# PATH utilities. Taken from:
# https://www.smartmontools.org/browser/trunk/smartmontools/os_win32/installer.nsi?rev=5310#L689

; os_win32/installer.nsi - smartmontools install NSIS script
;
; Home page of code is: https://www.smartmontools.org
;
; Copyright (C) 2006-22 Christian Franke
;
; SPDX-License-Identifier: GPL-2.0-or-later


;--------------------------------------------------------------------
; Path functions
;
; Based on example from:
; http://nsis.sourceforge.net/Path_Manipulation
;


!include "WinMessages.nsh"

; Registry Entry for system environment (NT4,2000,XP)
!define Environ 'HKLM "SYSTEM\CurrentControlSet\Control\Session Manager\Environment"'


; AddToPath - Appends dir to system PATH
;   (does not work on Win9x/ME)
;
; Usage:
;   Push "dir"
;   Call AddToPath

Function AddToPath
  Exch $0
  Push $1
  Push $2
  Push $3
  Push $4

  ; NSIS ReadRegStr returns empty string on string overflow
  ; Native calls are used here to check actual length of PATH

  ; $4 = RegOpenKey(HKEY_CURRENT_USER, "Environment", &$3)
  System::Call "advapi32::RegOpenKey(i 0x80000002, t'SYSTEM\CurrentControlSet\Control\Session Manager\Environment', *i.r3) i.r4"
  IntCmp $4 0 0 done done
  ; $4 = RegQueryValueEx($3, "PATH", (DWORD*)0, (DWORD*)0, &$1, ($2=NSIS_MAX_STRLEN, &$2))
  ; RegCloseKey($3)
  System::Call "advapi32::RegQueryValueEx(i $3, t'PATH', i 0, i 0, t.r1, *i ${NSIS_MAX_STRLEN} r2) i.r4"
  System::Call "advapi32::RegCloseKey(i $3)"

  ${If} $4 = 234 ; ERROR_MORE_DATA
    DetailPrint "AddToPath: original length $2 > ${NSIS_MAX_STRLEN}"
    MessageBox MB_OK "PATH not updated, original length $2 > ${NSIS_MAX_STRLEN}" /SD IDOK
    Goto done
  ${EndIf}

  ${If} $4 <> 0 ; NO_ERROR
    ${If} $4 <> 2 ; ERROR_FILE_NOT_FOUND
      DetailPrint "AddToPath: unexpected error code $4"
      Goto done
    ${EndIf}
    StrCpy $1 ""
  ${EndIf}

  ; Check if already in PATH
  Push "$1;"
  Push "$0;"
  Call StrStr
  Pop $2
  StrCmp $2 "" 0 done
  Push "$1;"
  Push "$0\;"
  Call StrStr
  Pop $2
  StrCmp $2 "" 0 done

  ; Prevent NSIS string overflow
  StrLen $2 $0
  StrLen $3 $1
  IntOp $2 $2 + $3
  IntOp $2 $2 + 2 ; $2 = strlen(dir) + strlen(PATH) + sizeof(";")
  ${If} $2 > ${NSIS_MAX_STRLEN}
    DetailPrint "AddToPath: new length $2 > ${NSIS_MAX_STRLEN}"
    MessageBox MB_OK "PATH not updated, new length $2 > ${NSIS_MAX_STRLEN}." /SD IDOK
    Goto done
  ${EndIf}

  ; Append dir to PATH
  DetailPrint "Add to PATH: $0"
  StrCpy $2 $1 1 -1
  ${If} $2 == ";"
    StrCpy $1 $1 -1 ; remove trailing ';'
  ${EndIf}
  ${If} $1 != "" ; no leading ';'
    StrCpy $0 "$1;$0"
  ${EndIf}
  WriteRegExpandStr ${Environ} "PATH" $0
  SendMessage ${HWND_BROADCAST} ${WM_WININICHANGE} 0 "STR:Environment" /TIMEOUT=5000

done:
  Pop $4
  Pop $3
  Pop $2
  Pop $1
  Pop $0
FunctionEnd


; RemoveFromPath - Removes dir from system PATH
;
; Usage:
;   Push "dir"
;   Call RemoveFromPath

Function un.RemoveFromPath
  Exch $0
  Push $1
  Push $2
  Push $3
  Push $4
  Push $5
  Push $6

  ReadRegStr $1 ${Environ} "PATH"
  StrCpy $5 $1 1 -1
  ${If} $5 != ";"
    StrCpy $1 "$1;" ; ensure trailing ';'
  ${EndIf}
  Push $1
  Push "$0;"
  Call un.StrStr
  Pop $2 ; pos of our dir
  StrCmp $2 "" done

  DetailPrint "Remove from PATH: $0"
  StrLen $3 "$0;"
  StrLen $4 $2
  StrCpy $5 $1 -$4 ; $5 is now the part before the path to remove
  StrCpy $6 $2 "" $3 ; $6 is now the part after the path to remove
  StrCpy $3 "$5$6"
  StrCpy $5 $3 1 -1
  ${If} $5 == ";"
    StrCpy $3 $3 -1 ; remove trailing ';'
  ${EndIf}
  WriteRegExpandStr ${Environ} "PATH" $3
  SendMessage ${HWND_BROADCAST} ${WM_WININICHANGE} 0 "STR:Environment" /TIMEOUT=5000

done:
  Pop $6
  Pop $5
  Pop $4
  Pop $3
  Pop $2
  Pop $1
  Pop $0
FunctionEnd


; StrStr - find substring in a string
;
; Usage:
;   Push "this is some string"
;   Push "some"
;   Call StrStr
;   Pop $0 ; "some string"

!macro StrStr un
Function ${un}StrStr
  Exch $R1 ; $R1=substring, stack=[old$R1,string,...]
  Exch     ;                stack=[string,old$R1,...]
  Exch $R2 ; $R2=string,    stack=[old$R2,old$R1,...]
  Push $R3
  Push $R4
  Push $R5
  StrLen $R3 $R1
  StrCpy $R4 0
  ; $R1=substring, $R2=string, $R3=strlen(substring)
  ; $R4=count, $R5=tmp
  ${Do}
    StrCpy $R5 $R2 $R3 $R4
    ${IfThen} $R5 == $R1 ${|} ${ExitDo} ${|}
    ${IfThen} $R5 == ""  ${|} ${ExitDo} ${|}
    IntOp $R4 $R4 + 1
  ${Loop}
  StrCpy $R1 $R2 "" $R4
  Pop $R5
  Pop $R4
  Pop $R3
  Pop $R2
  Exch $R1 ; $R1=old$R1, stack=[result,...]
FunctionEnd
!macroend
!insertmacro StrStr ""
!insertmacro StrStr "un."