function createUnfiledCaptures({
  storage,
  attachmentStore = null,
  getCaptureLogin = () => '',
  getCurrentLogin = () => '',
  createId = () => globalThis.crypto?.randomUUID?.() || String(Date.now()) + '-' + Math.random().toString(16).slice(2),
  now = () => Date.now(),
  maxItems = 20,
}) {
  const storageKey = 'stackchain.unfiled-issues.v1';

  function read() {
    try {
      const record = JSON.parse(storage?.getItem(storageKey) || 'null');
      if (record?.version !== 1 || !Array.isArray(record.items)) return [];
      return record.items.filter(item =>
        item && typeof item.id === 'string' && typeof item.ownerLogin === 'string' &&
        typeof item.title === 'string' && item.title.trim() && typeof item.body === 'string'
      );
    } catch (_error) { return []; }
  }

  function write(items) {
    storage?.setItem(storageKey, JSON.stringify({version:1, items}));
  }

  function list() {
    const currentLogin = String(getCurrentLogin() || '').trim();
    return read().slice().sort((left, right) => Number(right.savedAt) - Number(left.savedAt))
      .map(item => ({...item, quarantined: !currentLogin || currentLogin !== item.ownerLogin}));
  }

  function capacity() {
    const items = read().slice().sort((left, right) => Number(right.savedAt) - Number(left.savedAt));
    return {full:items.length >= maxItems, count:items.length, maxItems, oldest:items.at(-1) || null};
  }

  function prepare(note) {
    const title = String(note?.title || '').trim().slice(0, 255);
    const body = String(note?.body || '').trim().slice(0, 10000);
    if (!title) throw new Error('Add a title before saving.');
    const ownerLogin = String(getCaptureLogin() || '').trim();
    if (!ownerLogin) throw new Error('Offline identity is unavailable. Reconnect once before saving private work.');
    const attachment = note?.attachment;
    const hasAttachment = Boolean(attachment?.blob && attachment?.filename &&
      ['image/png', 'image/jpeg', 'image/webp'].includes(String(attachment?.contentType || '')));
    if (attachment && !hasAttachment) throw new Error('The screenshot is unavailable. Choose it again before saving.');
    if (hasAttachment && !attachmentStore) {
      throw new Error('Screenshot storage is unavailable. Your capture is still open; retry after reloading.');
    }
    return {title, body, ownerLogin, attachment, hasAttachment};
  }

  function persist(prepared, existing, removed = null) {
    const item = {
      id:String(createId()), ownerLogin:prepared.ownerLogin, title:prepared.title, body:prepared.body,
      savedAt:Number(now()), ...(prepared.hasAttachment ? {hasAttachment:true} : {}),
    };
    const items = [item, ...existing.filter(candidate => candidate.id !== item.id)];
    const writeItems = () => {
      try { write(items); }
      catch (error) {
        if (prepared.hasAttachment) Promise.resolve(attachmentStore.delete(item.id)).catch(() => {});
        throw error;
      }
      return item;
    };
    const stage = prepared.hasAttachment
      ? Promise.resolve(attachmentStore.put(item.id, {
        filename:String(prepared.attachment.filename).slice(0, 255),
        contentType:String(prepared.attachment.contentType), blob:prepared.attachment.blob,
      }))
      : null;
    if (!stage && !removed?.hasAttachment) return writeItems();
    return Promise.resolve(stage).then(async () => {
      if (!removed?.hasAttachment) return writeItems();
      const removedAttachment = await attachmentStore.get(removed.id);
      try {
        await attachmentStore.delete(removed.id);
      } catch (error) {
        if (prepared.hasAttachment) await Promise.resolve(attachmentStore.delete(item.id)).catch(() => {});
        throw error;
      }
      try { return writeItems(); }
      catch (error) {
        if (removedAttachment) await Promise.resolve(attachmentStore.put(removed.id, removedAttachment)).catch(() => {});
        throw error;
      }
    });
  }

  function save(note) {
    const prepared = prepare(note);
    const existing = read();
    if (existing.length >= maxItems) throw new Error('Drafts full — nothing was deleted.');
    return persist(prepared, existing);
  }

  function replaceOldest(note, expectedOldestId) {
    const prepared = prepare(note);
    const existing = read().slice().sort((left, right) => Number(right.savedAt) - Number(left.savedAt));
    const oldest = existing.at(-1);
    if (existing.length < maxItems || !oldest || oldest.id !== expectedOldestId) {
      throw new Error('Drafts changed. Review them before replacing anything.');
    }
    return persist(prepared, existing.filter(item => item.id !== oldest.id), oldest);
  }

  function discard(id) {
    const items = read();
    const remaining = items.filter(item => item.id !== id);
    if (remaining.length === items.length) return false;
    const removed = items.find(item => item.id === id);
    if (!removed?.hasAttachment) {
      write(remaining);
      return true;
    }
    return Promise.resolve(attachmentStore?.get(id)).then(removedAttachment =>
      Promise.resolve(attachmentStore?.delete(id)).then(async () => {
        try { write(remaining); }
        catch (error) {
          if (removedAttachment) await Promise.resolve(attachmentStore?.put(id, removedAttachment)).catch(() => {});
          throw error;
        }
        return true;
      })
    );
  }

  function resume(id, confirmedLogin) {
    const item = read().find(candidate => candidate.id === id);
    if (!item) throw new Error('This capture is no longer available.');
    if (!confirmedLogin || String(confirmedLogin).trim() !== item.ownerLogin) {
      throw new Error('Reconnect with the account that saved this capture.');
    }
    const draft = {repository:'', title:item.title, body:item.body, labelIds:[]};
    if (!item.hasAttachment) return draft;
    if (!attachmentStore) throw new Error('The saved screenshot is unavailable. Retry after reloading.');
    return Promise.resolve(attachmentStore.get(id)).then(attachment => {
      if (!attachment?.blob || !attachment?.filename || !attachment?.contentType) {
        throw new Error('The saved screenshot is unavailable. Keep this Draft and retry.');
      }
      return {...draft, attachment};
    });
  }

  function completeResume(id) { return discard(id); }

  return {list, capacity, save, replaceOldest, discard, resume, completeResume};
}

if (typeof module !== 'undefined' && module.exports) module.exports = createUnfiledCaptures;