executor.js

import { addTableMeta, dbMeta, clearMeta } from "./meta.js";
import { createTableFile } from "./table.js";
import selectShape from "./commands.js";
export function executor(command, query) {
  structureQuerytoAst(command, query);
  switch (command) {
    case "select":
      console.log("A select will be triggered");
      break;
    case "insert":
      console.log("An insert operation will be triggerd");
      break;
    case "create":
      console.log("A create operation will be performed");
      create(query);
      break;
    case "drop":
      clearMeta();
  }
}

function extractTokens(startIndex, query) {
  console.log(startIndex, query, "This is the startIndex");
  let i = startIndex;
  while (i <= query.length - 1) {
    if (query[i].startsWith("(")) {
      query[i] = query[i].substring(1, query[i].length);
      i++;
    } else if (query[i].endsWith(")")) {
      query[i] = query[i].substring(0, query[i].length - 1);
      console.log("im here");
      console.log(query[i]);
      i++;
    } else if (query[i].endsWith(",")) {
      query[i] = query[i].substring(0, query[i].length - 1);
      console.log(", here");
      console.log(query[i]);
      i++;
    } else {
      i++;
    }
  }
  return query.slice(3);
}

function structureQuerytoAst(command, query) {
  //take the raw query and seperate data from commands
  switch (command) {
    case "create":
      const ast = {};

      //for create the elements before () will be the command and after that will be data
      console.log("hereee", query.split(" "));
      query = query.split(" ");
      const tableName = query[2];
      const cleanTokens = extractTokens(2, query);
      console.log("Here are the cleaned tokens");
      console.log(cleanTokens, tableName);

      for (let i = 0; i < cleanTokens.length - 1; i += 2) {
        console.log(cleanTokens[i], cleanTokens[i + 1]);
        const key = cleanTokens[i];
        const type = cleanTokens[i + 1];
        ast[key] = type;
      }
      console.log(ast);
    case "select":
      select(query);
  }
}

function create(query) {
  console.log("A table is being created");
  //implement write ahead logging
  const tokenedQuery = tokenizer(query);
  console.log(tokenedQuery);
  const shouldCreateFlag = addTableMeta(tokenedQuery[2], tokenedQuery[3]);
  if (shouldCreateFlag == true) {
    createTableFile(tokenedQuery[2]);
  }
}

function select(query, selectShape) {
  console.log("We are in the query subfunction");
  const queryList = tokenizer(query);
  console.log(queryList);
  console.log(selectShape);
}

function tokenizer(query) {
  console.log("We are starting the tokenizer");
  console.log(query);
  let queryList = [];
  let word = "";
  for (let i = 0; i < query.length; i++) {
    if (query[i] != " ") {
      word = word + query[i];
      console.log(word);
    } else {
      queryList.push(word);
      word = "";
    }
  }
  queryList.push(word);
  console.log(queryList);
  return queryList;
}