#r "ExcelProvider.1.0.1/lib/net45/ExcelProvider.Runtime.dll"
open FSharp.Interop.Excel
open System.Text.RegularExpressions;

type Excel = ExcelFile<"input.xls", Range="A7:I100000">
type Row = {
    Amount : decimal;
    Title : string;
}

let file = Excel()

let rows =
    file.Data
    |> Seq.map (fun row -> {Amount =  decimal row.Kwota; Title = row.``Tytuł operacji``})

let cleanRows =
    rows
    |> Seq.where (fun row -> (not (isNull row.Title)))
    |> Seq.map (fun row -> {
                            row
                            with Title =
                                    (
                                    Regex.Replace(row.Title, @"[\d-]", "")
                                    |> fun title -> Regex.Replace(title,  ",", "")
                                    |> fun title -> if title.Length > 38
                                                    then title.Substring(38)
                                                    else title
                                    )
                           }
                )

let groups =
    cleanRows
    |> Seq.groupBy (fun r -> r.Title)
    |> Seq.map (fun r -> (fst r, (snd r) |> Seq.sumBy (fun r -> r.Amount)))


let expenses =
    groups
    |> Seq.where(fun row -> snd row < 0m)
    |> Seq.map(fun row -> (fst row, -(snd row)))
    |> Seq.sortByDescending (snd)

expenses
|> Seq.iter (fun(t, a) -> printf "%s, %M" t a)

let csv =
    expenses
    |> Seq.map (fun(t, a) -> sprintf "%s, %M" t a)

System.IO.File.WriteAllLines("output.csv", csv)