feat: add self-contained link composer

- Add structured URL codec with compact alphabets and dictionary support.
- Add public decode, redirect, and QR endpoints for composed links.
- Add authenticated encode API and link composer UI.
- Generate PNG QR codes via qrcode with Pillow support.
- Register the new blueprint and navigation entry.
- Cover public decode, auth gating, redirect URL parsing, and QR output.
- Bump NanoShare to 1.27.0 and lock new dependencies.

templates/side/elements/navigation.htm

@@ -9,6 +9,8 @@
   <ul id="nav-list">
     <li><a href="{{ url_for('side_main.index') }}">NanoShare</a></li>
 
+    <li><a href="{{ url_for('link_composer.link_composer_page') }}">Links</a></li>
+
     {% if user %}
       <li><a href="{{ url_for('side_main.index') }}">Upload</a></li>
       <li><a href="{{ url_for('side_main.files_list') }}">Files</a></li>

templates/side/views/webpage/links/composer.htm

@@ -0,0 +1,218 @@
+{% extends "base.htm" %}
+
+{% block title %}NanoShare - Link Composer{% endblock %}
+
+{% block meta %}
+  <meta name="description" content="Encode, decode and QR-share self-contained NanoShare links.">
+  <meta name="robots" content="noindex, nofollow" />
+{% endblock %}
+
+{% block content %}
+  <main class="wrap link-composer">
+    <section class="card hero-card">
+      <span class="hero-badge"><i class="fa-solid fa-link"></i> Link Composer</span>
+      <h1 class="title">Encode, decode and QR links</h1>
+      <p class="subtitle">Decode is public. Log in to create compressed links and QR codes.</p>
+    </section>
+
+    <section class="composer-grid {% if not can_encode %}is-single{% endif %}">
+      {% if can_encode %}
+      <section class="card composer-card">
+        <div class="card-heading">
+          <h2>Encode</h2>
+        </div>
+
+        <label for="compose-url">URL</label>
+        <textarea id="compose-url" placeholder="https://example.com/docs?page=1"></textarea>
+        <label class="switch-row">
+          <input id="qr-mode" type="checkbox">
+          QR alphabet mode
+        </label>
+        <div class="actions-row">
+          <button id="encode-btn" class="btn" type="button">Encode URL</button>
+          <button id="clear-btn" class="btn btn-ghost" type="button">Clear</button>
+        </div>
+        <div id="encode-error" class="form-error"></div>
+      </section>
+      {% endif %}
+
+      <section class="card composer-card">
+        <div class="card-heading">
+          <h2>Decode</h2>
+        </div>
+        <label for="compose-code">Code or redirect link</label>
+        <textarea id="compose-code" placeholder="u... or https://example.com/l/u..."></textarea>
+        {% if can_encode %}
+          <div class="switch-row switch-row-spacer" aria-hidden="true">&nbsp;</div>
+        {% endif %}
+        <div class="actions-row">
+          <button id="decode-btn" class="btn" type="button">Decode Code</button>
+          {% if not can_encode %}
+            <a class="btn btn-ghost" href="{{ url_for('auth_login.login') }}">Login to encode</a>
+          {% endif %}
+        </div>
+        <div id="decode-error" class="form-error"></div>
+      </section>
+    </section>
+
+    <section id="result-panel" class="card result-panel">
+      <div class="card-heading">
+        <h2>Result</h2>
+        <span id="mode-badge" class="badge">structured</span>
+      </div>
+
+      <div class="result-grid">
+        <div class="result-main">
+          <div class="output-block">
+            <span class="output-label">Compressed code</span>
+            <div class="copy-field">
+              <code id="out-code"></code>
+              <button class="btn btn-ghost mini" type="button" data-copy="out-code">Copy</button>
+            </div>
+          </div>
+
+          <div class="output-block">
+            <span class="output-label">Redirect link</span>
+            <div class="copy-field">
+              <code id="out-redirect"></code>
+              <button class="btn btn-ghost mini" type="button" data-copy="out-redirect">Copy</button>
+            </div>
+          </div>
+
+          <div class="output-block">
+            <span class="output-label">Decoded URL</span>
+            <div class="copy-field">
+              <code id="out-url"></code>
+              <button class="btn btn-ghost mini" type="button" data-copy="out-url">Copy</button>
+            </div>
+          </div>
+
+          <div class="stats-grid">
+            <div class="stat-card"><strong id="stat-original">–</strong><span>Original</span></div>
+            <div class="stat-card"><strong id="stat-code">–</strong><span>Code</span></div>
+            <div class="stat-card"><strong id="stat-ratio">–</strong><span>Ratio</span></div>
+            <div class="stat-card"><strong id="stat-bits">–</strong><span>Bits</span></div>
+          </div>
+        </div>
+
+        <div class="qr-card">
+          <img id="qr-image" alt="Generated QR code">
+          <div class="actions-row centered">
+            <a id="qr-open" class="btn btn-ghost" target="_blank" rel="noreferrer">Open PNG</a>
+            <a id="qr-download" class="btn" download="nanoshare-link-qr.png">Download PNG</a>
+          </div>
+        </div>
+      </div>
+    </section>
+  </main>
+{% endblock %}
+
+{% block script %}
+  <script>
+    const canEncode = {{ 'true' if can_encode else 'false' }};
+    const encodeApiUrl = {{ encode_api_url | tojson }};
+    const decodeApiUrl = {{ decode_api_url | tojson }};
+    const redirectPrefix = {{ redirect_prefix | tojson }};
+    const qrPrefix = {{ qr_prefix | tojson }};
+    const $ = (id) => document.getElementById(id);
+
+    function setError(id, message) {
+      const el = $(id);
+      el.textContent = message || '';
+      el.classList.toggle('visible', Boolean(message));
+    }
+
+    function setText(id, value) {
+      $(id).textContent = value || '';
+    }
+
+    async function postJson(path, body) {
+      const response = await fetch(path, {
+        method: 'POST',
+        headers: { 'content-type': 'application/json' },
+        body: JSON.stringify(body),
+      });
+      const data = await response.json();
+      if (!response.ok || data.ok === false) throw new Error(data.error || data.detail || 'Request failed');
+      return data;
+    }
+
+    function showResult(data) {
+      setText('out-code', data.code || $('compose-code').value.trim());
+      setText('out-url', data.url);
+      setText('out-redirect', data.redirect_url || `${location.origin}${redirectPrefix}${encodeURIComponent(data.code || $('compose-code').value.trim())}`);
+      setText('stat-original', data.original_length ?? '–');
+      setText('stat-code', data.code_length ?? ((data.code || '').length || '–'));
+      setText('stat-ratio', data.ratio ?? '–');
+      setText('stat-bits', data.bit_length ?? '–');
+      setText('mode-badge', data.mode || 'decoded');
+
+      const code = data.code || $('compose-code').value.trim();
+      if (code) {
+        const qrUrl = data.qr_url || `${location.origin}${qrPrefix}${encodeURIComponent(code)}`;
+        $('qr-image').src = qrUrl;
+        $('qr-open').href = qrUrl;
+        $('qr-download').href = qrUrl;
+      }
+      $('result-panel').classList.add('visible');
+    }
+
+    $('encode-btn')?.addEventListener('click', async () => {
+      if (!canEncode) return;
+      setError('encode-error', '');
+      try {
+        const data = await postJson(encodeApiUrl, { url: $('compose-url').value, qr: $('qr-mode').checked });
+        $('compose-code').value = data.code;
+        showResult(data);
+      } catch (error) {
+        setError('encode-error', error.message);
+      }
+    });
+
+    function extractCode(value) {
+      const trimmed = value.trim();
+      try {
+        const url = new URL(trimmed);
+        const fullPath = url.pathname + url.search + url.hash;
+        if (fullPath.startsWith(redirectPrefix)) return decodeURIComponent(fullPath.slice(redirectPrefix.length));
+        if (fullPath.startsWith(qrPrefix)) return decodeURIComponent(fullPath.slice(qrPrefix.length));
+      } catch (_) {}
+      return trimmed;
+    }
+
+    $('decode-btn').addEventListener('click', async () => {
+      setError('decode-error', '');
+      try {
+        const input = $('compose-code').value.trim();
+        const code = extractCode(input);
+        const data = await postJson(decodeApiUrl, { code: input });
+        showResult({
+          ...data,
+          code,
+          redirect_url: `${location.origin}${redirectPrefix}${encodeURIComponent(code)}`,
+          qr_url: `${location.origin}${qrPrefix}${encodeURIComponent(code)}`,
+          mode: 'decoded',
+        });
+      } catch (error) {
+        setError('decode-error', error.message);
+      }
+    });
+
+    $('clear-btn')?.addEventListener('click', () => {
+      $('compose-url').value = '';
+      $('compose-code').value = '';
+      $('result-panel').classList.remove('visible');
+      setError('encode-error', '');
+      setError('decode-error', '');
+    });
+
+    document.addEventListener('click', async (event) => {
+      const button = event.target.closest('[data-copy]');
+      if (!button) return;
+      await navigator.clipboard.writeText($(button.dataset.copy).textContent);
+      const old = button.textContent;
+      button.textContent = 'Copied';
+      setTimeout(() => button.textContent = old, 900);
+    });
+  </script>
+{% endblock %}

templates/static/css/style.css

@@ -48,9 +48,14 @@
 }
 
 /* Globale Stile */
-html, body {
-  height: -webkit-fill-available;
-  height: 100%;
+html {
+  min-height: 100%;
+  background: var(--bg);
+}
+
+body {
+  min-height: 100vh;
+  min-height: 100dvh;
   display: flex;
   flex-direction: column;
   font-family: Arial, sans-serif;
@@ -300,6 +305,8 @@ body{
     radial-gradient(1200px 600px at 10% -10%, rgba(124,158,255,.18), transparent 60%),
     radial-gradient(900px 500px at 110% 10%, rgba(142,246,255,.18), transparent 60%),
     var(--bg);
+  background-attachment: fixed;
+  background-repeat: no-repeat;
   font:500 14px/1.5 system-ui,-apple-system,Segoe UI,Inter,Roboto,"Helvetica Neue",Arial,"Noto Sans","Apple Color Emoji","Segoe UI Emoji";
 }
 
@@ -528,6 +535,40 @@ input[type="file"]{display:none}
 .toast.show{display:flex;animation:pop .18s ease-out}
 @keyframes pop{from{transform:translateY(8px);opacity:0}to{transform:translateY(0);opacity:1}}
 
+/* ====== Link Composer ====== */
+.link-composer{max-width:1400px;width:min(1400px, calc(100% - 32px));padding:clamp(18px,2.6vw,34px)}
+.link-composer .hero-card{margin-bottom:22px;padding:clamp(24px,3vw,36px)}
+.link-composer .composer-card,.link-composer .result-panel{padding:clamp(24px,3vw,36px)}
+.composer-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:24px;margin-bottom:24px}
+.composer-grid.is-single{grid-template-columns:1fr}
+@media (max-width:860px){.composer-grid{grid-template-columns:1fr}}
+.composer-card textarea{
+  width:100%;height:190px;min-height:190px;resize:vertical;border-radius:14px;border:1px solid var(--border);
+  background:color-mix(in srgb,var(--panel) 88%, transparent);color:var(--text);padding:16px 18px;
+}
+.composer-card textarea:focus{outline:none;border-color:color-mix(in srgb,var(--accent) 50%, var(--border));box-shadow:0 0 0 3px color-mix(in srgb,var(--accent) 25%, transparent)}
+.composer-card textarea:disabled,.composer-card button:disabled{opacity:.55;cursor:not-allowed}
+.card-heading{display:flex;justify-content:space-between;gap:12px;align-items:center;margin-bottom:14px}
+.card-heading h2{margin:0;font-size:1.25rem}
+.badge-warning{color:#ffd37a;background:rgba(255,211,122,.12);border-color:rgba(255,211,122,.35)}
+.notice{display:grid;gap:4px;margin:10px 0 16px;padding:12px;border:1px solid rgba(255,211,122,.35);border-radius:12px;background:rgba(255,211,122,.08);color:var(--muted)}
+.switch-row{display:flex;align-items:center;gap:10px;margin:12px 0;color:var(--muted);font-weight:700}
+.switch-row-spacer{visibility:hidden;pointer-events:none}
+.switch-row input{accent-color:var(--accent)}
+.actions-row{display:flex;gap:12px;flex-wrap:wrap;margin-top:18px}.actions-row.centered{justify-content:center}
+.form-error{display:none;margin-top:12px;padding:12px;border-radius:12px;border:1px solid rgba(255,122,122,.45);background:rgba(255,122,122,.10);color:#ffd5d5}.form-error.visible{display:block}
+.result-panel{display:none}.result-panel.visible{display:block}
+.result-grid{display:grid;grid-template-columns:minmax(0,1fr) 320px;gap:24px;align-items:stretch}
+@media (max-width:820px){.result-grid{grid-template-columns:1fr}}
+.output-block{margin-top:12px}.output-label{display:block;color:var(--muted);font-size:.78rem;font-weight:800;text-transform:uppercase;letter-spacing:.08em;margin-bottom:7px}
+.copy-field{display:flex;gap:10px;align-items:center;justify-content:space-between;border:1px solid var(--border);border-radius:12px;background:rgba(0,0,0,.16);padding:10px 12px;overflow-wrap:anywhere}
+.copy-field code{font:700 .93rem ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;color:var(--text)}
+.btn.mini{padding:.4rem .6rem;font-size:.82rem;flex:0 0 auto}
+.stats-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:10px;margin-top:14px}
+@media (max-width:620px){.stats-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}
+.stat-card{border:1px solid var(--border);border-radius:12px;background:rgba(0,0,0,.16);padding:12px}.stat-card strong{display:block;font-size:1.15rem}.stat-card span{color:var(--muted);font-size:.82rem}
+.qr-card{display:flex;flex-direction:column;gap:12px;justify-content:space-between;align-items:center;border:1px solid var(--border);border-radius:14px;background:rgba(0,0,0,.12);padding:14px}.qr-card img{max-width:230px;width:100%;background:#fff;border-radius:12px;padding:10px}
+
 /* ====== Utilities ====== */
 .sr-only{
   position:absolute !important;width:1px;height:1px;padding:0;margin:-1px;