import * as fs from 'fs';
import * as path from 'path';
import * as os from 'os';
import * as vscode from 'vscode';
import * as rd from 'readline'
const { NodeSSH } = require('node-ssh')

import * as utils from './utils';
import User from './user';
import DevstarAPIHandler from './devstar-api';

export default class RemoteContainer {
  private user: User;

  constructor(user: User) {
    this.user = user
  }

  async firstOpenProject(host: string, port: number, username: string, path: string, context: vscode.ExtensionContext) {
    await this.firstConnect(host, username, port, context)
      .then((res) => {
        if (res === 'success') {
          //  only success then open folder
          this.openRemoteFolder(host, port, username, path);
        }
      })
  }

  // connect with key
  async firstConnect(hostname: string, username: string, port: number, context: vscode.ExtensionContext): Promise<string> {
    return new Promise(async (resolve) => {
      const ssh = new NodeSSH();
      vscode.window.withProgress({
        location: vscode.ProgressLocation.Notification,
        title: vscode.l10n.t("Installing vscode-server and devstar extension in container"),
        cancellable: false
      }, async (progress) => {
        try {
          // 无论local/remote，均需检查公私钥是否存在，如果不存在，需要创建（因为有可能在remote上创建了，但是local未创建）
          if (!this.user.existUserPrivateKey() || !this.user.existUserPublicKey()) {
            await this.user.createUserSSHKey()
            // 上传公钥
            const devstarAPIHandler = new DevstarAPIHandler()
            const uploadResult = await devstarAPIHandler.uploadUserPublicKey(this.user)
            if (uploadResult !== "ok") {
              throw new Error('Upload public key failed.')
            }
          }
        } catch (error) {
          console.error("Failed to first connect container: ", error)
        }

        if (vscode.env.remoteName) {
          // 远程环境
          try {
            // 第一次连接
            await ssh.connect({
              host: hostname,
              username: username,
              port: port,
              privateKeyPath: this.user.getUserPrivateKeyPath()
            });
            progress.report({ message: vscode.l10n.t("Connected! Start installation") });

            // 安装vscode-server and devstar extension
            const vscodeCommitId = await utils.getVsCodeCommitId()
            if ("" != vscodeCommitId) {
              const vscodeServerUrl = `https://vscode.download.prss.microsoft.com/dbazure/download/stable/${vscodeCommitId}/vscode-server-linux-x64.tar.gz`
              const installVscodeServerScript = `
            mkdir -p ~/.vscode-server/bin/${vscodeCommitId} && \\
            if [ "$(ls -A ~/.vscode-server/bin/${vscodeCommitId})" ]; then
                ~/.vscode-server/bin/${vscodeCommitId}/bin/code-server --install-extension mengning.devstar
            else
                wget ${vscodeServerUrl} -O vscode-server-linux-x64.tar.gz && \\
                mv vscode-server-linux-x64.tar.gz ~/.vscode-server/bin/${vscodeCommitId} && \\
                cd ~/.vscode-server/bin/${vscodeCommitId} && \\
                tar -xvzf vscode-server-linux-x64.tar.gz --strip-components 1 && \\
                rm vscode-server-linux-x64.tar.gz && \\
                ~/.vscode-server/bin/${vscodeCommitId}/bin/code-server --install-extension mengning.devstar
            fi
            `;
              await ssh.execCommand(installVscodeServerScript);
              console.log("vscode-server and extension installed");
              vscode.window.showInformationMessage(vscode.l10n.t('Installation completed!'));
            }

            await ssh.dispose();

            // ssh信息存储到ssh config file中
            // 远程环境，利用global state中记录的localSystemName来决定执行的命令
            const localSystemName = utils.getLocalSystemName(context)
            const localSSHConfigPath = utils.getLocalSSHConfigPath(context);
            const privateKeyPath = this.user.getLocalUserPrivateKeyPath();
            const host = `${hostname}-${port}` // host: hostname-port
            const newSShConfigContent =
              `\nHost ${host}\n  HostName ${hostname}\n  Port ${port}\n  User ${username}\n  PreferredAuthentications publickey\n  IdentityFile ${privateKeyPath}\n  `;
            let commandToAppend: string;
            const delimiter = `EOF_SSH_CONFIG_${Date.now()}`; // 使用一个唯一的分隔符用于 here-docs (Unix) 或 here-strings (PowerShell)

            if (localSystemName === "win32") {
              // --- Windows 平台 ---
              // 使用 PowerShell 的 Here-String (@'...'@) 来保证多行文本输入的健壮性
              // @'...'@ 内的内容会按字面解释，减少转义问题
              const escapedContent = newSShConfigContent.replace(/'/g, "''"); // 对内容中的单引号进行转义（替换为两个单引号），以防万一变量值包含单引号
              const psTargetPath = localSSHConfigPath;
              // 将内容包裹在 @'\n...\n'@ 中，确保前后有换行
              commandToAppend = `Add-Content -Path '${psTargetPath}' -Value @'\n${escapedContent}\n'@`;
            } else if (localSystemName === "darwin" || localSystemName === "linux") {
              // --- Linux, macOS, 或其他类 Unix 系统 ---
              const unixTargetPath = `"${localSSHConfigPath}"`;
              commandToAppend = `cat << '${delimiter}' >> ${unixTargetPath}
                ${newSShConfigContent}
                ${delimiter}
                `;
            }

            // 通过local terminal命令行写入
            vscode.commands.executeCommand('workbench.action.terminal.newLocal').then(() => {
              const terminal = vscode.window.terminals[vscode.window.terminals.length - 1];
              if (terminal) {
                terminal.sendText(commandToAppend, true);
              }
            })

            resolve('success')
          } catch (error) {
            console.error('Failed to install vscode-server and extension: ', error);
            await ssh.dispose();
          }
        } else {
          // 本地环境
          try {
            // connect with key
            await ssh.connect({
              host: hostname,
              username: username,
              port: port,
              privateKeyPath: this.user.getUserPrivateKeyPath()
            });
            progress.report({ message: vscode.l10n.t("Connected! Start installation") });

            // install vscode-server and devstar extension
            const vscodeCommitId = await utils.getVsCodeCommitId()
            if ("" != vscodeCommitId) {
              const vscodeServerUrl = `https://vscode.download.prss.microsoft.com/dbazure/download/stable/${vscodeCommitId}/vscode-server-linux-x64.tar.gz`
              const installVscodeServerScript = `
            mkdir -p ~/.vscode-server/bin/${vscodeCommitId} && \\
            if [ "$(ls -A ~/.vscode-server/bin/${vscodeCommitId})" ]; then
                ~/.vscode-server/bin/${vscodeCommitId}/bin/code-server --install-extension mengning.devstar
            else
                wget ${vscodeServerUrl} -O vscode-server-linux-x64.tar.gz && \\
                mv vscode-server-linux-x64.tar.gz ~/.vscode-server/bin/${vscodeCommitId} && \\
                cd ~/.vscode-server/bin/${vscodeCommitId} && \\
                tar -xvzf vscode-server-linux-x64.tar.gz --strip-components 1 && \\
                rm vscode-server-linux-x64.tar.gz && \\
                ~/.vscode-server/bin/${vscodeCommitId}/bin/code-server --install-extension mengning.devstar
            fi
            `;
              await ssh.execCommand(installVscodeServerScript);
              console.log("vscode-server and extension installed");
              vscode.window.showInformationMessage(vscode.l10n.t('Installation completed!'));
            }

            await ssh.dispose();

            // only connect successfully then save the host info
            await this.storeHostInfo(hostname, port, username)

            resolve('success')
          } catch (error) {
            console.error('Failed to install vscode-server and extension: ', error);
            await ssh.dispose();
          }
        }
      });
    });
  }

  async storeHostInfo(hostname: string, port: number, username: string): Promise<void> {
    const sshConfigPath = path.join(os.homedir(), '.ssh', 'config');
    // check if the host and related info exist in local ssh config file before saving
    var canAppendSSHConfig = true
    if (fs.existsSync(sshConfigPath)) {
      var reader = rd.createInterface(fs.createReadStream(sshConfigPath))

      for await (const line of reader) {
        // host format: hostname-port
        if (line.includes(`Host ${hostname}-${port}`)) {
          // the container ssh info exists
          canAppendSSHConfig = false
          break;
        }
      }
    }

    if (canAppendSSHConfig) {
      // save the host to the local ssh config file 
      const host = `${hostname}-${port}` // host: hostname-port
      const privateKeyPath = this.user.getUserPrivateKeyPath();
      const newSShConfigContent =
        `\nHost ${host}\n  HostName ${hostname}\n  Port ${port}\n  User ${username}\n  PreferredAuthentications publickey\n  IdentityFile ${privateKeyPath}\n  `;
      fs.writeFileSync(sshConfigPath, newSShConfigContent, { encoding: 'utf8', flag: 'a' });
      console.log('Host registered in local ssh config');
    }
  }


  openRemoteFolder(hostname: string, port: number, username: string, path: string): void {
    if (vscode.env.remoteName) {
      // 远程环境，打开local terminal
      vscode.commands.executeCommand('workbench.action.terminal.newLocal').then(() => {
        // 获取最后一个打开的终端实例
        const terminal = vscode.window.terminals[vscode.window.terminals.length - 1];
        if (terminal) {
          var host = `${hostname}-${port}`
          // 在新窗口打开
          terminal.sendText(`code --remote ssh-remote+${username}@${host}:${port} ${path} --new-window`)
        }
      })
    } else {
      // 本地环境
      var host = `${hostname}-${port}`
      let terminal = vscode.window.activeTerminal || vscode.window.createTerminal(`Ext Terminal`);
      terminal.show(true);
      // 在原窗口打开
      terminal.sendText(`code --remote ssh-remote+${username}@${host}:${port} ${path} --reuse-window`);
    }
  }
}


export async function openProjectWithoutLogging(host: string, port: number, username: string, path: string): Promise<void> {
  const command = `code --remote ssh-remote+${username}@${host}:${port} ${path} --reuse-window`
  let terminal = vscode.window.activeTerminal || vscode.window.createTerminal(`Ext Terminal`);
  terminal.show(true);
  terminal.sendText(command);
}