </nav>
        <section className="lb-settings-panel" id={panelId} aria-labelledby={headingId}>
          <button type="button" className="lb-settings-close" aria-label={t.close} onClick={onClose}>
            <CloseIcon />
          </button>
          <h2 id={headingId}>{sectionLabel}</h2>
          <div className="lb-settings-body">
            {section === "general" ? <GeneralPanel /> : <UpdatesPanel computer={computer} />}
          </div>
        </section>
      </div>
    </OverlayShell>
  );
}

export function AboutDialog({ onClose }: { onClose: () => void }) {
  const { t, format } = useI18n();
  const [copied, setCopied] = useState(false);
  const [copyGeneration, setCopyGeneration] = useState(0);

  useEffect(() => {
    if (!copied) return;
    const timeout = window.setTimeout(() => setCopied(false), 1200);
    return () => window.clearTimeout(timeout);
  }, [copied, copyGeneration]);

  const copyVersion = async () => {
    try {
      await navigator.clipboard.writeText([
        `Version: ${APP_VERSION}`,
        `OS: ${detectOs()}`,
      ].join("\n"));
      setCopied(true);
      setCopyGeneration((n) => n + 1);
    } catch {
      /* leave the action idle, matching grok-bot */
    }
  };

  return (
    <OverlayShell label={t.about} className="lb-about-dialog" onClose={onClose}>
      <button type="button" className="lb-about-close" aria-label={t.close} onClick={onClose}>
        <CloseIcon />
      </button>
      <div className="lb-about-brand">
        <span className="lb-about-icon">
          <img src="/lazyboy-icon.png" width={64} height={64} alt="" draggable={false} decoding="async" />
        </span>
        <div>
          <h2>{APP_NAME}</h2>
          <p>{format("versionLine", { version: APP_VERSION })}</p>
        </div>
        <small>{t.copyright}</small>
      </div>
      <footer>
        <button type="button" onClick={() => void copyVersion()}>
          {copied ? t.copied : t.copyVersionInfo}
        </button>
      </footer>
    </OverlayShell>
  );
}