llm-in-text/src/composables/useFileSystem.js

import { ref, computed, watch } from 'vue'

const STORAGE_KEY = 'llm-in-text-file-system'
const MAX_FILE_SIZE = 50 * 1024 * 1024 // 50MB
const MAX_FILES = 100
const MAX_FOLDERS = 50

function generateId() {
  return Date.now().toString(36) + Math.random().toString(36).slice(2, 9)
}

function countFilesAndFolders(nodes) {
  let files = 0
  let folders = 0
  function traverse(items) {
    for (const item of items) {
      if (item.type === 'folder') {
        folders++
        traverse(item.children || [])
      } else {
        files++
      }
    }
  }
  traverse(nodes)
  return { files, folders }
}

function findNode(nodes, id) {
  for (const node of nodes) {
    if (node.id === id) return node
    if (node.type === 'folder') {
      const found = findNode(node.children || [], id)
      if (found) return found
    }
  }
  return null
}

function findParent(nodes, id, parent = null) {
  for (const node of nodes) {
    if (node.id === id) return parent
    if (node.type === 'folder') {
      const found = findParent(node.children || [], id, node)
      if (found !== undefined) return found
    }
  }
  return undefined
}

function removeNode(nodes, id) {
  return nodes.filter(n => n.id !== id).map(n => {
    if (n.type === 'folder') {
      return { ...n, children: removeNode(n.children || [], id) }
    }
    return n
  })
}

function getPath(nodes, id, path = []) {
  for (const node of nodes) {
    if (node.id === id) return [...path, node]
    if (node.type === 'folder') {
      const found = getPath(node.children || [], id, [...path, node])
      if (found) return found
    }
  }
  return null
}

export function useFileSystem() {
  const tree = ref([])
  const selectedId = ref(null)
  const expandedIds = ref(new Set())
  const clipboard = ref(null) // { mode: 'copy' | 'cut', node: {...} }
  const contextMenu = ref(null) // { x, y, node }
  const error = ref(null)

  function load() {
    try {
      const stored = localStorage.getItem(STORAGE_KEY)
      if (stored) {
        tree.value = JSON.parse(stored)
      } else {
        // 创建示例文件和文件夹
        const welcomeId = generateId()
        const folderId = generateId()
        tree.value = [
          {
            id: folderId,
            name: '示例文件夹',
            type: 'folder',
            children: [],
            parentId: null,
            createdAt: Date.now(),
            updatedAt: Date.now()
          },
          {
            id: welcomeId,
            name: '欢迎使用.md',
            type: 'file',
            content: '# 欢迎使用文件系统\n\n这是一个类似 GitHub 风格的文件浏览器。\n\n## 功能\n\n- ✅ 文件夹展开/折叠\n- ✅ 文件选中高亮\n- ✅ 拖拽移动\n- ✅ 右键菜单\n- ✅ 重命名\n- ✅ 新建/删除\n\n点击左侧的文件或文件夹来查看内容。\n',
            parentId: null,
            createdAt: Date.now(),
            updatedAt: Date.now()
          }
        ]
        save()
      }
    } catch {
      tree.value = []
    }
  }

  function save() {
    try {
      localStorage.setItem(STORAGE_KEY, JSON.stringify(tree.value))
    } catch {
      error.value = '存储空间不足'
    }
  }

  watch(tree, save, { deep: true })

  function createFile(parentId, name, content = '') {
    const { files } = countFilesAndFolders(tree.value)
    if (files >= MAX_FILES) {
      error.value = `文件数量已达上限（${MAX_FILES}个）`
      return false
    }
    if (new Blob([content]).size > MAX_FILE_SIZE) {
      error.value = '文件大小不能超过 50MB'
      return false
    }
    const newFile = {
      id: generateId(),
      name,
      type: 'file',
      content,
      parentId,
      createdAt: Date.now(),
      updatedAt: Date.now()
    }
    if (!parentId) {
      tree.value.push(newFile)
    } else {
      const parent = findNode(tree.value, parentId)
      if (parent && parent.type === 'folder') {
        parent.children = parent.children || []
        parent.children.push(newFile)
      }
    }
    error.value = null
    return true
  }

  function createFolder(parentId, name) {
    const { folders } = countFilesAndFolders(tree.value)
    if (folders >= MAX_FOLDERS) {
      error.value = `文件夹数量已达上限（${MAX_FOLDERS}个）`
      return false
    }
    const newFolder = {
      id: generateId(),
      name,
      type: 'folder',
      children: [],
      parentId,
      createdAt: Date.now(),
      updatedAt: Date.now()
    }
    if (!parentId) {
      tree.value.push(newFolder)
    } else {
      const parent = findNode(tree.value, parentId)
      if (parent && parent.type === 'folder') {
        parent.children = parent.children || []
        parent.children.push(newFolder)
      }
    }
    error.value = null
    return true
  }

  function rename(id, newName) {
    const node = findNode(tree.value, id)
    if (node) {
      node.name = newName
      node.updatedAt = Date.now()
      error.value = null
      return true
    }
    return false
  }

  function remove(id) {
    tree.value = removeNode(tree.value, id)
    if (selectedId.value === id) selectedId.value = null
    error.value = null
  }

function select(id) {
  selectedId.value = id
}

  function toggleFolder(id) {
    const node = findNode(tree.value, id)
    if (!node || node.type !== 'folder') return
    const set = new Set(expandedIds.value)
    if (set.has(id)) {
      set.delete(id)
    } else {
      set.add(id)
    }
    expandedIds.value = set
  }

  function copy(id) {
    const node = findNode(tree.value, id)
    if (node) {
      clipboard.value = { mode: 'copy', node: JSON.parse(JSON.stringify(node)) }
    }
  }

  function cut(id) {
    const node = findNode(tree.value, id)
    if (node) {
      clipboard.value = { mode: 'cut', node: JSON.parse(JSON.stringify(node)) }
    }
  }

  function paste(targetParentId) {
    if (!clipboard.value) return
    const { mode, node } = clipboard.value

    if (mode === 'cut') {
      const oldParent = findParent(tree.value, node.id)
      if (oldParent) {
        oldParent.children = (oldParent.children || []).filter(c => c.id !== node.id)
      } else {
        tree.value = tree.value.filter(n => n.id !== node.id)
      }
      node.parentId = targetParentId || null
      if (targetParentId) {
        const target = findNode(tree.value, targetParentId)
        if (target && target.type === 'folder') {
          target.children = target.children || []
          target.children.push(node)
        }
      } else {
        tree.value.push(node)
      }
      clipboard.value = null
    } else {
      const { files, folders } = countFilesAndFolders(tree.value)
      function countInNode(n) {
        let f = 0, fl = 0
        if (n.type === 'folder') {
          fl = 1
          for (const c of (n.children || [])) {
            const sub = countInNode(c)
            f += sub.f
            fl += sub.fl
          }
        } else {
          f = 1
        }
        return { f, fl }
      }
      const counts = countInNode(node)
      if (files + counts.f > MAX_FILES) {
        error.value = `文件数量将达上限`
        return
      }
      if (folders + counts.fl > MAX_FOLDERS) {
        error.value = `文件夹数量将达上限`
        return
      }

      function cloneWithNewIds(n) {
        const clone = { ...n, id: generateId(), createdAt: Date.now(), updatedAt: Date.now() }
        if (clone.type === 'folder') {
          clone.children = (n.children || []).map(c => cloneWithNewIds(c))
        }
        return clone
      }

      const cloned = cloneWithNewIds(node)
      cloned.parentId = targetParentId || null
      if (targetParentId) {
        const target = findNode(tree.value, targetParentId)
        if (target && target.type === 'folder') {
          target.children = target.children || []
          target.children.push(cloned)
        }
      } else {
        tree.value.push(cloned)
      }
    }
    error.value = null
  }

  function canPaste() {
    return clipboard.value !== null
  }

  function clearClipboard() {
    clipboard.value = null
  }

  function getSelectedNode() {
    return selectedId.value ? findNode(tree.value, selectedId.value) : null
  }

  function getBreadcrumbPath(id) {
    return getPath(tree.value, id) || []
  }

  function showContextMenu(x, y, node) {
    contextMenu.value = { x, y, node }
  }

  function hideContextMenu() {
    contextMenu.value = null
  }

  function getExtension(name) {
    const parts = name.split('.')
    return parts.length > 1 ? parts.pop().toLowerCase() : ''
  }

  function getFileIcon(name) {
    const ext = getExtension(name)
    const iconMap = {
      md: 'markdown',
      txt: 'text',
      json: 'json',
      js: 'javascript',
      ts: 'typescript',
      css: 'css',
      html: 'html',
      py: 'python',
      vue: 'vue',
      xml: 'xml',
      yaml: 'yaml',
      yml: 'yaml',
      csv: 'csv',
      log: 'log',
      sql: 'sql'
    }
    return iconMap[ext] || 'file'
  }

  return {
    tree,
    selectedId,
    expandedIds,
    clipboard,
    contextMenu,
    error,
    load,
    createFile,
    createFolder,
    rename,
    remove,
    select,
    toggleFolder,
    copy,
    cut,
    paste,
    canPaste,
    clearClipboard,
    getSelectedNode,
    getBreadcrumbPath,
    showContextMenu,
    hideContextMenu,
    getFileIcon,
    getExtension,
    MAX_FILE_SIZE,
    MAX_FILES,
    MAX_FOLDERS
  }
}