Unenforced character count in frontend

frontend/static/new-entry.js

@@ -16,11 +16,14 @@
   const refetchTitleButton = document.getElementById('refetch-title-button');
   const submitButton = document.getElementById('submit-button');
   const submitStatus = document.getElementById('submit-status');
+  const characterCount = document.getElementById('character-count');
 
   const token = localStorage.getItem('linklogAccessToken');
   let availableTags = [];
   let selectedTags = new Set();
   let currentUser = null;
+  let maxPostCharacters = 500;
+  let mastodonPostPrefix = 'From my #LinkLog: ';
 
   // Utility function to add status messages; splits on \n into real <br> line breaks without using innerHTML.
   function setStatus(statusEl, message, isError = false) {
@@ -53,7 +56,7 @@
     .then((user) => {
       currentUser = user;
       entryForm.classList.remove('hidden');
-      Promise.all([loadTags(), loadMastodonPublishing()]);
+      Promise.all([loadTags(), loadMastodonPublishing(), loadConfig()]).then(updateCharacterCount);
     })
     .catch(() => {
       localStorage.removeItem('linklogAccessToken');
@@ -61,6 +64,17 @@
       entryForm.classList.add('hidden');
     });
 
+  async function loadConfig() {
+    try {
+      const response = await fetch('/api/public/config');
+      if (!response.ok) throw new Error('Could not load config');
+      const config = await response.json();
+      if (config.max_post_characters) maxPostCharacters = config.max_post_characters;
+    } catch (error) {
+      console.error('Could not load config:', error);
+    }
+  }
+
   // Load available tags
   async function loadTags() {
     try {
@@ -82,11 +96,63 @@
       const config = await response.json();
       mastodonEnabledCheckbox.checked = Boolean(config.configured);
       mastodonPublishing.classList.toggle('hidden', !config.configured);
+      if (config.post_prefix) {
+        mastodonPostPrefix = config.post_prefix;
+      } else if (config.hashtag) {
+        mastodonPostPrefix = `#${String(config.hashtag).trim().replace(/^#/, '')} `;
+      }
     } catch (error) {
       console.error('Could not load Mastodon configuration:', error);
     }
   }
 
+  // Collect the selected checkbox tags plus any typed new tags, mirroring the submit-time logic.
+  function collectTags() {
+    const tags = Array.from(selectedTags);
+    const newTags = newTagsInput.value.trim();
+    if (newTags) {
+      tags.push(...newTags.split(',').map((t) => t.trim()).filter(Boolean));
+    }
+    return tags;
+  }
+
+  // Format a UTC timestamp the same way the Mastodon plugin does, so the estimated post length matches the server.
+  function formatMastodonTimestamp(date) {
+    const months = [
+      'January', 'February', 'March', 'April', 'May', 'June',
+      'July', 'August', 'September', 'October', 'November', 'December',
+    ];
+    const pad = (value) => String(value).padStart(2, '0');
+    return `${date.getUTCFullYear()} ${months[date.getUTCMonth()]} ${pad(date.getUTCDate())} - ${pad(date.getUTCHours())}:${pad(date.getUTCMinutes())}`;
+  }
+
+  // Estimate the assembled Mastodon post length, mirroring backend/app/services/plugin_manager.py.
+  function estimatePostLength() {
+    const title = titleInput.value.trim();
+    const comment = commentInput.value.trim();
+    const url = removeKnownTrackingParams(urlInput.value.trim());
+    const parts = [mastodonPostPrefix.trim()];
+    if (title) parts.push(title);
+    if (comment) parts.push(comment);
+    if (title) parts.push(`Logged on ${formatMastodonTimestamp(new Date())} UTC from: ${url}`);
+    const tags = collectTags();
+    if (tags.length) parts.push(tags.join(' '));
+    return parts.join('\n\n').length;
+  }
+
+  function updateCharacterCount() {
+    const length = estimatePostLength();
+    const overLimit = length > maxPostCharacters;
+    characterCount.textContent = overLimit
+      ? `${length}/${maxPostCharacters} characters - exceeds the Mastodon post limit by ${length - maxPostCharacters}`
+      : `${length}/${maxPostCharacters} characters`;
+    characterCount.classList.toggle('over-limit', overLimit);
+  }
+
+  [urlInput, titleInput, commentInput, newTagsInput].forEach((input) => {
+    input.addEventListener('input', updateCharacterCount);
+  });
+
   // Render tag checkboxes
   function renderTags() {
     existingTagsEl.innerHTML = '';
@@ -104,6 +170,7 @@
         } else {
           selectedTags.delete(tag);
         }
+        updateCharacterCount();
       });
 
       label.appendChild(checkbox);
@@ -224,22 +291,13 @@
     const url = removeKnownTrackingParams(urlInput.value.trim());
     const title = titleInput.value.trim();
     const comment = commentInput.value.trim();
-    const newTags = newTagsInput.value.trim();
 
     if (!url || !title) {
       setStatus(submitStatus, 'URL and title are required', true);
       return;
     }
 
-    // Combine selected tags and new tags
-    const tags = Array.from(selectedTags);
-    if (newTags) {
-      const newTagsList = newTags
-        .split(',')
-        .map((t) => t.trim())
-        .filter((t) => t);
-      tags.push(...newTagsList);
-    }
+    const tags = collectTags();
 
     submitButton.disabled = true;
     setStatus(submitStatus, 'Saving...', false);