import AbstractDriver from '@sqltools/base-driver';
import queries from './queries';
import { IConnectionDriver, MConnectionExplorer, NSDatabase, ContextValue, Arg0 } from '@sqltools/types';
import { v4 as generateId } from 'uuid';

/**
 * set Driver lib to the type of your connection.
 * Eg for postgres:
 * import { Pool, PoolConfig } from 'pg';
 * ...
 * type DriverLib = Pool;
 * type DriverOptions = PoolConfig;
 *
 * This will give you completions iside of the library
 */
type DriverLib = typeof fakeDbLib;
type DriverOptions = any;

/**
 * MOCKED DB DRIVER
 * THIS IS JUST AN EXAMPLE AND THE LINES BELOW SHOUDL BE REMOVED!
 */
// import fakeDbLib from './mylib'; // this is what you should do
const fakeDbLib = {
  open: () => Promise.resolve(fakeDbLib),
  query: (..._args: any[]) => {
    const nResults = parseInt((Math.random() * 1000).toFixed(0));
    const nCols = parseInt((Math.random() * 100).toFixed(0));
    const colNames = [...new Array(nCols)].map((_, index) => `col${index}`);
    const generateRow = () => {
      const row = {};
      colNames.forEach(c => {
        row[c] = Math.random() * 1000;
      });
      return row;
    }
    const results = [...new Array(nResults)].map(generateRow);
    return Promise.resolve([results]);
  },
  close: () => Promise.resolve(),
};


/* LINES ABOVE CAN BE REMOVED */


export default class YourDriverClass extends AbstractDriver<DriverLib, DriverOptions> implements IConnectionDriver {

  /**
   * If you driver depends on node packages, list it below on `deps` prop.
   * It will be installed automatically on first use of your driver.
   */
  public readonly deps: typeof AbstractDriver.prototype['deps'] = [{
    type: AbstractDriver.CONSTANTS.DEPENDENCY_PACKAGE,
    name: 'lodash',
    // version: 'x.x.x',
  }];


  queries = queries;

  /** if you need to require your lib in runtime and then
   * use `this.lib.methodName()` anywhere and vscode will take care of the dependencies
   * to be installed on a cache folder
   **/
  // private get lib() {
  //   return this.requireDep('node-packge-name') as DriverLib;
  // }

  public async open() {
    if (this.connection) {
      return this.connection;
    }

    this.needToInstallDependencies && await this.needToInstallDependencies();
    /**
     * open your connection here!!!
     */

    this.connection = fakeDbLib.open();
    return this.connection;
  }

  public async close() {
    if (!this.connection) return Promise.resolve();
    /**
     * cose you connection here!!
     */
    await fakeDbLib.close();
    this.connection = null;
  }

  public query: (typeof AbstractDriver)['prototype']['query'] = async (queries, opt = {}) => {
    const db = await this.open();
    const queriesResults = await db.query(queries);
    const resultsAgg: NSDatabase.IResult[] = [];
    queriesResults.forEach(queryResult => {
      resultsAgg.push({
        cols: Object.keys(queryResult[0]),
        connId: this.getId(),
        messages: [{ date: new Date(), message: `Query ok with ${queriesResults.length} results`}],
        results: queryResult,
        query: queries.toString(),
        requestId: opt.requestId,
        resultId: generateId(),
      });
    });
    /**
     * write the method to execute queries here!!
     */
    return resultsAgg;
  }

  /** if you need a different way to test your connection, you can set it here.
   * Otherwise by default we open and close the connection only
   */
  public async testConnection() {
    await this.open();
    await this.query('SELECT 1', {});
  }

  /**
   * This method is a helper to generate the connection explorer tree.
   * it gets the child items based on current item
   */
  public async getChildrenForItem({ item, parent }: Arg0<IConnectionDriver['getChildrenForItem']>) {
    switch (item.type) {
      case ContextValue.CONNECTION:
      case ContextValue.CONNECTED_CONNECTION:
        return <MConnectionExplorer.IChildItem[]>[
          { label: 'Tables', type: ContextValue.RESOURCE_GROUP, iconId: 'folder', childType: ContextValue.TABLE },
          { label: 'Views', type: ContextValue.RESOURCE_GROUP, iconId: 'folder', childType: ContextValue.VIEW },
        ];
      case ContextValue.TABLE:
      case ContextValue.VIEW:
        let i = 0;
        return <NSDatabase.IColumn[]>[{
          database: 'fakedb',
          label: `column${i++}`,
          type: ContextValue.COLUMN,
          dataType: 'faketype',
          schema: 'fakeschema',
          childType: ContextValue.NO_CHILD,
          isNullable: false,
          iconName: 'column',
          table: parent,
        },{
          database: 'fakedb',
          label: `column${i++}`,
          type: ContextValue.COLUMN,
          dataType: 'faketype',
          schema: 'fakeschema',
          childType: ContextValue.NO_CHILD,
          isNullable: false,
          iconName: 'column',
          table: parent,
        },{
          database: 'fakedb',
          label: `column${i++}`,
          type: ContextValue.COLUMN,
          dataType: 'faketype',
          schema: 'fakeschema',
          childType: ContextValue.NO_CHILD,
          isNullable: false,
          iconName: 'column',
          table: parent,
        },{
          database: 'fakedb',
          label: `column${i++}`,
          type: ContextValue.COLUMN,
          dataType: 'faketype',
          schema: 'fakeschema',
          childType: ContextValue.NO_CHILD,
          isNullable: false,
          iconName: 'column',
          table: parent,
        },{
          database: 'fakedb',
          label: `column${i++}`,
          type: ContextValue.COLUMN,
          dataType: 'faketype',
          schema: 'fakeschema',
          childType: ContextValue.NO_CHILD,
          isNullable: false,
          iconName: 'column',
          table: parent,
        }];
      case ContextValue.RESOURCE_GROUP:
        return this.getChildrenForGroup({ item, parent });
    }
    return [];
  }

  /**
   * This method is a helper to generate the connection explorer tree.
   * It gets the child based on child types
   */
  private async getChildrenForGroup({ parent, item }: Arg0<IConnectionDriver['getChildrenForItem']>) {
    console.log({ item, parent });
    switch (item.childType) {
      case ContextValue.TABLE:
      case ContextValue.VIEW:
        let i = 0;
        return <MConnectionExplorer.IChildItem[]>[{
          database: 'fakedb',
          label: `${item.childType}${i++}`,
          type: item.childType,
          schema: 'fakeschema',
          childType: ContextValue.COLUMN,
        },{
          database: 'fakedb',
          label: `${item.childType}${i++}`,
          type: item.childType,
          schema: 'fakeschema',
          childType: ContextValue.COLUMN,
        },
        {
          database: 'fakedb',
          label: `${item.childType}${i++}`,
          type: item.childType,
          schema: 'fakeschema',
          childType: ContextValue.COLUMN,
        }];
    }
    return [];
  }

  /**
   * This method is a helper for intellisense and quick picks.
   */
  public async searchItems(itemType: ContextValue, search: string, _extraParams: any = {}): Promise<NSDatabase.SearchableItem[]> {
    switch (itemType) {
      case ContextValue.TABLE:
      case ContextValue.VIEW:
        let j = 0;
        return [{
          database: 'fakedb',
          label: `${search || 'table'}${j++}`,
          type: itemType,
          schema: 'fakeschema',
          childType: ContextValue.COLUMN,
        },{
          database: 'fakedb',
          label: `${search || 'table'}${j++}`,
          type: itemType,
          schema: 'fakeschema',
          childType: ContextValue.COLUMN,
        },
        {
          database: 'fakedb',
          label: `${search || 'table'}${j++}`,
          type: itemType,
          schema: 'fakeschema',
          childType: ContextValue.COLUMN,
        }]
      case ContextValue.COLUMN:
        let i = 0;
        return [
          {
            database: 'fakedb',
            label: `${search || 'column'}${i++}`,
            type: ContextValue.COLUMN,
            dataType: 'faketype',
            schema: 'fakeschema',
            childType: ContextValue.NO_CHILD,
            isNullable: false,
            iconName: 'column',
            table: 'fakeTable'
          },{
            database: 'fakedb',
            label: `${search || 'column'}${i++}`,
            type: ContextValue.COLUMN,
            dataType: 'faketype',
            schema: 'fakeschema',
            childType: ContextValue.NO_CHILD,
            isNullable: false,
            iconName: 'column',
            table: 'fakeTable'
          },{
            database: 'fakedb',
            label: `${search || 'column'}${i++}`,
            type: ContextValue.COLUMN,
            dataType: 'faketype',
            schema: 'fakeschema',
            childType: ContextValue.NO_CHILD,
            isNullable: false,
            iconName: 'column',
            table: 'fakeTable'
          },{
            database: 'fakedb',
            label: `${search || 'column'}${i++}`,
            type: ContextValue.COLUMN,
            dataType: 'faketype',
            schema: 'fakeschema',
            childType: ContextValue.NO_CHILD,
            isNullable: false,
            iconName: 'column',
            table: 'fakeTable'
          },{
            database: 'fakedb',
            label: `${search || 'column'}${i++}`,
            type: ContextValue.COLUMN,
            dataType: 'faketype',
            schema: 'fakeschema',
            childType: ContextValue.NO_CHILD,
            isNullable: false,
            iconName: 'column',
            table: 'fakeTable'
          }
        ];
    }
    return [];
  }

  public getStaticCompletions: IConnectionDriver['getStaticCompletions'] = async () => {
    return {};
  }
}