{
  (c) 2014 ti_dic

  This library is free software; you can redistribute it and/or modify it
  under the terms of the GNU Library General Public License as published by
  the Free Software Foundation; either version 2 of the License, or (at your
  option) any later version.

  This program is distributed in the hope that it will be useful, but WITHOUT
  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
  for more details.

  You should have received a copy of the GNU Library General Public License
  along with this library; if not, write to the Free Software Foundation,
  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
}
unit mvMapProvider;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils;
Type
  { TTileId }
  TTileId = record
    X,Y : int64;
    Z : integer;
  end;


  TGetSvrStr = Function (id : integer) : string of object;
  TGetValStr = Function (const Tile : TTileId) : String of object;

  { TMapProvider }

  TMapProvider = Class
    private
      FLayer : integer;
      idServer : Array of Integer;
      FName : String;
      FUrl : Array of string;
      FNbSvr : Array of integer;
      FGetSvrStr : Array of TGetSvrStr;
      FGetXStr : Array of TGetValStr;
      FGetYStr : Array of TGetValStr;
      FGetZStr : Array of TGetValStr;
      FMinZoom : Array of integer;
      FMaxZoom : Array of integer;
      function getLayerCount: integer;
      procedure SetLayer(AValue: integer);

    public
      constructor Create(aName : String);
      destructor Destroy; override;
      procedure AddURL(Url: String; NbSvr: integer;aMinZoom : integer;aMaxZoom : integer; GetSvrStr: TGetSvrStr; GetXStr: TGetValStr; GetYStr: TGetValStr; GetZStr: TGetValStr);
      procedure GetZoomInfos(out zMin:integer;out zMax : integer);
      Function GetUrlForTile(id : TTileId) : String;
      property Name : String read FName;
      property LayerCount : integer read getLayerCount;
      property Layer : integer read FLayer write SetLayer;
  end;


implementation

{ TMapProvider }

function TMapProvider.getLayerCount: integer;
begin
  Result:=length(FUrl);
end;

procedure TMapProvider.SetLayer(AValue: integer);
begin
  if FLayer=AValue then Exit;
  if (aValue<low(FUrl)) and (aValue>high(FUrl)) then
  Begin
    Raise Exception.create('bad Layer');
  end;
  FLayer:=AValue;
end;

constructor TMapProvider.Create(aName: String);
begin
  FName:=aName;
end;

destructor TMapProvider.Destroy;
begin
  Finalize(idServer);
  Finalize(FName);
  Finalize(FUrl);
  Finalize(FNbSvr);
  Finalize(FGetSvrStr);
  Finalize(FGetXStr);
  Finalize(FGetYStr);
  Finalize(FGetZStr);
  Finalize(FMinZoom);
  Finalize(FMaxZoom);
  inherited;
end;

procedure TMapProvider.AddURL(Url: String; NbSvr: integer;
  aMinZoom : integer;aMaxZoom :  integer;
  GetSvrStr: TGetSvrStr; GetXStr: TGetValStr; GetYStr: TGetValStr;
  GetZStr: TGetValStr);
var nb : integer;
begin
  nb:=length(FUrl)+1;
  SetLength(IdServer,nb);
  SetLength(FUrl,nb);
  SetLength(FNbSvr,nb);
  SetLength(FGetSvrStr,nb);
  SetLength(FGetXStr,nb);
  SetLength(FGetYStr,nb);
  SetLength(FGetZStr,nb);
  SetLength(FMinZoom,nb);
  SetLength(FMaxZoom,nb);
  nb:=high(FUrl);
  FUrl[nb]:=Url;
  FNbSvr[nb]:=NbSvr;
  FMinZoom[nb]:=aMinZoom;
  FMaxZoom[nb]:=aMaxZoom;
  FGetSvrStr[nb]:=GetSvrStr;
  FGetXStr[nb]:=GetXStr;
  FGetYStr[nb]:=GetYStr;
  FGetZStr[nb]:=GetZStr;
  FLayer:=low(FUrl);
end;

procedure TMapProvider.GetZoomInfos(out zMin: integer; out zMax: integer);
begin
  zMin:=FMinZoom[layer];
  zMax:=FMaxZoom[layer];
end;

function TMapProvider.GetUrlForTile(id: TTileId): String;
var i : integer;
    XVal,yVal,zVal,SvrVal : String;
    idsvr: integer;
begin
  Result:='';
  i:=layer;
  if (i>high(idServer)) or (i<low(idServer)) or (FNbSvr[i]=0) then
    exit;

  idsvr:=idServer[i] mod FNbSvr[i];
  idServer[i]+=1;

  SvrVal:=inttostr(idsvr);
  XVal:=inttostr(id.X);
  YVal:=inttostr(id.Y);
  ZVal:=inttostr(id.Z);
  if Assigned(FGetSvrStr[i]) then
     SvrVal:=FGetSvrStr[i](idsvr);
  if Assigned(FGetXStr[i]) then
     XVal:=FGetXStr[i](id);
  if Assigned(FGetYStr[i]) then
     YVal:=FGetYStr[i](id);
  if Assigned(FGetZStr[i]) then
     ZVal:=FGetZStr[i](id);
  Result:=StringReplace(FUrl[i],'%serv%',SvrVal,[rfreplaceall]);
  Result:=StringReplace(Result,'%x%',XVal,[rfreplaceall]);
  Result:=StringReplace(Result,'%y%',YVal,[rfreplaceall]);
  Result:=StringReplace(Result,'%z%',ZVal,[rfreplaceall]);
end;

end.