TF2 Longest Sightlines

open FSharp.Json
open FSharp.Data
open System

//On fetching data if data is [] then it is the end
//http://api.heatmaps.tf/maps/ctf_2fort/kills?fields=["killer_class","killer_x","killer_y","killer_z","victim_x","victim_y","victim_z"]&limit=5000&offset=0
//sniper class: 2

//Data for kills
type Kills =
    { map_data: MapData; fields: string list; data: float list list }
and MapData =
    { name: string; offset_x: int; offset_y: int; scale: float; kill_count: int }

//Return a list of kills from heatmaps.tf with limit and offset
let FetchData map (limit:int) (page:int) =

    //Throttle requests to max 20/sec, heatmaps.tf requests max requests be 20/sec
    let event = new System.Threading.AutoResetEvent(false)
    let timer = new System.Timers.Timer(50.0)
    timer.Elapsed.Add (fun _ -> event.Set() |> ignore)

    timer.Start()
    event.WaitOne() |> ignore

    //printfn "Fetching page %i for %s" page map
    Http.RequestString ("http://api.heatmaps.tf/maps/" + map + "/kills?fields=[%22killer_class%22,%22killer_x%22,%22killer_y%22,%22killer_z%22,%22victim_x%22,%22victim_y%22,%22victim_z%22]&limit=" + string limit + "&offset=" + string (limit*page))

//Return length between 2 points using heatmapt.tf fields formatting
let CalculateDistance (values:float list) =
    let x = values.[1] - values.[4]
    let y = values.[2] - values.[5]
    let z = values.[3] - values.[6]
    pown x 2 + pown y 2 + pown z 2
    |> sqrt

//Parse map data to get a list of kills from snipers
let rec ParseData map (offset:int): float list =
    //printfn "Parsing offset %i of %s" offset map
    let data = Json.deserialize<Kills> (FetchData map 5000 offset)
    if data.data = [] || offset = 20 then
        []
    else
        data.data
        |> List.filter (fun x -> x.[0] = 2.0)
        |> List.map (fun x -> CalculateDistance x)
        |> List.append (ParseData map (offset+1))

//Take parsed data and get useful data
let ProcessData map =
    let data = ParseData map 0
    Console.ForegroundColor <- ConsoleColor.Yellow
    printfn "Longest kill in %A was %A" map (data |> List.max)

[<EntryPoint>]
let main argv =
    Console.ForegroundColor <- ConsoleColor.Blue
    ProcessData "ctf_2fort"

    System.Console.ReadKey() |> ignore
    0