@using Shogi.Contracts.Types;
@using System.Text.Json;

<article class="game-board">
	<!-- Game board -->
	<section class="board" data-perspective="@Perspective" style="grid-area: board">
		@for (var rank = 1; rank < 10; rank++)
		{
			foreach (var file in Files)
			{
				var position = $"{file}{rank}";
				var piece = Session?.BoardState.Board[position];
				var isSelected = piece != null && SelectedPosition == position;
				<div class="tile" @onclick="OnClickTileInternal(position)"
						 data-position="@(position)"
						 data-selected="@(isSelected)"
						 style="grid-area: @position">
					@if (piece != null)
					{
						<GamePiece Piece="piece" Perspective="Perspective" />
					}
				</div>
			}

		}
	</section>
	<div class="ruler vertical" style="grid-area: rank">
		<span>9</span>
		<span>8</span>
		<span>7</span>
		<span>6</span>
		<span>5</span>
		<span>4</span>
		<span>3</span>
		<span>2</span>
		<span>1</span>
	</div>
	<div class="ruler" style="grid-area: file">
		<span>A</span>
		<span>B</span>
		<span>C</span>
		<span>D</span>
		<span>E</span>
		<span>F</span>
		<span>G</span>
		<span>H</span>
		<span>I</span>
	</div>

	<!-- Side board -->
	@if (Session != null && UseSideboard == true)
	{
		<aside class="side-board PrimaryTheme ThemeVariant--Contrast" style="grid-area: opponent-side-board">
			@if (opponentHand.Any())
			{
				@foreach (var piece in opponentHand)
				{
					<div class="tile">
						<GamePiece Piece="piece" Perspective="Perspective" />
					</div>
				}
			}
		</aside>

		<div class="player-info" style="grid-area: opponent-info">
			<OpponentName Name="@opponentName"
										IsTurn="!IsMyTurn"
										InCheck="IsOpponentInCheck"
										IsVictor="IsOpponentVictor" />
		</div>
		<div class="player-info" style="grid-area: player-info">
			<PlayerName Name="@userName"
									IsTurn="IsMyTurn"
									InCheck="IsPlayerInCheck"
									IsVictor="IsPlayerVictor" />
		</div>

		<AuthorizeView>
			<Authorized>
				<aside class="side-board PrimaryTheme ThemeVariant--Contrast" style="grid-area: player-side-board">
					@if (Perspective == WhichPlayer.Player2 && string.IsNullOrEmpty(Session.Player2))
					{
						<div class="place-self-center">
							<button @onclick="OnClickJoinGameInternal">Join Game</button>
						</div>
					}
					else if (userHand.Any())
					{
						@foreach (var piece in userHand)
						{
							<div @onclick="OnClickHandInternal(piece)"
									 class="tile"
									 data-selected="@(piece.WhichPiece == SelectedPieceFromHand)">
								<GamePiece Piece="piece" Perspective="Perspective" />
							</div>
						}
					}
				</aside>
			</Authorized>
			<NotAuthorized>
				<aside class="login-to-play PrimaryTheme ThemeVariant--Contrast" style="grid-area: player-side-board">
					<p><a href="login">Log in</a> to play!</p>
				</aside>
			</NotAuthorized>
		</AuthorizeView>
	}
</article>

@code {
	static readonly string[] Files = new[] { "A", "B", "C", "D", "E", "F", "G", "H", "I" };

	/// <summary>
	/// When true, an icon is displayed indicating that the user is spectating.
	/// </summary>
	[Parameter] public bool IsSpectating { get; set; } = false;
	[Parameter] public WhichPlayer Perspective { get; set; }
	[Parameter] public Session? Session { get; set; }
	[Parameter] public string? SelectedPosition { get; set; }
	[Parameter] public WhichPiece? SelectedPieceFromHand { get; set; }
	// TODO: Exchange these OnClick actions for events like "SelectionChangedEvent" and "MoveFromBoardEvent" and "MoveFromHandEvent".
	[Parameter] public EventCallback<string> OnClickTile { get; set; }
	[Parameter] public EventCallback<Piece> OnClickHand { get; set; }
	[Parameter] public EventCallback OnClickJoinGame { get; set; }
	[Parameter] public bool UseSideboard { get; set; } = true;
	private IReadOnlyCollection<Piece> opponentHand;
	private IReadOnlyCollection<Piece> userHand;
	private string? userName;
	private string? opponentName;
	public GameBoardPresentation()
	{
		opponentHand = Array.Empty<Piece>();
		userHand = Array.Empty<Piece>();
		userName = string.Empty;
		opponentName = string.Empty;
	}

	protected override void OnParametersSet()
	{
		base.OnParametersSet();

		if (Session == null)
		{
			opponentHand = Array.Empty<Piece>();
			userHand = Array.Empty<Piece>();
			userName = string.Empty;
			opponentName = string.Empty;
		}
		else
		{
			opponentHand = Perspective == WhichPlayer.Player1
					? this.Session.BoardState.Player2Hand
					: this.Session.BoardState.Player1Hand;
			userHand = Perspective == WhichPlayer.Player1
					? this.Session.BoardState.Player1Hand
					: this.Session.BoardState.Player2Hand;
			userName = Perspective == WhichPlayer.Player1
					? this.Session.Player1
					: this.Session.Player2 ?? "Empty Seat";
			opponentName = Perspective == WhichPlayer.Player1
					? this.Session.Player2 ?? "Empty Seat"
					: this.Session.Player1;
		}
	}

	private bool IsMyTurn => Session?.BoardState.WhoseTurn == Perspective;
	private bool IsPlayerInCheck => Session?.BoardState.PlayerInCheck == Perspective;
	private bool IsOpponentInCheck => Session?.BoardState.PlayerInCheck != null && Session.BoardState.PlayerInCheck != Perspective;
	private bool IsPlayerVictor => Session?.BoardState.Victor == Perspective;
	private bool IsOpponentVictor => Session?.BoardState.Victor != null && Session.BoardState.Victor != Perspective;
	private Func<Task> OnClickTileInternal(string position) => () =>
	{
		if (IsMyTurn)
		{
			return OnClickTile.InvokeAsync(position);
		}
		return Task.CompletedTask;
	};
	private Func<Task> OnClickHandInternal(Piece piece) => () =>
	{
		if (IsMyTurn)
		{
			return OnClickHand.InvokeAsync(piece);
		}
		return Task.CompletedTask;
	};

	private Task OnClickJoinGameInternal() => OnClickJoinGame.InvokeAsync();
}