import pl, { DataFrame } from 'nodejs-polars'
import fs, { writeFile } from 'fs'

export function test_x(params: any) {
  const fooSeries = pl.Series("foo", [1, 2, 3])

  let res = fooSeries.sum()

  console.log(res)

  let df = pl.readCSV("data/iris.csv")
}

interface CSVDatabase2 {
  df: DataFrame
  filepath: string
}

export function create_csv_database(filepath: string): CSVDatabase2 {
  // let df = DataFrame([], { columns: ["key", "value"] })
  let df = DataFrame({ 'a_key': ['1'], 'a_value': ['2'] })

  // writeFile(filepath, 'key,value\nheader,next', () => { })
  // let df = pl.readCSV(filepath)
  df.writeCSV(filepath)

  return { df, filepath }
}

export function save_db(db: CSVDatabase2) {
  db.df.writeCSV(db.filepath)
}

export function add_row(db: CSVDatabase2, row: any) {
  let d = DataFrame(row)
  db.df = db.df.vstack(d)
}

export function print_head(db: CSVDatabase2) {
  console.log(db.df.head())
}

// can filter everything that is not the row, and do to db

export function delete_row_by_key__({ df, filepath }: CSVDatabase2, key: string) {
  // db.df.drop(pl.col("key").eq(key))
  // df = df.select((pl.col("key") != key).alias("nrs > 1"))
  // db.df = db.df.filter(pl.col("key").neq(key))
}

export function delete_row_by_key(db: CSVDatabase2, key: string) {
  console.log("NEXT COLUMNS")
  console.log(db.df.columns)
  db.df = db.df.filter(pl.col('a_key').neq(pl.lit(key)))
}

export function select_columns(db: CSVDatabase2, columns: string[]): DataFrame {
  return db.df.select(...columns)
}

export function join_dataframes(db1: CSVDatabase2, db2: CSVDatabase2, on: string): DataFrame {
  return db1.df.join(db2.df, { on, how: "inner" }) // or "left", "right", "outer"
}

export function add_simple_index(db: CSVDatabase2) {
  const indices = Array.from(Array(db.df.height).keys()) // Create 0-N index
  db.df = db.df.withColumn(pl.Series("index", indices))
}