@REM Do not use "echo off" to not affect any child calls.

@REM Enable extensions, the `verify` call is a trick from the setlocal help
@VERIFY other 2>nul
@SETLOCAL EnableDelayedExpansion
@IF ERRORLEVEL 1 (
    @ECHO Unable to enable extensions
    @GOTO failure
)

@REM Start the ssh-agent if needed by git
@FOR %%i IN ("git.exe") DO @SET GIT=%%~$PATH:i
@IF EXIST "%GIT%" @(
    @REM Get the ssh-agent executable
    @FOR %%i IN ("ssh-agent.exe") DO @SET SSH_AGENT=%%~$PATH:i
    @IF NOT EXIST "%SSH_AGENT%" @(
        @FOR %%s IN ("%GIT%") DO @SET GIT_DIR=%%~dps
        @FOR %%s IN ("!GIT_DIR!") DO @SET GIT_DIR=!GIT_DIR:~0,-1!
        @FOR %%s IN ("!GIT_DIR!") DO @SET GIT_ROOT=%%~dps
        @FOR %%s IN ("!GIT_ROOT!") DO @SET GIT_ROOT=!GIT_ROOT:~0,-1!
        @FOR /D %%s in ("!GIT_ROOT!\usr\bin\ssh-agent.exe") DO @SET SSH_AGENT=%%~s
        @IF NOT EXIST "!SSH_AGENT!" @GOTO ssh-agent-done
    )
    @REM Get the ssh-add executable
    @FOR %%s IN ("!SSH_AGENT!") DO @SET BIN_DIR=%%~dps
    @FOR %%s in ("!BIN_DIR!") DO @SET BIN_DIR=!BIN_DIR:~0,-1!
    @FOR /D %%s in ("!BIN_DIR!\ssh-add.exe") DO @SET SSH_ADD=%%~s
    @IF NOT EXIST "!SSH_ADD!" @GOTO ssh-agent-done
    @REM Check if the agent is running
    @FOR /f "tokens=1-2" %%a IN ('tasklist /fi "imagename eq ssh-agent.exe"') DO @(
        @ECHO %%b | @FINDSTR /r /c:"[0-9][0-9]*" > NUL
        @IF "!ERRORLEVEL!" == "0" @(
            @SET SSH_AGENT_PID=%%b
        ) else @(
            @REM Unset in the case a user kills the agent while a session is open
            @REM needed to remove the old files and prevent a false message
            @SET SSH_AGENT_PID=
        )
    )
    @REM Connect up the current ssh-agent
    @IF [!SSH_AGENT_PID!] == []  @(
        @ECHO Removing old ssh-agent sockets
        @FOR %%s IN (%USERPROFILE%\.ssh\agent\s.*) DO @DEL /q "%%s" 2>nul
    ) ELSE  @(
        @ECHO Found ssh-agent at !SSH_AGENT_PID!
        @FOR %%s IN (%USERPROFILE%\.ssh\agent\s.*) DO @(
            @SET SSH_AUTH_SOCK=%%s
            @SET SSH_AUTH_SOCK=!SSH_AUTH_SOCK:%USERPROFILE%=~!
            @SET SSH_AUTH_SOCK=!SSH_AUTH_SOCK:\=/!
        )
        @IF NOT [!SSH_AUTH_SOCK!] == [] @(
            @ECHO Found ssh-agent socket at !SSH_AUTH_SOCK!
        ) ELSE (
            @ECHO Failed to find ssh-agent socket
            @SET SSH_AGENT_PID=
        )
    )
    @REM See if we have the key
    @"!SSH_ADD!" -l 1>NUL 2>NUL
    @SET result=!ERRORLEVEL!
    @IF NOT !result! == 0 @(
        @IF !result! == 2 @(
            @ECHO | @SET /p=Starting ssh-agent:
            @FOR /f "tokens=1-2 delims==;" %%a IN ('"!SSH_AGENT!"') DO @(
                @IF NOT [%%b] == [] @SET %%a=%%b
            )
            @ECHO. done
        )
        @"!SSH_ADD!"
        @ECHO.
    )
)

:ssh-agent-done
:failure

@ENDLOCAL & @SET "SSH_AUTH_SOCK=%SSH_AUTH_SOCK%" ^
          & @SET "SSH_AGENT_PID=%SSH_AGENT_PID%"

@ECHO %cmdcmdline% | @FINDSTR /l "\"\"" >NUL
@IF NOT ERRORLEVEL 1 @(
    @CALL cmd %*
)
