import { useState } from "react";

function Section({ title, children }: { title: string; children: React.ReactNode }) {
  return (
    <div className="mb-8">
      <h3 className="text-sm font-bold text-[var(--flux-heading)] mb-3">{title}</h3>
      <div className="p-6 rounded border border-[var(--flux-grey-100)] bg-[var(--flux-surface)]">
        {children}
      </div>
    </div>
  );
}

function Switch({
  checked,
  onChange,
  disabled = false,
  size = "md",
}: {
  checked: boolean;
  onChange: (checked: boolean) => void;
  disabled?: boolean;
  size?: "sm" | "md" | "lg";
}) {
  const dims = {
    sm: { track: "w-9 h-5", thumb: "w-4 h-4", translate: "translate-x-4" },
    md: { track: "w-11 h-6", thumb: "w-5 h-5", translate: "translate-x-5" },
    lg: { track: "w-[52px] h-7", thumb: "w-6 h-6", translate: "translate-x-6" },
  }[size];

  return (
    <button
      type="button"
      role="switch"
      aria-checked={checked}
      disabled={disabled}
      onClick={() => onChange(!checked)}
      className={`
        relative inline-flex items-center rounded-full shrink-0
        transition-colors duration-200 ease-in-out
        ${dims.track}
        ${checked ? "bg-[var(--flux-primary-400)]" : "bg-[var(--flux-grey-200)]"}
        ${disabled ? "opacity-50 cursor-not-allowed" : "cursor-pointer"}
      `}
    >
      <span
        className={`
          inline-block rounded-full bg-white shadow-md
          transition-transform duration-200 ease-in-out
          ${dims.thumb}
          ${checked ? dims.translate : "translate-x-0.5"}
        `}
      />
    </button>
  );
}

export default function SwitchDemo() {
  const [defaultOn, setDefaultOn] = useState(false);
  const [smOn, setSmOn] = useState(false);
  const [lgOn, setLgOn] = useState(true);

  return (
    <div>
      <Section title="Default">
        <div className="flex items-center gap-3">
          <Switch checked={defaultOn} onChange={setDefaultOn} />
          <span className="text-sm text-[var(--flux-black)]">{defaultOn ? "On" : "Off"}</span>
        </div>
      </Section>

      <Section title="Sizes">
        <div className="flex flex-col gap-4">
          <div className="flex items-center gap-3">
            <Switch checked={smOn} onChange={setSmOn} size="sm" />
            <span className="text-xs text-[var(--flux-black)]">Small</span>
          </div>
          <div className="flex items-center gap-3">
            <Switch checked={defaultOn} onChange={setDefaultOn} />
            <span className="text-xs text-[var(--flux-black)]">Medium (default)</span>
          </div>
          <div className="flex items-center gap-3">
            <Switch checked={lgOn} onChange={setLgOn} size="lg" />
            <span className="text-xs text-[var(--flux-black)]">Large</span>
          </div>
        </div>
      </Section>

      <Section title="Disabled">
        <div className="flex items-center gap-3">
          <Switch checked={false} onChange={() => {}} disabled />
          <span className="text-sm text-[var(--flux-black)]">Disabled</span>
        </div>
      </Section>
    </div>
  );
}