import _ from 'lodash';
import * as fs from 'fs';
import { BaseModel } from './base.model';
import { DialogPanel, Question } from '../utils/dialog-panel';
import mysql from 'promise-mysql';

export class MysqlModel extends BaseModel {

  name: string = 'mysql';

  constructor (_options: any) {
    super(_options);

    this.questions = new DialogPanel({ 
      cmd: this.cmd, 
      questions: [
        { text: '', type: 'break' },
        { text: this.TEXTS.IMPORT_MYSQL, type: 'title' },
        { question: this.TEXTS.MYSQL.BDD_HOST, default: 'localhost', index: 'host' },
        { question: this.TEXTS.MYSQL.BDD_PORT, default: 30306, index: 'port' },
        { question: this.TEXTS.MYSQL.DATABASE, default: 'site', index: 'database' },
        { question: this.TEXTS.MYSQL.BDD_USER, default: 'root', index: 'user' },
        { question: this.TEXTS.MYSQL.BDD_PASSWORD, default: 'root', index: 'password' },
        { text: this.TEXTS.SUCCESS.CONNECTION_SUCCESS, condition: this.checkMysqlConnection.bind(this), type: 'success' },
        { question: this.TEXTS.MYSQL.MYSQL_FILE_PATH, default: './init.sql', index: 'filePath' },
        { text: this.TEXTS.SUCCESS.FILE_OK, condition: this.checkFileRead.bind(this), type: 'success' },
        { question: this.TEXTS.MYSQL.RUN_SEARCH_AND_REPLACE, default: false, index: 'replace' },
        { question: this.TEXTS.MYSQL.SEARCH_STR, index: 'searchStr', condition: 'this.res.replace == true', required: true },
        { question: this.TEXTS.MYSQL.REPLACE_STR, index: 'replaceStr', default: 'localhost:8080', condition: 'this.res.replace == true' }
      ]
    });
  }

  init(): void {
    this.questions.start().then(this.mysqlRunImport.bind(this));
  }
  
   async mysqlRunImport(res: any): Promise<void> {
    try {
      this.cmd.log('start mysql import');
      res.multipleStatements = true;
      let connection = await mysql.createConnection(res);
      let content = await fs.promises.readFile(res.filePath, {encoding: 'utf8'});

      if(res.replace)
        content = content.replace(new RegExp(res.searchStr,'gi'),res.replaceStr);

      if(await this.hasTable(connection,res.database))
        await this.dropAllTables(connection,res.database);
  
      await this.runMysqlFile(connection,content);
      await connection.end()
      this.cmd.success('Import success');
    } catch (e) {
      this.cmd.error('Import fail');
      this.cmd.error(e);
    }

    this.shutdown();
  }
  
  async runMysqlFile(connection: any, content: string): Promise<void> {
    content = content.replace(/^\/\*[\s\S]*?\*\/;?|(^|\s)\/\/.*$/gm,'');
    content = content.replace(/^--.*$/gm,'');
  
    await connection.query(content);
  }
  
  async dropAllTables(connection: any, database: string): Promise<any> {
    return await connection.query(`
      SET FOREIGN_KEY_CHECKS = 0; 
      SET @tables = NULL;
      SELECT GROUP_CONCAT('\`', table_schema, '\`.\`', table_name, '\`') INTO @tables
        FROM information_schema.tables 
        WHERE table_schema = '${database}';
      
      SET @tables = CONCAT('DROP TABLE ', @tables);
      PREPARE stmt FROM @tables;
      EXECUTE stmt;
      DEALLOCATE PREPARE stmt;
      SET FOREIGN_KEY_CHECKS = 1;`
    );
  }
  
  async hasTable(connection: any, database: string): Promise<boolean> {
    let result = await connection.query(`SELECT COUNT(*) as val
      FROM information_schema.tables 
      WHERE table_schema = '${database}'`);
    return result[0].val > 0;
  };

  async checkMysqlConnection(qst: Question, question: any): Promise<boolean|number> {
    try {
      await mysql.createConnection(question.res);
      return true;
    } catch (e) {
      console.warn(e);
      return 1;
    }
  }

  async checkFileRead(qst: Question, question: any): Promise<boolean|string> {
    try {
      await fs.promises.access(question.res.filePath, fs.constants.R_OK);
      return true;
    } catch (e) {
      return 'repeat';
    }
  }

}