unit VCSInfoMenuWzrd;

interface
uses
  System.Generics.Collections,
  ToolsAPI;


type
  TRepoClient = class;
  TRepoClientClass = class of TRepoClient;

  TRepoInfo = record
    Root: string;
    IsRepo: Boolean;
    Client: TRepoClient;
    Incoming: Cardinal;
    Outgoing: Cardinal;
    LastUpdated: TDateTime;
    function IsRepo: Boolean;
  end;

  TRepoClient = class abstract
  private
    FRootPath: string;
  public
    constructor Create(const Path: string);
    property Root: string read FRootPath;
  public
    class function IsRepo(const Path: string): boolean; virtual;
    class function GetRoot(const Path: string): string; virtual;
    class function GetIncoming(const Path: string): Cardinal; virtual;
    class function GetOutgoing(const Path: string): Cardinal; virtual;
    class function GetSummary(const Path: string): Cardinal; virtual;
  private
    class var FClients: TList<TRepoClientClass>;
  public
    class procedure RegisterClient(const RepoClientClass: TRepoClientClass);
    class function CreateClient(const Path: string): TRepoClient;
  end;

  THgClient = class(TRepoClient)
    class function IsRepo(const Path: string): boolean; override;
    class function GetRoot(const Path: string): string; override;
    class function GetIncoming(const Path: string): Cardinal; override;
    class function GetOutgoing(const Path: string): Cardinal; override;
    class function GetSummary(const Path: string): Cardinal; override;
  end;

  TFossilClient = class(TRepoClient)
    class function IsRepo(const Path: string): boolean; override;
    class function GetRoot(const Path: string): string; override;
    class function GetIncoming(const Path: string): Cardinal; override;
    class function GetOutgoing(const Path: string): Cardinal; override;
    class function GetSummary(const Path: string): Cardinal; override;
  end;

  // TODO: implement IOTAEditorNotifier and/or IOTAIDENotifier so we know which file is active
  TVCSInfoWizard = class(TNotifierObject, IOTAWizard, IOTAMenuWizard)
    private
      FRepos: TDictionary<string,TRepoInfo>;

  Result := scMenuIDString;
end;

{ ------------------------------------------------------------------------------------------------ }
function TVCSInfoWizard.GetRepoInfo(const AFileName: string; const AForceUpdate: Boolean): TRepoInfo;
var
  FilePath, FinalFilePath, RootPath, FinalRootPath: string;
  Client: TRepoClient;
  Lines: TStringList;
  iRes: Cardinal;
begin
  Result := Default(TRepoInfo);
  if not Assigned(FRepos) then
    FRepos := TDictionary<string,TRepoInfo>.Create;

  FilePath := ExtractFileDir(AFileName);
  FinalFilePath := GetFinalPathName(FilePath);
  if AForceUpdate or (not FRepos.TryGetValue(FinalFilePath, Result)) or (Now - Result.LastUpdated > 5 / SecsPerDay) then begin

    // TODO: try all registered repo clients to identify whether FilePath is a repo, and get its root
    Client := TRepoClient.CreateClient(FilePath);

    iRes := ExecuteCmd('hg -yq root', RootPath, False, nil, FilePath);
    if iRes >= 255 then begin
      Result.Root := FilePath;
      Result.LastUpdated := Now;
      FinalRootPath := FinalFilePath;
    end else begin
      RootPath := RootPath.Trim;