/**
 * @file SettingsHub.tsx
 * @description The Settings page: `/settings/<section>`, a left nav grouped
 * General / Agents / Data (a `<select>` below `md`), a
 * search box over `SETTINGS_INDEX` (`lib/settingsSearch.ts`; Ctrl/Cmd+F
 * focuses it — and selects its text when it already has focus —, a result list
 * deep-links a row's sub-tab and anchor, Enter opens the first result, Escape
 * clears), and one page per section. A `#anchor` in the URL scrolls to the
 * element with that `id` or `data-settings-anchor` and briefly highlights it.
 * Back returns to the page before Settings when there is one, else /workspace;
 * an unknown section shows a skeleton until the tool list loads, then toasts
 * and falls back to Appearance (which also holds the language and the pet;
 * `general` and `pet` redirect there). Small pages share one: System is the old
 * About (`about` redirects), Git holds git logins and worktree suggestions
 * (`git-credentials`, `worktrees`), Snapshots & reports is `reports`
 * (`snapshots`). A page's content is capped at a readable width. A tool's own settings live under `agents/<id>` — Claude Code and
 * Codex have their own pages, every other installed, enabled catalog tool the
 * generic `AiToolConfig` — and a tool's page is hidden while that tool is
 * disabled. Those pages are not in the nav: they are tabs on AI tools (the nav
 * marks AI tools current, the search shows their matches under it), and a
 * row in the AI tools list opens its tool's tab. A workspace's own settings live on its home, not here.
 * The old `?tool=<id>` query and `#ai-tools` hash redirect to the path form.
 * With `section` it is a workspace's Settings tab instead (`?settings=` on
 * /workspace, `lib/settingsLink.ts`): the same pages, every link kept in the
 * tab (replaced, as a tab click), no Back link, and Ctrl/Cmd+F left alone
 * while the tab is hidden behind a session.
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */
import {
  useEffect,
  useRef,
  useState,
  type ComponentType,
  type MouseEvent,
  type ReactNode,
} from "react";
import { Link, Navigate, useLocation, useNavigate } from "react-router-dom";
import { useTranslation } from "react-i18next";
import {
  ArrowLeft,
  Bell,
  Database,
  Bot,
  CalendarClock,
  Coins,
  GitBranch,
  Palette,
  Router,
  Search,
  Server,
} from "lucide-react";
import { Settings } from "./Settings";
import { useSettingsHref } from "../lib/settingsLink";
import { CcConfig } from "./CcConfig";
import { CodexConfig } from "./CodexConfig";
import { AiToolConfig } from "./AiToolConfig";
import { AiProxyConfig } from "./AiProxyConfig";
import { GitCredentialsConfig } from "./GitCredentialsConfig";
import { AppearanceSettings } from "../components/settings/AppearanceSettings";
import { SnapshotSettings } from "../components/settings/SnapshotSettings";
import { ReportSettings } from "../components/settings/ReportSettings";
import { AiToolsSettings } from "../components/settings/AiToolsSettings";
import { AgentInstructionsSettings } from "../components/settings/AgentInstructionsSettings";
import { PricingSettings } from "../components/settings/PricingSettings";
import { WorktreeVisibilitySettings } from "../components/settings/WorktreeVisibilitySettings";
import { useAiTools } from "../hooks/useAiTools";
import {
  rankSettings,
  rankSettingsEntries,
  SETTINGS_INDEX,
  type SettingsEntry,
} from "../lib/settingsSearch";
import { Skeleton } from "../components/Skeleton";
import { AiToolIcon } from "../components/AiToolIcon";
import { toast } from "../lib/toast";
import { usePermissions } from "../components/AuthGate";
import { PageTabs } from "../components/PageTabs";

const GROUPS = ["general", "agents", "data"] as const;
type Group = (typeof GROUPS)[number];

interface Section {
  id: string;
  group: Group;
  title: string;
  description: string;
  Icon: ComponentType<{ className?: string }>;
  render: () => ReactNode;
  /** A tool's own page: a tab on AI tools, not a nav item. */
  tool?: string;
}

/** The nav item a section sits under: a tool's page is a tab on AI tools. */
const navId = (id: string) => (id.startsWith("agents/") ? "agents" : id);

/** The pre-1.9 `?tool=` ids, as section ids. Anything else was a catalog tool. */
const LEGACY_TOOL: Record<string, string> = {
  dashboard: "appearance",
  "claude-code": "agents/claude-code",
  codex: "agents/codex",
  "ai-router": "ai-proxy",
  "git-credentials": "git",
};

/** Classes a deep-linked row wears for a moment after the hub scrolls to it. */
const HIGHLIGHT = ["ring-2", "ring-accent/60", "rounded-lg"];

/** A history entry's index as react-router's BrowserRouter records it. */
const historyIdx = (): number => {
  const idx = (window.history.state as { idx?: unknown } | null)?.idx;
  return typeof idx === "number" ? idx : 0;
};

/**
 * How far Back moves: to the entry before the one Settings was entered at, and
 * always at least one step — after a browser Back below that entry, the plain
 * difference would be 0 (`history.go(0)`, a reload) or a step forward.
 */
export const backDelta = (current: number, entry: number): number =>
  -Math.max(1, current - entry + 1);

/** Sections folded into Appearance: old links and bookmarks still land. */
/** A tool's own mark as a nav icon, one stable component per tool id. */
const navIcons = new Map<string, ComponentType<{ className?: string }>>();
function toolNavIcon(id: string, label: string) {
  let Icon = navIcons.get(id);
  if (!Icon) {
    Icon = ({ className }) => (
      <AiToolIcon tool={{ id, label }} className={`${className ?? ""} !bg-transparent !p-0`} />
    );
    navIcons.set(id, Icon);
  }
  return Icon;
}

const MOVED: Record<string, string> = {
  general: "appearance",
  pet: "appearance#pet",
  // The AI Router → AI Proxy rename.
  "ai-router": "ai-proxy",
  // Small pages merged into one.
  about: "system",
  snapshots: "reports#snapshots",
  "git-credentials": "git",
  worktrees: "git#worktrees",
};

/** Sections that only configure the host (ADMIN_WRITE_PREFIXES in server/lib/auth.js). */
// AI Proxy is not here: every user keeps personal profiles (S3).
const ADMIN_SECTIONS = new Set(["data", "pricing"]);

/** An unknown section: say so, then show Appearance (`to`). */
function UnknownSection({ name, to }: { name: string; to: string }) {
  const { t } = useTranslation("settings");
  useEffect(() => {
    toast.info(t("settingsNav.unknownSection", { section: name }));
  }, [name, t]);
  return <Navigate to={to} replace />;
}

export function SettingsHub({ section }: { section?: string } = {}) {
  const { t } = useTranslation("settings");
  const location = useLocation();
  const navigate = useNavigate();
  const embedded = section !== undefined;
  const href = useSettingsHref();
  const nav = embedded ? { replace: true } : undefined;
  const rootRef = useRef<HTMLDivElement>(null);
  const aiTools = useAiTools();
  const [query, setQuery] = useState("");
  const searchRef = useRef<HTMLInputElement>(null);
  // The history index Settings was entered at: Back unwinds to the entry
  // before it rather than always landing on /workspace.
  const entryIdx = useRef<number | null>(null);
  if (entryIdx.current === null) entryIdx.current = historyIdx();
  const canGoBack = entryIdx.current > 0;

  useEffect(() => {
    const onKey = (e: KeyboardEvent) => {
      if (!(e.ctrlKey || e.metaKey) || e.key.toLowerCase() !== "f") return;
      // A workspace's Settings tab hidden behind a session: not on screen.
      if (rootRef.current?.closest(".hidden")) return;
      // A config editor's own find keeps the shortcut.
      const el = e.target;
      if (el instanceof Element && el.closest("textarea, [contenteditable='true'], .cm-editor"))
        return;
      // An open modal owns the keyboard: never pull focus to a box behind it.
      if (document.querySelector('[aria-modal="true"]')) return;
      e.preventDefault();
      const box = searchRef.current;
      if (!box) return;
      // A second press while the box has focus selects its text, so the
      // shortcut always does something visible (and never opens the browser's).
      if (document.activeElement === box) box.select();
      else box.focus();
    };
    window.addEventListener("keydown", onKey);
    return () => window.removeEventListener("keydown", onKey);
  }, []);

  // Deep link to a row: scroll to the anchor once the page has rendered it
  // (content loads async, so poll briefly) and highlight it for a moment.
  useEffect(() => {
    let id = location.hash.slice(1);
    try {
      id = decodeURIComponent(id);
    } catch {
      // A malformed escape (`#%`): look the raw text up instead of crashing.
    }
    if (!id) return;
    let timer: number | undefined;
    let lit: Element | null = null;
    let tries = 0;
    const find = () =>
      document.getElementById(id) ??
      document.querySelector(`[data-settings-anchor="${id.replace(/["\\]/g, "")}"]`);
    const tick = () => {
      const el = find();
      if (!el) {
        if (++tries < 30) timer = window.setTimeout(tick, 100);
        return;
      }
      const reduce = window.matchMedia?.("(prefers-reduced-motion: reduce)").matches;
      el.scrollIntoView?.({ block: "start", behavior: reduce ? "auto" : "smooth" });
      el.classList.add(...HIGHLIGHT);
      lit = el;
      timer = window.setTimeout(() => {
        el.classList.remove(...HIGHLIGHT);
        lit = null;
      }, 1600);
    };
    tick();
    return () => {
      window.clearTimeout(timer);
      lit?.classList.remove(...HIGHLIGHT);
    };
  }, [location.key, location.hash]);

  const { isAdmin } = usePermissions();
  const enabled = (id: string) => aiTools.byId(id)?.enabled !== false;
  const s = (key: string) => ({
    title: t(`settingsNav.section.${key}.title`),
    description: t(`settingsNav.section.${key}.description`),
  });
  const allSections: Section[] = [
    {
      id: "appearance",
      group: "general",
      Icon: Palette,
      ...s("appearance"),
      render: () => <AppearanceSettings />,
    },
    {
      id: "notifications",
      group: "general",
      Icon: Bell,
      ...s("notifications"),
      render: () => <Settings section="notifications" />,
    },
    {
      id: "system",
      group: "general",
      Icon: Server,
      ...s("system"),
      render: () => <Settings section="about" />,
    },
    {
      id: "agents",
      group: "agents",
      Icon: Bot,
      ...s("agents"),
      render: () => (
        <div className="space-y-6">
          <AgentInstructionsSettings />
          <AiToolsSettings settingsHref={toolHref} />
        </div>
      ),
    },
    ...(enabled("claude")
      ? [
          {
            id: "agents/claude-code",
            group: "agents" as const,
            tool: "claude",
            Icon: toolNavIcon("claude", "Claude Code"),
            ...s("claudeCode"),
            render: () => <CcConfig />,
          },
        ]
      : []),
    ...(enabled("codex")
      ? [
          {
            id: "agents/codex",
            group: "agents" as const,
            tool: "codex",
            Icon: toolNavIcon("codex", "Codex"),
            ...s("codex"),
            render: () => <CodexConfig />,
          },
        ]
      : []),
    ...aiTools.tools
      .filter(
        (x) => x.installed && x.enabled && !x.launcher && x.id !== "claude" && x.id !== "codex"
      )
      .map((x) => ({
        id: `agents/${x.id}`,
        group: "agents" as const,
        tool: x.id,
        Icon: toolNavIcon(x.id, x.label),
        title: x.label,
        description: t("settingsNav.section.tool.description", { tool: x.label }),
        render: () => <AiToolConfig key={x.id} toolId={x.id} />,
      })),
    {
      id: "ai-proxy",
      group: "agents",
      Icon: Router,
      ...s("aiProxy"),
      render: () => <AiProxyConfig />,
    },
    {
      id: "data",
      group: "data",
      Icon: Database,
      ...s("data"),
      render: () => <Settings section="data" />,
    },
    {
      id: "pricing",
      group: "data",
      Icon: Coins,
      ...s("pricing"),
      render: () => (
        <div className="space-y-6">
          <PricingSettings
            vendor="claude"
            allowReset
            id="pricing-claude"
            heading={t("pricing.vendor.claude")}
          />
          <PricingSettings
            vendor="openai"
            id="pricing-openai"
            heading={t("pricing.vendor.openai")}
          />
          <PricingSettings
            vendor="google"
            id="pricing-google"
            heading={t("pricing.vendor.google")}
          />
        </div>
      ),
    },
    {
      id: "reports",
      group: "data",
      Icon: CalendarClock,
      ...s("reports"),
      render: () => (
        <div className="space-y-6">
          <div id="snapshots" className="scroll-mt-24">
            <SnapshotSettings />
          </div>
          {/* Scheduled reports read every user's sessions: an admin's. */}
          {isAdmin && <ReportSettings />}
        </div>
      ),
    },
    {
      id: "git",
      group: "data",
      Icon: GitBranch,
      ...s("git"),
      render: () => (
        <div className="space-y-6">
          {/* Git logins are the host's own: an admin's. */}
          {isAdmin && (
            <section id="git-credentials" className="scroll-mt-24">
              <h2 className="mb-2 text-sm font-semibold text-fg-primary">{t("gitCreds.title")}</h2>
              <GitCredentialsConfig />
            </section>
          )}
          <div id="worktrees" className="scroll-mt-24">
            <WorktreeVisibilitySettings />
          </div>
        </div>
      ),
    },
  ];
  // Server mode: only an admin changes the host's own configuration (the
  // server answers 403 EADMIN), so its pages — every tool's too — are hidden.
  const sections = isAdmin
    ? allSections
    : allSections.filter((x) => !x.tool && !ADMIN_SECTIONS.has(x.id));
  const navSections = sections.filter((x) => !x.tool);
  const toolTabs = sections.filter((x) => x.tool);
  function toolHref(id: string) {
    const page = toolTabs.find((x) => x.tool === id);
    return page ? href(page.id) : undefined;
  }

  const entries: SettingsEntry[] = sections.flatMap((sec) => [
    { section: sec.id, title: sec.title, description: sec.description, sectionTitle: true },
    ...SETTINGS_INDEX.filter(
      (e) =>
        (isAdmin || !e.adminOnly) &&
        (e.section === sec.id ||
          (e.section === "agents/*" &&
            sec.id.startsWith("agents/") &&
            !SETTINGS_INDEX.some((x) => x.section === sec.id)))
    ).map((e) => ({
      section: sec.id,
      title: t(e.titleKey),
      description: e.descKey ? t(e.descKey) : undefined,
      keywords: e.keywords,
      to: e.to,
    })),
  ]);

  const rest = embedded
    ? section
    : location.pathname.replace(/^\/settings\/?/, "").replace(/\/$/, "");
  if (!rest) {
    const params = new URLSearchParams(location.search);
    const tool = params.get("tool");
    const to =
      location.hash === "#ai-tools"
        ? "agents"
        : tool
          ? (LEGACY_TOOL[tool] ?? `agents/${tool}`)
          : "appearance";
    return <Navigate to={href(to)} replace />;
  }
  if (MOVED[rest]) return <Navigate to={href(MOVED[rest])} replace />;
  const active = sections.find((x) => x.id === rest);
  if (!active) {
    // A catalog tool page exists only once the tool list has loaded.
    if (!aiTools.loaded)
      return (
        <div className="space-y-3" aria-busy="true">
          <Skeleton className="h-6 w-48" />
          <Skeleton className="h-4 w-80" />
          <Skeleton className="h-40 w-full" />
        </div>
      );
    return <UnknownSection name={rest} to={href("appearance")} />;
  }

  const ranked = query.trim() ? rankSettings(query, entries) : null;
  const shown = ranked
    ? navSections.filter((x) => ranked.some((r) => navId(r.section) === x.id))
    : navSections;
  const first = ranked?.[0] ? navId(ranked[0].section) : null;
  const navActive = navId(active.id);
  const results = ranked ? rankSettingsEntries(query, entries) : [];
  const titleOf = (id: string) => sections.find((x) => x.id === id)?.title ?? id;
  const hrefOf = (e: SettingsEntry) => href(`${e.section}${e.to ?? ""}`);
  const go = (id: string) => navigate(href(id), nav);
  const back = (e: MouseEvent) => {
    if (!canGoBack) return;
    e.preventDefault();
    navigate(backDelta(historyIdx(), entryIdx.current ?? 0));
  };

  const searchBox = (
    <label className="relative block">
      <Search className="pointer-events-none absolute left-2.5 top-1/2 h-3.5 w-3.5 -translate-y-1/2 text-fg-muted" />
      <input
        ref={searchRef}
        type="search"
        value={query}
        onChange={(e) => setQuery(e.target.value)}
        onKeyDown={(e) => {
          if (e.key === "Enter" && results[0]) navigate(hrefOf(results[0]), nav);
          if (e.key === "Escape") setQuery("");
        }}
        placeholder={t("search.placeholder")}
        aria-label={t("search.placeholder")}
        className="w-full rounded-lg border border-border bg-surface-1 py-1.5 pl-8 pr-2 text-sm text-fg-primary placeholder:text-fg-muted focus:border-accent focus:outline-none"
      />
    </label>
  );
  const searchResults = ranked && results.length > 0 && (
    <ul
      aria-label={t("search.results")}
      className="card mt-2 divide-y divide-border/60 overflow-hidden"
    >
      {results.map((r, i) => (
        <li key={`${r.section}${r.to ?? ""}${r.title}`}>
          <Link
            to={hrefOf(r)}
            replace={embedded}
            onClick={() => setQuery("")}
            className={`block px-3 py-2 text-xs hover:bg-surface-3 ${i === 0 ? "bg-surface-2" : ""}`}
          >
            <span className="block text-fg-primary">{r.title}</span>
            {!r.sectionTitle && (
              <span className="block text-[11px] text-fg-muted">{titleOf(r.section)}</span>
            )}
          </Link>
        </li>
      ))}
    </ul>
  );

  return (
    <div ref={rootRef}>
      {!embedded && (
        <Link
          to="/workspace"
          onClick={back}
          className="mb-4 inline-flex items-center gap-1.5 text-xs text-fg-secondary hover:text-fg-primary"
        >
          <ArrowLeft className="h-3.5 w-3.5" />
          {canGoBack ? t("settingsNav.backPrevious") : t("settingsNav.back")}
        </Link>
      )}
      <div className="flex gap-8">
        <aside className="sticky top-0 hidden max-h-[calc(100vh-4rem)] w-60 shrink-0 self-start overflow-y-auto pb-6 md:block">
          {searchBox}
          {searchResults}
          <nav aria-label={t("settingsNav.label")} className="mt-4 space-y-5">
            {ranked && shown.length === 0 && (
              <p className="px-2 py-1 text-xs text-fg-muted">{t("search.noMatch", { query })}</p>
            )}
            {GROUPS.map((g) => {
              const items = shown.filter((x) => x.group === g);
              if (items.length === 0) return null;
              const label = t(`settingsNav.group.${g}`);
              return (
                <div key={g} role="group" aria-label={label}>
                  <p className="px-2 pb-1.5 text-[11px] font-semibold uppercase tracking-wider text-fg-muted">
                    {label}
                  </p>
                  <div className="space-y-0.5">
                    {items.map(({ id, title, Icon }) => (
                      <Link
                        key={id}
                        to={href(id)}
                        replace={embedded}
                        aria-current={id === navActive ? "page" : undefined}
                        data-first-match={id === first ? "true" : undefined}
                        className={`relative flex items-center gap-2.5 rounded-md px-2.5 py-1.5 text-sm transition-colors ${
                          id === navActive
                            ? "bg-surface-3 font-medium text-fg-primary before:absolute before:inset-y-1.5 before:left-0 before:w-0.5 before:rounded-full before:bg-accent"
                            : id === first
                              ? "bg-surface-3 text-fg-primary"
                              : "text-fg-secondary hover:bg-surface-2 hover:text-fg-primary"
                        }`}
                      >
                        <Icon
                          className={`h-4 w-4 shrink-0 ${id === navActive ? "text-accent" : "text-fg-muted"}`}
                        />
                        <span className="truncate">{title}</span>
                      </Link>
                    ))}
                  </div>
                </div>
              );
            })}
          </nav>
        </aside>

        <div className="min-w-0 max-w-5xl flex-1 pb-10">
          <div className="mb-4 md:hidden">
            <select
              aria-label={t("settingsNav.label")}
              value={navActive}
              onChange={(e) => go(e.target.value)}
              className="select w-full py-1.5"
            >
              {GROUPS.map((g) => {
                const own = navSections.filter((x) => x.group === g);
                return own.length === 0 ? null : (
                  <optgroup key={g} label={t(`settingsNav.group.${g}`)}>
                    {own.map((x) => (
                      <option key={x.id} value={x.id}>
                        {x.title}
                      </option>
                    ))}
                  </optgroup>
                );
              })}
            </select>
          </div>
          <header className="mb-6 flex items-start gap-3 border-b border-border pb-5">
            <span className="mt-0.5 flex h-9 w-9 shrink-0 items-center justify-center rounded-lg bg-surface-2 text-accent">
              <active.Icon className="h-5 w-5" />
            </span>
            <div className="min-w-0">
              <h1 className="text-xl font-semibold text-fg-primary">{active.title}</h1>
              <p className="mt-0.5 text-sm text-fg-muted">{active.description}</p>
            </div>
          </header>
          {navActive === "agents" && toolTabs.length > 0 ? (
            <PageTabs
              ariaLabel={t("settingsNav.toolTabs")}
              activeId={active.id}
              onSelect={go}
              tabs={[
                { id: "agents", label: t("settingsNav.toolsTab"), Icon: Bot },
                ...toolTabs.map(({ id, title, Icon }) => ({ id, label: title, Icon })),
              ]}
            >
              <div className="pt-4">{active.render()}</div>
            </PageTabs>
          ) : (
            active.render()
          )}
        </div>
      </div>
    </div>
  );
}