process_raw_data.js

import {
  xlsx,
  readXLSX,
  writeCSV,
  readCSV
} from "https://deno.land/x/flat@0.0.11/mod.ts";
import { parse as parseYaml } from "https://deno.land/std@0.63.0/encoding/yaml.ts";
import { parse } from "https://deno.land/std@0.92.0/encoding/csv.ts";
import { unZipFromFile } from 'https://deno.land/x/zip@v1.1.0/mod.ts'
import { walk, emptyDir } from "https://deno.land/std@0.100.0/fs/mod.ts";
import { gunzipFile } from "https://deno.land/x/compress@v0.3.8/mod.ts";

let inputFilename = Deno.args[0];
const inputFilenameRoot = inputFilename.split("/")[1].split(".")[0];
const outputFilename = `processed/${inputFilenameRoot}.csv`;

const manifest = await readCSV("data_manifest.csv");
const config = manifest.find((d) => d.name === inputFilenameRoot);
if (!config) Deno.exit();
console.log("config", config);

let fileType = config.format

let fileContents

try {
  if (fileType === "zip") {
    await emptyDir("./tmp")
    await unZipFromFile(inputFilename, "./tmp")

    for await (const file of walk("./tmp")) {
      const extension = file.path.split(".").pop();
      if (["xlsx", "csv", "csv.gz", "tsv", "yaml", "json"].includes(extension)) {
        fileType = extension
        inputFilename = file.path
        break
      }
    }
  }

  if (fileType === "csv") {
    fileContents = await readCSV(inputFilename);
  } else if (fileType === "tsv") {
    fileContents = await readCSV(inputFilename, {
      separator: "\t",
    });
  } else if (fileType === "csv.gz") {
    await gunzipFile(inputFilename, outputFilename);
    Deno.exit()
  } else if (fileType === "json") {
    fileContents = await readJSON(inputFilename);
  } else if (fileType === "yaml") {
    const yaml = await Deno.readFile(inputFilename);
    const decoder = new TextDecoder("utf-8");
    fileContents = await parseYaml(decoder.decode(yaml));
  } else if (fileType === "xlsx") {
    const workbook = await readXLSX(inputFilename);

    const sheetData =
      workbook.Sheets[workbook.SheetNames[config["Excel sheet #"] - 1]];
    const csvString = await xlsx.utils.sheet_to_csv(sheetData); // can use to_json, to_txt, to_html, to_formulae
    const rows = csvString.split("\n");
    const filteredRows = rows.slice((config["Excel sheet top row #"] || 1) - 1);
    const data = await parse(filteredRows.join("\n"), { skipFirstRow: true });
    const columns = filteredRows[0].split(",");
    const countryKey = config["Country Column #"]
      ? columns[config["Country Column #"] - 1]
      : "";
    const yearKey = config["Year Column #"]
      ? columns[config["Year Column #"] - 1]
      : "";
    fileContents = data.map((d) => ({
      ...d,
      data_country: d[countryKey],
      data_year: d[yearKey],
    }));
  }
} catch (e) {
  console.log(e)
}

await emptyDir("./tmp")

if (fileContents) await writeCSV(outputFilename, fileContents);