"use client";

import { useEffect, useState } from "react";

// Extend the BeforeInstallPromptEvent type (not in standard lib)
interface BeforeInstallPromptEvent extends Event {
  prompt(): Promise<void>;
  readonly userChoice: Promise<{ outcome: "accepted" | "dismissed" }>;
}

function IOSInstallInstructions({ onDismiss }: { onDismiss: () => void }) {
  return (
    <div className="fixed bottom-4 left-4 right-4 z-50 bg-white border border-rose-100 rounded-2xl shadow-lg p-4">
      <div className="flex justify-between items-start mb-2">
        <div className="flex items-center gap-2">
          <span className="text-2xl">🌸</span>
          <span className="font-semibold text-gray-900">Install Tia</span>
        </div>
        <button
          onClick={onDismiss}
          className="text-gray-400 text-xl leading-none p-1"
          aria-label="Dismiss"
        >
          ✕
        </button>
      </div>
      <p className="text-sm text-gray-600 mb-2">
        Add Tia to your home screen for the best experience.
      </p>
      <div className="flex items-center gap-2 text-sm text-gray-700">
        <span>Tap</span>
        <span className="inline-flex items-center justify-center w-7 h-7 bg-gray-100 rounded-md text-base">⬆️</span>
        <span>then</span>
        <span className="font-medium">"Add to Home Screen"</span>
      </div>
    </div>
  );
}

const DISMISSED_KEY = "tia_install_prompt_dismissed";

export function InstallPrompt() {
  const [deferred, setDeferred] = useState<BeforeInstallPromptEvent | null>(null);
  const [isIOS, setIsIOS] = useState(false);
  const [dismissed, setDismissed] = useState(true); // start hidden to avoid flash

  useEffect(() => {
    if (typeof window === "undefined") return;

    const alreadyDismissed = localStorage.getItem(DISMISSED_KEY) === "1";
    if (alreadyDismissed) return;

    const standalone = window.matchMedia("(display-mode: standalone)").matches;
    if (standalone) return; // already installed

    // iOS Safari: no beforeinstallprompt, needs manual instructions
    const ios = /iphone|ipad|ipod/i.test(navigator.userAgent);
    const isSafari = /^((?!chrome|android).)*safari/i.test(navigator.userAgent);
    if (ios && isSafari) {
      setIsIOS(true);
      setDismissed(false);
    }

    // Android / Chrome: capture the deferred install event
    const handler = (e: Event) => {
      e.preventDefault();
      setDeferred(e as BeforeInstallPromptEvent);
      setDismissed(false);
    };
    window.addEventListener("beforeinstallprompt", handler);
    return () => window.removeEventListener("beforeinstallprompt", handler);
  }, []);

  const handleDismiss = () => {
    setDismissed(true);
    localStorage.setItem(DISMISSED_KEY, "1");
  };

  const handleInstall = async () => {
    if (!deferred) return;
    await deferred.prompt();
    const { outcome } = await deferred.userChoice;
    if (outcome === "accepted") {
      setDeferred(null);
      setDismissed(true);
    }
  };

  if (dismissed) return null;

  if (deferred) {
    return (
      <div className="fixed bottom-4 left-4 right-4 z-50 bg-white border border-rose-100 rounded-2xl shadow-lg p-4 flex items-center gap-3">
        <span className="text-2xl">🌸</span>
        <div className="flex-1">
          <p className="font-semibold text-gray-900 text-sm">Install Tia</p>
          <p className="text-xs text-gray-500">Add to home screen for quick access</p>
        </div>
        <button onClick={handleDismiss} className="text-gray-400 p-1 text-lg" aria-label="Dismiss">✕</button>
        <button
          onClick={handleInstall}
          className="px-4 py-2 bg-rose-400 text-white rounded-xl text-sm font-semibold"
        >
          Install
        </button>
      </div>
    );
  }

  if (isIOS) {
    return <IOSInstallInstructions onDismiss={handleDismiss} />;
  }

  return null;
}