import { useState, useCallback } from 'react'
import { toast } from 'sonner'

export interface FileNode {
  id: string
  name: string
  type: 'file' | 'folder'
  content?: string
  language?: string
  children?: FileNode[]
  expanded?: boolean
}

/**
 * Hook to manage file tree operations
 * Handles tree traversal, node creation, deletion, and updates
 */
export function useFileTree(initialFiles: FileNode[] = []) {
  const [files, setFiles] = useState<FileNode[]>(initialFiles)

  const findNodeById = useCallback((id: string, nodes = files): FileNode | null => {
    for (const node of nodes) {
      if (node.id === id) return node
      if (node.children) {
        const found = findNodeById(id, node.children)
        if (found) return found
      }
    }
    return null
  }, [files])

  const updateNode = useCallback((id: string, updates: Partial<FileNode>) => {
    const update = (nodes: FileNode[]): FileNode[] =>
      nodes.map(node => {
        if (node.id === id) {
          return { ...node, ...updates }
        }
        if (node.children) {
          return { ...node, children: update(node.children) }
        }
        return node
      })

    setFiles(update)
  }, [])

  const deleteNode = useCallback((id: string) => {
    const remove = (nodes: FileNode[]): FileNode[] =>
      nodes.filter(node => node.id !== id).map(node => ({
        ...node,
        children: node.children ? remove(node.children) : undefined,
      }))

    setFiles(remove)
    toast.success('Deleted')
  }, [])

  const toggleFolder = useCallback((id: string) => {
    updateNode(id, { expanded: (node => !node.expanded)(findNodeById(id)!) })
  }, [updateNode, findNodeById])

  const addChild = useCallback((parentId: string, child: FileNode) => {
    const parent = findNodeById(parentId)
    if (!parent || parent.type !== 'folder') return

    setFiles(files =>
      files.map(node => {
        if (node.id === parentId) {
          return {
            ...node,
            children: [...(node.children || []), child],
          }
        }
        if (node.children) {
          return {
            ...node,
            children: files.map(n => (n.id === parentId ? { ...n, children: [...(n.children || []), child] } : n))[0]?.children || node.children,
          }
        }
        return node
      })
    )
    toast.success('Created')
  }, [findNodeById, files])

  return {
    files,
    setFiles,
    findNodeById,
    updateNode,
    deleteNode,
    toggleFolder,
    addChild,
  }
}