"use client";

import { RiFireLine as Flame, RiSubtractLine as Minus, RiAddLine as Plus } from "@remixicon/react";
import { useEffect, useRef, useState, useSyncExternalStore } from "react";
import type { Recipe } from "@/app/types";
import { RecipeDetail } from "./RecipeDetail";

const noopSubscribe = () => () => {};

/** RecipeDetail with an accessible servings stepper + Screen Wake Lock ("Cook mode") toggle. */
export function RecipeServings({ recipe }: { recipe: Recipe }) {
  const [servings, setServings] = useState(recipe.servings);
  const [cookMode, setCookMode] = useState(false);
  const wakeSupported = useSyncExternalStore(noopSubscribe, () => "wakeLock" in navigator, () => false);
  const wakeLockRef = useRef<WakeLockSentinel | null>(null);

  useEffect(() => {
    if (!cookMode || !wakeSupported) {
      wakeLockRef.current?.release().catch(() => {});
      wakeLockRef.current = null;
      return;
    }

    let cancelled = false;
    async function acquire() {
      try {
        const sentinel = await navigator.wakeLock.request("screen");
        if (cancelled) {
          await sentinel.release();
          return;
        }
        wakeLockRef.current = sentinel;
      } catch {
        // Battery saver or background tab can refuse wakeLock; fail gracefully.
      }
    }

    acquire();
    const onVisibility = () => {
      if (document.visibilityState === "visible" && cookMode) acquire();
    };
    document.addEventListener("visibilitychange", onVisibility);

    return () => {
      cancelled = true;
      document.removeEventListener("visibilitychange", onVisibility);
      wakeLockRef.current?.release().catch(() => {});
      wakeLockRef.current = null;
    };
  }, [cookMode, wakeSupported]);

  return (
    <div>
      <div className="mb-6 flex flex-wrap items-center justify-between gap-3 border-b border-line pb-4">
        <div className="flex items-center gap-3">
          <span className="text-sm font-medium text-ink-muted">Scale servings</span>
          <div className="inline-flex items-center rounded-lg border border-line-strong bg-raised p-0.5">
            <button
              type="button"
              onClick={() => setServings((s) => Math.max(1, s - 1))}
              className="grid size-9 place-items-center rounded-md text-ink-muted transition-colors hover:bg-surface hover:text-ink"
              aria-label="Fewer servings"
            >
              <Minus className="size-4" aria-hidden />
            </button>
            <span className="min-w-9 text-center font-mono text-sm font-semibold tabular-nums" aria-live="polite">
              {servings}
            </span>
            <button
              type="button"
              onClick={() => setServings((s) => Math.min(12, s + 1))}
              className="grid size-9 place-items-center rounded-md text-ink-muted transition-colors hover:bg-surface hover:text-ink"
              aria-label="More servings"
            >
              <Plus className="size-4" aria-hidden />
            </button>
          </div>
          <span className="hidden text-xs text-ink-faint sm:inline">Tap any ingredient or step below to check it off</span>
        </div>

        {wakeSupported && (
          <button
            type="button"
            aria-pressed={cookMode}
            onClick={() => setCookMode((c) => !c)}
            className={`trim-cap inline-flex min-h-9 items-center gap-1.5 rounded-lg border px-3 py-1.5 text-xs font-semibold transition-colors ${
              cookMode
                ? "border-status-ok-line bg-status-ok-bg text-status-ok"
                : "border-line-strong bg-surface text-ink-muted hover:bg-raised hover:text-ink"
            }`}
          >
            <Flame className="size-3.5" aria-hidden />
            {cookMode ? "Screen kept awake" : "Keep screen awake"}
          </button>
        )}
      </div>

      <RecipeDetail recipe={recipe} servings={servings} showMeta={false} interactive />
    </div>
  );
}