const fs = require('fs')
const path = require('path')

function getProjectDir(projectPath) {
  return projectPath
}

function getSrcDir(projectPath) {
  const dir = path.join(projectPath, '.web2app', 'src')
  fs.mkdirSync(dir, { recursive: true })
  return dir
}

function getConfigPath(projectPath) {
  return path.join(projectPath, '.web2app', 'project.json')
}

function getDistDir(projectPath) {
  const dir = path.join(projectPath, '.web2app', 'dist')
  fs.mkdirSync(dir, { recursive: true })
  return dir
}

function createProject(projectPath) {
  if (!fs.existsSync(projectPath)) {
    fs.mkdirSync(projectPath, { recursive: true })
  }

  const configPath = getConfigPath(projectPath)
  if (fs.existsSync(configPath)) {
    throw new Error(`该目录已是 Web2App 项目`)
  }

  fs.mkdirSync(path.join(projectPath, '.web2app', 'src'), { recursive: true })
  fs.mkdirSync(path.join(projectPath, '.web2app', 'dist'), { recursive: true })

  const config = {
    name: path.basename(projectPath),
    version: '1.0.0',
    description: '',
    author: '',
    entry: 'index.html',
    backendEntry: '',
    windowWidth: 1200,
    windowHeight: 800,
    minWidth: 800,
    minHeight: 600,
    resizable: true,
    icon: '',
    copyright: '',
    createdAt: new Date().toISOString(),
    updatedAt: new Date().toISOString()
  }

  fs.writeFileSync(configPath, JSON.stringify(config, null, 2))
  return { projectPath, config }
}

function loadProject(projectPath) {
  const configPath = getConfigPath(projectPath)
  if (!fs.existsSync(configPath)) {
    throw new Error('不是有效的 Web2App 项目')
  }
  const config = JSON.parse(fs.readFileSync(configPath, 'utf-8'))

  const srcDir = getSrcDir(projectPath)
  const files = readFileTree(srcDir)

  return { projectPath, config, files }
}

function saveProject(projectPath, data) {
  const configPath = getConfigPath(projectPath)
  const existing = JSON.parse(fs.readFileSync(configPath, 'utf-8'))
  const updated = { ...existing, ...data, updatedAt: new Date().toISOString() }
  fs.writeFileSync(configPath, JSON.stringify(updated, null, 2))
  return updated
}

function importFiles(projectPath, files) {
  const srcDir = getSrcDir(projectPath)
  const imported = []

  for (const filePath of files) {
    const stat = fs.statSync(filePath)
    if (stat.isDirectory()) {
      const destDir = path.join(srcDir, path.basename(filePath))
      copyDirSync(filePath, destDir)
      imported.push({ source: filePath, dest: destDir })
    } else {
      const destPath = path.join(srcDir, path.basename(filePath))
      fs.copyFileSync(filePath, destPath)
      imported.push({ source: filePath, dest: destPath })
    }
  }

  return readFileTree(srcDir)
}

function removeFile(projectPath, relativePath) {
  const srcDir = getSrcDir(projectPath)
  const fullPath = path.join(srcDir, relativePath)

  if (!fs.existsSync(fullPath)) {
    throw new Error(`文件不存在: ${relativePath}`)
  }

  const stat = fs.statSync(fullPath)
  if (stat.isDirectory()) {
    fs.rmSync(fullPath, { recursive: true, force: true })
  } else {
    fs.unlinkSync(fullPath)
  }

  return readFileTree(srcDir)
}

function setProjectIcon(projectPath, iconPath) {
  const srcDir = getSrcDir(projectPath)
  const ext = path.extname(iconPath)
  const destName = `app-icon${ext}`
  const destPath = path.join(srcDir, destName)
  fs.copyFileSync(iconPath, destPath)

  const config = JSON.parse(fs.readFileSync(getConfigPath(projectPath), 'utf-8'))
  config.icon = destName
  fs.writeFileSync(getConfigPath(projectPath), JSON.stringify(config, null, 2))
  return config
}

function readFileTree(dirPath, basePath = '') {
  const items = []
  if (!fs.existsSync(dirPath)) return items

  const entries = fs.readdirSync(dirPath, { withFileTypes: true })
  for (const entry of entries) {
    if (entry.name.startsWith('.')) continue
    const relativePath = basePath ? path.join(basePath, entry.name) : entry.name
    const fullPath = path.join(dirPath, entry.name)
    if (entry.isDirectory()) {
      items.push({
        name: entry.name,
        path: relativePath,
        type: 'directory',
        children: readFileTree(fullPath, relativePath)
      })
    } else {
      items.push({
        name: entry.name,
        path: relativePath,
        type: 'file',
        size: fs.statSync(fullPath).size,
        ext: path.extname(entry.name).toLowerCase()
      })
    }
  }

  items.sort((a, b) => {
    if (a.type !== b.type) return a.type === 'directory' ? -1 : 1
    return a.name.localeCompare(b.name)
  })
  return items
}

function copyDirSync(src, dest) {
  fs.mkdirSync(dest, { recursive: true })
  const entries = fs.readdirSync(src, { withFileTypes: true })
  for (const entry of entries) {
    if (entry.name.startsWith('.')) continue
    const srcPath = path.join(src, entry.name)
    const destPath = path.join(dest, entry.name)
    if (entry.isDirectory()) {
      copyDirSync(srcPath, destPath)
    } else {
      fs.copyFileSync(srcPath, destPath)
    }
  }
}

module.exports = {
  createProject,
  loadProject,
  saveProject,
  importFiles,
  removeFile,
  setProjectIcon,
  getSrcDir,
  getDistDir,
  getConfigPath,
  getProjectDir
}