// Copyright (c) Microsoft Corporation.  All Rights Reserved.  See License.txt in the project root for license information.

namespace Internal.Utilities

open FSharp.Core.OptimizedClosures

[<CompilationRepresentation(CompilationRepresentationFlags.ModuleSuffix)>]
module internal ResizeArray =

    let length (arr: ResizeArray<'T>) = arr.Count

    let get (arr: ResizeArray<'T>) (n: int) = arr[n]

    let set (arr: ResizeArray<'T>) (n: int) (x: 'T) = arr[n] <- x

    let create (n: int) x =
        ResizeArray<_>(seq { for _ in 1..n -> x })

    let init (n: int) (f: int -> 'T) =
        ResizeArray<_>(seq { for i in 0 .. n - 1 -> f i })

    let blit (arr1: ResizeArray<'T>) start1 (arr2: ResizeArray<'T>) start2 len =
        if start1 < 0 then
            invalidArg "start1" "index must be positive"

        if start2 < 0 then
            invalidArg "start2" "index must be positive"

        if len < 0 then
            invalidArg "len" "length must be positive"

        if start1 + len > length arr1 then
            invalidArg "start1" "(start1+len) out of range"

        if start2 + len > length arr2 then
            invalidArg "start2" "(start2+len) out of range"

        for i = 0 to len - 1 do
            arr2[start2 + i] <- arr1[start1 + i]

    let concat (arrs: ResizeArray<'T> list) =
        ResizeArray<_>(
            seq {
                for arr in arrs do
                    for x in arr do
                        yield x
            }
        )

    let append (arr1: ResizeArray<'T>) (arr2: ResizeArray<'T>) = concat [ arr1; arr2 ]

    let sub (arr: ResizeArray<'T>) start len =
        if start < 0 then
            invalidArg "start" "index must be positive"

        if len < 0 then
            invalidArg "len" "length must be positive"

        if start + len > length arr then
            invalidArg "len" "length must be positive"

        ResizeArray<_>(seq { for i in start .. start + len - 1 -> arr[i] })

    let fill (arr: ResizeArray<'T>) (start: int) (len: int) (x: 'T) =
        if start < 0 then
            invalidArg "start" "index must be positive"

        if len < 0 then
            invalidArg "len" "length must be positive"

        if start + len > length arr then
            invalidArg "len" "length must be positive"

        for i = start to start + len - 1 do
            arr[i] <- x

    let copy (arr: ResizeArray<'T>) = ResizeArray<_>(arr)

    let toList (arr: ResizeArray<_>) =
        let mutable res = []

        for i = length arr - 1 downto 0 do
            res <- arr[i] :: res

        res

    let ofList (l: _ list) =
        let len = l.Length
        let res = ResizeArray<_>(len)

        let rec add =
            function
            | [] -> ()
            | e :: l ->
                res.Add(e)
                add l

        add l
        res

    let iter f (arr: ResizeArray<_>) =
        for i = 0 to arr.Count - 1 do
            f arr[i]

    let map f (arr: ResizeArray<_>) =
        let len = length arr
        let res = ResizeArray<_>(len)

        for i = 0 to len - 1 do
            res.Add(f arr[i])

        res

    let mapi f (arr: ResizeArray<_>) =
        let f = FSharpFunc<_, _, _>.Adapt (f)
        let len = length arr
        let res = ResizeArray<_>(len)

        for i = 0 to len - 1 do
            res.Add(f.Invoke(i, arr[i]))

        res

    let iteri f (arr: ResizeArray<_>) =
        let f = FSharpFunc<_, _, _>.Adapt (f)

        for i = 0 to arr.Count - 1 do
            f.Invoke(i, arr[i])

    let exists (f: 'T -> bool) (arr: ResizeArray<'T>) =
        let len = length arr
        let rec loop i = i < len && (f arr[i] || loop (i + 1))
        loop 0

    let forall f (arr: ResizeArray<_>) =
        let len = length arr
        let rec loop i = i >= len || (f arr[i] && loop (i + 1))
        loop 0

    let indexNotFound () =
        raise (System.Collections.Generic.KeyNotFoundException("An index satisfying the predicate was not found in the collection"))

    let find f (arr: ResizeArray<_>) =
        let rec loop i =
            if i >= length arr then indexNotFound ()
            elif f arr[i] then arr[i]
            else loop (i + 1)

        loop 0

    let tryPick f (arr: ResizeArray<_>) =
        let rec loop i =
            if i >= length arr then
                None
            else
                match f arr[i] with
                | None -> loop (i + 1)
                | res -> res

        loop 0

    let tryFind f (arr: ResizeArray<_>) =
        let rec loop i =
            if i >= length arr then None
            elif f arr[i] then Some arr[i]
            else loop (i + 1)

        loop 0

    let iter2 f (arr1: ResizeArray<'T>) (arr2: ResizeArray<'b>) =
        let f = FSharpFunc<_, _, _>.Adapt (f)
        let len1 = length arr1

        if len1 <> length arr2 then
            invalidArg "arr2" "the arrays have different lengths"

        for i = 0 to len1 - 1 do
            f.Invoke(arr1[i], arr2[i])

    let map2 f (arr1: ResizeArray<'T>) (arr2: ResizeArray<'b>) =
        let f = FSharpFunc<_, _, _>.Adapt (f)
        let len1 = length arr1

        if len1 <> length arr2 then
            invalidArg "arr2" "the arrays have different lengths"

        let res = ResizeArray<_>(len1)

        for i = 0 to len1 - 1 do
            res.Add(f.Invoke(arr1[i], arr2[i]))

        res

    let choose f (arr: ResizeArray<_>) =
        let res = ResizeArray<_>()

        for i = 0 to length arr - 1 do
            match f arr[i] with
            | None -> ()
            | Some b -> res.Add(b)

        res

    let filter f (arr: ResizeArray<_>) =
        let res = ResizeArray<_>()

        for i = 0 to length arr - 1 do
            let x = arr[i]

            if f x then
                res.Add(x)

        res

    let partition f (arr: ResizeArray<_>) =
        let res1 = ResizeArray<_>()
        let res2 = ResizeArray<_>()

        for i = 0 to length arr - 1 do
            let x = arr[i]
            if f x then res1.Add(x) else res2.Add(x)

        res1, res2

    let rev (arr: ResizeArray<_>) =
        let len = length arr
        let res = ResizeArray<_>(len)

        for i = len - 1 downto 0 do
            res.Add(arr[i])

        res

    let foldBack (f: 'T -> 'State -> 'State) (arr: ResizeArray<'T>) (acc: 'State) =
        let mutable res = acc
        let len = length arr

        for i = len - 1 downto 0 do
            res <- f (get arr i) res

        res

    let fold (f: 'State -> 'T -> 'State) (acc: 'State) (arr: ResizeArray<'T>) =
        let mutable res = acc
        let len = length arr

        for i = 0 to len - 1 do
            res <- f res (get arr i)

        res

    let toArray (arr: ResizeArray<'T>) = arr.ToArray()

    let ofArray (arr: 'T[]) = ResizeArray<_>(arr)

    let toSeq (arr: ResizeArray<'T>) = Seq.readonly arr

    let sort f (arr: ResizeArray<'T>) = arr.Sort(System.Comparison(f))

    let sortBy f (arr: ResizeArray<'T>) =
        arr.Sort(System.Comparison(fun x y -> compare (f x) (f y)))

    let exists2 f (arr1: ResizeArray<_>) (arr2: ResizeArray<_>) =
        let len1 = length arr1

        if len1 <> length arr2 then
            invalidArg "arr2" "the arrays have different lengths"

        let rec loop i =
            i < len1 && (f arr1[i] arr2[i] || loop (i + 1))

        loop 0

    let findIndex f (arr: ResizeArray<_>) =
        let rec go n =
            if n >= length arr then indexNotFound ()
            elif f arr[n] then n
            else go (n + 1)

        go 0

    let findIndexi f (arr: ResizeArray<_>) =
        let rec go n =
            if n >= length arr then indexNotFound ()
            elif f n arr[n] then n
            else go (n + 1)

        go 0

    let foldSub f acc (arr: ResizeArray<_>) start fin =
        let mutable res = acc

        for i = start to fin do
            res <- f res arr[i]

        res

    let foldBackSub f (arr: ResizeArray<_>) start fin acc =
        let mutable res = acc

        for i = fin downto start do
            res <- f arr[i] res

        res

    let reduce f (arr: ResizeArray<_>) =
        let arrn = length arr

        if arrn = 0 then
            invalidArg "arr" "the input array may not be empty"
        else
            foldSub f arr[0] arr 1 (arrn - 1)

    let reduceBack f (arr: ResizeArray<_>) =
        let arrn = length arr

        if arrn = 0 then
            invalidArg "arr" "the input array may not be empty"
        else
            foldBackSub f arr 0 (arrn - 2) arr[arrn - 1]

    let fold2 f (acc: 'T) (arr1: ResizeArray<'T1>) (arr2: ResizeArray<'T2>) =
        let f = FSharpFunc<_, _, _, _>.Adapt (f)
        let mutable res = acc
        let len = length arr1

        if len <> length arr2 then
            invalidArg "arr2" "the arrays have different lengths"

        for i = 0 to len - 1 do
            res <- f.Invoke(res, arr1[i], arr2[i])

        res

    let foldBack2 f (arr1: ResizeArray<'T1>) (arr2: ResizeArray<'T2>) (acc: 'b) =
        let f = FSharpFunc<_, _, _, _>.Adapt (f)
        let mutable res = acc
        let len = length arr1

        if len <> length arr2 then
            invalidArg "arr2" "the arrays have different lengths"

        for i = len - 1 downto 0 do
            res <- f.Invoke(arr1[i], arr2[i], res)

        res

    let forall2 f (arr1: ResizeArray<_>) (arr2: ResizeArray<_>) =
        let len1 = length arr1

        if len1 <> length arr2 then
            invalidArg "arr2" "the arrays have different lengths"

        let rec loop i =
            i >= len1 || (f arr1[i] arr2[i] && loop (i + 1))

        loop 0

    let isEmpty (arr: ResizeArray<_>) = length (arr: ResizeArray<_>) = 0

    let iteri2 f (arr1: ResizeArray<'T>) (arr2: ResizeArray<'b>) =
        let f = FSharpFunc<_, _, _, _>.Adapt (f)
        let len1 = length arr1

        if len1 <> length arr2 then
            invalidArg "arr2" "the arrays have different lengths"

        for i = 0 to len1 - 1 do
            f.Invoke(i, arr1[i], arr2[i])

    let mapi2 (f: int -> 'T -> 'b -> 'c) (arr1: ResizeArray<'T>) (arr2: ResizeArray<'b>) =
        let f = FSharpFunc<_, _, _, _>.Adapt (f)
        let len1 = length arr1

        if len1 <> length arr2 then
            invalidArg "arr2" "the arrays have different lengths"

        init len1 (fun i -> f.Invoke(i, arr1[i], arr2[i]))

    let scanBackSub f (arr: ResizeArray<'T>) start fin acc =
        let f = FSharpFunc<_, _, _>.Adapt (f)
        let mutable state = acc
        let res = create (2 + fin - start) acc

        for i = fin downto start do
            state <- f.Invoke(arr[i], state)
            res[i - start] <- state

        res

    let scanSub f acc (arr: ResizeArray<'T>) start fin =
        let f = FSharpFunc<_, _, _>.Adapt (f)
        let mutable state = acc
        let res = create (fin - start + 2) acc

        for i = start to fin do
            state <- f.Invoke(state, arr[i])
            res[i - start + 1] <- state

        res

    let scan f acc (arr: ResizeArray<'T>) =
        let arrn = length arr
        scanSub f acc arr 0 (arrn - 1)

    let scanBack f (arr: ResizeArray<'T>) acc =
        let arrn = length arr
        scanBackSub f arr 0 (arrn - 1) acc

    let singleton x =
        let res = ResizeArray<_>(1)
        res.Add(x)
        res

    let tryFindIndex f (arr: ResizeArray<'T>) =
        let rec go n =
            if n >= length arr then None
            elif f arr[n] then Some n
            else go (n + 1)

        go 0

    let tryFindIndexi f (arr: ResizeArray<'T>) =
        let rec go n =
            if n >= length arr then None
            elif f n arr[n] then Some n
            else go (n + 1)

        go 0

    let zip (arr1: ResizeArray<_>) (arr2: ResizeArray<_>) =
        let len1 = length arr1

        if len1 <> length arr2 then
            invalidArg "arr2" "the arrays have different lengths"

        init len1 (fun i -> arr1[i], arr2[i])

    let unzip (arr: ResizeArray<_>) =
        let len = length arr
        let res1 = ResizeArray<_>(len)
        let res2 = ResizeArray<_>(len)

        for i = 0 to len - 1 do
            let x, y = arr[i]
            res1.Add(x)
            res2.Add(y)

        res1, res2
