(*  _                     _
 * | |__  _ __ ___   ___ | | __
 * | '_ \| '__/ _ \ / _ \| |/ /
 * | |_) | | | (_) | (_) |   <
 * |_.__/|_|  \___/ \___/|_|\_\
 *
 * Microframework which helps to develop web Pascal applications.
 *
 * Copyright (c) 2012-2021 Silvio Clecio <silvioprog@gmail.com>
 *
 * Brook framework is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * Brook framework 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with Brook framework; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 *)

{ Contains class which receives data sent by the client. }

unit BrookHTTPRequest;

{$I BrookDefines.inc}

interface

uses
  SysUtils,
  Marshalling,
  libsagui,
  BrookUtility,
  BrookHandledClasses,
  BrookExtra,
  BrookString,
  BrookStringMap,
  BrookHTTPUploads,
  BrookHTTPResponse;

type
  TBrookHTTPRequest = class;

  { Procedure signature used to trigger isolated requests. }
  TBrookHTTPRequestIsolatedProc = procedure(ARequest: TBrookHTTPRequest;
    AResponse: TBrookHTTPResponse; AUserData: Pointer);

{$IFNDEF FPC}

  { Procedure anonymous signature used to trigger isolated requests. }
  TBrookHTTPRequestIsolatedAnonymousProc = reference to procedure(
    ARequest: TBrookHTTPRequest; AResponse: TBrookHTTPResponse;
    AUserData: Pointer);

{$ENDIF}

  { Class which provides headers, cookies, query-string, fields, payloads,
    uploads and other data sent by the client. }
  TBrookHTTPRequest = class(TBrookHandledPersistent)
  private
    FUploads: TBrookHTTPUploads;
    FServerHandle: Pointer;
    FHeaders: TBrookStringMap;
    FCookies: TBrookStringMap;
    FParams: TBrookStringMap;
    FFields: TBrookStringMap;
    FPayload: TBrookString;
    FVersion: string;
    FMethod: string;
    FPath: string;
    FIsIsolated: Boolean;
    FIsUploading: Boolean;
    FClient: Pointer;
    FTLSSession: Pointer;
    FHandle: Psg_httpreq;
    function GetIP: string;
    function GetPaths: TArray<string>; {$IFNDEF DEBUG}inline;{$ENDIF}
    function GetContentType: string; {$IFNDEF DEBUG}inline;{$ENDIF}
    function GetReferer: string; {$IFNDEF DEBUG}inline;{$ENDIF}
    function GetUserAgent: string; {$IFNDEF DEBUG}inline;{$ENDIF}
    procedure SetIsIsolated(AValue: Boolean); {$IFNDEF DEBUG}inline;{$ENDIF}
  protected
    class procedure DoRequestIsolatedProcCallback(Acls: Pcvoid;
      Areq: Psg_httpreq; Ares: Psg_httpres); cdecl; static;
{$IFNDEF FPC}
    class procedure DoRequestIsolatedAnonymousProcCallback(Acls: Pcvoid;
      Areq: Psg_httpreq; Ares: Psg_httpres); cdecl; static;
{$ENDIF}
    class function CreateRequest(AHandle: Pointer): TBrookHTTPRequest; virtual;
    class function CreateResponse(AHandle: Pointer): TBrookHTTPResponse; virtual;
    function CreateUploads(AHandle: Pointer): TBrookHTTPUploads; virtual;
    function CreateHeaders(AHandle: Pointer): TBrookStringMap; virtual;
    function CreateCookies(AHandle: Pointer): TBrookStringMap; virtual;
    function CreateParams(AHandle: Pointer): TBrookStringMap; virtual;
    function CreateFields(AHandle: Pointer): TBrookStringMap; virtual;
    function CreatePayload(AHandle: Pointer): TBrookString; virtual;
    procedure HandleRequestError(ARequest: TBrookHTTPRequest;
      AResponse: TBrookHTTPResponse; AException: Exception);
    procedure DoRequestError(ASender: TObject; ARequest: TBrookHTTPRequest;
      AResponse: TBrookHTTPResponse; AException: Exception); virtual;
    function GetHandle: Pointer; override;
    function GetUserData: Pointer; virtual;
    procedure SetUserData(AValue: Pointer); virtual;
  public
    { Creates an instance of @code(TBrookHTTPRequest).
      @param(AHandle[in] Request handle.) }
    constructor Create(AHandle: Pointer); virtual;
    { Frees an instance of @code(TBrookHTTPRequest). }
    destructor Destroy; override;
    { Checks if the HTTP method is @code(POST), @code(PUT), @code(DELETE) or
      @code(OPTIONS). }
    function IsPost: Boolean; {$IFNDEF DEBUG}inline;{$ENDIF}
    { Checks if current path refers to @code('/favicon.ico'). }
    function IsFavicon: Boolean; {$IFNDEF DEBUG}inline;{$ENDIF}
    { Checks if request contains a valid TLS session. }
    function IsSecure: Boolean; {$IFNDEF DEBUG}inline;{$ENDIF}
    { Checks if the HTTP method is @code(HEAD) or @code(GET). }
    function IsCachable: Boolean; {$IFNDEF DEBUG}inline;{$ENDIF}
    { Checks if the request was done by an Ajax client. }
    function IsXhr: Boolean; {$IFNDEF DEBUG}inline;{$ENDIF}
    { Isolates a request from the main event loop to an own dedicated thread,
      bringing it back when the request finishes.
      @param(AProc[in] Procedure to handle requests and responses isolated from
      the main event loop.)
      @param(AUserData[in] User-defined data.) }
    procedure Isolate(AProc: TBrookHTTPRequestIsolatedProc;
      AUserData: Pointer = nil);{$IFNDEF FPC}overload;{$ENDIF}virtual;
{$IFNDEF FPC}
    { Isolates a request from the main event loop to an own dedicated thread,
      bringing it back when the request finishes.
      @param(AProc[in] Anonymous Procedure to handle requests and responses
      isolated from the main event loop.)
      @param(AUserData[in] User-defined data.) }
    procedure Isolate(const AProc: TBrookHTTPRequestIsolatedAnonymousProc;
      AUserData: Pointer = nil); overload; virtual;
{$ENDIF}
    { Reference to the server instance. }
    property ServerHandle: Pointer read FServerHandle;
    { Hash table containing the request headers. }
    property Headers: TBrookStringMap read FHeaders;
    { Hash table containing the request cookies. }
    property Cookies: TBrookStringMap read FCookies;
    { Hash table containing the request parameters (query-string). }
    property Params: TBrookStringMap read FParams;
    { Hash table containing the request fields (HTML form fields). }
    property Fields: TBrookStringMap read FFields;
    { String buffer containing the request payload. }
    property Payload: TBrookString read FPayload;
    { Contains the requested HTTP version. }
    property Version: string read FVersion;
    { Contains the requested HTTP method. }
    property Method: string read FMethod;
    { Contains the path component. }
    property Path: string read FPath;
    { Contains the client IP. }
    property IP: string read GetIP;
    { Contains the requested Content-Type. }
    property ContentType: string read GetContentType;
    { Contains the client User-Agent. }
    property UserAgent: string read GetUserAgent;
    { Where the request originated. }
    property Referer: string read GetReferer;
    { Contains the levels of the path component. }
    property Paths: TArray<string> read GetPaths;
    { Checks if the request was isolated from the main event loop to an own
      dedicated thread. }
    property IsIsolated: Boolean read FIsIsolated;
    { Checks if the client is uploading data. }
    property IsUploading: Boolean read FIsUploading;
    { List of the uploaded files. }
    property Uploads: TBrookHTTPUploads read FUploads;
    { List of the uploaded files. This is an alias to property @code(Uploads). }
    property Files: TBrookHTTPUploads read FUploads;
    { Contains the socket handle of the client. }
    property Client: Pointer read FClient;
    { Contains the TLS session handle (GnuTLS). }
    property TLSSession: Pointer read FTLSSession;
    { User-defined data to be stored temporally in the request object. }
    property UserData: Pointer read GetUserData write SetUserData;
  end;

implementation

type

  { TBrookHTTPReqIsolatedProcHolder }

  TBrookHTTPReqIsolatedProcHolder<T> = class
  private
    FProc: T;
    FUserData: Pointer;
  public
    constructor Create(const AProc: T; AUserData: Pointer);
    property Proc: T read FProc;
    property UserData: Pointer read FUserData;
  end;

{ TBrookHTTPReqIsolatedProcHolder }

constructor TBrookHTTPReqIsolatedProcHolder<T>.Create(const AProc: T;
  AUserData: Pointer);
begin
  inherited Create;
  FProc := AProc;
  FUserData := AUserData;
end;

{ TBrookHTTPRequest }

constructor TBrookHTTPRequest.Create(AHandle: Pointer);
begin
  inherited Create;
  FHandle := AHandle;
  FUploads := CreateUploads(sg_httpreq_uploads(FHandle));
  FHeaders := CreateHeaders(sg_httpreq_headers(FHandle));
  FCookies := CreateCookies(sg_httpreq_cookies(FHandle));
  FParams := CreateParams(sg_httpreq_params(FHandle));
  FFields := CreateFields(sg_httpreq_fields(FHandle));
  FPayload := CreatePayload(sg_httpreq_payload(FHandle));
  FServerHandle := sg_httpreq_srv(FHandle);
  FVersion := TMarshal.ToString(sg_httpreq_version(FHandle));
  FMethod := TMarshal.ToString(sg_httpreq_method(FHandle));
  FPath := TMarshal.ToString(sg_httpreq_path(FHandle));
  FIsUploading := sg_httpreq_is_uploading(FHandle);
  FClient := sg_httpreq_client(FHandle);
  if Assigned(sg_httpreq_tls_session) then
    FTLSSession := sg_httpreq_tls_session(FHandle);
end;

destructor TBrookHTTPRequest.Destroy;
begin
  FUploads.Free;
  FHeaders.Free;
  FCookies.Free;
  FParams.Free;
  FFields.Free;
  FPayload.Free;
  inherited Destroy;
end;

class procedure TBrookHTTPRequest.DoRequestIsolatedProcCallback(Acls: Pcvoid;
  Areq: Psg_httpreq; Ares: Psg_httpres);
var
  VHolder: TBrookHTTPReqIsolatedProcHolder<TBrookHTTPRequestIsolatedProc>;
  VReq: TBrookHTTPRequest;
  VRes: TBrookHTTPResponse;
begin
  VHolder := Acls;
  try
    VReq := CreateRequest(Areq);
    VRes := CreateResponse(Ares);
    try
      try
        VHolder.Proc(VReq, VRes, VHolder.UserData);
      except
        on E: Exception do
          VReq.HandleRequestError(VReq, VRes, E);
      end;
    finally
      VRes.Free;
      VReq.Free;
    end;
  finally
    VHolder.Free;
  end;
end;

{$IFNDEF FPC}

class procedure TBrookHTTPRequest.DoRequestIsolatedAnonymousProcCallback(
  Acls: Pcvoid; Areq: Psg_httpreq; Ares: Psg_httpres);
var
  VHolder: TBrookHTTPReqIsolatedProcHolder<
    TBrookHTTPRequestIsolatedAnonymousProc>;
  VReq: TBrookHTTPRequest;
  VRes: TBrookHTTPResponse;
begin
  VHolder := Acls;
  try
    VReq := CreateRequest(Areq);
    VRes := CreateResponse(Ares);
    try
      try
        VHolder.Proc(VReq, VRes, VHolder.UserData);
      except
        on E: Exception do
          VReq.HandleRequestError(VReq, VRes, E);
      end;
    finally
      VRes.Free;
      VReq.Free;
    end;
  finally
    VHolder.Free;
  end;
end;

{$ENDIF}

class function TBrookHTTPRequest.CreateRequest(
  AHandle: Pointer): TBrookHTTPRequest;
begin
  Result := TBrookHTTPRequest.Create(AHandle);
end;

class function TBrookHTTPRequest.CreateResponse(
  AHandle: Pointer): TBrookHTTPResponse;
begin
  Result := TBrookHTTPResponse.Create(AHandle);
end;

function TBrookHTTPRequest.CreateUploads(AHandle: Pointer): TBrookHTTPUploads;
begin
  Result := TBrookHTTPUploads.Create(AHandle);
end;

function TBrookHTTPRequest.CreateHeaders(AHandle: Pointer): TBrookStringMap;
begin
  Result := TBrookStringMap.Create(AHandle);
  Result.ClearOnDestroy := False;
end;

function TBrookHTTPRequest.CreateCookies(AHandle: Pointer): TBrookStringMap;
begin
  Result := TBrookStringMap.Create(AHandle);
  Result.ClearOnDestroy := False;
end;

function TBrookHTTPRequest.CreateParams(AHandle: Pointer): TBrookStringMap;
begin
  Result := TBrookStringMap.Create(AHandle);
  Result.ClearOnDestroy := False;
end;

function TBrookHTTPRequest.CreateFields(AHandle: Pointer): TBrookStringMap;
begin
  Result := TBrookStringMap.Create(AHandle);
  Result.ClearOnDestroy := False;
end;

function TBrookHTTPRequest.CreatePayload(AHandle: Pointer): TBrookString;
begin
  Result := TBrookString.Create(AHandle);
end;

procedure TBrookHTTPRequest.HandleRequestError(ARequest: TBrookHTTPRequest;
  AResponse: TBrookHTTPResponse; AException: Exception);
begin
  AResponse.Reset;
  try
    DoRequestError(Self, ARequest, AResponse, AException);
  except
    on E: Exception do
      AResponse.Send(E.Message, BROOK_CT_TEXT_PLAIN, 500);
  end;
end;

{$IFDEF FPC}
 {$PUSH}{$WARN 5024 OFF}
{$ENDIF}

procedure TBrookHTTPRequest.DoRequestError(ASender: TObject; //FI:O804
  ARequest: TBrookHTTPRequest; //FI:O804
  AResponse: TBrookHTTPResponse;
  AException: Exception);
begin
  AResponse.Send(AException.Message, BROOK_CT_TEXT_PLAIN, 500);
end;

{$IFDEF FPC}
 {$POP}
{$ENDIF}

function TBrookHTTPRequest.GetHandle: Pointer;
begin
  Result := FHandle;
end;

procedure TBrookHTTPRequest.SetIsIsolated(AValue: Boolean);
begin
  FIsIsolated := AValue;
end;

function TBrookHTTPRequest.GetIP: string;
var
  P: array[0..45] of cchar;
  C: Pcvoid;
begin
  SgLib.Check;
  C := sg_httpreq_client(FHandle);
  if not Assigned(C) then
    Exit('');
  SgLib.CheckLastError(sg_ip(C, @P[0], SizeOf(P)));
  Result := TMarshal.ToString(@P[0]);
end;

function TBrookHTTPRequest.GetPaths: TArray<string>;
begin
  Result := Path.Split(['/'], TStringSplitOptions.ExcludeEmpty);
end;

function TBrookHTTPRequest.GetContentType: string;
begin
  Result := FHeaders.Get('Content-Type');
end;

function TBrookHTTPRequest.GetReferer: string;
begin
  if not FHeaders.TryValue('Referer', Result) then
    Result := FHeaders.Get('Referrer');
end;

function TBrookHTTPRequest.GetUserAgent: string;
begin
  Result := FHeaders.Get('User-Agent');
end;

function TBrookHTTPRequest.IsPost: Boolean;
begin
  Result := Sagui.IsPost(FMethod);
end;

function TBrookHTTPRequest.IsFavicon: Boolean;
begin
  Result := SameText(Path, '/favicon.ico');
end;

function TBrookHTTPRequest.IsSecure: Boolean;
begin
  Result := Assigned(FTLSSession);
end;

function TBrookHTTPRequest.IsCachable: Boolean;
begin
  Result := (FMethod = 'HEAD') or (FMethod = 'GET');
end;

function TBrookHTTPRequest.IsXhr: Boolean;
begin
  Result := SameText(FHeaders.Get('X-Requested-With'), 'xmlhttprequest');
end;

procedure TBrookHTTPRequest.Isolate(AProc: TBrookHTTPRequestIsolatedProc;
  AUserData: Pointer);
var
  VHolder: TBrookHTTPReqIsolatedProcHolder<TBrookHTTPRequestIsolatedProc>;
begin
  SgLib.Check;
  SetIsIsolated(True);
  VHolder := TBrookHTTPReqIsolatedProcHolder<
    TBrookHTTPRequestIsolatedProc>.Create(AProc, AUserData);
  try
    SgLib.CheckLastError(sg_httpreq_isolate(FHandle,
      DoRequestIsolatedProcCallback, VHolder));
  except
    VHolder.Free;
    raise;
  end;
end;

{$IFNDEF FPC}

procedure TBrookHTTPRequest.Isolate(
  const AProc: TBrookHTTPRequestIsolatedAnonymousProc; AUserData: Pointer);
var
  VHolder: TBrookHTTPReqIsolatedProcHolder<
    TBrookHTTPRequestIsolatedAnonymousProc>;
begin
  SgLib.Check;
  SetIsIsolated(True);
  VHolder := TBrookHTTPReqIsolatedProcHolder<
    TBrookHTTPRequestIsolatedAnonymousProc>.Create(AProc, AUserData);
  try
    SgLib.CheckLastError(sg_httpreq_isolate(FHandle,
      DoRequestIsolatedAnonymousProcCallback, VHolder));
  except
    VHolder.Free;
    raise;
  end;
end;

{$ENDIF}

procedure TBrookHTTPRequest.SetUserData(AValue: Pointer);
begin
  SgLib.Check;
  SgLib.CheckLastError(sg_httpreq_set_user_data(FHandle, AValue));
end;

function TBrookHTTPRequest.GetUserData: Pointer;
begin
  SgLib.Check;
  Result := sg_httpreq_user_data(FHandle);
end;

end.