/**
 * @file AppearanceSettings.tsx
 * @description Settings → Appearance (`/settings/appearance`): the per-user
 * Chat UI default (`ChatUiSettings`, `#chat-ui`), whether the session view's
 * tabs hold every workspace's sessions (`lib/workspaceTabs.ts`,
 * `#workspace-tabs`), the interface language, the
 * terminal font (`lib/terminalFont.ts`, with a preview line), the
 * Dark / Light / System mode switch and one named-theme picker per mode, and the
 * corner pet (`PetSettings`, deep-linked as `#pet`) — the old General and Pet
 * pages redirect here. Theme state is in `hooks/useTheme.ts`, palettes in
 * `index.css`. Each card's swatch re-scopes the theme's CSS variables on its
 * own element (`dark` class or `data-mode`, plus `data-theme`), so the preview
 * is painted by the same tokens as the app — no hex is duplicated here.
 * **Reset to defaults** (after a confirm) returns to Dark with both stock themes.
 * **Run setup again** reopens the first-run wizard (`components/onboarding`).
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

import { useState } from "react";
import { useTranslation } from "react-i18next";
import { Monitor, Moon, RotateCcw, Sun } from "lucide-react";
import { SettingsRow, SettingsSection, SettingsSegmented, SettingsSwitchRow } from "./SettingsRow";
import { PetSettings } from "./PetSettings";
import { ChatUiSettings } from "./ChatUiSettings";
import { Select } from "../Select";
import { THEMES, useTheme, type Theme, type ThemeMode } from "../../hooks/useTheme";
import { confirmDialog } from "../../lib/confirm";
import { resetOnboarding } from "../../lib/userPrefs";
import { toast } from "../../lib/toast";
import {
  TERMINAL_FONTS,
  readTerminalFont,
  writeTerminalFont,
  type TerminalFont,
} from "../../lib/terminalFont";
import { readAllTabs, writeAllTabs } from "../../lib/workspaceTabs";

export const THEME_LABELS: Record<string, string> = {
  darcula: "Darcula",
  "apple-dark": "Apple Dark",
  "apple-light": "Apple Light",
  canvas: "Canvas",
  "orca-dark": "Orca Dark",
  "orca-light": "Orca Light",
};

const MODES: { mode: ThemeMode; Icon: typeof Moon }[] = [
  { mode: "dark", Icon: Moon },
  { mode: "light", Icon: Sun },
  { mode: "system", Icon: Monitor },
];

export function Swatch({ mode, name }: { mode: Theme; name: string }) {
  return (
    <div
      aria-hidden
      className={`${mode === "dark" ? "dark" : ""} rounded-md border border-border bg-surface-0 p-2 text-fg-primary`}
      data-mode={mode}
      data-theme={name === "default" ? undefined : name}
    >
      <div className="rounded bg-surface-3 p-2 shadow-[var(--shadow-card)] space-y-1.5">
        <div className="flex items-center gap-1.5">
          <span className="h-2 w-2 rounded-full bg-accent" />
          <span className="h-1.5 w-10 rounded-full bg-fg-primary/70" />
        </div>
        <div className="font-mono text-[10px] leading-tight">
          <span className="text-syntax-keyword">const</span>{" "}
          <span className="text-syntax-function">x</span>{" "}
          <span className="text-syntax-operator">=</span>{" "}
          <span className="text-syntax-string">"ok"</span>
        </div>
        <div className="flex gap-1">
          <span className="h-1.5 flex-1 rounded-full bg-status-success/40" />
          <span className="h-1.5 flex-1 rounded-full bg-status-danger/40" />
        </div>
      </div>
    </div>
  );
}

export function AppearanceSettings() {
  const { t, i18n } = useTranslation("settings");
  const { mode, theme, themeFor, setMode, setThemeFor } = useTheme();
  const [termFont, setTermFont] = useState(readTerminalFont);
  const [allTabs, setAllTabs] = useState(readAllTabs);
  const pickTermFont = (font: TerminalFont) => {
    writeTerminalFont(font);
    setTermFont(font);
  };

  const reset = async () => {
    const ok = await confirmDialog({
      title: t("appearance.resetTitle"),
      message: t("appearance.resetBody"),
      confirmLabel: t("appearance.reset"),
    });
    if (!ok) return;
    setMode("dark");
    setThemeFor("dark", "default");
    setThemeFor("light", "default");
    toast.success(t("appearance.resetDone"));
  };

  return (
    <div className="space-y-6">
      <ChatUiSettings />

      <SettingsSection
        id="workspace-tabs"
        title={t("workspaceTabs.title")}
        description={t("workspaceTabs.description")}
      >
        <SettingsSwitchRow
          label={t("workspaceTabs.label")}
          description={t("workspaceTabs.labelDesc")}
          checked={allTabs}
          onChange={(on) => {
            writeAllTabs(on);
            setAllTabs(on);
          }}
        />
      </SettingsSection>

      <SettingsSection
        id="language"
        title={t("language.title")}
        description={t("language.description")}
      >
        <SettingsRow
          label={t("language.label")}
          control={
            <SettingsSegmented
              ariaLabel={t("language.label")}
              value={(i18n.resolvedLanguage ?? i18n.language).startsWith("vi") ? "vi" : "en"}
              onChange={(v) => void i18n.changeLanguage(v)}
              options={[
                { value: "en" as const, label: t("language.names.en") },
                { value: "vi" as const, label: t("language.names.vi") },
              ]}
            />
          }
        />
      </SettingsSection>

      <SettingsSection
        id="terminal-font"
        title={t("terminalFont.title")}
        description={t("terminalFont.description")}
      >
        <SettingsRow
          label={t("terminalFont.label")}
          description={termFont === "system" ? t("terminalFont.systemNote") : undefined}
          control={
            // A dropdown: five font names overflow a segmented row.
            <Select<TerminalFont>
              label={t("terminalFont.title")}
              value={termFont}
              onChange={pickTermFont}
              options={(Object.keys(TERMINAL_FONTS) as TerminalFont[]).map((f) => ({
                value: f,
                label: t(`terminalFont.names.${f}`),
              }))}
            />
          }
        />
        <p
          data-testid="terminal-font-preview"
          aria-label={t("terminalFont.preview")}
          className="mt-2 rounded-md border border-border bg-surface-0 px-3 py-2 text-[13px] text-fg-primary"
          // No ligatures: xterm draws one glyph per cell, so the terminal has none.
          style={{ fontFamily: TERMINAL_FONTS[termFont], fontVariantLigatures: "none" }}
        >
          ❯ Tiếng Việt: ấ ế ố ồ ủ ữ — const x = {"{ ok: true }"}; 0O il1|
        </p>
      </SettingsSection>

      <section id="theme" className="card p-5 space-y-5 scroll-mt-24">
        <h3 className="text-sm font-semibold text-fg-primary">{t("appearance.theme")}</h3>
        <SettingsRow
          label={t("appearance.mode")}
          control={
            <SettingsSegmented
              ariaLabel={t("appearance.mode")}
              value={mode}
              onChange={setMode}
              options={MODES.map(({ mode: m, Icon }) => ({
                value: m,
                label: (
                  <>
                    <Icon className="w-3.5 h-3.5" />
                    {t(`appearance.modes.${m}`)}
                  </>
                ),
              }))}
            />
          }
        />

        {(["dark", "light"] as const).map((group) => (
          <div key={group}>
            <p className="text-xs font-medium text-fg-secondary mb-2">
              {t(`appearance.${group}Themes`)}
              {theme === group && (
                <span className="ml-2 text-fg-muted font-normal">{t("appearance.active")}</span>
              )}
            </p>
            <div className="grid grid-cols-2 sm:grid-cols-3 lg:grid-cols-4 gap-3">
              {THEMES[group].map((name) => {
                const selected = themeFor[group] === name;
                const label = THEME_LABELS[name] ?? t("appearance.default");
                return (
                  <button
                    key={name}
                    type="button"
                    onClick={() => setThemeFor(group, name)}
                    aria-pressed={selected}
                    aria-label={`${t(`appearance.${group}Themes`)}: ${label}`}
                    className={`rounded-lg border p-1.5 text-left transition-colors ${
                      selected
                        ? "border-accent ring-2 ring-accent/40"
                        : "border-border hover:border-border-light"
                    }`}
                  >
                    <Swatch mode={group} name={name} />
                    <span className="block px-1 pt-1.5 text-xs text-fg-primary">{label}</span>
                  </button>
                );
              })}
            </div>
          </div>
        ))}

        <div className="flex justify-end border-t border-border pt-3">
          <button type="button" onClick={() => void reset()} className="btn-ghost text-xs">
            <RotateCcw className="w-3.5 h-3.5" />
            {t("appearance.reset")}
          </button>
        </div>
      </section>

      <section id="pet" className="space-y-3 scroll-mt-24">
        <div>
          <h3 className="text-sm font-semibold text-fg-primary">{t("appearance.pet")}</h3>
          <p className="mt-0.5 text-xs text-fg-muted">{t("appearance.petDescription")}</p>
        </div>
        <PetSettings />
      </section>

      <SettingsSection
        id="setup"
        title={t("onboarding:rerun.label")}
        description={t("onboarding:rerun.description")}
      >
        <SettingsRow
          label={t("onboarding:rerun.label")}
          control={
            <button
              type="button"
              onClick={resetOnboarding}
              data-testid="rerun-setup"
              className="btn-ghost border border-border text-xs"
            >
              {t("onboarding:rerun.button")}
            </button>
          }
        />
      </SettingsSection>
    </div>
  );
}