/**
 * @file AppearanceSettings.tsx
 * @description Settings → Appearance: the Dark / Light / System mode switch and
 * one named-theme picker per mode (state 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.
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

import { useTranslation } from "react-i18next";
import { Monitor, Moon, Palette, Sun } from "lucide-react";
import { THEMES, useTheme, type Theme, type ThemeMode } from "../../hooks/useTheme";

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

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

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 } = useTranslation("settings");
  const { mode, theme, themeFor, setMode, setThemeFor } = useTheme();

  return (
    <section id="appearance" className="scroll-mt-24">
      <h3 className="text-sm font-medium text-fg-secondary flex items-center gap-2 mb-1">
        <Palette className="w-4 h-4 text-fg-muted" />
        {t("appearance.title")}
      </h3>
      <p className="text-xs text-fg-muted mb-4">{t("appearance.description")}</p>

      <div className="card p-5 space-y-5">
        <div>
          <p className="text-xs font-medium text-fg-secondary mb-2">{t("appearance.mode")}</p>
          <div className="inline-flex rounded-lg border border-border bg-surface-2 p-0.5">
            {MODES.map(({ mode: m, Icon }) => (
              <button
                key={m}
                type="button"
                onClick={() => setMode(m)}
                aria-pressed={mode === m}
                className={`flex items-center gap-1.5 rounded-md px-3 py-1.5 text-xs font-medium transition-colors ${
                  mode === m
                    ? "bg-accent/20 text-accent"
                    : "text-fg-secondary hover:bg-surface-3 hover:text-fg-primary"
                }`}
              >
                <Icon className="w-3.5 h-3.5" />
                {t(`appearance.modes.${m}`)}
              </button>
            ))}
          </div>
        </div>

        {(["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>
    </section>
  );
}