MinGW_Installer.iss

; Preprocessor directives and comments first. The Environment.iss include below
; opens a [Code] section, so every line between it and [Setup] is Pascal source
; -- a ';' comment placed after the include is parsed as code and fails with
; "'BEGIN' expected".

; WizardStyle's "dynamic" appearance mode (automatic light/dark) landed in Inno
; Setup 6.6.0. On anything older the directive below is rejected and the error
; points at a line the contributor did not write, so fail early and say why.
; WizardStyle itself does not exist at all in Inno Setup 5.
#if VER < EncodeVer(6,6,0)
  #error "Inno Setup 6.6.0 or later is required (WizardStyle 'dynamic'). Download: https://jrsoftware.org/isdl.php"
#endif

#define MyAppPublisher "Ehsan"
#define MyAppURL "https://ehsan.pages.dev"

#ifndef MyAppName
  #define MyAppName "Easy MinGW Installer"
#endif

#ifndef MyOutputName
  #define MyOutputName MyAppName
#endif

#ifndef MyAppVersion
  #define MyAppVersion "0.0.1"
#endif

#ifndef Arch
  #define Arch "64"
#endif

; Deliberately NOT called SourcePath. ISPP predefines a variable of that name
; holding the directory of the .iss itself, so "#ifndef SourcePath" was always
; false and this guard never fired. Compiling the script directly, without the
; build passing a value, silently resolved {#MinGWSource} to the repo root and
; failed later with a confusing message about a missing version_info.txt.
#ifndef MinGWSource
  #error "MinGWSource not defined. Pass /DMinGWSource=<extracted mingw dir> -- Builder.ps1 does this for you."
#endif

; Defines EnvironmentKeyPath and the [Code] EnvRemovePath used below.
#include "inno\Environment.iss"

[Setup]
AppId={{078C8544-DE40-43A5-B293-58408E30C089}
AppName={#MyAppName}
SetupIconFile="assets\icon{#Arch}.ico"
UninstallDisplayIcon="{sd}\MinGW{#Arch}\icon{#Arch}.ico"
AppVersion={#MyAppVersion}
AppPublisher={#MyAppPublisher}
AppPublisherURL={#MyAppURL}
AppSupportURL={#MyAppURL}
AppUpdatesURL={#MyAppURL}
; Without these the published setup.exe has a blank FileVersion and no company:
; VersionInfoVersion defaults to 0.0.0.0 and is NOT derived from AppVersion.
VersionInfoVersion={#MyAppVersion}
VersionInfoCompany={#MyAppPublisher}
VersionInfoProductName={#MyAppName}
VersionInfoDescription={#MyAppName} {#Arch}-bit Setup
; Only one architecture is ever installed, but nothing in the Add/Remove
; Programs entry said which one. Without this it falls back to AppVerName.
UninstallDisplayName={#MyAppName} ({#Arch}-bit)
; With CreateAppDir=no, {app} is {win}, so Inno puts the uninstall data in the
; Windows directory -- roughly 12 MB of unins000.exe/.dat in C:\Windows.
;
; That is untidy, and UninstallFilesDir={sd}\MinGW{#Arch} was tried to fix it.
; Do not do that. It puts the uninstaller inside the tree PrepareToInstall
; deletes, and DelTree deletes every file it CAN before reporting failure. A
; locked file -- the exact case the removal error message describes -- then
; destroys unins000.exe while Setup aborts and installs nothing, leaving an
; Add/Remove Programs entry pointing at a file that no longer exists and cannot
; be uninstalled. Keeping the uninstaller outside the deleted tree means a
; failed removal is always recoverable: the entry still works and its log can
; clean up whatever survived.
CreateAppDir=no
PrivilegesRequired=admin
OutputDir={#OutputPath}
OutputBaseFilename="{#MyOutputName}.v{#MyAppVersion}.{#Arch}-bit"
Compression=lzma2/ultra64
SolidCompression=yes
WizardStyle=modern dynamic
ChangesEnvironment=yes
InfoBeforeFile="{#MinGWSource}\version_info.txt"
DisableWelcomePage=yes
DisableDirPage=yes
DisableProgramGroupPage=yes
DisableReadyPage=yes

[Languages]
Name: "english"; MessagesFile: "compiler:Default.isl"

[Messages]
; Custom string overrides
ButtonNext=&Install
WizardInfoBefore=Package Info
InfoBeforeLabel=Details regarding the packages included in this build.
SetupWindowTitle={#MyAppName} v{#MyAppVersion}

[Files]
Source: "{#MinGWSource}\*"; DestDir: "{sd}\MinGW{#Arch}"; Flags: ignoreversion recursesubdirs createallsubdirs
; ignoreversion to match the line above: an .ico carries no version resource, so
; without it Inno falls back to timestamps and can skip replacing the icon.
Source: "assets\icon{#Arch}.ico"; DestDir: "{sd}\MinGW{#Arch}"; Flags: ignoreversion

[Registry]
; Prepend the MinGW bin directory to the system PATH. {olddata} preserves the
; existing value, which is why this entry cannot carry uninsdeletevalue -- it
; does not own the value it writes. Removal on uninstall is NOT automatic; it is
; done explicitly by CurUninstallStepChanged at the bottom of [Code].
Root: HKLM; Subkey: "{#EnvironmentKeyPath}"; \
  ValueType: expandsz; ValueName: "Path"; ValueData: "{sd}\MinGW{#Arch}\bin;{olddata}"; \
  Check: NeedsAddPath(ExpandConstant('{sd}\MinGW{#Arch}\bin'))

[Code]
const
  { Auto-click constants for skipping pages }
  BN_CLICKED = 0;
  WM_COMMAND = $0111;
  CN_BASE = $BC00;
  CN_COMMAND = CN_BASE + WM_COMMAND;

var
  MinGWDir: string;      { Initialized in InitializeSetup }
  MinGWBinDir: string;   { Initialized in InitializeSetup }
  OtherDir: string;      { The other architecture's install, if any }
  OtherBinDir: string;   { Initialized in InitializeSetup }
  IsUpgrade: Boolean;    { True if this architecture is already installed }
  HasOtherArch: Boolean; { True if the other architecture is installed }

function NeedsAddPath(Path: string): Boolean;
var
  Paths: string;
begin
  { Returns True if the path is not already in PATH. EnvironmentKey comes from
    the included Environment.iss, so this and EnvRemovePath cannot end up
    reading and writing different registry keys. }
  if not RegQueryStringValue(HKLM, EnvironmentKey, 'Path', Paths) then
    Result := True
  else
    Result := Pos(Uppercase(Path) + ';', Uppercase(Paths + ';')) = 0;
end;

function InitializeSetup: Boolean;
begin
  MinGWDir := ExpandConstant('{sd}\MinGW{#Arch}');
  MinGWBinDir := MinGWDir + '\bin';

  { Only one architecture may be installed at a time. Both builds put a gcc.exe
    on the system PATH, and whichever entry comes first silently wins, so a
    32-bit install left sitting next to a 64-bit one hands the user a toolchain
    they did not ask for. Installing either build therefore replaces the other.

    Sharing one AppId across both architectures is deliberate -- it keeps a
    single Add/Remove Programs entry -- but it does NOT make Inno remove the
    other build. Same AppId means Setup *appends* to the existing uninstall log.
    The replacement has to be done here. }
  if '{#Arch}' = '64' then
    OtherDir := ExpandConstant('{sd}\MinGW32')
  else
    OtherDir := ExpandConstant('{sd}\MinGW64');
  OtherBinDir := OtherDir + '\bin';

  IsUpgrade    := DirExists(MinGWDir);
  HasOtherArch := DirExists(OtherDir);
  Result := True;
end;

{ Removes one installation and its PATH entry. Returns False if the tree could
  not be fully deleted, which in practice means a file is still locked by a
  running gcc.exe, gdb.exe or a shell sitting in the directory.

  Safe to call for a directory that does not exist, which is what lets the
  caller ask for both architectures unconditionally. }
function RemoveInstallation(const Dir, BinDir: string): Boolean;
begin
  Result := True;
  if not DirExists(Dir) then
    Exit;

  { PATH entry first: if the delete then fails part-way, the user is left with a
    stale directory rather than a PATH entry pointing into a half-deleted tree. }
  EnvRemovePath(BinDir);
  Result := DelTree(Dir, True, True, True);
end;

function PrepareToInstall(var NeedsRestart: Boolean): String;
var
  ProgressPage: TOutputProgressWizardPage;
  Prompt: string;
  Removed: Boolean;
begin
  Result := '';

  if IsUpgrade or HasOtherArch then
  begin
    { Ask the user for confirmation, but only when there is a user to ask.
      PrepareToInstall still runs under /SILENT and /VERYSILENT, where this
      MsgBox appears with no visible parent and blocks Setup until someone
      finds and clicks it -- a headless deployment hangs until it is killed.
      Passing /SILENT is itself consent to an unattended upgrade, so silent
      runs proceed as if Yes was chosen.

      Note: this is deliberately a nested if rather than
      "if (not WizardSilent) and (MsgBox(...) = IDNO)". Pascal Script does not
      guarantee short-circuit evaluation, so the combined form would still
      call MsgBox during a silent install. }
    if not WizardSilent then
    begin
      Prompt := '';
      if IsUpgrade then
        Prompt := 'A previous version of Easy MinGW Installer is installed.' + #13#10;
      if HasOtherArch then
        Prompt := Prompt +
                  'A different architecture is installed at ' + OtherDir + '.' + #13#10 +
                  'Only one architecture can be installed at a time, because both' + #13#10 +
                  'add a compiler to the system PATH.' + #13#10;

      if MsgBox(Prompt + #13#10 +
                'The existing installation will be removed before installing this version.' + #13#10 + #13#10 +
                'Do you want to continue?', mbConfirmation, MB_YESNO) = IDNO then
      begin
        { Inno renders any non-empty return as an error message, so say plainly
          that nothing happened rather than making a deliberate choice read as
          a failure. }
        Result := 'Setup was cancelled. Nothing was installed or removed.';
        Exit;
      end;
    end;

    { Create progress page }
    ProgressPage := CreateOutputProgressPage('Removing Previous Version',
      'Please wait while the previous installation is being removed...');
    
    try
      ProgressPage.Show;
      ProgressPage.SetText('Removing previous installation...', '');
      ProgressPage.SetProgress(0, 2);

      { This architecture first, then the other one. Each call is a no-op when
        its directory is absent, so one pair of calls covers all three cases:
        a same-arch upgrade, an architecture switch, and a machine that ended
        up with both installed before this replacement logic existed.

        The second removal is skipped when the first failed. Setup is already
        going to abort at that point, so tearing down the other architecture as
        well would destroy a working toolchain and install nothing in its place.
        Both are only ever present in the legacy both-installed state, which is
        exactly where that would hurt.

        Written as a nested if, not "if A and B", because Pascal Script does not
        guarantee short-circuit evaluation and the second call must not run when
        the first failed. }
      Removed := RemoveInstallation(MinGWDir, MinGWBinDir);
      ProgressPage.SetProgress(1, 2);
      if Removed then
      begin
        if not RemoveInstallation(OtherDir, OtherBinDir) then
          Removed := False;
      end;
      ProgressPage.SetProgress(2, 2);

      { A locked file used to fail silently: DeleteFile's result was discarded
        and the page still reported success, so Setup went on to install over a
        half-removed tree.

        Unlike the confirmation prompt above, this is a real error and must stop
        the install. Inno shows it in a message box, which under /SILENT blocks
        exactly like any other Setup error, so unattended callers should pass
        /SUPPRESSMSGBOXES -- they then get exit code 7 instead of a hang. }
      if not Removed then
        Result := 'The previous installation could not be fully removed.' + #13#10 + #13#10 +
                  'Close anything using MinGW -- a terminal, an editor, a running' + #13#10 +
                  'gcc or gdb -- and run Setup again.';
    finally
      ProgressPage.Hide;
    end;
  end;
end;

procedure InitializeWizard;
begin
  WizardForm.InfoBeforeClickLabel.Hide;
end;

procedure CurPageChanged(CurPageID: Integer);
var
  Param: Longint;
begin
  { Auto-click Next on Ready page since we disabled it }
  if CurPageID = wpReady then
  begin
    Param := 0 or BN_CLICKED shl 16;
    PostMessage(WizardForm.NextButton.Handle, CN_COMMAND, Param, 0);
  end;
end;

procedure CurUninstallStepChanged(CurUninstallStep: TUninstallStep);
begin
  if CurUninstallStep = usPostUninstall then
    EnvRemovePath(ExpandConstant('{sd}\MinGW{#Arch}\bin'));
end;