@using Shogi.Contracts.Api;
@using Shogi.Contracts.Types;
@using System.Text.RegularExpressions;
@using System.Net;
@inject PromotePrompt PromotePrompt;
@inject IShogiApi ShogiApi;

<GameBoardPresentation Session="Session"
                       Perspective="Perspective"
                       OnClickHand="OnClickHand"
                       OnClickTile="OnClickTile"
                       SelectedPosition="@selectedBoardPosition"
                       SelectedPieceFromHand="@selectedPieceFromHand"
                       IsMyTurn="IsMyTurn" />

@code {
    [Parameter, EditorRequired]
    public WhichPlayer Perspective { get; set; }
    [Parameter, EditorRequired]
    public Session Session { get; set; }
    private bool IsMyTurn => Session?.BoardState.WhoseTurn == Perspective;
    private string? selectedBoardPosition;
    private WhichPiece? selectedPieceFromHand;

    protected override void OnParametersSet()
    {
        base.OnParametersSet();
        selectedBoardPosition = null;
        selectedPieceFromHand = null;
        if (Session == null)
        {
            throw new ArgumentException($"{nameof(Session)} cannot be null.", nameof(Session));
        }
    }

    bool ShouldPromptForPromotion(string position)
    {
        if (Perspective == WhichPlayer.Player1 && Regex.IsMatch(position, ".[7-9]"))
        {
            return true;
        }
        if (Perspective == WhichPlayer.Player2 && Regex.IsMatch(position, ".[1-3]"))
        {
            return true;
        }
        return false;
    }

    async Task OnClickTile(Piece? pieceAtPosition, string position)
    {
        if (!IsMyTurn) return;


        if (selectedBoardPosition == position)
        {
            // Deselect the selected position.
            selectedBoardPosition = null;
            StateHasChanged();
            return;
        }

        if (selectedBoardPosition == null && pieceAtPosition?.Owner == Perspective)
        {
            // Select an owned piece.
            Console.WriteLine("Selecting piece owned by {0} while I am perspective {1}", pieceAtPosition?.Owner, Perspective);
            selectedBoardPosition = position;
            // Prevent selecting pieces from the hand and board at the same time.
            selectedPieceFromHand = null;
            StateHasChanged();
            return;
        }

        if (selectedPieceFromHand is not null)
        {
            if (pieceAtPosition is null)
            {
                Console.WriteLine("Moving piece from hand.");
                // Placing a piece from the hand to an empty space.
                // await ShogiApi.Move(
                //  Session.SessionName,
                // new MovePieceCommand(selectedPieceFromHand.Value, position));
            }
            StateHasChanged();
            return;
        }

        if (selectedBoardPosition != null)
        {
            if (pieceAtPosition == null || pieceAtPosition?.Owner != Perspective)
            {
                // Moving to an empty space or capturing an opponent's piece.
                if (ShouldPromptForPromotion(position) || ShouldPromptForPromotion(selectedBoardPosition))
                {
                    PromotePrompt.Show(
                        Session.SessionName,
                        new MovePieceCommand(selectedBoardPosition, position, false));
                }
                else
                {
                    await ShogiApi.Move(Session.SessionName, new MovePieceCommand(selectedBoardPosition, position, false));
                }
                StateHasChanged();
                return;
            }
        }
    }

    async Task OnClickHand(Piece piece)
    {
        if (!IsMyTurn) return;

        // Prevent selecting from both the hand and the board.
        selectedBoardPosition = null;

        selectedPieceFromHand = piece.WhichPiece == selectedPieceFromHand
            // Deselecting the already-selected piece
            ? selectedPieceFromHand = null
            : selectedPieceFromHand = piece.WhichPiece;

        StateHasChanged();
    }
}