KLib.MyIdHTTPServer.pas

{
  KLib Version = 3.0
  The Clear BSD License

  Copyright (c) 2020 by Karol De Nery Ortiz LLave. All rights reserved.
  zitrokarol@gmail.com

  Redistribution and use in source and binary forms, with or without
  modification, are permitted (subject to the limitations in the disclaimer
  below) provided that the following conditions are met:

  * Redistributions of source code must retain the above copyright notice,
  this list of conditions and the following disclaimer.

  * Redistributions in binary form must reproduce the above copyright
  notice, this list of conditions and the following disclaimer in the
  documentation and/or other materials provided with the distribution.

  * Neither the name of the copyright holder nor the names of its
  contributors may be used to endorse or promote products derived from this
  software without specific prior written permission.

  NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE GRANTED BY
  THIS LICENSE. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
  CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
  IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  POSSIBILITY OF SUCH DAMAGE.
}

//##############---EXAMPLE OF USE---############
//var
//  _server: TMyIdHTTPServer;
//  _myOnGetAnonymousMethod: TMyOnCommandGetAnonymousMethod;
//begin
//  _myOnGetAnonymousMethod := procedure(var AContext: TIdContext; var ARequestInfo: TIdHTTPRequestInfo; var AResponseInfo: TIdHTTPResponseInfo)
//    begin
//      AResponseInfo.ResponseNo := 200;
//      AResponseInfo.ContentType := 'application/json';
//      AResponseInfo.ContentText := '{"_timestamp":"2017-07-03 08:34:17","_error":""}';
//    end;
//
//  _server := TMyIdHTTPServer.Create(_myOnGetAnonymousMethod, 8000);
//  _server.listen();
//########################################################

unit KLib.MyIdHTTPServer;

interface

uses
  KLib.Generics.JSON, KLib.Generics.Attributes,
  KLib.MyEvent, KLib.Types, KLib.Constants,
  IdHTTPServer, IdContext, IdCustomHTTPServer;

type

  TIdContext = IdContext.TIdContext;
  TIdHTTPRequestInfo = IdCustomHTTPServer.TIdHTTPRequestInfo;
  TIdHTTPResponseInfo = IdCustomHTTPServer.TIdHTTPResponseInfo;

  TMyOnCommandGetAnonymousMethod =
    reference to procedure(var AContext: TIdContext; var ARequestInfo: TIdHTTPRequestInfo; var AResponseInfo: TIdHTTPResponseInfo);

  TDefaultServerErrorResponse = record
    timestamp: string;
    status: integer;
    error: string;
    _message: string;
    [IgnoreAttribute()]
    path: string;
  end;

  TMyIdHTTPServer = class(TIdHTTPServer)
  private
    _myOnCommandGetAnonymousMethod: TMyOnCommandGetAnonymousMethod;
    _isRunningEvent: TMyEvent;
    function _get_isRunning: boolean;
    procedure _set_status(value: TStatus);
  protected
    _status: TStatus;
    procedure _listen(asyncMode: boolean; port: integer = 0);
    procedure myOnCommandGet(AContext: TIdContext; ARequestInfo: TIdHTTPRequestInfo; AResponseInfo: TIdHTTPResponseInfo);
  public
    rejectCallBack: TCallBack;
    onChangeStatus: TCallBack;
    defaultServerErrorResponse: TDefaultServerErrorResponse;
    defaultServerErrorJSONResponse: string;
    property status: TStatus read _status write _set_status;

    constructor create(myOnCommandGetAnonymousMethod: TMyOnCommandGetAnonymousMethod; port: integer = 0;
      rejectCallBack: TCallBack = nil; defaultServerErrorJSONResponse: string = EMPTY_STRING;
      onChangeStatus: TCallBack = nil); overload;
    procedure Alisten(port: integer = 0);
    procedure listen(port: integer = 0);
    procedure stop(isRaiseExceptionEnabled: boolean = true);

    procedure waitUntilIsRunning;

    property isRunning: boolean read _get_isRunning;

    destructor Destroy; override;
  end;

implementation

uses
  KLib.Validate, KLib.Utils,
  System.SysUtils;

constructor TMyIdHTTPServer.create(myOnCommandGetAnonymousMethod: TMyOnCommandGetAnonymousMethod; port: integer = 0;
  rejectCallBack: TCallBack = nil; defaultServerErrorJSONResponse: string = EMPTY_STRING; onChangeStatus: TCallBack = nil);
begin
  inherited Create(nil);
  Self._myOnCommandGetAnonymousMethod := myOnCommandGetAnonymousMethod;
  Self.DefaultPort := port;
  Self.rejectCallBack := rejectCallBack;
  Self.defaultServerErrorJSONResponse := defaultServerErrorJSONResponse;
  Self.onChangeStatus := onChangeStatus;

  Self.OnCommandGet := Self.myOnCommandGet;
  Self._isRunningEvent := TMyEvent.Create;

  Self.status := TStatus.created;

  with defaultServerErrorResponse do
  begin
    timestamp := '';
    status := 500;
    error := 'Internal Server Error';
    _message := '';
  end;
end;

procedure TMyIdHTTPServer.Alisten(port: integer = 0);
begin
  _listen(true, port);
end;

procedure TMyIdHTTPServer.listen(port: integer = 0);
begin
  _listen(false, port);
end;

procedure TMyIdHTTPServer._listen(asyncMode: boolean; port: integer = 0);
const
  ERR_MSG = 'Port not assigned.';
begin
  try
    if (Self.DefaultPort = 0) and (port = 0) then
    begin
      raise Exception.Create(ERR_MSG);
    end
    else if (Self.DefaultPort = 0) then
    begin
      Self.DefaultPort := port;
    end;

    validateThatPortIsAvaliable(Self.DefaultPort);

    Self.Bindings.Clear;
    Self.Bindings.Add;
    Self.Bindings.Items[0].Port := Self.DefaultPort;
    // don't enabled by default
    //    Self.KeepAlive := true;
    Self.Active := true;
    Self.StartListening;
    _isRunningEvent.enable;
    Self.status := TStatus.running;

    if not asyncMode then
    begin
      waitUntilIsRunning;
    end;
  except
    on E: Exception do
    begin
      if Assigned(rejectCallBack) then
      begin
        rejectCallBack(E.Message);
      end
      else
      begin
        raise Exception.Create(E.Message);
      end;
    end;
  end;
end;

procedure TMyIdHTTPServer.stop(isRaiseExceptionEnabled: boolean = true);
const
  ERR_MSG = 'Server doesn''t running.';
begin
  if isRunning then
  begin
    Self.StopListening;
    Self.Active := False;
    _isRunningEvent.disable;
    Self.status := TStatus.stopped;
  end
  else if isRaiseExceptionEnabled then
  begin
    raise Exception.Create(ERR_MSG);
  end;
end;

procedure TMyIdHTTPServer.waitUntilIsRunning;
begin
  while isRunning do
  begin
    _isRunningEvent.WaitFor();
  end;
end;

procedure TMyIdHTTPServer.myOnCommandGet(AContext: TIdContext; ARequestInfo: TIdHTTPRequestInfo; AResponseInfo: TIdHTTPResponseInfo);
var
  _JSONResponse: string;
begin
  if Assigned(_myOnCommandGetAnonymousMethod) then
  begin
    try
      _myOnCommandGetAnonymousMethod(AContext, ARequestInfo, AResponseInfo);
    except
      on E: Exception do
      begin
        AResponseInfo.ResponseNo := 500;
        AResponseInfo.ContentType := APPLICATION_JSON_CONTENT_TYPE;

        if defaultServerErrorJSONResponse <> EMPTY_STRING then
        begin
          _JSONResponse := defaultServerErrorJSONResponse;
        end
        else
        begin
          defaultServerErrorResponse.timestamp := getCurrentDateTimeWithFormattingAsString(DATETIME_FORMAT);
          _JSONResponse := TJSONGenerics.getJSONAsString<TDefaultServerErrorResponse>(defaultServerErrorResponse, NOT_IGNORE_EMPTY_STRINGS);
        end;
        AResponseInfo.ContentText := _JSONResponse;

        if Assigned(rejectCallBack) then
        begin
          rejectCallBack(E.Message);
        end
        else
        begin
          raise Exception.Create(E.Message);
        end;
      end;
    end;
  end;
end;

procedure TMyIdHTTPServer._set_status(value: TStatus);
begin
  _status := value;
  if Assigned(onChangeStatus) then
  begin
    onChangeStatus(get_status_asString(_status));
  end;
end;

function TMyIdHTTPServer._get_isRunning: boolean;
begin
  Result := _isRunningEvent.value;
end;

destructor TMyIdHTTPServer.Destroy;
begin
  FreeAndNil(_isRunningEvent);
  inherited;
end;

end.