//open file
//init wb
//init ws

let rec row_array ws row_num =
    match ws.Rows[row_num] with
        if row_num <= ws.Rows.Length then
            ws.Range("A"+char(row_num)).Value
            |::ws.Range("B"+char(row_num)).Value
            |::ws.Range("C"+char(row_num)).Value
            |::ws.Range("D"+char(row_num)).Value
            |::ws.Range("E"+char(row_num)).Value
            |::[]::(row_array ws (row_num+1))
        else
            []


let sortedList this_array =
    List.sortBy(fun elem -> elem[1]) this_array

let merge_rows x y tail func=
    let [a, b, c, d, e] = x
    let [a1, b1, d1, c1, e1] = y
    if a==a1 then
        [a, b, (c+c1), ((c*d+c1*d1)/(e+e1)), (e+e1)]::(func tail)
    else
        [a, b, c, d, e]:: (func ([a1, b1, d1, c1, e1]::tail)

let merge_last_two_rows x y =
    let [a, b, c, d, e] = x
    let [a1, b1, d1, c1, e1] = y
    if a==a1 then
        [a, b, (c+c1), ((c*d+c1*d1)/(e+e1)), (e+e1)]::[]
    else
        [a, b, c, d, e]::[a1, b1, d1, c1, e1]::[]

let rec average_prices sorted_list =
    match  sorted_list with
        |x::y::tail ->
            merge_rows x y tail average_prices
        |x::y ->
            merge_last_two_rows x y

let ready_item_array =
    let array = row_array ws 2|> sorted_list|> average_prices