unit Forms.Map;

interface
uses
  System.Classes,
  System.Generics.Collections,
  Vcl.Controls,
  Vcl.ExtCtrls,
  Vcl.Forms,
  Vcl.Graphics,
  Vcl.StdCtrls,

  VirtualTrees,

  Frame.MapPreview,
  Game.Base,
  Game.Intf;


type
  TMapForm = class(TForm)
    btnCancel: TButton;
    btnOK: TButton;
    edtMapName: TEdit;
    lblMapName: TLabel;
    pnlButtons: TPanel;
    pnlMapName: TPanel;
    vstMap: TVirtualStringTree;
    pnlFilter: TPanel;
    lblFilter: TLabel;
    edtFilter: TEdit;
    frmMapPreview: TMapPreviewFrame;
    pnlMapPreview: TPanel;

    procedure btnOKClick(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure vstMapNodeDblClick(Sender: TBaseVirtualTree; const HitInfo: THitInfo);
    procedure vstMapGetText(Sender: TBaseVirtualTree; Node: PVirtualNode; Column: TColumnIndex; TextType: TVSTTextType; var CellText: string);
    procedure vstMapPaintText(Sender: TBaseVirtualTree; const TargetCanvas: TCanvas; Node: PVirtualNode; Column: TColumnIndex; TextType: TVSTTextType);
    procedure vstMapFocusChanging(Sender: TBaseVirtualTree; OldNode, NewNode: PVirtualNode; OldColumn, NewColumn: TColumnIndex; var Allowed: Boolean);
    procedure vstMapFocusChanged(Sender: TBaseVirtualTree; Node: PVirtualNode; Column: TColumnIndex);
    procedure vstMapChange(Sender: TBaseVirtualTree; Node: PVirtualNode);
    procedure vstMapCollapsing(Sender: TBaseVirtualTree; Node: PVirtualNode; var Allowed: Boolean);
    procedure vstMapCompareNodes(Sender: TBaseVirtualTree; Node1, Node2: PVirtualNode; Column: TColumnIndex; var Result: Integer);
    procedure edtMapNameChange(Sender: TObject);
    procedure edtFilterChange(Sender: TObject);
  private
    FLockMapChange: Boolean;

    function GetMapName: string;
    procedure SetMapName(const Value: string);
  protected
    procedure LoadPredefinedMapList(AGame: IGameMapList);
    procedure CreateMaps(AMaps: TList<TGameMap>);

    function FindMapNode(const AMapName: string): PVirtualNode;

    property MapName: string read GetMapName write SetMapName;
  public
    class function Insert(AOwner: TComponent; AGame: IGameMapList; AMaps: TList<TGameMap>): Boolean;
  end;


implementation
uses
  System.StrUtils,
  System.SysUtils,
  Winapi.Windows;


type
  PGameMap = ^TGameMap;


const
  EmptyCategory = 'Other';


{$R *.dfm}


{ TMapForm }
class function TMapForm.Insert(AOwner: TComponent; AGame: IGameMapList; AMaps: TList<TGameMap>): Boolean;
begin
  with Self.Create(AOwner) do
  try
    LoadPredefinedMapList(AGame);

    Result := (ShowModal = mrOk);
    if Result then
      CreateMaps(AMaps);
  finally
    Free;
  end;
end;


procedure TMapForm.FormCreate(Sender: TObject);
begin
  vstMap.NodeDataSize := SizeOf(PGameMap);
end;


procedure TMapForm.LoadPredefinedMapList(AGame: IGameMapList);
var
  map: TGameMap;
  categoryNodes: TDictionary<string, PVirtualNode>;
  parentNode: PVirtualNode;
  node: PVirtualNode;

begin
  vstMap.BeginUpdate;
  try
    vstMap.Clear;

    categoryNodes := TDictionary<string, PVirtualNode>.Create;
    try
      for map in AGame.PredefinedMapList do
      begin
        if categoryNodes.ContainsKey(map.Category) then
          parentNode := categoryNodes[map.Category]
        else
        begin
          parentNode := vstMap.AddChild(nil, map);
          categoryNodes.Add(map.Category, parentNode);
        end;

        vstMap.AddChild(parentNode, map);
      end;
    finally
      FreeAndNil(categoryNodes);
    end;
  finally
    vstMap.FullExpand;
    vstMap.EndUpdate;

    node := vstMap.GetFirstLevel(1);
    if Assigned(node) then
    begin
      vstMap.FocusedNode := node;
      vstMap.Selected[node] := True;
    end;
  end;
end;


procedure TMapForm.CreateMaps(AMaps: TList<TGameMap>);
var
  node: PVirtualNode;
  nodeData: PGameMap;

begin
  if vstMap.SelectedCount > 1 then
  begin
    for node in vstMap.SelectedNodes do
    begin
      if vstMap.GetNodeLevel(node) = 1 then
      begin
        nodeData := vstMap.GetNodeData(node);
        AMaps.Add(TGameMap.Create(nodeData^));
      end;
    end;
  end else
  begin
    node := FindMapNode(MapName);
    if Assigned(node) then
    begin
      nodeData := vstMap.GetNodeData(node);
      AMaps.Add(TGameMap.Create(nodeData^));
    end else
      AMaps.Add(TGameMap.Create(MapName, '', ''));
  end;
end;


function TMapForm.GetMapName: string;
begin
  Result := Trim(edtMapName.Text);
end;


procedure TMapForm.SetMapName(const Value: string);
begin
  edtMapName.Text := Value;
end;


function TMapForm.FindMapNode(const AMapName: string): PVirtualNode;
begin
  Result := vstMap.IterateSubtree(nil,
    procedure(Sender: TBaseVirtualTree; Node: PVirtualNode; Data: Pointer; var Abort: Boolean)
    var
      nodeData: PGameMap;

    begin
      nodeData := Sender.GetNodeData(Node);
      Abort := (Sender.GetNodeLevel(Node) > 0) and SameText(nodeData^.Name, AMapName);
    end,
    nil);
end;


procedure TMapForm.btnOKClick(Sender: TObject);
begin
  if (vstMap.SelectedCount <= 1) and (Length(MapName) = 0) then
  begin
    MessageBox(Self.Handle, 'Please enter a map name', 'Error', MB_OK or MB_ICONERROR);
    ActiveControl := edtMapName;
    exit;
  end;

  ModalResult := mrOk;
end;


procedure TMapForm.vstMapNodeDblClick(Sender: TBaseVirtualTree; const HitInfo: THitInfo);
begin
  btnOK.Click;
end;


procedure TMapForm.vstMapGetText(Sender: TBaseVirtualTree; Node: PVirtualNode; Column: TColumnIndex; TextType: TVSTTextType; var CellText: string);
var
  nodeData: PGameMap;

begin
  nodeData := Sender.GetNodeData(Node);

  if Sender.GetNodeLevel(Node) = 0 then
  begin
    if Length(nodeData^.Category) > 0 then
      CellText := nodeData^.Category
    else
      CellText := EmptyCategory;
  end else
    CellText := nodeData^.DisplayName;
end;


procedure TMapForm.vstMapPaintText(Sender: TBaseVirtualTree; const TargetCanvas: TCanvas; Node: PVirtualNode; Column: TColumnIndex; TextType: TVSTTextType);
begin
  if (TextType = ttNormal) and (Sender.GetNodeLevel(Node) = 0) then
    TargetCanvas.Font.Style := [fsBold];
end;


procedure TMapForm.vstMapFocusChanging(Sender: TBaseVirtualTree; OldNode, NewNode: PVirtualNode; OldColumn, NewColumn: TColumnIndex; var Allowed: Boolean);
var
  sibling: PVirtualNode;

begin
  Allowed := True;

  if not Assigned(NewNode) then
    exit;

  { Prevent selection of categories while being keyboard-friendly }
  if Sender.GetNodeLevel(NewNode) = 0 then
  begin
    if Assigned(OldNode) then
    begin
      if Sender.AbsoluteIndex(OldNode) < Sender.AbsoluteIndex(NewNode) then
      begin
        { Moving forwards }
        Sender.FocusedNode := Sender.GetFirstChild(NewNode);
      end else
      begin
        { Moving backwards }
        sibling := Sender.GetPreviousSibling(NewNode);
        if Assigned(sibling) then
          Sender.FocusedNode := Sender.GetLastChild(sibling);
      end;
    end;

    Allowed := False;
  end;
end;


procedure TMapForm.vstMapFocusChanged(Sender: TBaseVirtualTree; Node: PVirtualNode; Column: TColumnIndex);
var
  nodeData: PGameMap;

begin
  if FLockMapChange then
    exit;

  if Assigned(Node) then
  begin
    nodeData := Sender.GetNodeData(Node);
    frmMapPreview.Load(nodeData^.PreviewName);

    FLockMapChange := True;
    try
      edtMapName.Text := nodeData^.Name;
    finally
      FLockMapChange := False;
    end;
  end else
    frmMapPreview.Clear;
end;


procedure TMapForm.vstMapChange(Sender: TBaseVirtualTree; Node: PVirtualNode);
const
  EditColor: array[Boolean] of TColor = (clBtnFace, clWindow);

begin
  edtMapName.Enabled := (Sender.selectedCount <= 1);
  edtMapName.Color := EditColor[edtMapName.Enabled];
end;


procedure TMapForm.vstMapCollapsing(Sender: TBaseVirtualTree; Node: PVirtualNode; var Allowed: Boolean);
begin
  Allowed := False;
end;


procedure TMapForm.vstMapCompareNodes(Sender: TBaseVirtualTree; Node1, Node2: PVirtualNode; Column: TColumnIndex; var Result: Integer);
var
  nodeData1: PGameMap;
  nodeData2: PGameMap;

begin
  nodeData1 := Sender.GetNodeData(Node1);
  nodeData2 := Sender.GetNodeData(Node2);

  if Sender.GetNodeLevel(Node1) = 0 then
    Result := CompareText(nodeData1^.Category, nodeData2^.Category)
  else
    Result := CompareText(nodeData1^.DisplayName, nodeData2^.DisplayName);
end;


procedure TMapForm.edtFilterChange(Sender: TObject);
var
  node: PVirtualNode;

begin
  vstMap.BeginUpdate;
  try
    { First run; set visibility of map nodes }
    vstMap.IterateSubtree(nil,
      procedure(Sender: TBaseVirtualTree; Node: PVirtualNode; Data: Pointer; var Abort: Boolean)
      var
        nodeData: PGameMap;

      begin
        if Sender.GetNodeLevel(Node) > 0 then
        begin
          nodeData := Sender.GetNodeData(Node);
          Sender.IsFiltered[Node] := (Length(edtFilter.Text) > 0) and (not ContainsText(nodeData^.DisplayName, edtFilter.Text));
        end;
      end,
      nil);

    { Second run; hide empty categories }
    node := vstMap.GetFirst;
    while Assigned(node) do
    begin
      vstMap.IsFiltered[Node] := not Assigned(vstMap.IterateSubtree(node,
        procedure(Sender: TBaseVirtualTree; Node: PVirtualNode; Data: Pointer; var Abort: Boolean)
        begin
          Abort := not Sender.IsFiltered[Node];
        end,
        nil, [], False, True));

      node := vstMap.GetNextSibling(node);
    end;
  finally
    vstMap.EndUpdate;
  end;
end;


procedure TMapForm.edtMapNameChange(Sender: TObject);
var
  node: PVirtualNode;

begin
  if FLockMapChange then
    exit;

  node := FindMapNode(MapName);
  FLockMapChange := True;
  try
    vstMap.FocusedNode := node;
  finally
    FLockMapChange := False;
  end;

  if Assigned(node) then
  begin
    vstMap.Selected[node] := True;
    frmMapPreview.Load(MapName);
  end else
  begin
    vstMap.ClearSelection;
    frmMapPreview.Clear;
  end;
end;

end.