unit PM.Handler.Folders;

(*
  GET    /folders             -> JSON array of folder names
  POST   /folders             body {name}     -> {message,name}
  DELETE /folders/{name}                       -> {message}
*)

interface

implementation

uses
  System.SysUtils, System.JSON, System.NetEncoding,
  FireDAC.Comp.Client, FireDAC.Stan.Param,
  IdCustomHTTPServer,
  PM.Router, PM.JSON, PM.Database, PM.Session, PM.Audit, PM.RateLimit;

// ===== GET /folders ==========================================================

procedure HandleGetFolders(ARequest: TIdHTTPRequestInfo;
  AResponse: TIdHTTPResponseInfo; const AParams: TArray<string>);
var
  LUserId: Integer;
  LQ: TFDQuery;
  LArr: TJSONArray;
begin
  try
    LUserId := Authenticate(ARequest, AResponse);
  except
    on ESessionRejected do Exit;
  end;

  LArr := TJSONArray.Create;
  DB.Lock;
  try
    LQ := TFDQuery.Create(nil);
    try
      LQ.Connection := DB.Connection;
      LQ.SQL.Text := 'SELECT name FROM folders WHERE user_id = :uid ORDER BY name';
      LQ.ParamByName('uid').AsInteger := LUserId;
      LQ.Open;
      while not LQ.Eof do
      begin
        LArr.Add(LQ.FieldByName('name').AsString);
        LQ.Next;
      end;
    finally
      LQ.Free;
    end;
  finally
    DB.Unlock;
  end;
  TJSONHelper.SendJSON(AResponse, LArr);
end;

// ===== POST /folders =========================================================

procedure HandleCreateFolder(ARequest: TIdHTTPRequestInfo;
  AResponse: TIdHTTPResponseInfo; const AParams: TArray<string>);
var
  LUserId: Integer;
  LBody: TJSONObject;
  LName: string;
  LQ: TFDQuery;
  LObj: TJSONObject;
begin
  try
    LUserId := Authenticate(ARequest, AResponse);
    RequireCSRF(ARequest, AResponse, LUserId);
  except
    on ESessionRejected do Exit;
  end;

  LBody := TJSONHelper.ReadBody(ARequest);
  try
    LName := Trim(LBody.GetValue<string>('name', ''));
  finally
    LBody.Free;
  end;

  if LName = '' then
  begin
    TJSONHelper.SendError(AResponse, 400, 'Folder name required');
    Exit;
  end;
  if SameText(LName, 'All') then
  begin
    TJSONHelper.SendError(AResponse, 400, 'Cannot use All');
    Exit;
  end;

  DB.Lock;
  try
    LQ := TFDQuery.Create(nil);
    try
      LQ.Connection := DB.Connection;
      LQ.SQL.Text := 'INSERT INTO folders (user_id, name) VALUES (:uid, :name)';
      LQ.ParamByName('uid').AsInteger := LUserId;
      LQ.ParamByName('name').AsString := LName;
      try
        LQ.ExecSQL;
      except
        on E: Exception do
        begin
          TJSONHelper.SendError(AResponse, 409, 'Folder exists');
          Exit;
        end;
      end;
    finally
      LQ.Free;
    end;
  finally
    DB.Unlock;
  end;

  LogAudit(LUserId, 'add_folder', GetClientIP(ARequest));
  LObj := TJSONObject.Create;
  LObj.AddPair('message', 'Created');
  LObj.AddPair('name', LName);
  TJSONHelper.SendJSON(AResponse, LObj);
end;

// ===== DELETE /folders/{name} ================================================

procedure HandleDeleteFolder(ARequest: TIdHTTPRequestInfo;
  AResponse: TIdHTTPResponseInfo; const AParams: TArray<string>);
var
  LUserId: Integer;
  LName: string;
  LQ: TFDQuery;
  LChanges: Integer;
begin
  try
    LUserId := Authenticate(ARequest, AResponse);
    RequireCSRF(ARequest, AResponse, LUserId);
  except
    on ESessionRejected do Exit;
  end;

  if Length(AParams) < 1 then
  begin
    TJSONHelper.SendError(AResponse, 400, 'Folder name required');
    Exit;
  end;
  LName := TNetEncoding.URL.Decode(AParams[0]);

  if SameText(LName, 'All') then
  begin
    TJSONHelper.SendError(AResponse, 400, 'Cannot delete All');
    Exit;
  end;

  DB.Lock;
  try
    LQ := TFDQuery.Create(nil);
    try
      LQ.Connection := DB.Connection;
      LQ.SQL.Text := 'DELETE FROM folders WHERE user_id = :uid AND name = :name';
      LQ.ParamByName('uid').AsInteger := LUserId;
      LQ.ParamByName('name').AsString := LName;
      LQ.ExecSQL;
      LChanges := LQ.RowsAffected;
    finally
      LQ.Free;
    end;

    if LChanges = 0 then
    begin
      TJSONHelper.SendError(AResponse, 404, 'Not found');
      Exit;
    end;

    // Reassign entries from the deleted folder to 'All'
    LQ := TFDQuery.Create(nil);
    try
      LQ.Connection := DB.Connection;
      LQ.SQL.Text :=
        'UPDATE vault_entries SET folder = ''All'' ' +
        'WHERE user_id = :uid AND folder = :name';
      LQ.ParamByName('uid').AsInteger := LUserId;
      LQ.ParamByName('name').AsString := LName;
      LQ.ExecSQL;
    finally
      LQ.Free;
    end;
  finally
    DB.Unlock;
  end;

  LogAudit(LUserId, 'delete_folder', GetClientIP(ARequest));
  TJSONHelper.SendOK(AResponse, 'Deleted');
end;

initialization
  Router.Register('GET',    '/folders',       HandleGetFolders);
  Router.Register('POST',   '/folders',       HandleCreateFolder);
  Router.Register('DELETE', '/folders/(.+)',  HandleDeleteFolder);

end.