/* Offline reader. The public artifact is loaded by graph-data.js; no network calls. */
(() => {
  'use strict';
  const graph = window.RESEARCH_GRAPH;
  const $ = (id) => document.getElementById(id);
  if (!graph || !Array.isArray(graph.nodes) || !Array.isArray(graph.edges)) {
    $('results').replaceChildren(make('p', 'load-error', 'The public graph could not be loaded. Keep graph-data.js beside this reader, or inspect graph.json.'));
    return;
  }
  const nodes = graph.nodes, edges = graph.edges, regions = graph.regions || [], paths = graph.paths || [], evidence = graph.evidence || [];
  const documents = graph.documents || [], documentById = new Map(documents.map(d=>[d.id,d]));
  const nodeById = new Map(nodes.map(x => [x.id, x]));
  const regionById = new Map(regions.map(x => [x.id, x]));
  const pathById = new Map(paths.map(x => [x.id, x]));
  const evidenceById = new Map(evidence.map(x => [x.id, x]));
  const state = {mode:'nodes', query:'', regions:new Set(), match:'any', selected:null, path:null};
  const welcome = $('detail').firstElementChild.cloneNode(true);
  const kinds = {corpus_evidence:'Evidence paraphrase', reconstruction:'Reconstruction', retrospective_connection:'Retrospective connection', retrospective:'Retrospective connection', model_proposed:'Model proposal'};
  let noticeTimer;

  function make(tag, className, text) {
    const element = document.createElement(tag);
    if (className) element.className = className;
    if (text !== undefined && text !== null) element.textContent = text;
    return element;
  }
  function words(value) {
    if (value === undefined || value === null) return '';
    if (typeof value === 'string') return value;
    if (Array.isArray(value)) return value.map(words).filter(Boolean).join('\n');
    return Object.entries(value).map(([key, item]) => `${key.replaceAll('_', ' ')}: ${words(item)}`).join('\n');
  }
  function label(kind) { return kinds[kind] || String(kind || 'Reconstruction').replaceAll('_', ' '); }
  function badge(kind) { const e = make('span', 'status', label(kind)); e.dataset.kind = kind || 'reconstruction'; return e; }
  function hash(type, id, path) {
    const params = new URLSearchParams({[type]:id});
    if (path) params.set('path', path);
    return '#' + params.toString();
  }
  function link(text, type, id, className, path) {
    const e = make('a', className, text); e.href = hash(type, id, path); return e;
  }
  function section(title, content) {
    const e = make('section', 'detail-section'); e.append(make('h3', '', title));
    if (content) e.append(make('p', 'prose', words(content)));
    return e;
  }
  function evidenceChips(ids) {
    const e = make('div', 'inline-evidence');
    for (const id of ids || []) if (evidenceById.has(id)) e.append(link(id, 'evidence', id, 'evidence-chip'));
    return e;
  }
  function nodeRegions(node) {
    const ids = new Set(node.regions || []);
    for (const region of regions) if ((region.nodes || []).includes(node.id)) ids.add(region.id);
    return [...ids];
  }
  function matchesRegions(node) {
    if (!state.regions.size) return true;
    const available = nodeRegions(node);
    const checks = [...state.regions].map(id => available.includes(id));
    return state.match === 'all' ? checks.every(Boolean) : checks.some(Boolean);
  }
  function matchesQuery(value) {
    const haystack = words(value).toLocaleLowerCase();
    return state.query.toLocaleLowerCase().trim().split(/\s+/).every(term => haystack.includes(term));
  }
  function relevantNodes(item, type) {
    if (type === 'nodes') return [item];
    if (type === 'documents') return item.linked_nodes.map(id=>nodeById.get(id)).filter(Boolean);
    if (type === 'paths') return (item.steps || []).map(x => nodeById.get(x.node)).filter(Boolean);
    const ids = new Set(nodes.filter(n => (n.evidence || []).includes(item.id)).map(n => n.id));
    for (const edge of edges) if ((edge.evidence || []).includes(item.id)) { ids.add(edge.from); ids.add(edge.to); }
    return [...ids].map(id => nodeById.get(id)).filter(Boolean);
  }
  function listItems() {
    const items = state.mode === 'nodes' ? nodes : state.mode === 'paths' ? paths : state.mode === 'documents' ? documents : evidence;
    return items.filter(item => {
      const related = relevantNodes(item, state.mode);
      if (state.regions.size && !related.some(matchesRegions)) return false;
      if (matchesQuery(item)) return true;
      if (state.mode === 'nodes') return edges.some(e => (e.from === item.id || e.to === item.id) && matchesQuery(e));
      return false;
    });
  }
  function renderResults() {
    const items = listItems();
    document.querySelectorAll('[data-view]').forEach(b => b.setAttribute('aria-pressed', String(b.dataset.view === state.mode)));
    const noun = state.mode === 'nodes' ? 'problem' : state.mode === 'paths' ? 'path' : state.mode === 'documents' ? 'document' : 'evidence statement';
    $('results-count').textContent = `${items.length} ${noun}${items.length === 1 ? '' : 's'}`;
    $('filter-state').textContent = state.regions.size ? `${state.regions.size} region${state.regions.size === 1 ? '' : 's'} · ${state.match === 'all' ? 'intersection' : 'union'}` : '';
    const fragment = document.createDocumentFragment();
    for (const item of items) {
      const card = make('button', 'entry-card'); card.type = 'button';
      card.setAttribute('aria-current', String(state.selected === item.id));
      const meta = make('div', 'card-meta'); meta.append(badge(item.epistemic_kind), make('span', 'stable-id', item.id)); card.append(meta);
      if (state.mode === 'evidence') {
        card.append(make('h3', '', 'Editorial paraphrase'), make('p', '', words(item.statement)));
      } else {
        card.append(make('h3', '', item.title), make('p', '', words(item.question || item.purpose)));
        if (state.mode === 'nodes') card.append(make('div', 'card-regions', nodeRegions(item).map(id => regionById.get(id)?.title || id).join(' / ')));
        else card.append(make('div', 'card-regions', state.mode === 'documents' ? `${item.section_ids.length} sections · English` : `${(item.steps || []).length} steps`));
      }
      card.addEventListener('click', () => navigate(state.mode === 'nodes' ? 'node' : state.mode === 'paths' ? 'path' : state.mode === 'documents' ? 'document' : 'evidence', item.id));
      fragment.append(card);
    }
    if (!items.length) fragment.append(make('p', 'empty-state', 'No entries match this combination. Try fewer regions or a different search term.'));
    $('results').replaceChildren(fragment);
  }
  function renderRegions() {
    const fragment = document.createDocumentFragment();
    for (const region of regions) {
      const row = make('label', 'region-label');
      const input = make('input'); input.type = 'checkbox'; input.checked = state.regions.has(region.id);
      input.addEventListener('change', () => { input.checked ? state.regions.add(region.id) : state.regions.delete(region.id); renderResults(); });
      row.append(input, make('span', '', region.title), make('small', '', nodes.filter(n => nodeRegions(n).includes(region.id)).length));
      if (region.description) row.title = words(region.description);
      fragment.append(row);
    }
    $('regions').replaceChildren(fragment);
  }
  function notice(text) {
    clearTimeout(noticeTimer); $('notice').textContent = text; $('notice').classList.add('visible');
    noticeTimer = setTimeout(() => $('notice').classList.remove('visible'), 2600);
  }
  async function copyLink(type, id) {
    const url = location.href.split('#')[0] + hash(type, id);
    try {
      if (navigator.clipboard && window.isSecureContext) await navigator.clipboard.writeText(url);
      else {
        const textarea = make('textarea'); textarea.value = url; textarea.setAttribute('aria-label', 'Stable entry link');
        textarea.style.cssText = 'position:fixed;left:-9999px;top:0'; document.body.append(textarea); textarea.select();
        const copied = document.execCommand('copy'); textarea.remove();
        if (!copied) throw new Error('Clipboard unavailable');
      }
      notice('Stable link copied');
    } catch { notice('Copy the current address from your browser to share this entry.'); }
  }
  function detailTop(item, type) {
    const top = make('div', 'detail-top'), meta = make('div');
    meta.append(badge(item.epistemic_kind), make('span', 'stable-id', item.id));
    const button = make('button', 'copy-link', 'Copy link ↗'); button.type = 'button';
    button.addEventListener('click', () => copyLink(type, item.id)); top.append(meta, button); return top;
  }
  function renderEvidence(ids, title = 'Evidence paraphrases') {
    const s = section(title);
    s.append(make('p', 'evidence-note', 'These statements are editorial paraphrases of corpus evidence. They are not verbatim quotations or independent proof of a formulation.'));
    for (const id of ids || []) {
      const item = evidenceById.get(id); if (!item) continue;
      const card = make('div', 'evidence-item'); card.append(link(id, 'evidence', id), make('p', '', words(item.statement))); s.append(card);
    }
    if (!(ids || []).some(id => evidenceById.has(id))) s.append(make('p', 'evidence-note', 'No evidence statement is attached to this entry.'));
    return s;
  }
  function renderPathContext(node) {
    const path = pathById.get(state.path); if (!path) return null;
    const steps = path.steps || [], at = steps.findIndex(x => x.node === node.id); if (at < 0) return null;
    const box = make('div', 'path-context'); const p = make('p', '', 'Following: '); p.append(link(path.title, 'path', path.id)); box.append(p);
    const controls = make('div', 'path-controls');
    if (at > 0) controls.append(link('← Previous', 'node', steps[at - 1].node, '', path.id)); else controls.append(make('span', '', 'Beginning'));
    controls.append(make('span', '', `Step ${at + 1} of ${steps.length}`));
    if (at + 1 < steps.length) controls.append(link('Next →', 'node', steps[at + 1].node, '', path.id)); else controls.append(make('span', '', 'Path complete'));
    box.append(controls); return box;
  }
  function renderNode(node) {
    const fragment = document.createDocumentFragment();
    const context = renderPathContext(node); if (context) fragment.append(context);
    fragment.append(detailTop(node, 'node'), make('h2', '', node.title));
    const tags = make('div', 'region-tags');
    for (const id of nodeRegions(node)) {
      const tag = make('button', 'region-tag', regionById.get(id)?.title || id); tag.type = 'button';
      tag.title = 'Show problems in this region';
      tag.addEventListener('click', () => { state.regions = new Set([id]); state.mode = 'nodes'; state.query = ''; $('search').value = ''; renderRegions(); renderResults(); });
      tags.append(tag);
    }
    fragment.append(tags);
    if (node.question) fragment.append(make('p', 'question', words(node.question)));
    if (node.formulation) fragment.append(section('Working formulation', node.formulation));
    if (node.development) fragment.append(section(words(node.development).length < 40 ? 'Development state' : 'Development & revisions', words(node.development).replaceAll('_', ' ')));
    if (node.tension) fragment.append(section('Unresolved tension', node.tension));
    const additionalQuestions = [...new Set(node.open_questions || [])].filter(q => q !== node.question && q !== node.challenge);
    if (additionalQuestions.length) {
      const s = section('Open questions'), list = make('ul', 'prose');
      additionalQuestions.forEach(q => list.append(make('li', '', words(q)))); s.append(list); fragment.append(s);
    }
    if ((node.representations || []).length) {
      const s = section('Alternative representations');
      for (const representation of node.representations) {
        const block = make('div', 'representation'); block.append(make('h4', '', representation.name));
        if (representation.epistemic_kind && representation.epistemic_kind !== node.epistemic_kind) block.append(badge(representation.epistemic_kind));
        const facets = make('div', 'rep-facets');
        for (const [name, value] of [['What it makes available', representation.affords], ['What it leaves out', representation.loses]]) {
          const dl = make('dl'); dl.append(make('dt', '', name), make('dd', '', words(value))); facets.append(dl);
        }
        block.append(facets); s.append(block);
      }
      fragment.append(s);
    }
    if (node.challenge) { const s = section('Challenge this formulation'); const box = make('div', 'challenge-box'); box.append(make('p', 'prose', words(node.challenge))); s.append(box); fragment.append(s); }
    if (node.next_move) {
      const s = section('A possible next move'), box = make('div', 'proposal-box');
      box.append(badge(node.next_move.epistemic_kind || 'model_proposed'), make('p', '', words(node.next_move.text || node.next_move))); s.append(box); fragment.append(s);
    }
    fragment.append(renderEvidence(node.evidence));
    const related = edges.filter(e => e.from === node.id || e.to === node.id);
    const s = section(`Connections · ${related.length}`);
    for (const edge of related) {
      const outgoing = edge.from === node.id, otherId = outgoing ? edge.to : edge.from, other = nodeById.get(otherId);
      if (!other) continue;
      const card = make('div', 'relation-card');
      card.append(make('div', 'relation-direction', outgoing ? `From this problem → ${words(edge.relation).replaceAll('_', ' ')}` : `${words(edge.relation).replaceAll('_', ' ')} → into this problem`));
      card.append(link(other.title, 'node', other.id, 'relation-title'), badge(edge.epistemic_kind));
      if (edge.warrant) card.append(make('p', '', words(edge.warrant)));
      card.append(evidenceChips(edge.evidence)); s.append(card);
    }
    if (!related.length) s.append(make('p', 'evidence-note', 'No connection has yet been formulated.'));
    fragment.append(s);
    const editions = documents.filter(d=>d.linked_nodes.includes(node.id));
    if(editions.length){const ds=section('Research documents'),dl=make('div','backlinks');for(const d of editions)dl.append(link(d.title,'document',d.id));ds.append(dl);fragment.append(ds);}
    const containing = paths.filter(p => (p.steps || []).some(step => step.node === node.id));
    if (containing.length) { const s = section('Paths through this problem'), links = make('div', 'backlinks'); containing.forEach(p => links.append(link(p.title, 'path', p.id))); s.append(links); fragment.append(s); }
    $('detail').replaceChildren(fragment);
  }
  
  function inlineMarkdown(parent, text) {
    const re = /(\[([^\]]+)\]\(([^)]+)\)|\*\*([^*]+)\*\*|\x60([^\x60]+)\x60)/g;
    let at=0;
    for(const m of text.matchAll(re)){
      parent.append(document.createTextNode(text.slice(at,m.index)));
      if(m[2]){
        const target=documents.find(d=>d.path==='documents/'+m[3]||d.path===m[3]);
        if(target) parent.append(link(m[2],'document',target.id));
        else parent.append(document.createTextNode(m[2]));
      } else parent.append(make(m[4]?'strong':'code','',m[4]||m[5]));
      at=m.index+m[0].length;
    }
    parent.append(document.createTextNode(text.slice(at)));
  }
  function markdownBody(markdown) {
    const body=make('div','document-body'),lines=markdown.split('\n');
    let paragraph=[],list=null,pre=[],table=null,headingIndex=0;
    function flush(){if(paragraph.length){const p=make('p');inlineMarkdown(p,paragraph.join(' '));body.append(p);paragraph=[];}list=null;table=null;}
    function flushPre(){if(pre.length){body.append(make('pre','',pre.join('\n')));pre=[];}}
    for(const line of lines){
      if(line.startsWith('    ')){flush();pre.push(line.slice(4));continue;}
      flushPre();
      if(/^# /.test(line)){flush();continue;}
      const h=line.match(/^(#{2,4}) (.+)$/);
      if(h){flush();const e=make('h'+Math.min(h[1].length+1,5),'',h[2]);if(h[1].length===2)e.id='document-section-'+(++headingIndex);body.append(e);continue;}
      if(!line.trim()){flush();continue;}
      if(line.startsWith('|')){
        if(/^\|[\s:|-]+\|$/.test(line))continue;
        if(!table){flush();const wrap=make('div','document-table');table=make('table');wrap.append(table);body.append(wrap);}
        const tr=make('tr');for(const cell of line.split('|').slice(1,-1)){const td=make(table.children.length?'td':'th');inlineMarkdown(td,cell.trim());tr.append(td);}table.append(tr);continue;
      }
      const li=line.match(/^(?:- |(\d+)\. )(.+)$/);
      if(li){if(!list){flush();list=make(li[1]?'ol':'ul');body.append(list);}const el=make('li');inlineMarkdown(el,li[2]);list.append(el);continue;}
      if(line.startsWith('> ')){flush();const q=make('blockquote');inlineMarkdown(q,line.slice(2));body.append(q);continue;}
      paragraph.push(line);
    }
    flushPre();flush();return body;
  }
  function renderDocument(item){
    const f=document.createDocumentFragment();
    f.append(detailTop(item,'document'),make('h2','',item.title),make('p','evidence-note',item.editorial_scope));
    const download=make('button','copy-link','Download English Markdown ↓');download.type='button';
    download.addEventListener('click',()=>{const url=URL.createObjectURL(new Blob([item.markdown],{type:'text/markdown;charset=utf-8'}));const a=make('a');a.href=url;a.download=item.id+'.md';a.click();setTimeout(()=>URL.revokeObjectURL(url),1000);});
    f.append(download);
    const contents=make('details','document-contents');contents.append(make('summary','',item.section_ids.length+' sections · jump within the text'));
    const ol=make('ol');
    for(const s of graph.document_sections.filter(s=>s.document===item.id)){
      const li=make('li'),a=link(s.title,'document',item.id);a.href+='&section='+s.order;li.append(a);ol.append(li);
    }
    contents.append(ol);f.append(contents);
    f.append(markdownBody(item.markdown));
    const related=section('Related problems');
    for(const l of graph.document_links.filter(l=>l.document===item.id)){
      const p=make('p');p.append(link(nodeById.get(l.node).title,'node',l.node),document.createTextNode(' · '+label(l.epistemic_kind)));related.append(p);
    }
    f.append(related,renderEvidence(item.context_evidence,'Contextual evidence anchors'));
    f.append(make('p','evidence-note','Context links locate related formulations. The edition is not a new independent witness for each anchor.'));
    $('detail').replaceChildren(f);
  }

  function renderPath(path) {
    const fragment = document.createDocumentFragment(); fragment.append(detailTop(path, 'path'), make('h2', '', path.title), make('p', 'prose', words(path.purpose)));
    if (path.caution) fragment.append(make('p', 'evidence-note', words(path.caution)));
    const list = make('ol', 'path-steps');
    for (const step of path.steps || []) {
      const node = nodeById.get(step.node); if (!node) continue;
      const li = make('li'); li.append(link(node.title, 'node', node.id, '', path.id), make('p', '', words(step.reason))); list.append(li);
    }
    fragment.append(section('A route, open to revision')); fragment.lastChild.append(list); $('detail').replaceChildren(fragment);
  }
  function renderEvidenceDetail(item) {
    const fragment = document.createDocumentFragment(); fragment.append(detailTop(item, 'evidence'), make('h2', '', 'Evidence statement'));
    fragment.append(make('p', 'evidence-note', 'Editorial paraphrase of corpus evidence. This is not a verbatim quotation or an independently verified result.'));
    fragment.append(make('p', 'question', words(item.statement)));
    const used = nodes.filter(n => (n.evidence || []).includes(item.id));
    const s = section('Formulations drawing on this statement'), links = make('div', 'backlinks');
    used.forEach(n => links.append(link(n.title, 'node', n.id))); s.append(links);
    if (!used.length) s.append(make('p', 'evidence-note', 'No problem directly cites this statement. It may support a connection or research direction.'));
    fragment.append(s);
    const relations = edges.filter(e => (e.evidence || []).includes(item.id));
    if (relations.length) {
      const s = section('Connections drawing on this statement');
      for (const edge of relations) {
        const card = make('div', 'relation-card');
        if (nodeById.has(edge.from)) card.append(link(nodeById.get(edge.from).title, 'node', edge.from));
        card.append(make('p', '', `→ ${words(edge.relation).replaceAll('_', ' ')} →`));
        if (nodeById.has(edge.to)) card.append(link(nodeById.get(edge.to).title, 'node', edge.to));
        card.append(make('p', '', words(edge.warrant)), badge(edge.epistemic_kind)); s.append(card);
      }
      fragment.append(s);
    }
    $('detail').replaceChildren(fragment);
  }
  function navigate(type, id) { const target = hash(type, id); if (location.hash === target) readRoute(true); else location.hash = target; }
  function readRoute(focus = false) {
    const params = new URLSearchParams(location.hash.slice(1));
    const type = params.has('node') ? 'node' : params.has('path') ? 'path' : params.has('evidence') ? 'evidence' : params.has('document') ? 'document' : null;
    if (!type) {
      state.selected = null; state.path = null;
      $('detail').replaceChildren(welcome.cloneNode(true));
      document.title = graph.title || 'Research problem-space';
      renderResults(); return;
    }
    const id = params.get(type); const item = (type === 'node' ? nodeById : type === 'path' ? pathById : type === 'document' ? documentById : evidenceById).get(id);
    if (!item) { $('detail').replaceChildren(make('h2', '', 'Entry not found'), make('p', 'prose', 'This identifier is not present in this version of the research space. Use the problem list to find a current formulation.')); state.selected = null; renderResults(); return; }
    state.selected = id; state.mode = type === 'node' ? 'nodes' : type === 'path' ? 'paths' : type === 'document' ? 'documents' : 'evidence'; state.path = type === 'node' ? params.get('path') : null;
    if (type === 'node') renderNode(item); else if (type === 'path') renderPath(item); else if(type === 'document') renderDocument(item); else renderEvidenceDetail(item);
    renderResults(); $('detail').scrollTop = 0;
    if (focus) { $('detail').focus({preventScroll:true}); if (matchMedia('(max-width:620px)').matches) $('detail').scrollIntoView({block:'start',behavior:'instant'}); }
    if(type==='document' && params.has('section')){const sectionId='document-section-'+Number(params.get('section'));requestAnimationFrame(()=>{const target=document.getElementById(sectionId);if(target)target.scrollIntoView({block:'start'});});}
    document.title = `${item.title || 'Evidence statement'} · ${graph.title || 'Research problem-space'}`;
  }

  $('artifact-title').textContent = graph.title || 'Research problem-space';
  document.title = graph.title || 'Research problem-space';
  $('artifact-version').textContent = `EVOLVING RESEARCH PROBLEM-SPACE${graph.version ? ` / ${graph.version}` : ''}`;
  if (graph.intention?.statement) {
    $('intention-text').textContent = words(graph.intention.statement);
    $('intention-kind').textContent = label(graph.intention.epistemic_kind);
    $('intention-evidence').append(evidenceChips(graph.intention.evidence));
  } else $('intention-section').hidden = true;
  $('document-count').textContent = documents.length;
  $('node-count').textContent = nodes.length; $('path-count').textContent = paths.length; $('evidence-count').textContent = evidence.length;
  $('search').addEventListener('input', event => { state.query = event.target.value; renderResults(); });
  $('region-match').addEventListener('change', event => { state.match = event.target.value; renderResults(); });
  $('clear-filters').addEventListener('click', () => { state.regions.clear(); state.query = ''; $('search').value = ''; renderRegions(); renderResults(); });
  document.querySelectorAll('[data-view]').forEach(button => button.addEventListener('click', () => { state.mode = button.dataset.view; renderResults(); }));
  window.addEventListener('hashchange', () => readRoute(true));
  if (matchMedia('(max-width:860px)').matches) document.querySelector('.region-filter').open = false;
  renderRegions(); renderResults(); readRoute(false);
})();