import * as vscode from 'vscode';
import * as fs from 'fs';
import * as path from 'path';
import { getToolWebviewStyles, singletonPanel } from './shared';

const store: { panel: vscode.WebviewPanel | null } = { panel: null };

export function openBase64Scanner(_context: vscode.ExtensionContext) {
  const { panel, isNew } = singletonPanel(store, 'hplToolbox.base64Scanner', 'Base64 Scanner');
  if (!isNew) return;

  panel.webview.html = getHtml();
  panel.webview.onDidReceiveMessage(async (msg) => {
    if (msg.type === 'ready') {
      const ws = vscode.workspace.workspaceFolders?.[0];
      if (ws) {
        const distPath = path.join(ws.uri.fsPath, 'dist');
        if (fs.existsSync(distPath) && fs.statSync(distPath).isDirectory()) {
          const files = await collectHtmlFiles(distPath);
          panel.webview.postMessage({ type: 'filesPicked', paths: files });
        }
      }
    } else if (msg.type === 'pickFolder') {
      const picked = await vscode.window.showOpenDialog({
        canSelectFolders: true,
        canSelectFiles: false,
        canSelectMany: false,
        openLabel: 'Select Folder',
      });
      if (picked && picked[0]) {
        const files = await collectHtmlFiles(picked[0].fsPath);
        panel.webview.postMessage({ type: 'filesPicked', paths: files });
      }
    } else if (msg.type === 'pickFiles') {
      const picked = await vscode.window.showOpenDialog({
        canSelectFolders: false,
        canSelectFiles: true,
        canSelectMany: true,
        openLabel: 'Select Files',
        filters: { 'HTML': ['html', 'htm'] },
      });
      if (picked && picked.length) {
        panel.webview.postMessage({ type: 'filesPicked', paths: picked.map(u => u.fsPath) });
      }
    } else if (msg.type === 'scan') {
      const folder: string | undefined = msg.folder;
      const files: string[] | undefined = msg.files;
      let targets: string[] = [];
      let baseDir = '';
      if (files && files.length) {
        targets = files.filter(f => fs.existsSync(f));
        baseDir = targets.length ? commonBaseDir(targets) : '';
      } else if (folder && fs.existsSync(folder)) {
        targets = await collectHtmlFiles(folder);
        baseDir = folder;
      } else {
        panel.webview.postMessage({ type: 'results', results: [], error: 'Pick a folder or files first' });
        return;
      }
      const results: { file: string; ok: boolean; assets: string[] }[] = [];
      for (const file of targets) {
        try {
          const content = fs.readFileSync(file, 'utf8');
          const offenders = findNonBase64Assets(content);
          const display = baseDir ? path.relative(baseDir, file) || path.basename(file) : file;
          results.push({ file: display, ok: offenders.length === 0, assets: offenders });
        } catch {
          // skip unreadable
        }
      }
      panel.webview.postMessage({ type: 'results', results });
    }
  });
}

function commonBaseDir(files: string[]): string {
  if (files.length === 0) return '';
  if (files.length === 1) return path.dirname(files[0]);
  const split = files.map(f => path.dirname(f).split(path.sep));
  const first = split[0];
  let i = 0;
  while (i < first.length && split.every(parts => parts[i] === first[i])) i++;
  return first.slice(0, i).join(path.sep);
}

async function collectHtmlFiles(root: string): Promise<string[]> {
  const out: string[] = [];
  const stack: string[] = [root];
  while (stack.length) {
    const dir = stack.pop()!;
    let entries: fs.Dirent[];
    try {
      entries = fs.readdirSync(dir, { withFileTypes: true });
    } catch {
      continue;
    }
    for (const e of entries) {
      const full = path.join(dir, e.name);
      if (e.isDirectory()) {
        if (e.name === 'node_modules' || e.name === '.git') continue;
        stack.push(full);
      } else if (e.isFile() && /\.html?$/i.test(e.name)) {
        out.push(full);
      }
    }
  }
  return out;
}

function findNonBase64Assets(html: string): string[] {
  const markup = html.replace(/<script\b[^>]*>[\s\S]*?<\/script>/gi, '');
  const offenders = new Set<string>();
  const attrRegex = /\b(?:src|href|poster|data-src)\s*=\s*("([^"]*)"|'([^']*)')/gi;
  let m: RegExpExecArray | null;
  while ((m = attrRegex.exec(markup)) !== null) {
    const url = (m[2] ?? m[3] ?? '').trim();
    if (!url) continue;
    if (isAssetReference(url) && !isBase64DataUri(url)) {
      offenders.add(url);
    }
  }
  const cssUrlRegex = /url\(\s*(?:"([^"]*)"|'([^']*)'|([^)]*))\s*\)/gi;
  while ((m = cssUrlRegex.exec(markup)) !== null) {
    const url = (m[1] ?? m[2] ?? m[3] ?? '').trim();
    if (!url) continue;
    if (!isBase64DataUri(url)) {
      offenders.add(url);
    }
  }
  return [...offenders];
}

function isBase64DataUri(url: string): boolean {
  return /^data:[^;,]*;base64,/i.test(url);
}

function isAssetReference(url: string): boolean {
  if (url.startsWith('#') || url.toLowerCase().startsWith('javascript:')) return false;
  if (/^(mailto:|tel:)/i.test(url)) return false;
  return true;
}

function getHtml(): string {
  return `<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<style>
${getToolWebviewStyles()}
  .asset-list { margin: 0; padding-left: 16px; }
  .asset-list li + li { margin-top: 3px; }
  .selected-list { margin-top: 8px; }
  .remove-selected {
    min-width: 28px;
    width: 28px;
    padding: 3px 0;
    color: var(--vscode-errorForeground);
    font-size: 16px;
    line-height: 1;
  }
  .pager { margin-top: 8px; display: flex; align-items: center; gap: 8px; justify-content: flex-end; }
</style>
</head>
<body>
<main class="tool-page">
  <header class="tool-header">
    <h2 class="tool-title">Base64 Scanner</h2>
    <p class="tool-description">Scan folders or selected HTML files for asset references that are not embedded as base64 data URIs.</p>
  </header>

  <section class="tool-panel input-panel">
    <div class="panel-header">
      <h3 class="panel-title">Inputs</h3>
    </div>
    <div class="panel-body">
      <div class="control-group">
        <div class="field-row">
          <input id="folder" type="hidden" />
          <button id="pick" class="secondary">Select Folder</button>
          <button id="pickFiles" class="secondary">Select File(s)</button>
          <button id="clear" class="secondary">Clear</button>
        </div>
        <div id="selection" class="selected-list"></div>
      </div>
      <div class="action-row">
        <button id="scan">Scan</button>
      </div>
      <div id="status" class="status-panel"></div>
    </div>
  </section>

  <div id="outputPanel" class="is-hidden">
    <div id="results" class="results-panel"></div>
  </div>
</main>
<script>
  const vscode = acquireVsCodeApi();
  vscode.postMessage({ type: 'ready' });
  const folderEl = document.getElementById('folder');
  const statusEl = document.getElementById('status');
  const resultsEl = document.getElementById('results');
  const outputPanel = document.getElementById('outputPanel');
  const selectionEl = document.getElementById('selection');
  const PAGE_SIZE = 5;
  let pickedFolder = '';
  let pickedFiles = [];
  let selectedPage = 0;

  function basename(p) {
    const i = Math.max(p.lastIndexOf('/'), p.lastIndexOf('\\\\'));
    return i >= 0 ? p.slice(i + 1) : p;
  }

  function escapeHtml(s) {
    return String(s).replace(/[&<>"']/g, c => ({'&':'&amp;','<':'&lt;','>':'&gt;','"':'&quot;',"'":'&#39;'}[c]));
  }

  function renderSelection() {
    const oldPager = document.getElementById('selectedPager');
    if (oldPager) oldPager.remove();
    const items = pickedFiles.length
      ? pickedFiles.map((p, i) => ({ label: basename(p), index: i, type: 'file' }))
      : (pickedFolder ? [{ label: pickedFolder, index: 0, type: 'folder' }] : []);
    if (!items.length) {
      selectionEl.innerHTML = '<span class="file-name">(no files selected)</span>';
      return;
    }
    const maxPage = Math.max(0, Math.ceil(items.length / PAGE_SIZE) - 1);
    selectedPage = Math.min(selectedPage, maxPage);
    const visibleItems = items.slice(selectedPage * PAGE_SIZE, selectedPage * PAGE_SIZE + PAGE_SIZE);
    selectionEl.innerHTML =
      '<div class="results-panel" style="margin-top:0;">' +
        '<table class="data-table">' +
          '<thead><tr><th>Filename</th><th style="width:44px;"></th></tr></thead>' +
          '<tbody>' +
          visibleItems.map(item =>
            '<tr><td class="mono wrap">' + escapeHtml(item.label) + '</td>' +
            '<td><button class="remove-selected danger" data-index="' + item.index + '" data-type="' + item.type + '" title="Remove">×</button></td></tr>'
          ).join('') +
        '</tbody></table>' +
      '</div>';
    selectionEl.querySelectorAll('.remove-selected').forEach(btn => {
      btn.addEventListener('click', () => {
        if (btn.dataset.type === 'folder') {
          pickedFolder = '';
          folderEl.value = '';
        } else {
          pickedFiles.splice(Number(btn.dataset.index), 1);
        }
        renderSelection();
      });
    });
    if (items.length > PAGE_SIZE) {
      const pager = document.createElement('div');
      pager.id = 'selectedPager';
      pager.className = 'pager';
      pager.innerHTML =
        '<button class="secondary" id="prevPage"' + (selectedPage === 0 ? ' disabled' : '') + '>Previous</button>' +
        '<span class="file-name">Page ' + (selectedPage + 1) + ' of ' + (maxPage + 1) + '</span>' +
        '<button class="secondary" id="nextPage"' + (selectedPage === maxPage ? ' disabled' : '') + '>Next</button>';
      selectionEl.appendChild(pager);
      pager.querySelector('#prevPage').addEventListener('click', () => { selectedPage--; renderSelection(); });
      pager.querySelector('#nextPage').addEventListener('click', () => { selectedPage++; renderSelection(); });
    }
  }

  renderSelection();

  document.getElementById('pick').addEventListener('click', () => {
    vscode.postMessage({ type: 'pickFolder' });
  });
  document.getElementById('pickFiles').addEventListener('click', () => {
    vscode.postMessage({ type: 'pickFiles' });
  });
  document.getElementById('clear').addEventListener('click', () => {
    folderEl.value = '';
    pickedFiles = [];
    pickedFolder = '';
    selectedPage = 0;
    renderSelection();
    statusEl.textContent = '';
    resultsEl.innerHTML = '';
    outputPanel.classList.add('is-hidden');
  });
  document.getElementById('scan').addEventListener('click', () => {
    statusEl.textContent = 'Scanning...';
    resultsEl.innerHTML = '';
    outputPanel.classList.add('is-hidden');
    if (pickedFiles.length) {
      vscode.postMessage({ type: 'scan', files: pickedFiles });
    } else {
      const folder = folderEl.value.trim();
      if (!folder) { statusEl.textContent = 'Pick a folder or files first.'; return; }
      vscode.postMessage({ type: 'scan', folder });
    }
  });

  window.addEventListener('message', (event) => {
    const msg = event.data;
    if (msg.type === 'folderPicked') {
      folderEl.value = msg.path;
      pickedFolder = msg.path;
      pickedFiles = [];
      selectedPage = 0;
      renderSelection();
    } else if (msg.type === 'filesPicked') {
      const existing = new Set(pickedFiles);
      pickedFiles = pickedFiles.concat((msg.paths || []).filter(p => !existing.has(p)));
      folderEl.value = '';
      pickedFolder = '';
      selectedPage = Math.max(0, Math.ceil(pickedFiles.length / PAGE_SIZE) - 1);
      renderSelection();
    } else if (msg.type === 'results') {
      if (msg.error) {
        statusEl.textContent = 'Error: ' + msg.error;
        outputPanel.classList.add('is-hidden');
        return;
      }
      const total = msg.results.length;
      const flagged = msg.results.filter(r => !r.ok).length;
      statusEl.textContent = 'Scanned ' + total + ' HTML file(s). ' + flagged + ' contain non-base64 assets.';
      if (!total) {
        resultsEl.innerHTML = '';
        outputPanel.classList.add('is-hidden');
        return;
      }
      outputPanel.classList.remove('is-hidden');
      resultsEl.innerHTML =
        '<table class="data-table">' +
          '<thead><tr><th style="width:90px;">Status</th><th>File</th><th style="width:90px;">Issues</th><th>Non-base64 assets</th></tr></thead>' +
          '<tbody></tbody>' +
        '</table>';
      const tbody = resultsEl.querySelector('tbody');
      for (const r of msg.results) {
        const row = document.createElement('tr');
        const status = document.createElement('td');
        status.innerHTML = r.ok ? '<span class="badge ok">OK</span>' : '<span class="badge err">Review</span>';
        const name = document.createElement('td');
        name.className = 'mono wrap';
        name.textContent = r.file;
        const count = document.createElement('td');
        count.textContent = String(r.assets.length);
        const assets = document.createElement('td');
        assets.className = 'wrap';
        if (!r.ok) {
          const list = document.createElement('ul');
          list.className = 'asset-list mono';
          r.assets.forEach(asset => {
            const item = document.createElement('li');
            item.textContent = asset;
            list.appendChild(item);
          });
          assets.appendChild(list);
        } else {
          assets.innerHTML = '<span class="muted">None</span>';
        }
        row.append(status, name, count, assets);
        tbody.appendChild(row);
      }
    }
  });
</script>
</body>
</html>`;
}