Get stats from cost page usage

Cost.fsx

#r "nuget: FSharp.Data,4.2.6"
#r "nuget: FSharpPlus,1.2.2"
#r "nuget: FSharp.Stats, 0.4.2"

open FSharp.Data
open FSharpPlus
open System.Web
open System
open FSharp.Stats

let csv =
    CsvFile
        .Load(__SOURCE_DIRECTORY__ + "/cost.csv")
        .Cache()

type Entry = { Date: DateOnly; Start: DateOnly }

let extract_start query =
    let uri = System.Uri($"http://foo.com{query}")
    let kvps = HttpUtility.ParseQueryString uri.Query
    let idStr = kvps.["tcChartStart"]
    idStr

let parse_date string =
    try
        string |> DateOnly.Parse |> Ok
    with
    | _ -> Error("Unable to parse")

let parse_entry (row: CsvRow) =
    let maybe_date = row.GetColumn("Date") |> parse_date

    let maybe_start =
        row.GetColumn("search")
        |> extract_start
        |> parse_date

    Result.map2 (fun date start -> { Date = date; Start = start }) maybe_date maybe_start

let range_on_entry (entry: Entry) =
    let date =
        entry.Date.ToDateTime(new TimeOnly(0, 0))

    let start =
        entry.Start.ToDateTime(new TimeOnly(0, 0))

    let diff = date.Subtract(start).Days

    max diff 0

let max_folder (acc: int) entry =
    let range =
        entry
        |> parse_entry
        |> Result.map range_on_entry
        |> Result.defaultValue 0

    max acc range


let max_period = csv.Rows |> Seq.fold max_folder 0

let print_entry (entry: Entry) =
    printf "%s" (entry.Start.ToString "yyyy/MM/dd")

// csv.Rows
// |> Seq.head
// |> parse_entry
// |> Result.map print_entry

// printf "%i" max_period
let all_diffs =
    csv.Rows
    |> Seq.choose (parse_entry >> Option.ofResult)
    |> Seq.map range_on_entry


let stats =
    let diffs = all_diffs
    let stats = Seq.stats diffs
    // let mean = (Seq.meanBy float diffs)
    let median = (Seq.median diffs)
    printf "Max %d Mean (Average) %d Median (Middle number) %d" stats.Max stats.Mean median