function newIssueOperationId() {
  if (globalThis.crypto?.randomUUID) return globalThis.crypto.randomUUID();
  if (globalThis.crypto?.getRandomValues) {
    const bytes = new Uint8Array(16);
    globalThis.crypto.getRandomValues(bytes);
    return Array.from(bytes, byte => byte.toString(16).padStart(2, '0')).join('');
  }
  return String(Date.now()) + '-' + Math.random().toString(16).slice(2);
}

function normalizeSharedContent(value = {}) {
  const clean = input => String(input || '').replace(/\s+/g, ' ').trim();
  const text = String(value.text || '').trim().slice(0, 9500);
  const textSummary = clean(text);
  const sentence = (textSummary.match(/^.{1,80}?[.!?](?:\s|$)/)?.[0] || textSummary.slice(0, 80)).trim();
  const title = (clean(value.title) || sentence).slice(0, 240);
  const url = clean(value.url).slice(0, 2000);
  const body = text && url && text.includes(url) ? text : [text, url].filter(Boolean).join('\n\n');
  return { title, body };
}

function createIssueCapture({ fetchJson, storage, createOperationId = newIssueOperationId }) {
  const storageKey = 'stackchain.issue-capture.v1';
  const sharedStorageKey = 'stackchain.issue-share.v1';
  const followUpStorageKey = 'stackchain.issue-follow-up.v1';
  let pending = null;
  let duplicateRequest = 0;
  let repositorySearchRequest = 0;
  let blockerSearchRequest = 0;
  let duplicateState = {status: 'idle', key: '', candidates: []};
  let acknowledgedDuplicateKey = '';
  const repositoryPageRequests = new Map();
  const safeLabelIds = value => Array.from(new Set(
    (Array.isArray(value) ? value : []).filter(id => Number.isInteger(id) && id > 0)
  )).slice(0, 20);
  const safeBlockers = value => {
    const seen = new Set();
    return (Array.isArray(value) ? value : []).reduce((items, blocker) => {
      const repository = String(blocker?.repository || '').trim();
      const number = Number(blocker?.number);
      const key = repository + '#' + number;
      if (items.length >= 5 || seen.has(key) ||
          !/^[A-Za-z0-9_.-]+\/[A-Za-z0-9_.-]+$/.test(repository) ||
          !Number.isInteger(number) || number < 1) return items;
      seen.add(key);
      items.push({repository, number,
        title:String(blocker?.title || '').replace(/\s+/g, ' ').trim().slice(0, 255)});
      return items;
    }, []);
  };
  const emptyDraft = () => ({ repository: '', title: '', body: '', labelIds: [] });
  const safeMilestoneId = value => Number.isInteger(Number(value)) && Number(value) > 0 ? Number(value) : null;
  const safeDueDate = value => /^\d{4}-\d{2}-\d{2}$/.test(String(value || '')) ? String(value) : '';

  function loadStored() {
    try {
      const parsed = JSON.parse(storage.getItem(storageKey) || 'null');
      if (!parsed || typeof parsed !== 'object') return {...emptyDraft(), operationId: ''};
      const draft = {
        repository: String(parsed.repository || ''),
        title: String(parsed.title || ''),
        body: String(parsed.body || ''),
        labelIds: safeLabelIds(parsed.labelIds),
        operationId: String(parsed.operationId || '').slice(0, 128),
      };
      const milestoneId = safeMilestoneId(parsed.milestoneId);
      const dueDate = safeDueDate(parsed.dueDate);
      if (milestoneId !== null) draft.milestoneId = milestoneId;
      if (dueDate) draft.dueDate = dueDate;
      const blockers = safeBlockers(parsed.blockers);
      if (blockers.length) draft.blockers = blockers;
      return draft;
    } catch (_error) {
      return {...emptyDraft(), operationId: ''};
    }
  }

  function writeStored(record) {
    try { storage.setItem(storageKey, JSON.stringify(record)); }
    catch (_error) { /* Keep the form as the in-memory fallback. */ }
  }

  function saveDraft(draft) {
    const previous = loadStored();
    const safe = {
      repository: String(draft?.repository || ''),
      title: String(draft?.title || ''),
      body: String(draft?.body || ''),
      labelIds: safeLabelIds(draft?.labelIds),
    };
    const milestoneId = safeMilestoneId(draft?.milestoneId);
    const dueDate = safeDueDate(draft?.dueDate);
    if (milestoneId !== null) safe.milestoneId = milestoneId;
    if (dueDate) safe.dueDate = dueDate;
    const blockers = safeBlockers(draft?.blockers);
    if (blockers.length) safe.blockers = blockers;
    const unchanged = ['repository', 'title', 'body', 'milestoneId', 'dueDate']
      .every(key => (previous[key] || '') === (safe[key] || '')) &&
      JSON.stringify(previous.labelIds) === JSON.stringify(safe.labelIds) &&
      JSON.stringify(previous.blockers || []) === JSON.stringify(safe.blockers || []);
    writeStored({...safe, operationId: unchanged ? previous.operationId : ''});
    return safe;
  }

  function loadDraft() {
    const {operationId: _operationId, ...draft} = loadStored();
    return draft;
  }

  function clearDraft() {
    try { storage.removeItem(storageKey); }
    catch (_error) { /* Confirmed creation remains authoritative. */ }
  }

  function pendingSharedContent() {
    try {
      const parsed = JSON.parse(storage.getItem(sharedStorageKey) || 'null');
      if (!parsed || typeof parsed !== 'object') return null;
      const shared = normalizeSharedContent({title: parsed.title, text: parsed.body});
      return shared.title || shared.body ? shared : null;
    } catch (_error) {
      return null;
    }
  }

  function acceptSharedContent() {
    const shared = pendingSharedContent();
    if (!shared) return loadDraft();
    const accepted = saveDraft({...loadDraft(), ...shared});
    try { storage.removeItem(sharedStorageKey); }
    catch (_error) { /* Accepted content is already persisted as the issue draft. */ }
    return accepted;
  }

  function discardSharedContent() {
    try { storage.removeItem(sharedStorageKey); }
    catch (_error) { /* The existing issue draft remains authoritative. */ }
  }

  function stageSharedContent(value) {
    const shared = normalizeSharedContent(value);
    if (!shared.title && !shared.body) return {status: 'empty'};
    try { storage.setItem(sharedStorageKey, JSON.stringify(shared)); }
    catch (_error) { /* The caller can still use the in-page share payload. */ }
    const existing = loadDraft();
    if (existing.title || existing.body) return {status: 'conflict'};
    acceptSharedContent();
    return {status: 'ready'};
  }

  function pendingFollowUp() {
    try {
      const parsed = JSON.parse(storage.getItem(followUpStorageKey) || 'null');
      if (!parsed || typeof parsed !== 'object') return null;
      const repository = /^[A-Za-z0-9_.-]+\/[A-Za-z0-9_.-]+$/.test(String(parsed.repository || '')) ? String(parsed.repository) : '';
      const title = String(parsed.title || '').trim().slice(0, 240);
      const body = String(parsed.body || '').trim().slice(0, 9500);
      return title || body ? {repository, title, body, labelIds: []} : null;
    } catch (_error) { return null; }
  }

  function acceptFollowUp() {
    const followUp = pendingFollowUp();
    if (!followUp) return loadDraft();
    const accepted = saveDraft(followUp);
    try { storage.removeItem(followUpStorageKey); }
    catch (_error) { /* Accepted content is already persisted as the issue draft. */ }
    return accepted;
  }

  function discardFollowUp() {
    try { storage.removeItem(followUpStorageKey); }
    catch (_error) { /* The existing capture remains authoritative. */ }
  }

  function stageFollowUp(value) {
    const followUp = {repository: String(value?.repository || ''), title: String(value?.title || ''), body: String(value?.body || '')};
    if (!followUp.title && !followUp.body) return {status: 'empty'};
    try { storage.setItem(followUpStorageKey, JSON.stringify(followUp)); }
    catch (_error) { /* The in-page flow can still continue. */ }
    const existing = loadDraft();
    if (existing.title || existing.body) return {status: 'conflict'};
    acceptFollowUp();
    return {status: 'ready'};
  }

  function loadLabels(repository) {
    const encoded = String(repository || '').split('/').map(encodeURIComponent).join('/');
    const priorities = new Set(['p0', 'priority-high', 'critical']);
    return fetchJson('api/v1/repos/' + encoded + '/labels').then(labels =>
      (Array.isArray(labels) ? labels : []).slice().sort((left, right) => {
        const leftPriority = priorities.has(String(left?.name || '').toLowerCase());
        const rightPriority = priorities.has(String(right?.name || '').toLowerCase());
        return Number(rightPriority) - Number(leftPriority);
      })
    );
  }

  function loadMilestones(repository) {
    const encoded = String(repository || '').split('/').map(encodeURIComponent).join('/');
    return fetchJson('api/v1/repos/' + encoded + '/milestones').then(milestones =>
      Array.isArray(milestones) ? milestones : []
    );
  }

  function loadRepositoryPage(page) {
    const safePage = Math.max(1, Math.floor(Number(page) || 1));
    if (repositoryPageRequests.has(safePage)) return repositoryPageRequests.get(safePage);
    const request = fetchJson('api/v1/repositories?page=' + safePage + '&limit=50')
      .then(payload => ({
        items: Array.isArray(payload?.items) ? payload.items : [],
        page: Number(payload?.page) || safePage,
        total: Math.max(0, Number(payload?.total) || 0),
        has_more: payload?.has_more === true,
      }))
      .finally(() => repositoryPageRequests.delete(safePage));
    repositoryPageRequests.set(safePage, request);
    return request;
  }

  async function searchRepositories(value) {
    const query = String(value || '').trim().slice(0, 80);
    const request = ++repositorySearchRequest;
    if (query.length < 2) return {status: 'idle', items: []};
    try {
      const payload = await fetchJson(
        'api/v1/repositories/search?q=' + encodeURIComponent(query) + '&limit=20'
      );
      if (request !== repositorySearchRequest) return {status: 'stale', items: []};
      return {
        status: 'ready',
        items: Array.isArray(payload?.items) ? payload.items : [],
      };
    } catch (error) {
      if (request !== repositorySearchRequest) return {status: 'stale', items: []};
      return {status: 'failed', items: [], error};
    }
  }

  async function searchBlockers(value) {
    const query = String(value || '').trim().slice(0, 80);
    const request = ++blockerSearchRequest;
    if (query.length < 2) return {status:'idle', items:[]};
    try {
      const payload = await fetchJson('api/v1/search?q=' + encodeURIComponent(query) + '&limit=20');
      if (request !== blockerSearchRequest) return {status:'stale', items:[]};
      return {status:'ready', items:(Array.isArray(payload?.items) ? payload.items : [])
        .filter(item => item?.kind === 'issue' && item?.state === 'open').slice(0, 20)};
    } catch (error) {
      if (request !== blockerSearchRequest) return {status:'stale', items:[]};
      return {status:'failed', items:[], error};
    }
  }

  function duplicateKey(draft) {
    const repository = String(draft?.repository || '').trim();
    const title = String(draft?.title || '').replace(/\s+/g, ' ').trim();
    return { repository, title, key: repository + '\n' + title.toLowerCase() };
  }

  async function findDuplicates(draft) {
    const input = duplicateKey(draft);
    const request = ++duplicateRequest;
    if (!input.repository || input.title.length < 4) {
      duplicateState = {status: 'idle', key: input.key, candidates: []};
      return duplicateState;
    }
    try {
      const payload = await fetchJson('api/v1/search?q=' + encodeURIComponent(input.title) + '&limit=10');
      if (request !== duplicateRequest) return {status: 'stale', key: input.key, candidates: []};
      duplicateState = {
        status: 'ready',
        key: input.key,
        partial: payload?.partial === true,
        candidates: (Array.isArray(payload?.items) ? payload.items : []).filter(item =>
          item?.kind === 'issue' && item?.state === 'open' && item?.repository === input.repository
        ).slice(0, 3),
      };
      return duplicateState;
    } catch (error) {
      if (request !== duplicateRequest) return {status: 'stale', key: input.key, candidates: []};
      duplicateState = {status: 'failed', key: input.key, candidates: [], error};
      return duplicateState;
    }
  }

  function needsDuplicateAcknowledgement(draft) {
    const {key} = duplicateKey(draft);
    return duplicateState.status === 'ready' && duplicateState.partial !== true && duplicateState.key === key &&
      duplicateState.candidates.length > 0 && acknowledgedDuplicateKey !== key;
  }

  function acknowledgeDuplicates(draft) {
    const {key} = duplicateKey(draft);
    if (duplicateState.status === 'ready' && duplicateState.key === key && duplicateState.candidates.length) {
      acknowledgedDuplicateKey = key;
    }
  }

  function submit(draft) {
    if (pending) return pending;
    const saved = saveDraft(draft);
    const stored = loadStored();
    const operationId = stored.operationId || String(createOperationId()).slice(0, 128);
    writeStored({...saved, operationId});
    const repository = saved.repository.split('/').map(encodeURIComponent).join('/');
    pending = fetchJson('api/v1/repos/' + repository + '/issues', {
      method: 'POST',
      headers: {
        Accept: 'application/json', 'Content-Type': 'application/json',
        'Idempotency-Key': operationId,
      },
      body: JSON.stringify({
        title: saved.title, body: saved.body, label_ids: saved.labelIds,
        ...(saved.milestoneId ? {milestone_id: saved.milestoneId} : {}),
        ...(saved.dueDate ? {due_date: saved.dueDate + 'T23:59:59Z'} : {}),
      }),
    }).then(issue => {
      clearDraft();
      return issue;
    }).finally(() => { pending = null; });
    return pending;
  }

  return {
    saveDraft, loadDraft, clearDraft, loadLabels, loadMilestones, loadRepositoryPage,
    searchRepositories, searchBlockers, findDuplicates,
    needsDuplicateAcknowledgement, acknowledgeDuplicates, submit,
    stageSharedContent, pendingSharedContent, acceptSharedContent, discardSharedContent,
    stageFollowUp, pendingFollowUp, acceptFollowUp, discardFollowUp,
  };
}

createIssueCapture.normalizeSharedContent = normalizeSharedContent;

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