import fs from 'fs'
import path from 'path'
import { fileURLToPath } from 'url'

const __filename = fileURLToPath(import.meta.url)
const __dirname = path.dirname(__filename)
const docsDir = path.resolve(__dirname, '../docs')

interface SidebarItem {
  text: string
  link: string
}

interface SidebarGroup {
  title: string
  path: string
  items: SidebarItem[]
}

function getTitleFromFile(filePath: string): string {
  const content = fs.readFileSync(filePath, 'utf-8')
  
  const frontmatterMatch = content.match(/^---\n([\s\S]*?)\n---/)
  if (frontmatterMatch) {
    const titleMatch = frontmatterMatch[1].match(/title:\s*["']?([^"'\n]+)["']?/)
    if (titleMatch) {
      return titleMatch[1].trim()
    }
  }
  
  const h1Match = content.match(/^#\s+(.+)$/m)
  if (h1Match) {
    return h1Match[1].trim()
  }
  
  return path.basename(filePath, '.md')
}

function getSidebarOrder(filePath: string, fileName: string): number {
  if (fileName === 'index.md') {
    return 0
  }
  
  const content = fs.readFileSync(filePath, 'utf-8')
  
  const frontmatterMatch = content.match(/^---\n([\s\S]*?)\n---/)
  if (frontmatterMatch) {
    const orderMatch = frontmatterMatch[1].match(/sidebarOrder:\s*(\d+)/)
    if (orderMatch) {
      return parseInt(orderMatch[1], 10)
    }
  }
  
  return 999
}

function generateSidebar(): SidebarGroup[] {
  const sidebar: SidebarGroup[] = []
  
  const entries = fs.readdirSync(docsDir, { withFileTypes: true })
  
  for (const entry of entries) {
    if (!entry.isDirectory() || entry.name.startsWith('.') || entry.name === '.vitepress') {
      continue
    }
    
    const dirPath = path.join(docsDir, entry.name)
    const files = fs.readdirSync(dirPath)
      .filter(f => f.endsWith('.md'))
      .map(f => ({
        name: f,
        path: path.join(dirPath, f),
        order: getSidebarOrder(path.join(dirPath, f), f)
      }))
      .sort((a, b) => a.order - b.order)
    
    if (files.length === 0) continue
    
    const items: SidebarItem[] = files.map(file => {
      let title = getTitleFromFile(file.path)
      if (file.name === 'index.md') {
        title = '概述'
      }
      const linkPath = file.name === 'index.md' 
        ? `/${entry.name}/` 
        : `/${entry.name}/${file.name.replace('.md', '')}`
      
      return {
        text: title,
        link: linkPath
      }
    })
    
    sidebar.push({
      title: entry.name,
      path: `/${entry.name}/`,
      items
    })
  }
  
  return sidebar
}

function updateConfig() {
  const sidebar = generateSidebar()
  
  const outputPath = path.resolve(__dirname, '../docs/.vitepress/theme/data/sidebar.json')
  const outputDir = path.dirname(outputPath)
  
  if (!fs.existsSync(outputDir)) {
    fs.mkdirSync(outputDir, { recursive: true })
  }
  
  fs.writeFileSync(outputPath, JSON.stringify(sidebar, null, 2))
  
  console.log('Sidebar JSON generated:')
  console.log(JSON.stringify(sidebar, null, 2))
}

updateConfig()