import fs from 'node:fs';
import path from 'node:path';
import { PAGE_TEMPLATE_SKILL_PREFIX, isPageTemplateSkill } from './skills-registry.mjs';

const PLACEHOLDER_PATTERN = /\{\{[A-Z0-9_]+\}\}/g;

export function resolvePageTemplateHtmlPath(skillName, h5Root = process.cwd()) {
  if (!isPageTemplateSkill(skillName)) return null;
  const templatesDir = path.join(h5Root, 'skills', skillName, 'templates');
  if (!fs.existsSync(templatesDir)) return null;
  const files = fs
    .readdirSync(templatesDir)
    .filter((name) => name.endsWith('.html'))
    .sort();
  if (!files.length) return null;
  return path.join(templatesDir, files[0]);
}

export function extractStyleBlock(html) {
  const match = String(html ?? '').match(/<style[^>]*>([\s\S]*?)<\/style>/i);
  return match?.[1] ?? '';
}

export function normalizeTemplateStyleFingerprint(styleText) {
  return String(styleText ?? '')
    .replace(PLACEHOLDER_PATTERN, 'VALUE')
    .replace(/#[0-9a-fA-F]{3,8}/g, 'VALUE')
    .replace(/url\(['"]?[^'")]+['"]?\)/g, 'url(VALUE)')
    .replace(/\s+/g, ' ')
    .trim();
}

export function extractStyleSelectors(styleText) {
  const selectors = new Set();
  const withoutComments = String(styleText ?? '').replace(/\/\*[\s\S]*?\*\//g, '');
  for (const chunk of withoutComments.split('}')) {
    const idx = chunk.lastIndexOf('{');
    if (idx <= 0) continue;
    const selectorPart = chunk.slice(0, idx).trim();
    if (!selectorPart || selectorPart.startsWith('@')) continue;
    for (const sel of selectorPart.split(',')) {
      const normalized = sel.trim().replace(/\s+/g, ' ');
      if (normalized) selectors.add(normalized);
    }
  }
  return selectors;
}

export function resolveSelectedPageTemplateSkill(messages) {
  for (let index = (Array.isArray(messages) ? messages.length : 0) - 1; index >= 0; index -= 1) {
    const message = messages[index];
    if (message?.role !== 'user') continue;
    const metadata = message?.metadata ?? {};
    const runMetadata = metadata.memindRun ?? metadata.agentRun ?? {};
    const skill = String(runMetadata.selectedChatSkill ?? metadata.selectedChatSkill ?? '').trim();
    if (isPageTemplateSkill(skill)) return skill;
  }
  return null;
}

export function buildPageTemplateMandatoryInstruction(skillName, h5Root = process.cwd()) {
  const templatePath = resolvePageTemplateHtmlPath(skillName, h5Root);
  const workspaceTemplatePath = templatePath
    ? `.agents/skills/${skillName}/templates/${path.basename(templatePath)}`
    : `.agents/skills/${skillName}/templates/*.html`;

  return [
    `【强制页面模板：${skillName}】`,
    `1. 必须先 load_skill → ${skillName}，再 read_file → ${workspaceTemplatePath}`,
    '2. 只能替换模板中的 {{PLACEHOLDER}}；禁止重写 <!DOCTYPE>、<style>、header/main/footer 结构',
    '3. 禁止在 <style> 中新增模板没有的 CSS 选择器；正文扩展只能写入占位符对应的 HTML 片段（如 MAIN_CONTENT_HTML）',
    '4. 禁止从零手写新页面或复制 static-page-publish 示例另起炉灶',
    '5. write_file 到 public/*.html 后按 static-page-publish 交付 MindSpace 完整 URL',
  ].join('\n');
}

export function buildPageTemplateSkillPromptSuffix() {
  return (
    '【硬性要求】必须先 load_skill 并 read_file 官方 templates/*.html，仅替换 {{PLACEHOLDER}}；' +
    '禁止修改 <style> 结构或新增模板外 CSS 类；正文内容只能填入占位符 HTML 片段。' +
    '交付链接必须含 /MindSpace/<用户ID>/public/...，禁止 http://127.0.0.1:5173/public/...。'
  );
}

export function validatePublishedPageAgainstTemplate({
  skillName,
  html,
  h5Root = process.cwd(),
} = {}) {
  if (!isPageTemplateSkill(skillName)) {
    return { ok: true, skipped: 'not_page_template' };
  }
  const templatePath = resolvePageTemplateHtmlPath(skillName, h5Root);
  if (!templatePath) {
    return { ok: false, reason: 'template_missing', skillName };
  }

  const pageHtml = String(html ?? '');
  if (PLACEHOLDER_PATTERN.test(pageHtml)) {
    return { ok: false, reason: 'placeholder_left', skillName };
  }

  const templateHtml = fs.readFileSync(templatePath, 'utf8');
  const templateStyleFingerprint = normalizeTemplateStyleFingerprint(extractStyleBlock(templateHtml));
  const pageStyleFingerprint = normalizeTemplateStyleFingerprint(extractStyleBlock(pageHtml));
  if (templateStyleFingerprint !== pageStyleFingerprint) {
    return {
      ok: false,
      reason: 'style_drift',
      skillName,
      templatePath,
    };
  }

  if (
    templateHtml.includes('data-mindspace-page-tag="platform-brand"') &&
    !pageHtml.includes('data-mindspace-page-tag="platform-brand"')
  ) {
    return {
      ok: false,
      reason: 'missing_platform_brand',
      skillName,
      templatePath,
    };
  }

  return { ok: true, skillName, templatePath };
}

export function collectPageTemplateViolations({
  messages,
  publishDir,
  syncResult = null,
  h5Root = process.cwd(),
} = {}) {
  const skillName = resolveSelectedPageTemplateSkill(messages);
  if (!skillName) return [];

  const relativePaths = new Set(
    (syncResult?.publicHtmlRelativePaths ?? [])
      .map((item) => String(item ?? '').trim())
      .filter((item) => item.toLowerCase().endsWith('.html')),
  );
  for (const message of Array.isArray(messages) ? messages : []) {
    for (const item of message?.content ?? []) {
      if (item?.type !== 'toolRequest') continue;
      const toolCall = item.toolCall?.value;
      const name = String(toolCall?.name ?? '').trim().split('__').at(-1);
      if (!['write_file', 'edit_file', 'write', 'edit'].includes(name)) continue;
      const args = toolCall?.arguments ?? {};
      const relativePath = String(args.path ?? args.file_path ?? '').trim().replace(/^\.\//, '');
      if (relativePath.toLowerCase().endsWith('.html') && relativePath.startsWith('public/')) {
        relativePaths.add(relativePath);
      }
    }
  }

  const violations = [];
  for (const relativePath of [...relativePaths].sort()) {
    const absolutePath = path.join(path.resolve(String(publishDir ?? '')), relativePath);
    if (!fs.existsSync(absolutePath)) continue;
    const html = fs.readFileSync(absolutePath, 'utf8');
    const result = validatePublishedPageAgainstTemplate({ skillName, html, h5Root });
    if (!result.ok) {
      violations.push({ relativePath, ...result });
    }
  }
  return violations;
}

export function buildPageTemplateRepairPrompt(violations = [], skillName) {
  const lines = [
    `【系统模板合规补正】用户已选择页面模板「${skillName}」，当前 public HTML 未按官方模板交付。`,
    `必须先 load_skill → ${skillName}，read_file 官方 templates/*.html，仅替换 {{PLACEHOLDER}} 后重新 write_file。`,
    '禁止保留自定义 <style> 或新增模板外 CSS 类；所有正文只能写入占位符 HTML 片段。',
  ];
  for (const item of violations) {
    lines.push('', `- ${item.relativePath}：${item.reason}`);
    if (item.extraSelectors?.length) {
      lines.push(`  多余 CSS 选择器：${item.extraSelectors.join(', ')}`);
    }
    if (item.missingSelectors?.length) {
      lines.push(`  缺失 CSS 选择器：${item.missingSelectors.join(', ')}`);
    }
    if (item.missingStructure?.length) {
      lines.push(`  缺失结构：${item.missingStructure.join(', ')}`);
    }
  }
  return lines.join('\n');
}

export { isPageTemplateSkill };