import fs from 'node:fs';
import path from 'node:path';
import { PUBLISH_KEY_UUID, PUBLISH_ROOT_DIR } from './user-publish.mjs';
import { normalizeWorkspaceRelativePath } from './mindspace-pages.mjs';

const LOCAL_HOST_PATTERN = /^(localhost|127\.0\.0\.1|\[::1\]|192\.168\.|10\.|100\.)/i;

export function resolvePublicRequestOrigin({ hostHeader = '', forwardedProto = '', protocol = 'http' } = {}) {
  const host = String(hostHeader ?? '').split(',')[0].trim();
  if (!host) return '';
  const fwdProto = String(forwardedProto ?? '').split(',')[0].trim();
  const isLocalHost = LOCAL_HOST_PATTERN.test(host);
  const resolvedProtocol = isLocalHost ? fwdProto || protocol || 'http' : 'https';
  return `${resolvedProtocol}://${host}`;
}

export function buildPublishedHtmlViewContext({
  origin = '',
  requestPath = '',
  filePath = '',
  thumbnailPngPathForSvg = (value) => value,
  fileExists = fs.existsSync,
} = {}) {
  const cleanPath = String(requestPath ?? '').split('?')[0].split('#')[0];
  const servedName = path.basename(String(filePath ?? ''));
  const urlLast = decodeURIComponent(cleanPath.split('/').filter(Boolean).pop() ?? '');
  const isImplicitIndex = urlLast.toLowerCase() !== servedName.toLowerCase();
  const pageUrl = !origin
    ? ''
    : `${origin}${isImplicitIndex && !cleanPath.endsWith('/') ? `${cleanPath}/` : cleanPath}`;
  const pageDirUrl = !origin
    ? ''
    : isImplicitIndex
      ? `${origin}${cleanPath.endsWith('/') ? cleanPath : `${cleanPath}/`}`
      : `${origin}${cleanPath.slice(0, cleanPath.lastIndexOf('/') + 1)}`;

  let fallbackImageUrl = '';
  const svgSibling = String(filePath ?? '').replace(/\.[^./]+$/, '.thumbnail.svg');
  if (pageDirUrl && fileExists(svgSibling)) {
    const pngName = path.basename(thumbnailPngPathForSvg(svgSibling));
    fallbackImageUrl = `${pageDirUrl}${pngName}`;
  }

  return {
    origin,
    cleanPath,
    pageUrl,
    pageDirUrl,
    fallbackImageUrl,
  };
}

export function parseMindSpacePublishFilePath(absoluteFilePath, h5Root) {
  const resolved = path.resolve(String(absoluteFilePath ?? ''));
  const publishRoot = path.resolve(h5Root, PUBLISH_ROOT_DIR);
  if (resolved !== publishRoot && !resolved.startsWith(`${publishRoot}${path.sep}`)) {
    return null;
  }
  const rest = resolved.slice(publishRoot.length + 1).split(path.sep).filter(Boolean);
  if (rest.length < 2) return null;
  const ownerKey = String(rest[0] ?? '').trim().toLowerCase();
  if (!PUBLISH_KEY_UUID.test(ownerKey)) return null;
  const relativePath = normalizeWorkspaceRelativePath(rest.slice(1).join('/'));
  if (!relativePath) return null;
  return { userId: ownerKey, relativePath };
}

export function buildMindSpacePageDataPayload({ pageId, accessMode = null } = {}) {
  const id = String(pageId ?? '').trim();
  if (!id) return null;
  const payload = { pageId: id };
  const mode = String(accessMode ?? '').trim();
  if (mode) payload.accessMode = mode;
  return payload;
}

export function injectMindSpacePageDataContext(html, context = {}) {
  const payload = buildMindSpacePageDataPayload(context);
  if (!payload) return String(html ?? '');
  let nextHtml = String(html ?? '');
  const serialized = JSON.stringify(payload).replace(/</g, '\\u003c');
  const escapedPageId = String(payload.pageId).replace(/"/g, '&quot;');
  const injection = [
    `<meta name="mindspace-page-data-page-id" content="${escapedPageId}">`,
    `<script>window.__MINDSPACE_PAGE_DATA__=${serialized};</script>`,
  ].join('\n');
  if (/<\/head>/i.test(nextHtml)) {
    return nextHtml.replace(/<\/head>/i, `${injection}\n</head>`);
  }
  if (/<body\b/i.test(nextHtml)) {
    return nextHtml.replace(/<body\b/i, `${injection}\n<body`);
  }
  return `${injection}\n${nextHtml}`;
}

export function injectPublishedPageDataContext(html, { pageSource = null, publication = null } = {}) {
  const pageId = String(pageSource?.pageId ?? publication?.pageId ?? '').trim();
  if (!pageId) return String(html ?? '');
  return injectMindSpacePageDataContext(html, {
    pageId,
    accessMode: publication?.accessMode ?? null,
  });
}

export const mindspacePublicPageContextInternals = {
  LOCAL_HOST_PATTERN,
};