/**
 * SFTP Transport — 通过 Wails IPC 调用 Go 后端 SFTP 客户端
 */

import type {
  FsTransport, FileItem, FileOperationResult, DetectTypeResult,
} from './transport'
import { transformFileList, joinPath, probeAlive } from './transport'
import type { ConnectionProfile } from './connection-manager'
import {
  SftpConnect, SftpDisconnect, SftpListDir, SftpReadFile,
  SftpWriteFile, SftpGetFileInfo, SftpCreateDir, SftpCreateFile,
  SftpDeletePath, SftpRenamePath, SftpDownloadToTemp, SftpDownloadSiteForPreview,
  SftpDownloadToFile, SftpUploadFromFile,
  SftpGetCommonPaths, SftpWriteBase64File,
} from '@bindings/u-desk/app'

export class SftpTransport implements FsTransport {
  private profile: ConnectionProfile
  private connID: string | null = null

  constructor(profile: ConnectionProfile) {
    this.profile = profile
  }

  async connect(): Promise<string> {
    const result = await SftpConnect({
      host: this.profile.host,
      port: this.profile.port || 22,
      username: this.profile.username || 'root',
      password: this.profile.password || '',
      key_path: this.profile.keyPath || '',
      key_passphrase: '',
    })
    this.connID = result
    return result
  }

  async isAlive(): Promise<boolean> {
    return probeAlive(this.connID, id => SftpGetFileInfo(id, '/'))
  }

  get sessionId(): string | null { return this.connID }

  async disconnect(): Promise<void> {
    if (this.connID) {
      try { await SftpDisconnect(this.connID) } catch (e) {
        console.warn('[SFTP] disconnect error:', e)
      }
      this.connID = null
    }
  }

  private requireConn(): string {
    if (!this.connID) throw new Error('SFTP 未连接')
    return this.connID
  }

  // ====== 文件列表与信息 ======

  async listDir(path: string): Promise<FileItem[]> {
    return transformFileList(await SftpListDir(this.requireConn(), path))
  }

  async getFileInfo(path: string): Promise<Record<string, any>> {
    return SftpGetFileInfo(this.requireConn(), path)
  }

  // ====== 文件读写 ======

  async readFile(path: string): Promise<string> {
    return SftpReadFile(this.requireConn(), path)
  }

  async writeFile(path: string, content: string): Promise<void> {
    await SftpWriteFile({
      session_id: this.requireConn(),
      path,
      content,
    })
  }

  async saveBase64File(path: string, content: string): Promise<void> {
    if (!content) throw new Error('无效的 base64 内容')
    await SftpWriteBase64File(this.requireConn(), path, content)
  }

  // ====== 文件操作 ======

  async createFile(dirPath: string, filename: string): Promise<FileOperationResult> {
    return SftpCreateFile(this.requireConn(), joinPath(dirPath, filename))
  }

  async createDir(parentPath: string, dirname: string): Promise<FileOperationResult> {
    return SftpCreateDir(this.requireConn(), joinPath(parentPath, dirname))
  }

  async deletePath(path: string): Promise<FileOperationResult> {
    return SftpDeletePath(this.requireConn(), path)
  }

  async renamePath(oldPath: string, newPath: string): Promise<FileOperationResult> {
    return SftpRenamePath({
      session_id: this.requireConn(),
      old_path: oldPath,
      new_path: newPath,
    })
  }

  // ====== 复制/移动（粘贴仅本地面板支持）======

  async copyPath(_src: string, _dst: string): Promise<void> {
    throw new Error('SFTP 面板暂不支持粘贴，可使用拖拽上传')
  }

  async movePath(_src: string, _dst: string): Promise<void> {
    throw new Error('SFTP 面板暂不支持粘贴，可使用拖拽上传')
  }

  // ====== 传输 ======

  /** 下载远程文件/目录到用户指定目录（流式无上限，重名自动副本），返回本地落地路径 */
  async downloadToFile(remotePath: string, localDstDir: string): Promise<string> {
    return SftpDownloadToFile(this.requireConn(), remotePath, localDstDir)
  }

  /** 上传本地文件/目录到远程目录（流式，目录递归） */
  async uploadFromFile(localPath: string, remoteDir: string): Promise<void> {
    await SftpUploadFromFile(this.requireConn(), localPath, remoteDir)
  }

  // ====== ZIP 操作（不支持）======

  async listZipContents(_zipPath: string): Promise<FileItem[]> {
    throw new Error('ZIP 操作在 SFTP 模式暂未实现')
  }

  async extractFileFromZip(_zipPath: string, _filePath: string): Promise<string> {
    throw new Error('ZIP 操作在 SFTP 模式暂未实现')
  }

  async extractFileFromZipToTemp(_zipPath: string, _filePath: string): Promise<string> {
    throw new Error('ZIP 操作在 SFTP 模式暂未实现')
  }

  async getZipFileInfo(_zipPath: string, _filePath: string): Promise<FileItem> {
    throw new Error('ZIP 操作在 SFTP 模式暂未实现')
  }

  // ====== 系统操作 ======

  async openPath(_path: string): Promise<void> {
    throw new Error('SFTP 模式不支持打开本地路径')
  }

  async getFileServerURL(): Promise<string> {
    const { getFileServerBaseURL } = await import('./file-server')
    return getFileServerBaseURL()
  }

  getPreviewToken(): string {
    return ''
  }

  async resolveShortcut(_lnkPath: string): Promise<any> {
    return null
  }

  async detectFileTypeByContent(_path: string): Promise<DetectTypeResult> {
    return { extension: '', category: 'unknown', mime_type: '', confidence: 0 }
  }

  async getCommonPaths(): Promise<Record<string, string>> {
    return SftpGetCommonPaths(this.requireConn())
  }

  // ====== 回收站（无）======

  async getRecycleBinEntries(): Promise<any[]> {
    return []
  }

  async restoreFromRecycleBin(_path: string): Promise<void> {}

  async deletePermanently(_path: string): Promise<void> {}

  async emptyRecycleBin(): Promise<void> {}

  // ====== 预览辅助 ======

  /** 下载远程文件到本地临时目录用于预览（缓存由 Go 后端管理） */
  async downloadForPreview(remotePath: string): Promise<string> {
    return SftpDownloadToTemp(this.requireConn(), remotePath)
  }

  /** 下载 HTML 及其网站资源到临时目录用于预览 */
  async downloadSiteForPreview(remotePath: string): Promise<string> {
    return SftpDownloadSiteForPreview(this.requireConn(), remotePath)
  }

  async watchFile(_path: string): Promise<void> { /* SFTP 模式不支持文件监听 */ }
  async unwatchFile(): Promise<void> { /* SFTP 模式不支持文件监听 */ }
}