import { assetPath, privateImageBlob, hydrateImage, transientImageUrl, revokeImageUrl } from '../generatedImages.js';
import { captureSharingOwner, assertSharingOwner, validSharingOwner, sharingFilename } from './sharing.js';
import { escapeAttr } from './citations.js';

export function createAssistantImageStore() {
  var generatedImages = {};
  var generatedImageSeq = 0;
  var previewClose = null;

  function renderGeneratedImage(src, alt, downloadUrl) {
    var id = 'img-' + (++generatedImageSeq);
    generatedImages[id] = { src: src, downloadUrl: downloadUrl || (assetPath(src) ? src + '?download=1' : '') };
    return '<div class="assistant-generated-image"><img src="' + escapeAttr(src) + '" alt="' + escapeAttr(alt || 'Generated image') + '">' +
      '<div class="assistant-image-actions">' +
      '<button type="button" class="btn-sm btn-ghost" data-assistant-open-image="' + escapeAttr(id) + '"><i class="fas fa-expand"></i> Preview</button>' +
      '<button type="button" class="btn-sm btn-ghost" data-assistant-download-image="' + escapeAttr(id) + '"><i class="fas fa-download"></i> Download</button>' +
      '</div></div>';
  }

  function openImagePreview(id) {
    var item = generatedImages[id];
    var src = item && (item.src || item);
    if (!src) return;
    var owner;
    try { owner = captureSharingOwner(); } catch (e) { return; }
    closeImagePreview();
    var modal = document.createElement('div');
    modal.className = 'assistant-image-modal';
    modal.setAttribute('role', 'dialog');
    modal.setAttribute('aria-modal', 'true');
    modal.innerHTML = '<div class="assistant-image-modal-card"><button type="button" class="assistant-image-modal-close" aria-label="Close">&times;</button><img src="' + escapeAttr(assetPath(src) ? '' : src) + '" alt="Generated clinical visual"><button type="button" class="assistant-image-modal-cancel">Close preview</button></div>';
    function close() {
      modal.remove();
      owner.signal.removeEventListener('abort', close);
      document.removeEventListener('keydown', keyHandler);
      if (previewClose === close) {
        previewClose = null;
        document.body.classList.remove('assistant-image-preview-open');
      }
    }
    function keyHandler(event) { if (event.key === 'Escape') close(); }
    previewClose = close;
    owner.signal.addEventListener('abort', close, { once: true });
    modal.addEventListener('click', function (event) {
      if (event.target === modal || event.target.closest('.assistant-image-modal-close') || event.target.closest('.assistant-image-modal-cancel')) close();
    });
    document.addEventListener('keydown', keyHandler);
    document.body.appendChild(modal);
    document.body.classList.add('assistant-image-preview-open');
    if (assetPath(src)) hydrateImage(modal.querySelector('img'), src, owner).catch(function(e) {
      if (!validSharingOwner(owner) || e.name === 'AbortError') { close(); return; }
      modal.querySelector('img').alt = 'Private image unavailable';
    });
  }

  function closeImagePreview() {
    if (previewClose) previewClose();
  }

  async function downloadImage(id) {
    var item = generatedImages[id];
    var src = item && (item.src || item);
    var downloadUrl = item && item.downloadUrl;
    if (!src) return;
    try {
      var ticket = captureSharingOwner();
      if (downloadUrl) {
        await downloadFromServer(downloadUrl, ticket);
        assertSharingOwner(ticket);
        return;
      }
      var saved = await saveWithNativeShare(src, ticket);
      assertSharingOwner(ticket);
      if (saved) return;
      if (isNativeApp()) {
        if (typeof window.showToast === 'function') window.showToast('Image saving is not available in this app build yet. Update the app and try again.', 'error');
        return;
      }
      if (isMobileBrowser()) {
        if (typeof window.showToast === 'function') window.showToast('Mobile browser download is not supported here. Use Preview and long-press the image to save it.', 'info');
        return;
      }
      await downloadWithBrowser(src, ticket);
      assertSharingOwner(ticket);
    } catch (e) {
      if (!validSharingOwner(ticket) || e.name === 'AbortError') return;
      if (typeof window.showToast === 'function') window.showToast(e.message || 'Image download failed', 'error');
    }
  }

  function clear() {
    generatedImages = {};
    closeImagePreview();
  }

  return {
    renderGeneratedImage: renderGeneratedImage,
    openImagePreview: openImagePreview,
    downloadImage: downloadImage,
    closeImagePreview: closeImagePreview,
    clear: clear
  };
}

async function saveWithNativeShare(src, ticket) {
  assertSharingOwner(ticket);
  if (isNativeApp()) {
    var nativeSaved = await saveWithNativeImageBridge(src, ticket);
    assertSharingOwner(ticket);
    if (nativeSaved) return true;
  } else {
    var webShare = await shareWithWebFile(src, ticket);
    assertSharingOwner(ticket);
    if (webShare !== 'unavailable') return true;
  }
  var saved = await saveWithCapacitorShare(src, ticket);
  assertSharingOwner(ticket);
  return saved;
}

async function saveWithNativeImageBridge(src, ticket) {
  assertSharingOwner(ticket);
  if (!window.NativeFiles || typeof window.NativeFiles.saveImage !== 'function') return false;
  try {
    var base64 = await imageSourceToBase64(src, ticket);
    assertSharingOwner(ticket);
    var name = sharingFilename('clinical-visual', 'png');
    var result = String(window.NativeFiles.saveImage(name, base64) || '');
    assertSharingOwner(ticket);
    if (result.indexOf('saved:') === 0) {
      if (typeof window.showToast === 'function') window.showToast('Image saved to Photos', 'success');
      return true;
    }
    if (result.indexOf('error:') === 0 && typeof window.showToast === 'function') {
      window.showToast(result.slice(6) || 'Native image save failed', 'error');
    }
  } catch (e) {
    assertSharingOwner(ticket);
    if (e.name === 'AbortError') throw e;
    if (typeof window.showToast === 'function') window.showToast(e.message || 'Native image save failed', 'error');
  }
  return false;
}

async function saveWithCapacitorShare(src, ticket) {
  assertSharingOwner(ticket);
  var plugins = window.Capacitor && window.Capacitor.Plugins ? window.Capacitor.Plugins : null;
  if (!plugins) return false;
  if (!plugins.Filesystem && plugins.Share && !/^data:image\//i.test(src)) {
    try {
      assertSharingOwner(ticket);
      await plugins.Share.share({ title: 'Clinical visual', text: 'Clinical Assistant generated visual', url: src, dialogTitle: 'Save or share clinical visual' });
      assertSharingOwner(ticket);
      return true;
    } catch (e) {
      assertSharingOwner(ticket);
      if (e.name === 'AbortError') throw e;
      return isShareCancel(e);
    }
  }
  if (!plugins.Filesystem) return false;
  try {
    var base64 = await imageSourceToBase64(src, ticket);
    assertSharingOwner(ticket);
    var name = sharingFilename('clinical-visual', 'png');
    var saved = await plugins.Filesystem.writeFile({ path: name, data: base64, directory: 'CACHE' });
    assertSharingOwner(ticket);
    if (plugins.Share && saved && saved.uri) {
      try {
        assertSharingOwner(ticket);
        await plugins.Share.share({ title: 'Clinical visual', text: 'Clinical Assistant generated visual', url: saved.uri, dialogTitle: 'Save or share clinical visual' });
        assertSharingOwner(ticket);
      } catch (e) {
        assertSharingOwner(ticket);
        if (e.name === 'AbortError') throw e;
        if (!isShareCancel(e)) throw e;
      }
    }
    if (typeof window.showToast === 'function') window.showToast('Image prepared', 'success');
    return true;
  } catch (e) {
    assertSharingOwner(ticket);
    if (e.name === 'AbortError') throw e;
    if (typeof window.showToast === 'function') window.showToast('Could not save with the app. Use Preview and long-press the image to save it.', 'error');
    return false;
  }
}

async function shareWithWebFile(src, ticket) {
  assertSharingOwner(ticket);
  if (!navigator.share || !navigator.canShare || typeof File === 'undefined') return 'unavailable';
  try {
    var blob = await imageSourceToBlob(src, ticket);
    assertSharingOwner(ticket);
    var file = new File([blob], 'clinical-visual.png', { type: blob.type || 'image/png' });
    if (!navigator.canShare({ files: [file] })) return 'unavailable';
    assertSharingOwner(ticket);
    await navigator.share({ files: [file], title: 'Clinical visual', text: 'Clinical Assistant generated visual' });
    assertSharingOwner(ticket);
    return 'shared';
  } catch (e) {
    assertSharingOwner(ticket);
    if (e.name === 'AbortError') throw e;
    return 'unavailable';
  }
}

async function downloadWithBrowser(src, ticket) {
  assertSharingOwner(ticket);
  if (isMobileBrowser()) {
    if (typeof window.showToast === 'function') window.showToast('Mobile browser download is not supported here. Use Preview and long-press the image to save it.', 'info');
    return;
  }
  var blob = await imageSourceToBlob(src, ticket);
  assertSharingOwner(ticket);
  var objectUrl = transientImageUrl(blob, ticket);
  var a = document.createElement('a');
  a.href = objectUrl;
  a.download = 'clinical-visual.png';
  a.rel = 'noopener';
  document.body.appendChild(a);
  a.click();
  a.remove();
  setTimeout(function() { revokeImageUrl(objectUrl); }, 60000);
}

async function downloadFromServer(url, ticket) {
  assertSharingOwner(ticket);
  var blob;
  if (assetPath(url)) {
    blob = await privateImageBlob(url, ticket);
    assertSharingOwner(ticket);
  } else {
    var response = await fetch(url, { headers: authHeadersForDownload(), credentials: 'same-origin', signal: ticket.signal });
    assertSharingOwner(ticket);
    if (!response.ok) throw new Error('Image download failed');
    blob = await response.blob();
    assertSharingOwner(ticket);
  }
  var name = sharingFilename('clinical-visual', 'png');
  var saved = await saveBlobWithNativeImageBridge(blob, name, ticket);
  assertSharingOwner(ticket);
  if (saved) return;
  saved = await saveBlobWithCapacitorShare(blob, name, ticket);
  assertSharingOwner(ticket);
  if (saved) return;
  saved = await shareBlobWithWebFile(blob, name, ticket);
  assertSharingOwner(ticket);
  if (saved) return;
  if (isMobileBrowser()) {
    if (typeof window.showToast === 'function') window.showToast('Could not start download here. Use Preview and long-press the image to save it.', 'error');
    return;
  }
  assertSharingOwner(ticket);
  downloadBlobWithAnchor(blob, name, ticket);
}

function authHeadersForDownload() {
  var headers = window.getAuthHeaders ? window.getAuthHeaders() : {};
  var clean = {};
  Object.keys(headers || {}).forEach(function(key) {
    if (key.toLowerCase() !== 'content-type') clean[key] = headers[key];
  });
  return clean;
}

async function saveBlobWithNativeImageBridge(blob, name, ticket) {
  assertSharingOwner(ticket);
  if (!window.NativeFiles || typeof window.NativeFiles.saveImage !== 'function') return false;
  try {
    var base64 = await blobToBase64(blob, ticket);
    assertSharingOwner(ticket);
    var result = String(window.NativeFiles.saveImage(name, base64) || '');
    assertSharingOwner(ticket);
    if (result.indexOf('saved:') === 0) {
      if (typeof window.showToast === 'function') window.showToast('Image saved to Photos', 'success');
      return true;
    }
  } catch (e) {
    assertSharingOwner(ticket);
    if (e.name === 'AbortError') throw e;
  }
  return false;
}

async function saveBlobWithCapacitorShare(blob, name, ticket) {
  assertSharingOwner(ticket);
  var plugins = window.Capacitor && window.Capacitor.Plugins ? window.Capacitor.Plugins : null;
  if (!plugins || !plugins.Filesystem) return false;
  try {
    var base64 = await blobToBase64(blob, ticket);
    assertSharingOwner(ticket);
    var saved = await plugins.Filesystem.writeFile({ path: name, data: base64, directory: 'CACHE' });
    assertSharingOwner(ticket);
    if (plugins.Share && saved && saved.uri) {
      assertSharingOwner(ticket);
      await plugins.Share.share({ title: 'Clinical visual', text: 'Clinical Assistant generated visual', url: saved.uri, dialogTitle: 'Save or share clinical visual' });
      assertSharingOwner(ticket);
    }
    if (typeof window.showToast === 'function') window.showToast('Image prepared', 'success');
    return true;
  } catch (e) {
    assertSharingOwner(ticket);
    if (e.name === 'AbortError') throw e;
    return false;
  }
}

async function shareBlobWithWebFile(blob, name, ticket) {
  assertSharingOwner(ticket);
  if (!navigator.share || !navigator.canShare || typeof File === 'undefined') return false;
  try {
    var file = new File([blob], name, { type: blob.type || 'image/png' });
    if (!navigator.canShare({ files: [file] })) return false;
    assertSharingOwner(ticket);
    await navigator.share({ files: [file], title: 'Clinical visual', text: 'Clinical Assistant generated visual' });
    assertSharingOwner(ticket);
    return true;
  } catch (e) {
    assertSharingOwner(ticket);
    if (e.name === 'AbortError') throw e;
    return false;
  }
}

function downloadBlobWithAnchor(blob, name, ticket) {
  assertSharingOwner(ticket);
  var objectUrl = transientImageUrl(blob, ticket);
  var a = document.createElement('a');
  a.href = objectUrl;
  a.download = name;
  a.rel = 'noopener';
  document.body.appendChild(a);
  a.click();
  a.remove();
  setTimeout(function() { revokeImageUrl(objectUrl); }, 60000);
}

function isMobileBrowser() {
  return !isNativeApp() && /Android|iPhone|iPad|iPod|Mobile/i.test(navigator.userAgent || '');
}

function isNativeApp() {
  return !!(window.Capacitor && (!window.Capacitor.isNativePlatform || window.Capacitor.isNativePlatform()));
}

function isShareCancel(error) {
  var message = String(error && (error.message || error.name) || '').toLowerCase();
  return /cancel|abort|dismiss|user denied|share canceled/.test(message);
}

async function imageSourceToBase64(src, ticket) {
  assertSharingOwner(ticket);
  if (/^data:image\//i.test(src)) return src.split(',')[1] || '';
  var blob = await imageSourceToBlob(src, ticket);
  assertSharingOwner(ticket);
  var base64 = await blobToBase64(blob, ticket);
  assertSharingOwner(ticket);
  return base64;
}

async function blobToBase64(blob, ticket) {
  assertSharingOwner(ticket);
  return new Promise(function(resolve, reject) {
    var reader = new FileReader();
    reader.onload = function() {
      try { assertSharingOwner(ticket); resolve(String(reader.result || '').split(',')[1] || ''); } catch (e) { reject(e); }
    };
    reader.onerror = function() { reject(reader.error || new Error('Could not read image')); };
    reader.readAsDataURL(blob);
  });
}

async function imageSourceToBlob(src, ticket) {
  assertSharingOwner(ticket);
  if (/^data:image\//i.test(src)) {
    var parts = src.split(',');
    var meta = parts[0] || 'data:image/png;base64';
    var binary = atob(parts[1] || '');
    var bytes = new Uint8Array(binary.length);
    for (var i = 0; i < binary.length; i++) bytes[i] = binary.charCodeAt(i);
    return new Blob([bytes], { type: (meta.match(/data:([^;]+)/) || [])[1] || 'image/png' });
  }
  if (assetPath(src)) {
    var privateBlob = await privateImageBlob(src, ticket);
    assertSharingOwner(ticket);
    return privateBlob;
  }
  var response = await fetch(src, { credentials: 'omit', signal: ticket.signal });
  assertSharingOwner(ticket);
  if (!response.ok) throw new Error('Image download failed');
  var blob = await response.blob();
  assertSharingOwner(ticket);
  return blob;
}

export function buildContextualImagePrompt(request, lastAnswer) {
  var prompt = String(request || '').trim();
  if (!lastAnswer) return prompt;
  var answer = String(lastAnswer || '').replace(/\[\d+(?:\s*,\s*\d+)*\]/g, '').slice(0, 3000);
  return prompt + '\n\nUse this clinical answer as the required context. Do not switch topics or introduce unrelated scenes such as gardening. Create a medical teaching visual faithful to the answer. Do not include citations, reference numbers, footnotes, source lists, or named organizations; do not invent references.\n\nAnswer:\n' + answer;
}

export function isImageRequest(text) {
  text = String(text || '').trim();
  var visualNoun = /\b(image|photo|picture|visual|illustration|diagram|figure|flowchart|infographic)\b/i;
  return /^(image|photo|picture|visual|illustration|diagram|figure|flowchart|infographic)$/i.test(text) ||
    (/\b(show|see|display|view)\b/i.test(text) && visualNoun.test(text) && text.split(/\s+/).length <= 8) ||
    /\b(generate|create|draw|make|render)\b[\s\S]{0,80}\b(image|picture|illustration|visual|infographic|diagram|flowchart)\b/i.test(text) ||
    /\b(generate|create|draw|make|render)\b[\s\S]{0,80}\b(an?|the)?\s*(algorithm|pathway|poster|teaching visual)\b/i.test(text);
}