import fs from 'node:fs';
import path from 'node:path';
import { buildHealthAssessSummary } from './health-assess-summary.mjs';
import { buildHealthTimeline } from './health-timeline.mjs';
import { buildMindSpacePublicUrlForUser } from './mindspace-runtime-config.mjs';
import { resolvePublishDir } from './user-publish.mjs';
import { looksLikeHealthReportPageRequest } from './health-channel-aliases.mjs';

export { looksLikeHealthReportPageRequest } from './health-channel-aliases.mjs';

/** 健康页落盘目录：remote MindSpace 交付时须与 MINDSPACE_SERVICE_H5_ROOT 一致。 */
export function resolveHealthMaterializeH5Root(portalH5Root = process.cwd(), env = process.env) {
  const portalRoot = path.resolve(portalH5Root);
  const adapter = String(env.MINDSPACE_SERVER_ADAPTER ?? 'local').trim().toLowerCase();
  if (adapter === 'local') return portalRoot;
  const sharedRoot = String(
    env.MINDSPACE_SERVICE_H5_ROOT
    ?? env.MEMIND_SHARED_PUBLISH_ROOT
    ?? env.GOOSED_SANDBOX_PUBLISH_ROOT
    ?? '',
  ).trim();
  if (sharedRoot) {
    const resolved = path.resolve(sharedRoot);
    if (fs.existsSync(resolved)) return resolved;
  }
  return portalRoot;
}

export const HEALTH_REPORT_PAGE_PREFIX = 'health-report';
export const HEALTH_REPORT_FILENAME_PATTERN = /^health-report-\d{4}-\d{2}-\d{2}\.html$/i;
export const HEALTH_PUBLIC_HTML_PATTERN = /^public\/health-[a-z0-9-]+\.html$/i;

export function writeHealthPublicHtmlPage({
  h5Root = process.cwd(),
  userId,
  relativePath,
  html,
  minSize = 64,
} = {}) {
  if (!userId || !relativePath || !html) {
    const error = Object.assign(new Error('缺少写入参数'), { code: 'invalid_input' });
    throw error;
  }
  const clean = String(relativePath).replace(/^\/+/, '');
  if (!HEALTH_PUBLIC_HTML_PATTERN.test(clean)) {
    const error = Object.assign(new Error('健康页路径不合法'), { code: 'invalid_health_page_path' });
    throw error;
  }
  const publishDir = resolvePublishDir(h5Root, { id: String(userId) });
  const absolutePath = path.join(publishDir, clean);
  fs.mkdirSync(path.dirname(absolutePath), { recursive: true });
  fs.writeFileSync(absolutePath, html, 'utf8');
  if (!fs.existsSync(absolutePath) || fs.statSync(absolutePath).size < minSize) {
    const error = Object.assign(new Error('健康页写入失败'), { code: 'health_page_write_failed' });
    throw error;
  }
  return {
    relativePath: clean,
    absolutePath,
    size: fs.statSync(absolutePath).size,
  };
}

export function defaultHealthReportFilename(now = Date.now()) {
  const date = new Date(now);
  const y = date.getFullYear();
  const m = String(date.getMonth() + 1).padStart(2, '0');
  const d = String(date.getDate()).padStart(2, '0');
  return `${HEALTH_REPORT_PAGE_PREFIX}-${y}-${m}-${d}.html`;
}

function escapeHtml(value) {
  return String(value ?? '')
    .replace(/&/g, '&amp;')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;');
}

function formatMetricLines(timeline) {
  return timeline.slice(0, 14).flatMap((day) => {
    const metrics = Object.values(day.metrics ?? {})
      .map((item) => `${item.label} ${item.value}`)
      .join('；');
    if (!metrics) return [];
    return [`${day.date}：${metrics}`];
  });
}

export function buildHealthReportHtml(observations = [], { now = Date.now(), title = '本人健康报告' } = {}) {
  const timeline = buildHealthTimeline(observations, { limitDays: 30 });
  const summary = buildHealthAssessSummary(observations, { now });
  const metricLines = formatMetricLines(timeline);
  const generatedAt = new Date(now).toISOString().slice(0, 10);

  const sections = [
    `<section><h2>概况</h2><pre class="block">${escapeHtml(summary)}</pre></section>`,
  ];
  if (metricLines.length > 0) {
    sections.push(
      `<section><h2>近 14 日记录</h2><ul>${metricLines
        .map((line) => `<li>${escapeHtml(line)}</li>`)
        .join('')}</ul></section>`,
    );
  }
  sections.push(
    '<section><h2>说明</h2><p>本页基于你<strong>确认过</strong>的健康记录生成，仅供本人回顾，'
      + '不构成医疗诊断。如有不适请及时就医。</p></section>',
  );

  return `<!DOCTYPE html>
<html lang="zh-CN">
<head>
  <meta charset="utf-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1" />
  <meta name="robots" content="noindex,nofollow" />
  <title>${escapeHtml(title)}</title>
  <style>
    body { font-family: system-ui, sans-serif; max-width: 46rem; margin: 2rem auto; padding: 0 1rem; color: #1f2937; line-height: 1.65; }
    h1 { font-size: 1.45rem; margin-bottom: 0.25rem; }
    h2 { font-size: 1.05rem; margin: 1.5rem 0 0.5rem; }
    .meta { color: #6b7280; font-size: 0.92rem; margin-bottom: 1.25rem; }
    pre.block { white-space: pre-wrap; background: #f9fafb; border: 1px solid #e5e7eb; border-radius: 8px; padding: 0.85rem 1rem; font-family: inherit; font-size: 0.95rem; }
    ul { padding-left: 1.2rem; }
    .footer { margin-top: 2rem; font-size: 0.85rem; color: #9ca3af; }
  </style>
</head>
<body>
  <h1>${escapeHtml(title)}</h1>
  <p class="meta">生成日期：${escapeHtml(generatedAt)} · MeMind Health · 加密健康档案区</p>
  ${sections.join('\n  ')}
  <p class="footer">禁止完全公开；外部访问须口令或登录。</p>
</body>
</html>`;
}

export function writeHealthReportPage({
  h5Root = process.cwd(),
  userId,
  observations = [],
  now = Date.now(),
  filename = null,
} = {}) {
  if (!userId) {
    const error = Object.assign(new Error('缺少 userId'), { code: 'invalid_input' });
    throw error;
  }
  const relativePath = `public/${filename ?? defaultHealthReportFilename(now)}`;
  if (!HEALTH_REPORT_FILENAME_PATTERN.test(path.posix.basename(relativePath))) {
    const error = Object.assign(new Error('健康报告文件名不合法'), { code: 'invalid_health_report_filename' });
    throw error;
  }
  const html = buildHealthReportHtml(observations, { now });
  const written = writeHealthPublicHtmlPage({
    h5Root,
    userId,
    relativePath,
    html,
  });
  return written;
}

export function healthReportPageExists(h5Root, userId, relativePath) {
  const clean = String(relativePath ?? '').replace(/^\/+/, '');
  if (!clean.startsWith('public/') || !HEALTH_REPORT_FILENAME_PATTERN.test(path.posix.basename(clean))) {
    return false;
  }
  const publishDir = resolvePublishDir(h5Root, { id: String(userId) });
  const target = path.join(publishDir, clean);
  return fs.existsSync(target) && fs.statSync(target).isFile() && fs.statSync(target).size >= 64;
}

export function buildHealthReportPublicUrl({
  h5Root = process.cwd(),
  env = process.env,
  userId,
  username = null,
  relativePath,
} = {}) {
  return buildMindSpacePublicUrlForUser({
    h5Root,
    env,
    user: { id: userId, username },
    relativePath,
  });
}