import { useEffect, useState, useCallback } from "react";
import { useSignaling } from "../hooks/useSignaling";
import { useStore } from "../stores/useStore";
import { useProfileStore } from "../stores/useProfileStore";
import PeerList from "../components/PeerList";
import ProfileSetup from "../components/ProfileSetup";

interface SharedData {
  files: File[];
  text: string;
}

/** Read shared files/text from the cache stashed by the service worker */
async function readSharedData(): Promise<SharedData> {
  const result: SharedData = { files: [], text: "" };

  try {
    const cache = await caches.open("share-target");

    // Read metadata
    const metaResponse = await cache.match("/share-target-meta");
    if (!metaResponse) return result;

    const meta = await metaResponse.json();
    result.text = meta.text || "";

    // Read files
    for (let i = 0; i < (meta.count || 0); i++) {
      const fileResponse = await cache.match(`/share-target-file/${i}`);
      if (!fileResponse) continue;

      const blob = await fileResponse.blob();
      const fileName = decodeURIComponent(
        fileResponse.headers.get("X-File-Name") || `fichier-${i}`,
      );
      result.files.push(new File([blob], fileName, { type: blob.type }));
    }

    // Clean up cache
    await caches.delete("share-target");
  } catch (err) {
    console.error("[share] Failed to read shared data:", err);
  }

  return result;
}

export default function Share() {
  const isSetUp = useProfileStore((s) => s.isSetUp);

  if (!isSetUp) {
    return <ProfileSetup onDone={() => {}} />;
  }

  return <ShareConnected />;
}

function ShareConnected() {
  const { sendFiles, sendText } = useSignaling();
  const peers = useStore((s) => s.peers);
  const setSelectedPeerId = useStore((s) => s.setSelectedPeerId);

  const [shared, setShared] = useState<SharedData | null>(null);
  const [sent, setSent] = useState(false);

  useEffect(() => {
    readSharedData().then(setShared);
  }, []);

  const handlePeerSelect = useCallback(
    (peerId: string) => {
      if (!shared || sent) return;

      setSelectedPeerId(peerId);

      if (shared.files.length > 0) {
        sendFiles(peerId, shared.files);
      }
      if (shared.text && shared.files.length === 0) {
        sendText(peerId, shared.text);
      }

      setSent(true);
    },
    [shared, sent, sendFiles, sendText, setSelectedPeerId],
  );

  const fileCount = shared?.files.length || 0;
  const hasText = !!shared?.text;

  return (
    <div className="min-h-screen bg-gradient-to-b from-slate-950 via-slate-900 to-slate-950">
      <div className="max-w-lg mx-auto px-4 py-8">
        {/* Header */}
        <header className="text-center mb-6">
          <h1 className="text-3xl font-bold text-white mb-1">
            Any<span className="text-brand-400">Drop</span>
          </h1>

          {!shared ? (
            <p className="text-slate-500 text-sm mt-4">Chargement...</p>
          ) : sent ? (
            <div className="mt-6">
              <div className="text-4xl mb-3">✓</div>
              <p className="text-brand-400 font-medium">Envoi en cours</p>
              <a
                href="/"
                className="inline-block mt-4 text-sm text-slate-500 hover:text-slate-300 transition-colors"
              >
                Retour à l'accueil
              </a>
            </div>
          ) : (
            <>
              <p className="text-slate-400 text-sm mt-4">Envoyer à quel appareil ?</p>

              {/* What's being shared */}
              <div className="mt-3 inline-flex items-center gap-2 px-3 py-1.5 rounded-full bg-slate-800/50 text-xs text-slate-400">
                {fileCount > 0 && (
                  <span>
                    📎 {fileCount} {fileCount > 1 ? "fichiers" : "fichier"}
                  </span>
                )}
                {hasText && !fileCount && <span>💬 Texte</span>}
                {hasText && fileCount > 0 && <span>+ texte</span>}
              </div>
            </>
          )}
        </header>

        {/* Peer list — tap to send immediately */}
        {!sent && shared && (
          <section>
            {peers.length === 0 ? (
              <div className="flex flex-col items-center justify-center py-16 text-slate-500">
                <div className="text-5xl mb-4">📡</div>
                <p className="text-lg font-medium">En attente d'appareils...</p>
                <p className="text-sm mt-2 text-center max-w-xs">
                  Ouvrez AnyDrop sur l'appareil destinataire.
                </p>
              </div>
            ) : (
              <div className="flex flex-wrap justify-center gap-6 py-8">
                <PeerList onPeerSelect={handlePeerSelect} />
              </div>
            )}
          </section>
        )}

        {/* Footer */}
        <footer className="text-center text-xs text-slate-600 mt-12">
          <p>Peer-to-peer · Chiffré · Aucun fichier ne transite par le serveur</p>
        </footer>
      </div>
    </div>
  );
}