PROGRAM checkGrib

    USE cgutils

    IMPLICIT NONE

    INTEGER :: i, stat
    INTEGER :: num_filepaths, expected_num_levels
    CHARACTER(LEN=16) :: source_str, levels_str
    CHARACTER(LEN=256), DIMENSION(100) :: filepaths
    LOGICAL :: check_fcst, check_anl, check_grib2

    INTEGER :: return_code


    CALL get_command_args(source_str, levels_str, &
&                         filepaths, num_filepaths, &
&                         check_fcst, check_anl, check_grib2)
    !WRITE(6,*) '----- got args ------'
    !WRITE(6,*) 'source_str: ', TRIM(source_str)
    !WRITE(6,*) 'levels_str: ', TRIM(levels_str)
    !WRITE(6,*) 'filepaths:'
    !DO i=1,num_filepaths
    !    WRITE(6,*) TRIM(filepaths(i))
    !END DO 
    !WRITE(6,*) '----- got args ------'

    ! Convert string to integer
    READ(levels_str,*,IOSTAT=stat) expected_num_levels

    DO i=1,num_filepaths

        IF ( TRIM(source_str) .EQ. 'ECMWF' ) THEN

            return_code = cgutils_check_ecmwf_grib(filepaths(i), &
&                                                   expected_num_levels, &
&                                                   check_fcst, check_anl, check_grib2)
        ELSE IF ( TRIM(source_str) .EQ. 'NCEP' ) THEN
            return_code = cgutils_check_ncep_grib2(filepaths(i), &
&                                                   expected_num_levels, &
&                                                   check_fcst, check_anl, check_grib2)
        ELSE IF ( TRIM(source_str) .EQ. 'NCEPFV3' ) THEN
            return_code = cgutils_check_fv3_grib2(filepaths(i), &
&                                                   expected_num_levels, &
&                                                   check_fcst, check_anl, check_grib2)

        ELSE

            WRITE(6,*) 'Invalid source string: ', TRIM(source_str)
            CALL EXIT(2)

        ENDIF

        !PRINT *, 'return_code: ', return_code
        IF (return_code .EQ. 0) THEN
            WRITE(6,*) 'Passed: ', TRIM(filepaths(i))
        ELSE 
            WRITE(6,*) 'Failed on: ', TRIM(filepaths(i))
            CALL EXIT(return_code)
        ENDIF
    END DO 



END PROGRAM checkGrib


SUBROUTINE get_command_args(source_arg, levels_arg, &
&          filepaths, num_filepaths, &
&          check_fcst, check_anl, check_grib2)

    !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
    ! This subroutine makes an effort to retrieve the command line arguments
    ! in string format.  It makes no effort to verify their values
    !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

    CHARACTER(LEN=16), INTENT(OUT) :: source_arg, levels_arg
    CHARACTER(LEN=256), DIMENSION(100), INTENT(OUT) :: filepaths
    INTEGER, INTENT(OUT) :: num_filepaths
    LOGICAL, INTENT(OUT) :: check_fcst, check_anl, check_grib2

    INTEGER :: arg_idx

    INTEGER :: num_cli_args
    CHARACTER(LEN=256) :: arg_str
    LOGICAL :: required_flags_processed

    ! Logic in the following loop will set this to True only if
    ! the required args are storing something other than 'NUL'
    required_flags_processed = .FALSE.
    source_arg = 'NUL'
    levels_arg = 'NUL'

    ! Default values
    check_fcst = .FALSE.
    check_anl = .FALSE.
    check_grib2 = .FALSE.


    num_cli_args = IARGC()
    ! Abort if there were no args
    IF (num_cli_args .LT. 1) THEN
        WRITE(0,*) 'No arguments provided'
        CALL print_usage 
        CALL EXIT(2)
    ENDIF

    ! We expect commandline flags, usually with arguments, followed
    ! by a variable-size list of filepaths
    num_filepaths = 0
    arg_idx = 1
    DO WHILE (arg_idx .LE. num_cli_args)


        CALL GETARG(arg_idx, arg_str)

        SELECT CASE ( TRIM(arg_str) )
            CASE ('--source')
                arg_idx = arg_idx + 1
                CALL GETARG(arg_idx, source_arg)
                IF (.NOT. ( (source_arg .EQ. 'NUL') .OR. &
&                           (levels_arg .EQ. 'NUL') ) ) THEN
                    required_flags_processed = .TRUE.
                ENDIF
                
            CASE ('--levels')
                arg_idx = arg_idx + 1
                CALL GETARG(arg_idx, levels_arg)
                IF (.NOT. ( (source_arg .EQ. 'NUL') .OR. &
&                           (levels_arg .EQ. 'NUL') ) ) THEN
                    required_flags_processed = .TRUE.
                ENDIF

            CASE ('--checkfcst')
                check_fcst = .TRUE.

            CASE ('--checkanl')
                check_anl = .TRUE.

            CASE ('--checkgrib2')
                check_grib2 = .TRUE.


            CASE default
                ! We should only be here if required flags have been
                ! processed, in which case we assume any remaining tokens
                ! are paths to GRIB files
                !
                ! Note - an additional sanity check might be to see if the
                ! first two characters of the token are '--', in which case
                ! someone might have slipped in another command flag at a
                ! time when we're only expecting pathnames.  But, I chose
                ! not to implement that at this time.  I figure the utility
                ! will barf when it tries to open an invalid file.
                IF (.NOT. required_flags_processed) THEN
                    WRITE(0,*) 'args missing or out of sync'
                    CALL print_usage 
                    CALL EXIT(2)
                ENDIF
                num_filepaths = num_filepaths + 1
                filepaths(num_filepaths) = TRIM(arg_str)
                
        END SELECT

        !PRINT *, TRIM(arg_str)
        arg_idx = arg_idx + 1
    END DO

    ! Let's make sure that at least one filepath was counted
    IF (num_filepaths .LT. 1) THEN
        WRITE(0,*) 'No GRIB files were specified'
        CALL print_usage 
        CALL EXIT(2)
    ENDIF

    ! Let's make sure that both checkfcst and checkanl weren't specified
    IF (check_fcst .AND. check_anl) THEN
        WRITE(0,*) 'Only one of --checkfcst and --checkanl can be specified'
        CALL print_usage 
        CALL EXIT(2)
    ENDIF



END SUBROUTINE get_command_args

SUBROUTINE print_usage

    WRITE(0,*) ' '
    WRITE(0,*) 'Usage: '
    WRITE(0,*) ' '
    WRITE(0,*) 'checkgrib --source [ECMWF | NCEP | NCEPFV3] --levels <int> '
    WRITE(0,*) '          [ --checkfcst | --checkanl | --checkgrib2 ]'
    WRITE(0,*) '          path1 path2 ...'
    WRITE(0,*) ' '

END SUBROUTINE print_usage